mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-28 11:57:28 +00:00
5597 lines
177 KiB
C
5597 lines
177 KiB
C
/* Medium-level subroutines: convert bit-field store and extract
|
||
and shifts, multiplies and divides to rtl instructions.
|
||
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
|
||
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
|
||
Free Software Foundation, Inc.
|
||
|
||
This file is part of GCC.
|
||
|
||
GCC is free software; you can redistribute it and/or modify it under
|
||
the terms of the GNU General Public License as published by the Free
|
||
Software Foundation; either version 2, or (at your option) any later
|
||
version.
|
||
|
||
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
|
||
WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||
for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with GCC; see the file COPYING. If not, write to the Free
|
||
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
|
||
02110-1301, USA. */
|
||
|
||
|
||
#include "config.h"
|
||
#include "system.h"
|
||
#include "coretypes.h"
|
||
#include "tm.h"
|
||
#include "toplev.h"
|
||
#include "rtl.h"
|
||
#include "tree.h"
|
||
#include "tm_p.h"
|
||
#include "flags.h"
|
||
#include "insn-config.h"
|
||
#include "expr.h"
|
||
#include "optabs.h"
|
||
#include "real.h"
|
||
#include "recog.h"
|
||
#include "langhooks.h"
|
||
|
||
static void store_fixed_bit_field (rtx, unsigned HOST_WIDE_INT,
|
||
unsigned HOST_WIDE_INT,
|
||
unsigned HOST_WIDE_INT, rtx);
|
||
static void store_split_bit_field (rtx, unsigned HOST_WIDE_INT,
|
||
unsigned HOST_WIDE_INT, rtx);
|
||
static rtx extract_fixed_bit_field (enum machine_mode, rtx,
|
||
unsigned HOST_WIDE_INT,
|
||
unsigned HOST_WIDE_INT,
|
||
unsigned HOST_WIDE_INT, rtx, int);
|
||
static rtx mask_rtx (enum machine_mode, int, int, int);
|
||
static rtx lshift_value (enum machine_mode, rtx, int, int);
|
||
static rtx extract_split_bit_field (rtx, unsigned HOST_WIDE_INT,
|
||
unsigned HOST_WIDE_INT, int);
|
||
static void do_cmp_and_jump (rtx, rtx, enum rtx_code, enum machine_mode, rtx);
|
||
static rtx expand_smod_pow2 (enum machine_mode, rtx, HOST_WIDE_INT);
|
||
static rtx expand_sdiv_pow2 (enum machine_mode, rtx, HOST_WIDE_INT);
|
||
|
||
/* Test whether a value is zero of a power of two. */
|
||
#define EXACT_POWER_OF_2_OR_ZERO_P(x) (((x) & ((x) - 1)) == 0)
|
||
|
||
/* Nonzero means divides or modulus operations are relatively cheap for
|
||
powers of two, so don't use branches; emit the operation instead.
|
||
Usually, this will mean that the MD file will emit non-branch
|
||
sequences. */
|
||
|
||
static bool sdiv_pow2_cheap[NUM_MACHINE_MODES];
|
||
static bool smod_pow2_cheap[NUM_MACHINE_MODES];
|
||
|
||
#ifndef SLOW_UNALIGNED_ACCESS
|
||
#define SLOW_UNALIGNED_ACCESS(MODE, ALIGN) STRICT_ALIGNMENT
|
||
#endif
|
||
|
||
/* For compilers that support multiple targets with different word sizes,
|
||
MAX_BITS_PER_WORD contains the biggest value of BITS_PER_WORD. An example
|
||
is the H8/300(H) compiler. */
|
||
|
||
#ifndef MAX_BITS_PER_WORD
|
||
#define MAX_BITS_PER_WORD BITS_PER_WORD
|
||
#endif
|
||
|
||
/* Reduce conditional compilation elsewhere. */
|
||
#ifndef HAVE_insv
|
||
#define HAVE_insv 0
|
||
#define CODE_FOR_insv CODE_FOR_nothing
|
||
#define gen_insv(a,b,c,d) NULL_RTX
|
||
#endif
|
||
#ifndef HAVE_extv
|
||
#define HAVE_extv 0
|
||
#define CODE_FOR_extv CODE_FOR_nothing
|
||
#define gen_extv(a,b,c,d) NULL_RTX
|
||
#endif
|
||
#ifndef HAVE_extzv
|
||
#define HAVE_extzv 0
|
||
#define CODE_FOR_extzv CODE_FOR_nothing
|
||
#define gen_extzv(a,b,c,d) NULL_RTX
|
||
#endif
|
||
|
||
/* Cost of various pieces of RTL. Note that some of these are indexed by
|
||
shift count and some by mode. */
|
||
static int zero_cost;
|
||
static int add_cost[NUM_MACHINE_MODES];
|
||
static int neg_cost[NUM_MACHINE_MODES];
|
||
static int shift_cost[NUM_MACHINE_MODES][MAX_BITS_PER_WORD];
|
||
static int shiftadd_cost[NUM_MACHINE_MODES][MAX_BITS_PER_WORD];
|
||
static int shiftsub_cost[NUM_MACHINE_MODES][MAX_BITS_PER_WORD];
|
||
static int mul_cost[NUM_MACHINE_MODES];
|
||
static int sdiv_cost[NUM_MACHINE_MODES];
|
||
static int udiv_cost[NUM_MACHINE_MODES];
|
||
static int mul_widen_cost[NUM_MACHINE_MODES];
|
||
static int mul_highpart_cost[NUM_MACHINE_MODES];
|
||
|
||
void
|
||
init_expmed (void)
|
||
{
|
||
struct
|
||
{
|
||
struct rtx_def reg; rtunion reg_fld[2];
|
||
struct rtx_def plus; rtunion plus_fld1;
|
||
struct rtx_def neg;
|
||
struct rtx_def mult; rtunion mult_fld1;
|
||
struct rtx_def sdiv; rtunion sdiv_fld1;
|
||
struct rtx_def udiv; rtunion udiv_fld1;
|
||
struct rtx_def zext;
|
||
struct rtx_def sdiv_32; rtunion sdiv_32_fld1;
|
||
struct rtx_def smod_32; rtunion smod_32_fld1;
|
||
struct rtx_def wide_mult; rtunion wide_mult_fld1;
|
||
struct rtx_def wide_lshr; rtunion wide_lshr_fld1;
|
||
struct rtx_def wide_trunc;
|
||
struct rtx_def shift; rtunion shift_fld1;
|
||
struct rtx_def shift_mult; rtunion shift_mult_fld1;
|
||
struct rtx_def shift_add; rtunion shift_add_fld1;
|
||
struct rtx_def shift_sub; rtunion shift_sub_fld1;
|
||
} all;
|
||
|
||
rtx pow2[MAX_BITS_PER_WORD];
|
||
rtx cint[MAX_BITS_PER_WORD];
|
||
int m, n;
|
||
enum machine_mode mode, wider_mode;
|
||
|
||
zero_cost = rtx_cost (const0_rtx, 0);
|
||
|
||
for (m = 1; m < MAX_BITS_PER_WORD; m++)
|
||
{
|
||
pow2[m] = GEN_INT ((HOST_WIDE_INT) 1 << m);
|
||
cint[m] = GEN_INT (m);
|
||
}
|
||
|
||
memset (&all, 0, sizeof all);
|
||
|
||
PUT_CODE (&all.reg, REG);
|
||
/* Avoid using hard regs in ways which may be unsupported. */
|
||
REGNO (&all.reg) = LAST_VIRTUAL_REGISTER + 1;
|
||
|
||
PUT_CODE (&all.plus, PLUS);
|
||
XEXP (&all.plus, 0) = &all.reg;
|
||
XEXP (&all.plus, 1) = &all.reg;
|
||
|
||
PUT_CODE (&all.neg, NEG);
|
||
XEXP (&all.neg, 0) = &all.reg;
|
||
|
||
PUT_CODE (&all.mult, MULT);
|
||
XEXP (&all.mult, 0) = &all.reg;
|
||
XEXP (&all.mult, 1) = &all.reg;
|
||
|
||
PUT_CODE (&all.sdiv, DIV);
|
||
XEXP (&all.sdiv, 0) = &all.reg;
|
||
XEXP (&all.sdiv, 1) = &all.reg;
|
||
|
||
PUT_CODE (&all.udiv, UDIV);
|
||
XEXP (&all.udiv, 0) = &all.reg;
|
||
XEXP (&all.udiv, 1) = &all.reg;
|
||
|
||
PUT_CODE (&all.sdiv_32, DIV);
|
||
XEXP (&all.sdiv_32, 0) = &all.reg;
|
||
XEXP (&all.sdiv_32, 1) = 32 < MAX_BITS_PER_WORD ? cint[32] : GEN_INT (32);
|
||
|
||
PUT_CODE (&all.smod_32, MOD);
|
||
XEXP (&all.smod_32, 0) = &all.reg;
|
||
XEXP (&all.smod_32, 1) = XEXP (&all.sdiv_32, 1);
|
||
|
||
PUT_CODE (&all.zext, ZERO_EXTEND);
|
||
XEXP (&all.zext, 0) = &all.reg;
|
||
|
||
PUT_CODE (&all.wide_mult, MULT);
|
||
XEXP (&all.wide_mult, 0) = &all.zext;
|
||
XEXP (&all.wide_mult, 1) = &all.zext;
|
||
|
||
PUT_CODE (&all.wide_lshr, LSHIFTRT);
|
||
XEXP (&all.wide_lshr, 0) = &all.wide_mult;
|
||
|
||
PUT_CODE (&all.wide_trunc, TRUNCATE);
|
||
XEXP (&all.wide_trunc, 0) = &all.wide_lshr;
|
||
|
||
PUT_CODE (&all.shift, ASHIFT);
|
||
XEXP (&all.shift, 0) = &all.reg;
|
||
|
||
PUT_CODE (&all.shift_mult, MULT);
|
||
XEXP (&all.shift_mult, 0) = &all.reg;
|
||
|
||
PUT_CODE (&all.shift_add, PLUS);
|
||
XEXP (&all.shift_add, 0) = &all.shift_mult;
|
||
XEXP (&all.shift_add, 1) = &all.reg;
|
||
|
||
PUT_CODE (&all.shift_sub, MINUS);
|
||
XEXP (&all.shift_sub, 0) = &all.shift_mult;
|
||
XEXP (&all.shift_sub, 1) = &all.reg;
|
||
|
||
for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
|
||
mode != VOIDmode;
|
||
mode = GET_MODE_WIDER_MODE (mode))
|
||
{
|
||
PUT_MODE (&all.reg, mode);
|
||
PUT_MODE (&all.plus, mode);
|
||
PUT_MODE (&all.neg, mode);
|
||
PUT_MODE (&all.mult, mode);
|
||
PUT_MODE (&all.sdiv, mode);
|
||
PUT_MODE (&all.udiv, mode);
|
||
PUT_MODE (&all.sdiv_32, mode);
|
||
PUT_MODE (&all.smod_32, mode);
|
||
PUT_MODE (&all.wide_trunc, mode);
|
||
PUT_MODE (&all.shift, mode);
|
||
PUT_MODE (&all.shift_mult, mode);
|
||
PUT_MODE (&all.shift_add, mode);
|
||
PUT_MODE (&all.shift_sub, mode);
|
||
|
||
add_cost[mode] = rtx_cost (&all.plus, SET);
|
||
neg_cost[mode] = rtx_cost (&all.neg, SET);
|
||
mul_cost[mode] = rtx_cost (&all.mult, SET);
|
||
sdiv_cost[mode] = rtx_cost (&all.sdiv, SET);
|
||
udiv_cost[mode] = rtx_cost (&all.udiv, SET);
|
||
|
||
sdiv_pow2_cheap[mode] = (rtx_cost (&all.sdiv_32, SET)
|
||
<= 2 * add_cost[mode]);
|
||
smod_pow2_cheap[mode] = (rtx_cost (&all.smod_32, SET)
|
||
<= 4 * add_cost[mode]);
|
||
|
||
wider_mode = GET_MODE_WIDER_MODE (mode);
|
||
if (wider_mode != VOIDmode)
|
||
{
|
||
PUT_MODE (&all.zext, wider_mode);
|
||
PUT_MODE (&all.wide_mult, wider_mode);
|
||
PUT_MODE (&all.wide_lshr, wider_mode);
|
||
XEXP (&all.wide_lshr, 1) = GEN_INT (GET_MODE_BITSIZE (mode));
|
||
|
||
mul_widen_cost[wider_mode] = rtx_cost (&all.wide_mult, SET);
|
||
mul_highpart_cost[mode] = rtx_cost (&all.wide_trunc, SET);
|
||
}
|
||
|
||
shift_cost[mode][0] = 0;
|
||
shiftadd_cost[mode][0] = shiftsub_cost[mode][0] = add_cost[mode];
|
||
|
||
n = MIN (MAX_BITS_PER_WORD, GET_MODE_BITSIZE (mode));
|
||
for (m = 1; m < n; m++)
|
||
{
|
||
XEXP (&all.shift, 1) = cint[m];
|
||
XEXP (&all.shift_mult, 1) = pow2[m];
|
||
|
||
shift_cost[mode][m] = rtx_cost (&all.shift, SET);
|
||
shiftadd_cost[mode][m] = rtx_cost (&all.shift_add, SET);
|
||
shiftsub_cost[mode][m] = rtx_cost (&all.shift_sub, SET);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Return an rtx representing minus the value of X.
|
||
MODE is the intended mode of the result,
|
||
useful if X is a CONST_INT. */
|
||
|
||
rtx
|
||
negate_rtx (enum machine_mode mode, rtx x)
|
||
{
|
||
rtx result = simplify_unary_operation (NEG, mode, x, mode);
|
||
|
||
if (result == 0)
|
||
result = expand_unop (mode, neg_optab, x, NULL_RTX, 0);
|
||
|
||
return result;
|
||
}
|
||
|
||
/* Report on the availability of insv/extv/extzv and the desired mode
|
||
of each of their operands. Returns MAX_MACHINE_MODE if HAVE_foo
|
||
is false; else the mode of the specified operand. If OPNO is -1,
|
||
all the caller cares about is whether the insn is available. */
|
||
enum machine_mode
|
||
mode_for_extraction (enum extraction_pattern pattern, int opno)
|
||
{
|
||
const struct insn_data *data;
|
||
|
||
switch (pattern)
|
||
{
|
||
case EP_insv:
|
||
if (HAVE_insv)
|
||
{
|
||
data = &insn_data[CODE_FOR_insv];
|
||
break;
|
||
}
|
||
return MAX_MACHINE_MODE;
|
||
|
||
case EP_extv:
|
||
if (HAVE_extv)
|
||
{
|
||
data = &insn_data[CODE_FOR_extv];
|
||
break;
|
||
}
|
||
return MAX_MACHINE_MODE;
|
||
|
||
case EP_extzv:
|
||
if (HAVE_extzv)
|
||
{
|
||
data = &insn_data[CODE_FOR_extzv];
|
||
break;
|
||
}
|
||
return MAX_MACHINE_MODE;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
|
||
if (opno == -1)
|
||
return VOIDmode;
|
||
|
||
/* Everyone who uses this function used to follow it with
|
||
if (result == VOIDmode) result = word_mode; */
|
||
if (data->operand[opno].mode == VOIDmode)
|
||
return word_mode;
|
||
return data->operand[opno].mode;
|
||
}
|
||
|
||
|
||
/* Generate code to store value from rtx VALUE
|
||
into a bit-field within structure STR_RTX
|
||
containing BITSIZE bits starting at bit BITNUM.
|
||
FIELDMODE is the machine-mode of the FIELD_DECL node for this field.
|
||
ALIGN is the alignment that STR_RTX is known to have.
|
||
TOTAL_SIZE is the size of the structure in bytes, or -1 if varying. */
|
||
|
||
/* ??? Note that there are two different ideas here for how
|
||
to determine the size to count bits within, for a register.
|
||
One is BITS_PER_WORD, and the other is the size of operand 3
|
||
of the insv pattern.
|
||
|
||
If operand 3 of the insv pattern is VOIDmode, then we will use BITS_PER_WORD
|
||
else, we use the mode of operand 3. */
|
||
|
||
rtx
|
||
store_bit_field (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
|
||
unsigned HOST_WIDE_INT bitnum, enum machine_mode fieldmode,
|
||
rtx value)
|
||
{
|
||
unsigned int unit
|
||
= (MEM_P (str_rtx)) ? BITS_PER_UNIT : BITS_PER_WORD;
|
||
unsigned HOST_WIDE_INT offset, bitpos;
|
||
rtx op0 = str_rtx;
|
||
int byte_offset;
|
||
rtx orig_value;
|
||
|
||
enum machine_mode op_mode = mode_for_extraction (EP_insv, 3);
|
||
|
||
while (GET_CODE (op0) == SUBREG)
|
||
{
|
||
/* The following line once was done only if WORDS_BIG_ENDIAN,
|
||
but I think that is a mistake. WORDS_BIG_ENDIAN is
|
||
meaningful at a much higher level; when structures are copied
|
||
between memory and regs, the higher-numbered regs
|
||
always get higher addresses. */
|
||
int inner_mode_size = GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)));
|
||
int outer_mode_size = GET_MODE_SIZE (GET_MODE (op0));
|
||
|
||
byte_offset = 0;
|
||
|
||
/* Paradoxical subregs need special handling on big endian machines. */
|
||
if (SUBREG_BYTE (op0) == 0 && inner_mode_size < outer_mode_size)
|
||
{
|
||
int difference = inner_mode_size - outer_mode_size;
|
||
|
||
if (WORDS_BIG_ENDIAN)
|
||
byte_offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD;
|
||
if (BYTES_BIG_ENDIAN)
|
||
byte_offset += difference % UNITS_PER_WORD;
|
||
}
|
||
else
|
||
byte_offset = SUBREG_BYTE (op0);
|
||
|
||
bitnum += byte_offset * BITS_PER_UNIT;
|
||
op0 = SUBREG_REG (op0);
|
||
}
|
||
|
||
/* No action is needed if the target is a register and if the field
|
||
lies completely outside that register. This can occur if the source
|
||
code contains an out-of-bounds access to a small array. */
|
||
if (REG_P (op0) && bitnum >= GET_MODE_BITSIZE (GET_MODE (op0)))
|
||
return value;
|
||
|
||
/* Use vec_set patterns for inserting parts of vectors whenever
|
||
available. */
|
||
if (VECTOR_MODE_P (GET_MODE (op0))
|
||
&& !MEM_P (op0)
|
||
&& (vec_set_optab->handlers[GET_MODE (op0)].insn_code
|
||
!= CODE_FOR_nothing)
|
||
&& fieldmode == GET_MODE_INNER (GET_MODE (op0))
|
||
&& bitsize == GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0)))
|
||
&& !(bitnum % GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0)))))
|
||
{
|
||
enum machine_mode outermode = GET_MODE (op0);
|
||
enum machine_mode innermode = GET_MODE_INNER (outermode);
|
||
int icode = (int) vec_set_optab->handlers[outermode].insn_code;
|
||
int pos = bitnum / GET_MODE_BITSIZE (innermode);
|
||
rtx rtxpos = GEN_INT (pos);
|
||
rtx src = value;
|
||
rtx dest = op0;
|
||
rtx pat, seq;
|
||
enum machine_mode mode0 = insn_data[icode].operand[0].mode;
|
||
enum machine_mode mode1 = insn_data[icode].operand[1].mode;
|
||
enum machine_mode mode2 = insn_data[icode].operand[2].mode;
|
||
|
||
start_sequence ();
|
||
|
||
if (! (*insn_data[icode].operand[1].predicate) (src, mode1))
|
||
src = copy_to_mode_reg (mode1, src);
|
||
|
||
if (! (*insn_data[icode].operand[2].predicate) (rtxpos, mode2))
|
||
rtxpos = copy_to_mode_reg (mode1, rtxpos);
|
||
|
||
/* We could handle this, but we should always be called with a pseudo
|
||
for our targets and all insns should take them as outputs. */
|
||
gcc_assert ((*insn_data[icode].operand[0].predicate) (dest, mode0)
|
||
&& (*insn_data[icode].operand[1].predicate) (src, mode1)
|
||
&& (*insn_data[icode].operand[2].predicate) (rtxpos, mode2));
|
||
pat = GEN_FCN (icode) (dest, src, rtxpos);
|
||
seq = get_insns ();
|
||
end_sequence ();
|
||
if (pat)
|
||
{
|
||
emit_insn (seq);
|
||
emit_insn (pat);
|
||
return dest;
|
||
}
|
||
}
|
||
|
||
/* If the target is a register, overwriting the entire object, or storing
|
||
a full-word or multi-word field can be done with just a SUBREG.
|
||
|
||
If the target is memory, storing any naturally aligned field can be
|
||
done with a simple store. For targets that support fast unaligned
|
||
memory, any naturally sized, unit aligned field can be done directly. */
|
||
|
||
offset = bitnum / unit;
|
||
bitpos = bitnum % unit;
|
||
byte_offset = (bitnum % BITS_PER_WORD) / BITS_PER_UNIT
|
||
+ (offset * UNITS_PER_WORD);
|
||
|
||
if (bitpos == 0
|
||
&& bitsize == GET_MODE_BITSIZE (fieldmode)
|
||
&& (!MEM_P (op0)
|
||
? ((GET_MODE_SIZE (fieldmode) >= UNITS_PER_WORD
|
||
|| GET_MODE_SIZE (GET_MODE (op0)) == GET_MODE_SIZE (fieldmode))
|
||
&& byte_offset % GET_MODE_SIZE (fieldmode) == 0)
|
||
: (! SLOW_UNALIGNED_ACCESS (fieldmode, MEM_ALIGN (op0))
|
||
|| (offset * BITS_PER_UNIT % bitsize == 0
|
||
&& MEM_ALIGN (op0) % GET_MODE_BITSIZE (fieldmode) == 0))))
|
||
{
|
||
if (MEM_P (op0))
|
||
op0 = adjust_address (op0, fieldmode, offset);
|
||
else if (GET_MODE (op0) != fieldmode)
|
||
op0 = simplify_gen_subreg (fieldmode, op0, GET_MODE (op0),
|
||
byte_offset);
|
||
emit_move_insn (op0, value);
|
||
return value;
|
||
}
|
||
|
||
/* Make sure we are playing with integral modes. Pun with subregs
|
||
if we aren't. This must come after the entire register case above,
|
||
since that case is valid for any mode. The following cases are only
|
||
valid for integral modes. */
|
||
{
|
||
enum machine_mode imode = int_mode_for_mode (GET_MODE (op0));
|
||
if (imode != GET_MODE (op0))
|
||
{
|
||
if (MEM_P (op0))
|
||
op0 = adjust_address (op0, imode, 0);
|
||
else
|
||
{
|
||
gcc_assert (imode != BLKmode);
|
||
op0 = gen_lowpart (imode, op0);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* We may be accessing data outside the field, which means
|
||
we can alias adjacent data. */
|
||
if (MEM_P (op0))
|
||
{
|
||
op0 = shallow_copy_rtx (op0);
|
||
set_mem_alias_set (op0, 0);
|
||
set_mem_expr (op0, 0);
|
||
}
|
||
|
||
/* If OP0 is a register, BITPOS must count within a word.
|
||
But as we have it, it counts within whatever size OP0 now has.
|
||
On a bigendian machine, these are not the same, so convert. */
|
||
if (BYTES_BIG_ENDIAN
|
||
&& !MEM_P (op0)
|
||
&& unit > GET_MODE_BITSIZE (GET_MODE (op0)))
|
||
bitpos += unit - GET_MODE_BITSIZE (GET_MODE (op0));
|
||
|
||
/* Storing an lsb-aligned field in a register
|
||
can be done with a movestrict instruction. */
|
||
|
||
if (!MEM_P (op0)
|
||
&& (BYTES_BIG_ENDIAN ? bitpos + bitsize == unit : bitpos == 0)
|
||
&& bitsize == GET_MODE_BITSIZE (fieldmode)
|
||
&& (movstrict_optab->handlers[fieldmode].insn_code
|
||
!= CODE_FOR_nothing))
|
||
{
|
||
int icode = movstrict_optab->handlers[fieldmode].insn_code;
|
||
|
||
/* Get appropriate low part of the value being stored. */
|
||
if (GET_CODE (value) == CONST_INT || REG_P (value))
|
||
value = gen_lowpart (fieldmode, value);
|
||
else if (!(GET_CODE (value) == SYMBOL_REF
|
||
|| GET_CODE (value) == LABEL_REF
|
||
|| GET_CODE (value) == CONST))
|
||
value = convert_to_mode (fieldmode, value, 0);
|
||
|
||
if (! (*insn_data[icode].operand[1].predicate) (value, fieldmode))
|
||
value = copy_to_mode_reg (fieldmode, value);
|
||
|
||
if (GET_CODE (op0) == SUBREG)
|
||
{
|
||
/* Else we've got some float mode source being extracted into
|
||
a different float mode destination -- this combination of
|
||
subregs results in Severe Tire Damage. */
|
||
gcc_assert (GET_MODE (SUBREG_REG (op0)) == fieldmode
|
||
|| GET_MODE_CLASS (fieldmode) == MODE_INT
|
||
|| GET_MODE_CLASS (fieldmode) == MODE_PARTIAL_INT);
|
||
op0 = SUBREG_REG (op0);
|
||
}
|
||
|
||
emit_insn (GEN_FCN (icode)
|
||
(gen_rtx_SUBREG (fieldmode, op0,
|
||
(bitnum % BITS_PER_WORD) / BITS_PER_UNIT
|
||
+ (offset * UNITS_PER_WORD)),
|
||
value));
|
||
|
||
return value;
|
||
}
|
||
|
||
/* Handle fields bigger than a word. */
|
||
|
||
if (bitsize > BITS_PER_WORD)
|
||
{
|
||
/* Here we transfer the words of the field
|
||
in the order least significant first.
|
||
This is because the most significant word is the one which may
|
||
be less than full.
|
||
However, only do that if the value is not BLKmode. */
|
||
|
||
unsigned int backwards = WORDS_BIG_ENDIAN && fieldmode != BLKmode;
|
||
unsigned int nwords = (bitsize + (BITS_PER_WORD - 1)) / BITS_PER_WORD;
|
||
unsigned int i;
|
||
|
||
/* This is the mode we must force value to, so that there will be enough
|
||
subwords to extract. Note that fieldmode will often (always?) be
|
||
VOIDmode, because that is what store_field uses to indicate that this
|
||
is a bit field, but passing VOIDmode to operand_subword_force
|
||
is not allowed. */
|
||
fieldmode = GET_MODE (value);
|
||
if (fieldmode == VOIDmode)
|
||
fieldmode = smallest_mode_for_size (nwords * BITS_PER_WORD, MODE_INT);
|
||
|
||
for (i = 0; i < nwords; i++)
|
||
{
|
||
/* If I is 0, use the low-order word in both field and target;
|
||
if I is 1, use the next to lowest word; and so on. */
|
||
unsigned int wordnum = (backwards ? nwords - i - 1 : i);
|
||
unsigned int bit_offset = (backwards
|
||
? MAX ((int) bitsize - ((int) i + 1)
|
||
* BITS_PER_WORD,
|
||
0)
|
||
: (int) i * BITS_PER_WORD);
|
||
|
||
store_bit_field (op0, MIN (BITS_PER_WORD,
|
||
bitsize - i * BITS_PER_WORD),
|
||
bitnum + bit_offset, word_mode,
|
||
operand_subword_force (value, wordnum, fieldmode));
|
||
}
|
||
return value;
|
||
}
|
||
|
||
/* From here on we can assume that the field to be stored in is
|
||
a full-word (whatever type that is), since it is shorter than a word. */
|
||
|
||
/* OFFSET is the number of words or bytes (UNIT says which)
|
||
from STR_RTX to the first word or byte containing part of the field. */
|
||
|
||
if (!MEM_P (op0))
|
||
{
|
||
if (offset != 0
|
||
|| GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD)
|
||
{
|
||
if (!REG_P (op0))
|
||
{
|
||
/* Since this is a destination (lvalue), we can't copy
|
||
it to a pseudo. We can remove a SUBREG that does not
|
||
change the size of the operand. Such a SUBREG may
|
||
have been added above. */
|
||
gcc_assert (GET_CODE (op0) == SUBREG
|
||
&& (GET_MODE_SIZE (GET_MODE (op0))
|
||
== GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))));
|
||
op0 = SUBREG_REG (op0);
|
||
}
|
||
op0 = gen_rtx_SUBREG (mode_for_size (BITS_PER_WORD, MODE_INT, 0),
|
||
op0, (offset * UNITS_PER_WORD));
|
||
}
|
||
offset = 0;
|
||
}
|
||
|
||
/* If VALUE has a floating-point or complex mode, access it as an
|
||
integer of the corresponding size. This can occur on a machine
|
||
with 64 bit registers that uses SFmode for float. It can also
|
||
occur for unaligned float or complex fields. */
|
||
orig_value = value;
|
||
if (GET_MODE (value) != VOIDmode
|
||
&& GET_MODE_CLASS (GET_MODE (value)) != MODE_INT
|
||
&& GET_MODE_CLASS (GET_MODE (value)) != MODE_PARTIAL_INT)
|
||
{
|
||
value = gen_reg_rtx (int_mode_for_mode (GET_MODE (value)));
|
||
emit_move_insn (gen_lowpart (GET_MODE (orig_value), value), orig_value);
|
||
}
|
||
|
||
/* Now OFFSET is nonzero only if OP0 is memory
|
||
and is therefore always measured in bytes. */
|
||
|
||
if (HAVE_insv
|
||
&& GET_MODE (value) != BLKmode
|
||
&& bitsize > 0
|
||
&& GET_MODE_BITSIZE (op_mode) >= bitsize
|
||
&& ! ((REG_P (op0) || GET_CODE (op0) == SUBREG)
|
||
&& (bitsize + bitpos > GET_MODE_BITSIZE (op_mode)))
|
||
&& insn_data[CODE_FOR_insv].operand[1].predicate (GEN_INT (bitsize),
|
||
VOIDmode))
|
||
{
|
||
int xbitpos = bitpos;
|
||
rtx value1;
|
||
rtx xop0 = op0;
|
||
rtx last = get_last_insn ();
|
||
rtx pat;
|
||
enum machine_mode maxmode = mode_for_extraction (EP_insv, 3);
|
||
int save_volatile_ok = volatile_ok;
|
||
|
||
volatile_ok = 1;
|
||
|
||
/* If this machine's insv can only insert into a register, copy OP0
|
||
into a register and save it back later. */
|
||
if (MEM_P (op0)
|
||
&& ! ((*insn_data[(int) CODE_FOR_insv].operand[0].predicate)
|
||
(op0, VOIDmode)))
|
||
{
|
||
rtx tempreg;
|
||
enum machine_mode bestmode;
|
||
|
||
/* Get the mode to use for inserting into this field. If OP0 is
|
||
BLKmode, get the smallest mode consistent with the alignment. If
|
||
OP0 is a non-BLKmode object that is no wider than MAXMODE, use its
|
||
mode. Otherwise, use the smallest mode containing the field. */
|
||
|
||
if (GET_MODE (op0) == BLKmode
|
||
|| GET_MODE_SIZE (GET_MODE (op0)) > GET_MODE_SIZE (maxmode))
|
||
bestmode
|
||
= get_best_mode (bitsize, bitnum, MEM_ALIGN (op0), maxmode,
|
||
MEM_VOLATILE_P (op0));
|
||
else
|
||
bestmode = GET_MODE (op0);
|
||
|
||
if (bestmode == VOIDmode
|
||
|| GET_MODE_SIZE (bestmode) < GET_MODE_SIZE (fieldmode)
|
||
|| (SLOW_UNALIGNED_ACCESS (bestmode, MEM_ALIGN (op0))
|
||
&& GET_MODE_BITSIZE (bestmode) > MEM_ALIGN (op0)))
|
||
goto insv_loses;
|
||
|
||
/* Adjust address to point to the containing unit of that mode.
|
||
Compute offset as multiple of this unit, counting in bytes. */
|
||
unit = GET_MODE_BITSIZE (bestmode);
|
||
offset = (bitnum / unit) * GET_MODE_SIZE (bestmode);
|
||
bitpos = bitnum % unit;
|
||
op0 = adjust_address (op0, bestmode, offset);
|
||
|
||
/* Fetch that unit, store the bitfield in it, then store
|
||
the unit. */
|
||
tempreg = copy_to_reg (op0);
|
||
store_bit_field (tempreg, bitsize, bitpos, fieldmode, orig_value);
|
||
emit_move_insn (op0, tempreg);
|
||
return value;
|
||
}
|
||
volatile_ok = save_volatile_ok;
|
||
|
||
/* Add OFFSET into OP0's address. */
|
||
if (MEM_P (xop0))
|
||
xop0 = adjust_address (xop0, byte_mode, offset);
|
||
|
||
/* If xop0 is a register, we need it in MAXMODE
|
||
to make it acceptable to the format of insv. */
|
||
if (GET_CODE (xop0) == SUBREG)
|
||
/* We can't just change the mode, because this might clobber op0,
|
||
and we will need the original value of op0 if insv fails. */
|
||
xop0 = gen_rtx_SUBREG (maxmode, SUBREG_REG (xop0), SUBREG_BYTE (xop0));
|
||
if (REG_P (xop0) && GET_MODE (xop0) != maxmode)
|
||
xop0 = gen_rtx_SUBREG (maxmode, xop0, 0);
|
||
|
||
/* On big-endian machines, we count bits from the most significant.
|
||
If the bit field insn does not, we must invert. */
|
||
|
||
if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
|
||
xbitpos = unit - bitsize - xbitpos;
|
||
|
||
/* We have been counting XBITPOS within UNIT.
|
||
Count instead within the size of the register. */
|
||
if (BITS_BIG_ENDIAN && !MEM_P (xop0))
|
||
xbitpos += GET_MODE_BITSIZE (maxmode) - unit;
|
||
|
||
unit = GET_MODE_BITSIZE (maxmode);
|
||
|
||
/* Convert VALUE to maxmode (which insv insn wants) in VALUE1. */
|
||
value1 = value;
|
||
if (GET_MODE (value) != maxmode)
|
||
{
|
||
if (GET_MODE_BITSIZE (GET_MODE (value)) >= bitsize)
|
||
{
|
||
/* Optimization: Don't bother really extending VALUE
|
||
if it has all the bits we will actually use. However,
|
||
if we must narrow it, be sure we do it correctly. */
|
||
|
||
if (GET_MODE_SIZE (GET_MODE (value)) < GET_MODE_SIZE (maxmode))
|
||
{
|
||
rtx tmp;
|
||
|
||
tmp = simplify_subreg (maxmode, value1, GET_MODE (value), 0);
|
||
if (! tmp)
|
||
tmp = simplify_gen_subreg (maxmode,
|
||
force_reg (GET_MODE (value),
|
||
value1),
|
||
GET_MODE (value), 0);
|
||
value1 = tmp;
|
||
}
|
||
else
|
||
value1 = gen_lowpart (maxmode, value1);
|
||
}
|
||
else if (GET_CODE (value) == CONST_INT)
|
||
value1 = gen_int_mode (INTVAL (value), maxmode);
|
||
else
|
||
/* Parse phase is supposed to make VALUE's data type
|
||
match that of the component reference, which is a type
|
||
at least as wide as the field; so VALUE should have
|
||
a mode that corresponds to that type. */
|
||
gcc_assert (CONSTANT_P (value));
|
||
}
|
||
|
||
/* If this machine's insv insists on a register,
|
||
get VALUE1 into a register. */
|
||
if (! ((*insn_data[(int) CODE_FOR_insv].operand[3].predicate)
|
||
(value1, maxmode)))
|
||
value1 = force_reg (maxmode, value1);
|
||
|
||
pat = gen_insv (xop0, GEN_INT (bitsize), GEN_INT (xbitpos), value1);
|
||
if (pat)
|
||
emit_insn (pat);
|
||
else
|
||
{
|
||
delete_insns_since (last);
|
||
store_fixed_bit_field (op0, offset, bitsize, bitpos, value);
|
||
}
|
||
}
|
||
else
|
||
insv_loses:
|
||
/* Insv is not available; store using shifts and boolean ops. */
|
||
store_fixed_bit_field (op0, offset, bitsize, bitpos, value);
|
||
return value;
|
||
}
|
||
|
||
/* Use shifts and boolean operations to store VALUE
|
||
into a bit field of width BITSIZE
|
||
in a memory location specified by OP0 except offset by OFFSET bytes.
|
||
(OFFSET must be 0 if OP0 is a register.)
|
||
The field starts at position BITPOS within the byte.
|
||
(If OP0 is a register, it may be a full word or a narrower mode,
|
||
but BITPOS still counts within a full word,
|
||
which is significant on bigendian machines.) */
|
||
|
||
static void
|
||
store_fixed_bit_field (rtx op0, unsigned HOST_WIDE_INT offset,
|
||
unsigned HOST_WIDE_INT bitsize,
|
||
unsigned HOST_WIDE_INT bitpos, rtx value)
|
||
{
|
||
enum machine_mode mode;
|
||
unsigned int total_bits = BITS_PER_WORD;
|
||
rtx temp;
|
||
int all_zero = 0;
|
||
int all_one = 0;
|
||
|
||
/* There is a case not handled here:
|
||
a structure with a known alignment of just a halfword
|
||
and a field split across two aligned halfwords within the structure.
|
||
Or likewise a structure with a known alignment of just a byte
|
||
and a field split across two bytes.
|
||
Such cases are not supposed to be able to occur. */
|
||
|
||
if (REG_P (op0) || GET_CODE (op0) == SUBREG)
|
||
{
|
||
gcc_assert (!offset);
|
||
/* Special treatment for a bit field split across two registers. */
|
||
if (bitsize + bitpos > BITS_PER_WORD)
|
||
{
|
||
store_split_bit_field (op0, bitsize, bitpos, value);
|
||
return;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Get the proper mode to use for this field. We want a mode that
|
||
includes the entire field. If such a mode would be larger than
|
||
a word, we won't be doing the extraction the normal way.
|
||
We don't want a mode bigger than the destination. */
|
||
|
||
mode = GET_MODE (op0);
|
||
if (GET_MODE_BITSIZE (mode) == 0
|
||
|| GET_MODE_BITSIZE (mode) > GET_MODE_BITSIZE (word_mode))
|
||
mode = word_mode;
|
||
mode = get_best_mode (bitsize, bitpos + offset * BITS_PER_UNIT,
|
||
MEM_ALIGN (op0), mode, MEM_VOLATILE_P (op0));
|
||
|
||
if (mode == VOIDmode)
|
||
{
|
||
/* The only way this should occur is if the field spans word
|
||
boundaries. */
|
||
store_split_bit_field (op0, bitsize, bitpos + offset * BITS_PER_UNIT,
|
||
value);
|
||
return;
|
||
}
|
||
|
||
total_bits = GET_MODE_BITSIZE (mode);
|
||
|
||
/* Make sure bitpos is valid for the chosen mode. Adjust BITPOS to
|
||
be in the range 0 to total_bits-1, and put any excess bytes in
|
||
OFFSET. */
|
||
if (bitpos >= total_bits)
|
||
{
|
||
offset += (bitpos / total_bits) * (total_bits / BITS_PER_UNIT);
|
||
bitpos -= ((bitpos / total_bits) * (total_bits / BITS_PER_UNIT)
|
||
* BITS_PER_UNIT);
|
||
}
|
||
|
||
/* Get ref to an aligned byte, halfword, or word containing the field.
|
||
Adjust BITPOS to be position within a word,
|
||
and OFFSET to be the offset of that word.
|
||
Then alter OP0 to refer to that word. */
|
||
bitpos += (offset % (total_bits / BITS_PER_UNIT)) * BITS_PER_UNIT;
|
||
offset -= (offset % (total_bits / BITS_PER_UNIT));
|
||
op0 = adjust_address (op0, mode, offset);
|
||
}
|
||
|
||
mode = GET_MODE (op0);
|
||
|
||
/* Now MODE is either some integral mode for a MEM as OP0,
|
||
or is a full-word for a REG as OP0. TOTAL_BITS corresponds.
|
||
The bit field is contained entirely within OP0.
|
||
BITPOS is the starting bit number within OP0.
|
||
(OP0's mode may actually be narrower than MODE.) */
|
||
|
||
if (BYTES_BIG_ENDIAN)
|
||
/* BITPOS is the distance between our msb
|
||
and that of the containing datum.
|
||
Convert it to the distance from the lsb. */
|
||
bitpos = total_bits - bitsize - bitpos;
|
||
|
||
/* Now BITPOS is always the distance between our lsb
|
||
and that of OP0. */
|
||
|
||
/* Shift VALUE left by BITPOS bits. If VALUE is not constant,
|
||
we must first convert its mode to MODE. */
|
||
|
||
if (GET_CODE (value) == CONST_INT)
|
||
{
|
||
HOST_WIDE_INT v = INTVAL (value);
|
||
|
||
if (bitsize < HOST_BITS_PER_WIDE_INT)
|
||
v &= ((HOST_WIDE_INT) 1 << bitsize) - 1;
|
||
|
||
if (v == 0)
|
||
all_zero = 1;
|
||
else if ((bitsize < HOST_BITS_PER_WIDE_INT
|
||
&& v == ((HOST_WIDE_INT) 1 << bitsize) - 1)
|
||
|| (bitsize == HOST_BITS_PER_WIDE_INT && v == -1))
|
||
all_one = 1;
|
||
|
||
value = lshift_value (mode, value, bitpos, bitsize);
|
||
}
|
||
else
|
||
{
|
||
int must_and = (GET_MODE_BITSIZE (GET_MODE (value)) != bitsize
|
||
&& bitpos + bitsize != GET_MODE_BITSIZE (mode));
|
||
|
||
if (GET_MODE (value) != mode)
|
||
{
|
||
if ((REG_P (value) || GET_CODE (value) == SUBREG)
|
||
&& GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (value)))
|
||
value = gen_lowpart (mode, value);
|
||
else
|
||
value = convert_to_mode (mode, value, 1);
|
||
}
|
||
|
||
if (must_and)
|
||
value = expand_binop (mode, and_optab, value,
|
||
mask_rtx (mode, 0, bitsize, 0),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
if (bitpos > 0)
|
||
value = expand_shift (LSHIFT_EXPR, mode, value,
|
||
build_int_cst (NULL_TREE, bitpos), NULL_RTX, 1);
|
||
}
|
||
|
||
/* Now clear the chosen bits in OP0,
|
||
except that if VALUE is -1 we need not bother. */
|
||
/* We keep the intermediates in registers to allow CSE to combine
|
||
consecutive bitfield assignments. */
|
||
|
||
temp = force_reg (mode, op0);
|
||
|
||
if (! all_one)
|
||
{
|
||
temp = expand_binop (mode, and_optab, temp,
|
||
mask_rtx (mode, bitpos, bitsize, 1),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = force_reg (mode, temp);
|
||
}
|
||
|
||
/* Now logical-or VALUE into OP0, unless it is zero. */
|
||
|
||
if (! all_zero)
|
||
{
|
||
temp = expand_binop (mode, ior_optab, temp, value,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = force_reg (mode, temp);
|
||
}
|
||
|
||
if (op0 != temp)
|
||
emit_move_insn (op0, temp);
|
||
}
|
||
|
||
/* Store a bit field that is split across multiple accessible memory objects.
|
||
|
||
OP0 is the REG, SUBREG or MEM rtx for the first of the objects.
|
||
BITSIZE is the field width; BITPOS the position of its first bit
|
||
(within the word).
|
||
VALUE is the value to store.
|
||
|
||
This does not yet handle fields wider than BITS_PER_WORD. */
|
||
|
||
static void
|
||
store_split_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize,
|
||
unsigned HOST_WIDE_INT bitpos, rtx value)
|
||
{
|
||
unsigned int unit;
|
||
unsigned int bitsdone = 0;
|
||
|
||
/* Make sure UNIT isn't larger than BITS_PER_WORD, we can only handle that
|
||
much at a time. */
|
||
if (REG_P (op0) || GET_CODE (op0) == SUBREG)
|
||
unit = BITS_PER_WORD;
|
||
else
|
||
unit = MIN (MEM_ALIGN (op0), BITS_PER_WORD);
|
||
|
||
/* If VALUE is a constant other than a CONST_INT, get it into a register in
|
||
WORD_MODE. If we can do this using gen_lowpart_common, do so. Note
|
||
that VALUE might be a floating-point constant. */
|
||
if (CONSTANT_P (value) && GET_CODE (value) != CONST_INT)
|
||
{
|
||
rtx word = gen_lowpart_common (word_mode, value);
|
||
|
||
if (word && (value != word))
|
||
value = word;
|
||
else
|
||
value = gen_lowpart_common (word_mode,
|
||
force_reg (GET_MODE (value) != VOIDmode
|
||
? GET_MODE (value)
|
||
: word_mode, value));
|
||
}
|
||
|
||
while (bitsdone < bitsize)
|
||
{
|
||
unsigned HOST_WIDE_INT thissize;
|
||
rtx part, word;
|
||
unsigned HOST_WIDE_INT thispos;
|
||
unsigned HOST_WIDE_INT offset;
|
||
|
||
offset = (bitpos + bitsdone) / unit;
|
||
thispos = (bitpos + bitsdone) % unit;
|
||
|
||
/* THISSIZE must not overrun a word boundary. Otherwise,
|
||
store_fixed_bit_field will call us again, and we will mutually
|
||
recurse forever. */
|
||
thissize = MIN (bitsize - bitsdone, BITS_PER_WORD);
|
||
thissize = MIN (thissize, unit - thispos);
|
||
|
||
if (BYTES_BIG_ENDIAN)
|
||
{
|
||
int total_bits;
|
||
|
||
/* We must do an endian conversion exactly the same way as it is
|
||
done in extract_bit_field, so that the two calls to
|
||
extract_fixed_bit_field will have comparable arguments. */
|
||
if (!MEM_P (value) || GET_MODE (value) == BLKmode)
|
||
total_bits = BITS_PER_WORD;
|
||
else
|
||
total_bits = GET_MODE_BITSIZE (GET_MODE (value));
|
||
|
||
/* Fetch successively less significant portions. */
|
||
if (GET_CODE (value) == CONST_INT)
|
||
part = GEN_INT (((unsigned HOST_WIDE_INT) (INTVAL (value))
|
||
>> (bitsize - bitsdone - thissize))
|
||
& (((HOST_WIDE_INT) 1 << thissize) - 1));
|
||
else
|
||
/* The args are chosen so that the last part includes the
|
||
lsb. Give extract_bit_field the value it needs (with
|
||
endianness compensation) to fetch the piece we want. */
|
||
part = extract_fixed_bit_field (word_mode, value, 0, thissize,
|
||
total_bits - bitsize + bitsdone,
|
||
NULL_RTX, 1);
|
||
}
|
||
else
|
||
{
|
||
/* Fetch successively more significant portions. */
|
||
if (GET_CODE (value) == CONST_INT)
|
||
part = GEN_INT (((unsigned HOST_WIDE_INT) (INTVAL (value))
|
||
>> bitsdone)
|
||
& (((HOST_WIDE_INT) 1 << thissize) - 1));
|
||
else
|
||
part = extract_fixed_bit_field (word_mode, value, 0, thissize,
|
||
bitsdone, NULL_RTX, 1);
|
||
}
|
||
|
||
/* If OP0 is a register, then handle OFFSET here.
|
||
|
||
When handling multiword bitfields, extract_bit_field may pass
|
||
down a word_mode SUBREG of a larger REG for a bitfield that actually
|
||
crosses a word boundary. Thus, for a SUBREG, we must find
|
||
the current word starting from the base register. */
|
||
if (GET_CODE (op0) == SUBREG)
|
||
{
|
||
int word_offset = (SUBREG_BYTE (op0) / UNITS_PER_WORD) + offset;
|
||
word = operand_subword_force (SUBREG_REG (op0), word_offset,
|
||
GET_MODE (SUBREG_REG (op0)));
|
||
offset = 0;
|
||
}
|
||
else if (REG_P (op0))
|
||
{
|
||
word = operand_subword_force (op0, offset, GET_MODE (op0));
|
||
offset = 0;
|
||
}
|
||
else
|
||
word = op0;
|
||
|
||
/* OFFSET is in UNITs, and UNIT is in bits.
|
||
store_fixed_bit_field wants offset in bytes. */
|
||
store_fixed_bit_field (word, offset * unit / BITS_PER_UNIT, thissize,
|
||
thispos, part);
|
||
bitsdone += thissize;
|
||
}
|
||
}
|
||
|
||
/* Generate code to extract a byte-field from STR_RTX
|
||
containing BITSIZE bits, starting at BITNUM,
|
||
and put it in TARGET if possible (if TARGET is nonzero).
|
||
Regardless of TARGET, we return the rtx for where the value is placed.
|
||
|
||
STR_RTX is the structure containing the byte (a REG or MEM).
|
||
UNSIGNEDP is nonzero if this is an unsigned bit field.
|
||
MODE is the natural mode of the field value once extracted.
|
||
TMODE is the mode the caller would like the value to have;
|
||
but the value may be returned with type MODE instead.
|
||
|
||
TOTAL_SIZE is the size in bytes of the containing structure,
|
||
or -1 if varying.
|
||
|
||
If a TARGET is specified and we can store in it at no extra cost,
|
||
we do so, and return TARGET.
|
||
Otherwise, we return a REG of mode TMODE or MODE, with TMODE preferred
|
||
if they are equally easy. */
|
||
|
||
rtx
|
||
extract_bit_field (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
|
||
unsigned HOST_WIDE_INT bitnum, int unsignedp, rtx target,
|
||
enum machine_mode mode, enum machine_mode tmode)
|
||
{
|
||
unsigned int unit
|
||
= (MEM_P (str_rtx)) ? BITS_PER_UNIT : BITS_PER_WORD;
|
||
unsigned HOST_WIDE_INT offset, bitpos;
|
||
rtx op0 = str_rtx;
|
||
rtx spec_target = target;
|
||
rtx spec_target_subreg = 0;
|
||
enum machine_mode int_mode;
|
||
enum machine_mode extv_mode = mode_for_extraction (EP_extv, 0);
|
||
enum machine_mode extzv_mode = mode_for_extraction (EP_extzv, 0);
|
||
enum machine_mode mode1;
|
||
int byte_offset;
|
||
|
||
if (tmode == VOIDmode)
|
||
tmode = mode;
|
||
|
||
while (GET_CODE (op0) == SUBREG)
|
||
{
|
||
bitnum += SUBREG_BYTE (op0) * BITS_PER_UNIT;
|
||
op0 = SUBREG_REG (op0);
|
||
}
|
||
|
||
/* If we have an out-of-bounds access to a register, just return an
|
||
uninitialized register of the required mode. This can occur if the
|
||
source code contains an out-of-bounds access to a small array. */
|
||
if (REG_P (op0) && bitnum >= GET_MODE_BITSIZE (GET_MODE (op0)))
|
||
return gen_reg_rtx (tmode);
|
||
|
||
if (REG_P (op0)
|
||
&& mode == GET_MODE (op0)
|
||
&& bitnum == 0
|
||
&& bitsize == GET_MODE_BITSIZE (GET_MODE (op0)))
|
||
{
|
||
/* We're trying to extract a full register from itself. */
|
||
return op0;
|
||
}
|
||
|
||
/* Use vec_extract patterns for extracting parts of vectors whenever
|
||
available. */
|
||
if (VECTOR_MODE_P (GET_MODE (op0))
|
||
&& !MEM_P (op0)
|
||
&& (vec_extract_optab->handlers[GET_MODE (op0)].insn_code
|
||
!= CODE_FOR_nothing)
|
||
&& ((bitnum + bitsize - 1) / GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0)))
|
||
== bitnum / GET_MODE_BITSIZE (GET_MODE_INNER (GET_MODE (op0)))))
|
||
{
|
||
enum machine_mode outermode = GET_MODE (op0);
|
||
enum machine_mode innermode = GET_MODE_INNER (outermode);
|
||
int icode = (int) vec_extract_optab->handlers[outermode].insn_code;
|
||
unsigned HOST_WIDE_INT pos = bitnum / GET_MODE_BITSIZE (innermode);
|
||
rtx rtxpos = GEN_INT (pos);
|
||
rtx src = op0;
|
||
rtx dest = NULL, pat, seq;
|
||
enum machine_mode mode0 = insn_data[icode].operand[0].mode;
|
||
enum machine_mode mode1 = insn_data[icode].operand[1].mode;
|
||
enum machine_mode mode2 = insn_data[icode].operand[2].mode;
|
||
|
||
if (innermode == tmode || innermode == mode)
|
||
dest = target;
|
||
|
||
if (!dest)
|
||
dest = gen_reg_rtx (innermode);
|
||
|
||
start_sequence ();
|
||
|
||
if (! (*insn_data[icode].operand[0].predicate) (dest, mode0))
|
||
dest = copy_to_mode_reg (mode0, dest);
|
||
|
||
if (! (*insn_data[icode].operand[1].predicate) (src, mode1))
|
||
src = copy_to_mode_reg (mode1, src);
|
||
|
||
if (! (*insn_data[icode].operand[2].predicate) (rtxpos, mode2))
|
||
rtxpos = copy_to_mode_reg (mode1, rtxpos);
|
||
|
||
/* We could handle this, but we should always be called with a pseudo
|
||
for our targets and all insns should take them as outputs. */
|
||
gcc_assert ((*insn_data[icode].operand[0].predicate) (dest, mode0)
|
||
&& (*insn_data[icode].operand[1].predicate) (src, mode1)
|
||
&& (*insn_data[icode].operand[2].predicate) (rtxpos, mode2));
|
||
|
||
pat = GEN_FCN (icode) (dest, src, rtxpos);
|
||
seq = get_insns ();
|
||
end_sequence ();
|
||
if (pat)
|
||
{
|
||
emit_insn (seq);
|
||
emit_insn (pat);
|
||
return dest;
|
||
}
|
||
}
|
||
|
||
/* Make sure we are playing with integral modes. Pun with subregs
|
||
if we aren't. */
|
||
{
|
||
enum machine_mode imode = int_mode_for_mode (GET_MODE (op0));
|
||
if (imode != GET_MODE (op0))
|
||
{
|
||
if (MEM_P (op0))
|
||
op0 = adjust_address (op0, imode, 0);
|
||
else
|
||
{
|
||
gcc_assert (imode != BLKmode);
|
||
op0 = gen_lowpart (imode, op0);
|
||
|
||
/* If we got a SUBREG, force it into a register since we
|
||
aren't going to be able to do another SUBREG on it. */
|
||
if (GET_CODE (op0) == SUBREG)
|
||
op0 = force_reg (imode, op0);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* We may be accessing data outside the field, which means
|
||
we can alias adjacent data. */
|
||
if (MEM_P (op0))
|
||
{
|
||
op0 = shallow_copy_rtx (op0);
|
||
set_mem_alias_set (op0, 0);
|
||
set_mem_expr (op0, 0);
|
||
}
|
||
|
||
/* Extraction of a full-word or multi-word value from a structure
|
||
in a register or aligned memory can be done with just a SUBREG.
|
||
A subword value in the least significant part of a register
|
||
can also be extracted with a SUBREG. For this, we need the
|
||
byte offset of the value in op0. */
|
||
|
||
bitpos = bitnum % unit;
|
||
offset = bitnum / unit;
|
||
byte_offset = bitpos / BITS_PER_UNIT + offset * UNITS_PER_WORD;
|
||
|
||
/* If OP0 is a register, BITPOS must count within a word.
|
||
But as we have it, it counts within whatever size OP0 now has.
|
||
On a bigendian machine, these are not the same, so convert. */
|
||
if (BYTES_BIG_ENDIAN
|
||
&& !MEM_P (op0)
|
||
&& unit > GET_MODE_BITSIZE (GET_MODE (op0)))
|
||
bitpos += unit - GET_MODE_BITSIZE (GET_MODE (op0));
|
||
|
||
/* ??? We currently assume TARGET is at least as big as BITSIZE.
|
||
If that's wrong, the solution is to test for it and set TARGET to 0
|
||
if needed. */
|
||
|
||
/* Only scalar integer modes can be converted via subregs. There is an
|
||
additional problem for FP modes here in that they can have a precision
|
||
which is different from the size. mode_for_size uses precision, but
|
||
we want a mode based on the size, so we must avoid calling it for FP
|
||
modes. */
|
||
mode1 = (SCALAR_INT_MODE_P (tmode)
|
||
? mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0)
|
||
: mode);
|
||
|
||
if (((bitsize >= BITS_PER_WORD && bitsize == GET_MODE_BITSIZE (mode)
|
||
&& bitpos % BITS_PER_WORD == 0)
|
||
|| (mode1 != BLKmode
|
||
/* ??? The big endian test here is wrong. This is correct
|
||
if the value is in a register, and if mode_for_size is not
|
||
the same mode as op0. This causes us to get unnecessarily
|
||
inefficient code from the Thumb port when -mbig-endian. */
|
||
&& (BYTES_BIG_ENDIAN
|
||
? bitpos + bitsize == BITS_PER_WORD
|
||
: bitpos == 0)))
|
||
&& ((!MEM_P (op0)
|
||
&& TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
|
||
GET_MODE_BITSIZE (GET_MODE (op0)))
|
||
&& GET_MODE_SIZE (mode1) != 0
|
||
&& byte_offset % GET_MODE_SIZE (mode1) == 0)
|
||
|| (MEM_P (op0)
|
||
&& (! SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (op0))
|
||
|| (offset * BITS_PER_UNIT % bitsize == 0
|
||
&& MEM_ALIGN (op0) % bitsize == 0)))))
|
||
{
|
||
if (mode1 != GET_MODE (op0))
|
||
{
|
||
if (MEM_P (op0))
|
||
op0 = adjust_address (op0, mode1, offset);
|
||
else
|
||
{
|
||
rtx sub = simplify_gen_subreg (mode1, op0, GET_MODE (op0),
|
||
byte_offset);
|
||
if (sub == NULL)
|
||
goto no_subreg_mode_swap;
|
||
op0 = sub;
|
||
}
|
||
}
|
||
if (mode1 != mode)
|
||
return convert_to_mode (tmode, op0, unsignedp);
|
||
return op0;
|
||
}
|
||
no_subreg_mode_swap:
|
||
|
||
/* Handle fields bigger than a word. */
|
||
|
||
if (bitsize > BITS_PER_WORD)
|
||
{
|
||
/* Here we transfer the words of the field
|
||
in the order least significant first.
|
||
This is because the most significant word is the one which may
|
||
be less than full. */
|
||
|
||
unsigned int nwords = (bitsize + (BITS_PER_WORD - 1)) / BITS_PER_WORD;
|
||
unsigned int i;
|
||
|
||
if (target == 0 || !REG_P (target))
|
||
target = gen_reg_rtx (mode);
|
||
|
||
/* Indicate for flow that the entire target reg is being set. */
|
||
emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
|
||
|
||
for (i = 0; i < nwords; i++)
|
||
{
|
||
/* If I is 0, use the low-order word in both field and target;
|
||
if I is 1, use the next to lowest word; and so on. */
|
||
/* Word number in TARGET to use. */
|
||
unsigned int wordnum
|
||
= (WORDS_BIG_ENDIAN
|
||
? GET_MODE_SIZE (GET_MODE (target)) / UNITS_PER_WORD - i - 1
|
||
: i);
|
||
/* Offset from start of field in OP0. */
|
||
unsigned int bit_offset = (WORDS_BIG_ENDIAN
|
||
? MAX (0, ((int) bitsize - ((int) i + 1)
|
||
* (int) BITS_PER_WORD))
|
||
: (int) i * BITS_PER_WORD);
|
||
rtx target_part = operand_subword (target, wordnum, 1, VOIDmode);
|
||
rtx result_part
|
||
= extract_bit_field (op0, MIN (BITS_PER_WORD,
|
||
bitsize - i * BITS_PER_WORD),
|
||
bitnum + bit_offset, 1, target_part, mode,
|
||
word_mode);
|
||
|
||
gcc_assert (target_part);
|
||
|
||
if (result_part != target_part)
|
||
emit_move_insn (target_part, result_part);
|
||
}
|
||
|
||
if (unsignedp)
|
||
{
|
||
/* Unless we've filled TARGET, the upper regs in a multi-reg value
|
||
need to be zero'd out. */
|
||
if (GET_MODE_SIZE (GET_MODE (target)) > nwords * UNITS_PER_WORD)
|
||
{
|
||
unsigned int i, total_words;
|
||
|
||
total_words = GET_MODE_SIZE (GET_MODE (target)) / UNITS_PER_WORD;
|
||
for (i = nwords; i < total_words; i++)
|
||
emit_move_insn
|
||
(operand_subword (target,
|
||
WORDS_BIG_ENDIAN ? total_words - i - 1 : i,
|
||
1, VOIDmode),
|
||
const0_rtx);
|
||
}
|
||
return target;
|
||
}
|
||
|
||
/* Signed bit field: sign-extend with two arithmetic shifts. */
|
||
target = expand_shift (LSHIFT_EXPR, mode, target,
|
||
build_int_cst (NULL_TREE,
|
||
GET_MODE_BITSIZE (mode) - bitsize),
|
||
NULL_RTX, 0);
|
||
return expand_shift (RSHIFT_EXPR, mode, target,
|
||
build_int_cst (NULL_TREE,
|
||
GET_MODE_BITSIZE (mode) - bitsize),
|
||
NULL_RTX, 0);
|
||
}
|
||
|
||
/* From here on we know the desired field is smaller than a word. */
|
||
|
||
/* Check if there is a correspondingly-sized integer field, so we can
|
||
safely extract it as one size of integer, if necessary; then
|
||
truncate or extend to the size that is wanted; then use SUBREGs or
|
||
convert_to_mode to get one of the modes we really wanted. */
|
||
|
||
int_mode = int_mode_for_mode (tmode);
|
||
if (int_mode == BLKmode)
|
||
int_mode = int_mode_for_mode (mode);
|
||
/* Should probably push op0 out to memory and then do a load. */
|
||
gcc_assert (int_mode != BLKmode);
|
||
|
||
/* OFFSET is the number of words or bytes (UNIT says which)
|
||
from STR_RTX to the first word or byte containing part of the field. */
|
||
if (!MEM_P (op0))
|
||
{
|
||
if (offset != 0
|
||
|| GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD)
|
||
{
|
||
if (!REG_P (op0))
|
||
op0 = copy_to_reg (op0);
|
||
op0 = gen_rtx_SUBREG (mode_for_size (BITS_PER_WORD, MODE_INT, 0),
|
||
op0, (offset * UNITS_PER_WORD));
|
||
}
|
||
offset = 0;
|
||
}
|
||
|
||
/* Now OFFSET is nonzero only for memory operands. */
|
||
|
||
if (unsignedp)
|
||
{
|
||
if (HAVE_extzv
|
||
&& bitsize > 0
|
||
&& GET_MODE_BITSIZE (extzv_mode) >= bitsize
|
||
&& ! ((REG_P (op0) || GET_CODE (op0) == SUBREG)
|
||
&& (bitsize + bitpos > GET_MODE_BITSIZE (extzv_mode))))
|
||
{
|
||
unsigned HOST_WIDE_INT xbitpos = bitpos, xoffset = offset;
|
||
rtx bitsize_rtx, bitpos_rtx;
|
||
rtx last = get_last_insn ();
|
||
rtx xop0 = op0;
|
||
rtx xtarget = target;
|
||
rtx xspec_target = spec_target;
|
||
rtx xspec_target_subreg = spec_target_subreg;
|
||
rtx pat;
|
||
enum machine_mode maxmode = mode_for_extraction (EP_extzv, 0);
|
||
|
||
if (MEM_P (xop0))
|
||
{
|
||
int save_volatile_ok = volatile_ok;
|
||
volatile_ok = 1;
|
||
|
||
/* Is the memory operand acceptable? */
|
||
if (! ((*insn_data[(int) CODE_FOR_extzv].operand[1].predicate)
|
||
(xop0, GET_MODE (xop0))))
|
||
{
|
||
/* No, load into a reg and extract from there. */
|
||
enum machine_mode bestmode;
|
||
|
||
/* Get the mode to use for inserting into this field. If
|
||
OP0 is BLKmode, get the smallest mode consistent with the
|
||
alignment. If OP0 is a non-BLKmode object that is no
|
||
wider than MAXMODE, use its mode. Otherwise, use the
|
||
smallest mode containing the field. */
|
||
|
||
if (GET_MODE (xop0) == BLKmode
|
||
|| (GET_MODE_SIZE (GET_MODE (op0))
|
||
> GET_MODE_SIZE (maxmode)))
|
||
bestmode = get_best_mode (bitsize, bitnum,
|
||
MEM_ALIGN (xop0), maxmode,
|
||
MEM_VOLATILE_P (xop0));
|
||
else
|
||
bestmode = GET_MODE (xop0);
|
||
|
||
if (bestmode == VOIDmode
|
||
|| (SLOW_UNALIGNED_ACCESS (bestmode, MEM_ALIGN (xop0))
|
||
&& GET_MODE_BITSIZE (bestmode) > MEM_ALIGN (xop0)))
|
||
goto extzv_loses;
|
||
|
||
/* Compute offset as multiple of this unit,
|
||
counting in bytes. */
|
||
unit = GET_MODE_BITSIZE (bestmode);
|
||
xoffset = (bitnum / unit) * GET_MODE_SIZE (bestmode);
|
||
xbitpos = bitnum % unit;
|
||
xop0 = adjust_address (xop0, bestmode, xoffset);
|
||
|
||
/* Make sure register is big enough for the whole field. */
|
||
if (xoffset * BITS_PER_UNIT + unit
|
||
< offset * BITS_PER_UNIT + bitsize)
|
||
goto extzv_loses;
|
||
|
||
/* Fetch it to a register in that size. */
|
||
xop0 = force_reg (bestmode, xop0);
|
||
|
||
/* XBITPOS counts within UNIT, which is what is expected. */
|
||
}
|
||
else
|
||
/* Get ref to first byte containing part of the field. */
|
||
xop0 = adjust_address (xop0, byte_mode, xoffset);
|
||
|
||
volatile_ok = save_volatile_ok;
|
||
}
|
||
|
||
/* If op0 is a register, we need it in MAXMODE (which is usually
|
||
SImode). to make it acceptable to the format of extzv. */
|
||
if (GET_CODE (xop0) == SUBREG && GET_MODE (xop0) != maxmode)
|
||
goto extzv_loses;
|
||
if (REG_P (xop0) && GET_MODE (xop0) != maxmode)
|
||
xop0 = gen_rtx_SUBREG (maxmode, xop0, 0);
|
||
|
||
/* On big-endian machines, we count bits from the most significant.
|
||
If the bit field insn does not, we must invert. */
|
||
if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
|
||
xbitpos = unit - bitsize - xbitpos;
|
||
|
||
/* Now convert from counting within UNIT to counting in MAXMODE. */
|
||
if (BITS_BIG_ENDIAN && !MEM_P (xop0))
|
||
xbitpos += GET_MODE_BITSIZE (maxmode) - unit;
|
||
|
||
unit = GET_MODE_BITSIZE (maxmode);
|
||
|
||
if (xtarget == 0)
|
||
xtarget = xspec_target = gen_reg_rtx (tmode);
|
||
|
||
if (GET_MODE (xtarget) != maxmode)
|
||
{
|
||
if (REG_P (xtarget))
|
||
{
|
||
int wider = (GET_MODE_SIZE (maxmode)
|
||
> GET_MODE_SIZE (GET_MODE (xtarget)));
|
||
xtarget = gen_lowpart (maxmode, xtarget);
|
||
if (wider)
|
||
xspec_target_subreg = xtarget;
|
||
}
|
||
else
|
||
xtarget = gen_reg_rtx (maxmode);
|
||
}
|
||
|
||
/* If this machine's extzv insists on a register target,
|
||
make sure we have one. */
|
||
if (! ((*insn_data[(int) CODE_FOR_extzv].operand[0].predicate)
|
||
(xtarget, maxmode)))
|
||
xtarget = gen_reg_rtx (maxmode);
|
||
|
||
bitsize_rtx = GEN_INT (bitsize);
|
||
bitpos_rtx = GEN_INT (xbitpos);
|
||
|
||
pat = gen_extzv (xtarget, xop0, bitsize_rtx, bitpos_rtx);
|
||
if (pat)
|
||
{
|
||
emit_insn (pat);
|
||
target = xtarget;
|
||
spec_target = xspec_target;
|
||
spec_target_subreg = xspec_target_subreg;
|
||
}
|
||
else
|
||
{
|
||
delete_insns_since (last);
|
||
target = extract_fixed_bit_field (int_mode, op0, offset, bitsize,
|
||
bitpos, target, 1);
|
||
}
|
||
}
|
||
else
|
||
extzv_loses:
|
||
target = extract_fixed_bit_field (int_mode, op0, offset, bitsize,
|
||
bitpos, target, 1);
|
||
}
|
||
else
|
||
{
|
||
if (HAVE_extv
|
||
&& bitsize > 0
|
||
&& GET_MODE_BITSIZE (extv_mode) >= bitsize
|
||
&& ! ((REG_P (op0) || GET_CODE (op0) == SUBREG)
|
||
&& (bitsize + bitpos > GET_MODE_BITSIZE (extv_mode))))
|
||
{
|
||
int xbitpos = bitpos, xoffset = offset;
|
||
rtx bitsize_rtx, bitpos_rtx;
|
||
rtx last = get_last_insn ();
|
||
rtx xop0 = op0, xtarget = target;
|
||
rtx xspec_target = spec_target;
|
||
rtx xspec_target_subreg = spec_target_subreg;
|
||
rtx pat;
|
||
enum machine_mode maxmode = mode_for_extraction (EP_extv, 0);
|
||
|
||
if (MEM_P (xop0))
|
||
{
|
||
/* Is the memory operand acceptable? */
|
||
if (! ((*insn_data[(int) CODE_FOR_extv].operand[1].predicate)
|
||
(xop0, GET_MODE (xop0))))
|
||
{
|
||
/* No, load into a reg and extract from there. */
|
||
enum machine_mode bestmode;
|
||
|
||
/* Get the mode to use for inserting into this field. If
|
||
OP0 is BLKmode, get the smallest mode consistent with the
|
||
alignment. If OP0 is a non-BLKmode object that is no
|
||
wider than MAXMODE, use its mode. Otherwise, use the
|
||
smallest mode containing the field. */
|
||
|
||
if (GET_MODE (xop0) == BLKmode
|
||
|| (GET_MODE_SIZE (GET_MODE (op0))
|
||
> GET_MODE_SIZE (maxmode)))
|
||
bestmode = get_best_mode (bitsize, bitnum,
|
||
MEM_ALIGN (xop0), maxmode,
|
||
MEM_VOLATILE_P (xop0));
|
||
else
|
||
bestmode = GET_MODE (xop0);
|
||
|
||
if (bestmode == VOIDmode
|
||
|| (SLOW_UNALIGNED_ACCESS (bestmode, MEM_ALIGN (xop0))
|
||
&& GET_MODE_BITSIZE (bestmode) > MEM_ALIGN (xop0)))
|
||
goto extv_loses;
|
||
|
||
/* Compute offset as multiple of this unit,
|
||
counting in bytes. */
|
||
unit = GET_MODE_BITSIZE (bestmode);
|
||
xoffset = (bitnum / unit) * GET_MODE_SIZE (bestmode);
|
||
xbitpos = bitnum % unit;
|
||
xop0 = adjust_address (xop0, bestmode, xoffset);
|
||
|
||
/* Make sure register is big enough for the whole field. */
|
||
if (xoffset * BITS_PER_UNIT + unit
|
||
< offset * BITS_PER_UNIT + bitsize)
|
||
goto extv_loses;
|
||
|
||
/* Fetch it to a register in that size. */
|
||
xop0 = force_reg (bestmode, xop0);
|
||
|
||
/* XBITPOS counts within UNIT, which is what is expected. */
|
||
}
|
||
else
|
||
/* Get ref to first byte containing part of the field. */
|
||
xop0 = adjust_address (xop0, byte_mode, xoffset);
|
||
}
|
||
|
||
/* If op0 is a register, we need it in MAXMODE (which is usually
|
||
SImode) to make it acceptable to the format of extv. */
|
||
if (GET_CODE (xop0) == SUBREG && GET_MODE (xop0) != maxmode)
|
||
goto extv_loses;
|
||
if (REG_P (xop0) && GET_MODE (xop0) != maxmode)
|
||
xop0 = gen_rtx_SUBREG (maxmode, xop0, 0);
|
||
|
||
/* On big-endian machines, we count bits from the most significant.
|
||
If the bit field insn does not, we must invert. */
|
||
if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
|
||
xbitpos = unit - bitsize - xbitpos;
|
||
|
||
/* XBITPOS counts within a size of UNIT.
|
||
Adjust to count within a size of MAXMODE. */
|
||
if (BITS_BIG_ENDIAN && !MEM_P (xop0))
|
||
xbitpos += (GET_MODE_BITSIZE (maxmode) - unit);
|
||
|
||
unit = GET_MODE_BITSIZE (maxmode);
|
||
|
||
if (xtarget == 0)
|
||
xtarget = xspec_target = gen_reg_rtx (tmode);
|
||
|
||
if (GET_MODE (xtarget) != maxmode)
|
||
{
|
||
if (REG_P (xtarget))
|
||
{
|
||
int wider = (GET_MODE_SIZE (maxmode)
|
||
> GET_MODE_SIZE (GET_MODE (xtarget)));
|
||
xtarget = gen_lowpart (maxmode, xtarget);
|
||
if (wider)
|
||
xspec_target_subreg = xtarget;
|
||
}
|
||
else
|
||
xtarget = gen_reg_rtx (maxmode);
|
||
}
|
||
|
||
/* If this machine's extv insists on a register target,
|
||
make sure we have one. */
|
||
if (! ((*insn_data[(int) CODE_FOR_extv].operand[0].predicate)
|
||
(xtarget, maxmode)))
|
||
xtarget = gen_reg_rtx (maxmode);
|
||
|
||
bitsize_rtx = GEN_INT (bitsize);
|
||
bitpos_rtx = GEN_INT (xbitpos);
|
||
|
||
pat = gen_extv (xtarget, xop0, bitsize_rtx, bitpos_rtx);
|
||
if (pat)
|
||
{
|
||
emit_insn (pat);
|
||
target = xtarget;
|
||
spec_target = xspec_target;
|
||
spec_target_subreg = xspec_target_subreg;
|
||
}
|
||
else
|
||
{
|
||
delete_insns_since (last);
|
||
target = extract_fixed_bit_field (int_mode, op0, offset, bitsize,
|
||
bitpos, target, 0);
|
||
}
|
||
}
|
||
else
|
||
extv_loses:
|
||
target = extract_fixed_bit_field (int_mode, op0, offset, bitsize,
|
||
bitpos, target, 0);
|
||
}
|
||
if (target == spec_target)
|
||
return target;
|
||
if (target == spec_target_subreg)
|
||
return spec_target;
|
||
if (GET_MODE (target) != tmode && GET_MODE (target) != mode)
|
||
{
|
||
/* If the target mode is not a scalar integral, first convert to the
|
||
integer mode of that size and then access it as a floating-point
|
||
value via a SUBREG. */
|
||
if (!SCALAR_INT_MODE_P (tmode))
|
||
{
|
||
enum machine_mode smode
|
||
= mode_for_size (GET_MODE_BITSIZE (tmode), MODE_INT, 0);
|
||
target = convert_to_mode (smode, target, unsignedp);
|
||
target = force_reg (smode, target);
|
||
return gen_lowpart (tmode, target);
|
||
}
|
||
|
||
return convert_to_mode (tmode, target, unsignedp);
|
||
}
|
||
return target;
|
||
}
|
||
|
||
/* Extract a bit field using shifts and boolean operations
|
||
Returns an rtx to represent the value.
|
||
OP0 addresses a register (word) or memory (byte).
|
||
BITPOS says which bit within the word or byte the bit field starts in.
|
||
OFFSET says how many bytes farther the bit field starts;
|
||
it is 0 if OP0 is a register.
|
||
BITSIZE says how many bits long the bit field is.
|
||
(If OP0 is a register, it may be narrower than a full word,
|
||
but BITPOS still counts within a full word,
|
||
which is significant on bigendian machines.)
|
||
|
||
UNSIGNEDP is nonzero for an unsigned bit field (don't sign-extend value).
|
||
If TARGET is nonzero, attempts to store the value there
|
||
and return TARGET, but this is not guaranteed.
|
||
If TARGET is not used, create a pseudo-reg of mode TMODE for the value. */
|
||
|
||
static rtx
|
||
extract_fixed_bit_field (enum machine_mode tmode, rtx op0,
|
||
unsigned HOST_WIDE_INT offset,
|
||
unsigned HOST_WIDE_INT bitsize,
|
||
unsigned HOST_WIDE_INT bitpos, rtx target,
|
||
int unsignedp)
|
||
{
|
||
unsigned int total_bits = BITS_PER_WORD;
|
||
enum machine_mode mode;
|
||
|
||
if (GET_CODE (op0) == SUBREG || REG_P (op0))
|
||
{
|
||
/* Special treatment for a bit field split across two registers. */
|
||
if (bitsize + bitpos > BITS_PER_WORD)
|
||
return extract_split_bit_field (op0, bitsize, bitpos, unsignedp);
|
||
}
|
||
else
|
||
{
|
||
/* Get the proper mode to use for this field. We want a mode that
|
||
includes the entire field. If such a mode would be larger than
|
||
a word, we won't be doing the extraction the normal way. */
|
||
|
||
mode = get_best_mode (bitsize, bitpos + offset * BITS_PER_UNIT,
|
||
MEM_ALIGN (op0), word_mode, MEM_VOLATILE_P (op0));
|
||
|
||
if (mode == VOIDmode)
|
||
/* The only way this should occur is if the field spans word
|
||
boundaries. */
|
||
return extract_split_bit_field (op0, bitsize,
|
||
bitpos + offset * BITS_PER_UNIT,
|
||
unsignedp);
|
||
|
||
total_bits = GET_MODE_BITSIZE (mode);
|
||
|
||
/* Make sure bitpos is valid for the chosen mode. Adjust BITPOS to
|
||
be in the range 0 to total_bits-1, and put any excess bytes in
|
||
OFFSET. */
|
||
if (bitpos >= total_bits)
|
||
{
|
||
offset += (bitpos / total_bits) * (total_bits / BITS_PER_UNIT);
|
||
bitpos -= ((bitpos / total_bits) * (total_bits / BITS_PER_UNIT)
|
||
* BITS_PER_UNIT);
|
||
}
|
||
|
||
/* Get ref to an aligned byte, halfword, or word containing the field.
|
||
Adjust BITPOS to be position within a word,
|
||
and OFFSET to be the offset of that word.
|
||
Then alter OP0 to refer to that word. */
|
||
bitpos += (offset % (total_bits / BITS_PER_UNIT)) * BITS_PER_UNIT;
|
||
offset -= (offset % (total_bits / BITS_PER_UNIT));
|
||
op0 = adjust_address (op0, mode, offset);
|
||
}
|
||
|
||
mode = GET_MODE (op0);
|
||
|
||
if (BYTES_BIG_ENDIAN)
|
||
/* BITPOS is the distance between our msb and that of OP0.
|
||
Convert it to the distance from the lsb. */
|
||
bitpos = total_bits - bitsize - bitpos;
|
||
|
||
/* Now BITPOS is always the distance between the field's lsb and that of OP0.
|
||
We have reduced the big-endian case to the little-endian case. */
|
||
|
||
if (unsignedp)
|
||
{
|
||
if (bitpos)
|
||
{
|
||
/* If the field does not already start at the lsb,
|
||
shift it so it does. */
|
||
tree amount = build_int_cst (NULL_TREE, bitpos);
|
||
/* Maybe propagate the target for the shift. */
|
||
/* But not if we will return it--could confuse integrate.c. */
|
||
rtx subtarget = (target != 0 && REG_P (target) ? target : 0);
|
||
if (tmode != mode) subtarget = 0;
|
||
op0 = expand_shift (RSHIFT_EXPR, mode, op0, amount, subtarget, 1);
|
||
}
|
||
/* Convert the value to the desired mode. */
|
||
if (mode != tmode)
|
||
op0 = convert_to_mode (tmode, op0, 1);
|
||
|
||
/* Unless the msb of the field used to be the msb when we shifted,
|
||
mask out the upper bits. */
|
||
|
||
if (GET_MODE_BITSIZE (mode) != bitpos + bitsize)
|
||
return expand_binop (GET_MODE (op0), and_optab, op0,
|
||
mask_rtx (GET_MODE (op0), 0, bitsize, 0),
|
||
target, 1, OPTAB_LIB_WIDEN);
|
||
return op0;
|
||
}
|
||
|
||
/* To extract a signed bit-field, first shift its msb to the msb of the word,
|
||
then arithmetic-shift its lsb to the lsb of the word. */
|
||
op0 = force_reg (mode, op0);
|
||
if (mode != tmode)
|
||
target = 0;
|
||
|
||
/* Find the narrowest integer mode that contains the field. */
|
||
|
||
for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
|
||
mode = GET_MODE_WIDER_MODE (mode))
|
||
if (GET_MODE_BITSIZE (mode) >= bitsize + bitpos)
|
||
{
|
||
op0 = convert_to_mode (mode, op0, 0);
|
||
break;
|
||
}
|
||
|
||
if (GET_MODE_BITSIZE (mode) != (bitsize + bitpos))
|
||
{
|
||
tree amount
|
||
= build_int_cst (NULL_TREE,
|
||
GET_MODE_BITSIZE (mode) - (bitsize + bitpos));
|
||
/* Maybe propagate the target for the shift. */
|
||
rtx subtarget = (target != 0 && REG_P (target) ? target : 0);
|
||
op0 = expand_shift (LSHIFT_EXPR, mode, op0, amount, subtarget, 1);
|
||
}
|
||
|
||
return expand_shift (RSHIFT_EXPR, mode, op0,
|
||
build_int_cst (NULL_TREE,
|
||
GET_MODE_BITSIZE (mode) - bitsize),
|
||
target, 0);
|
||
}
|
||
|
||
/* Return a constant integer (CONST_INT or CONST_DOUBLE) mask value
|
||
of mode MODE with BITSIZE ones followed by BITPOS zeros, or the
|
||
complement of that if COMPLEMENT. The mask is truncated if
|
||
necessary to the width of mode MODE. The mask is zero-extended if
|
||
BITSIZE+BITPOS is too small for MODE. */
|
||
|
||
static rtx
|
||
mask_rtx (enum machine_mode mode, int bitpos, int bitsize, int complement)
|
||
{
|
||
HOST_WIDE_INT masklow, maskhigh;
|
||
|
||
if (bitsize == 0)
|
||
masklow = 0;
|
||
else if (bitpos < HOST_BITS_PER_WIDE_INT)
|
||
masklow = (HOST_WIDE_INT) -1 << bitpos;
|
||
else
|
||
masklow = 0;
|
||
|
||
if (bitpos + bitsize < HOST_BITS_PER_WIDE_INT)
|
||
masklow &= ((unsigned HOST_WIDE_INT) -1
|
||
>> (HOST_BITS_PER_WIDE_INT - bitpos - bitsize));
|
||
|
||
if (bitpos <= HOST_BITS_PER_WIDE_INT)
|
||
maskhigh = -1;
|
||
else
|
||
maskhigh = (HOST_WIDE_INT) -1 << (bitpos - HOST_BITS_PER_WIDE_INT);
|
||
|
||
if (bitsize == 0)
|
||
maskhigh = 0;
|
||
else if (bitpos + bitsize > HOST_BITS_PER_WIDE_INT)
|
||
maskhigh &= ((unsigned HOST_WIDE_INT) -1
|
||
>> (2 * HOST_BITS_PER_WIDE_INT - bitpos - bitsize));
|
||
else
|
||
maskhigh = 0;
|
||
|
||
if (complement)
|
||
{
|
||
maskhigh = ~maskhigh;
|
||
masklow = ~masklow;
|
||
}
|
||
|
||
return immed_double_const (masklow, maskhigh, mode);
|
||
}
|
||
|
||
/* Return a constant integer (CONST_INT or CONST_DOUBLE) rtx with the value
|
||
VALUE truncated to BITSIZE bits and then shifted left BITPOS bits. */
|
||
|
||
static rtx
|
||
lshift_value (enum machine_mode mode, rtx value, int bitpos, int bitsize)
|
||
{
|
||
unsigned HOST_WIDE_INT v = INTVAL (value);
|
||
HOST_WIDE_INT low, high;
|
||
|
||
if (bitsize < HOST_BITS_PER_WIDE_INT)
|
||
v &= ~((HOST_WIDE_INT) -1 << bitsize);
|
||
|
||
if (bitpos < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
low = v << bitpos;
|
||
high = (bitpos > 0 ? (v >> (HOST_BITS_PER_WIDE_INT - bitpos)) : 0);
|
||
}
|
||
else
|
||
{
|
||
low = 0;
|
||
high = v << (bitpos - HOST_BITS_PER_WIDE_INT);
|
||
}
|
||
|
||
return immed_double_const (low, high, mode);
|
||
}
|
||
|
||
/* Extract a bit field from a memory by forcing the alignment of the
|
||
memory. This efficient only if the field spans at least 4 boundaries.
|
||
|
||
OP0 is the MEM.
|
||
BITSIZE is the field width; BITPOS is the position of the first bit.
|
||
UNSIGNEDP is true if the result should be zero-extended. */
|
||
|
||
static rtx
|
||
extract_force_align_mem_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize,
|
||
unsigned HOST_WIDE_INT bitpos,
|
||
int unsignedp)
|
||
{
|
||
enum machine_mode mode, dmode;
|
||
unsigned int m_bitsize, m_size;
|
||
unsigned int sign_shift_up, sign_shift_dn;
|
||
rtx base, a1, a2, v1, v2, comb, shift, result, start;
|
||
|
||
/* Choose a mode that will fit BITSIZE. */
|
||
mode = smallest_mode_for_size (bitsize, MODE_INT);
|
||
m_size = GET_MODE_SIZE (mode);
|
||
m_bitsize = GET_MODE_BITSIZE (mode);
|
||
|
||
/* Choose a mode twice as wide. Fail if no such mode exists. */
|
||
dmode = mode_for_size (m_bitsize * 2, MODE_INT, false);
|
||
if (dmode == BLKmode)
|
||
return NULL;
|
||
|
||
do_pending_stack_adjust ();
|
||
start = get_last_insn ();
|
||
|
||
/* At the end, we'll need an additional shift to deal with sign/zero
|
||
extension. By default this will be a left+right shift of the
|
||
appropriate size. But we may be able to eliminate one of them. */
|
||
sign_shift_up = sign_shift_dn = m_bitsize - bitsize;
|
||
|
||
if (STRICT_ALIGNMENT)
|
||
{
|
||
base = plus_constant (XEXP (op0, 0), bitpos / BITS_PER_UNIT);
|
||
bitpos %= BITS_PER_UNIT;
|
||
|
||
/* We load two values to be concatenate. There's an edge condition
|
||
that bears notice -- an aligned value at the end of a page can
|
||
only load one value lest we segfault. So the two values we load
|
||
are at "base & -size" and "(base + size - 1) & -size". If base
|
||
is unaligned, the addresses will be aligned and sequential; if
|
||
base is aligned, the addresses will both be equal to base. */
|
||
|
||
a1 = expand_simple_binop (Pmode, AND, force_operand (base, NULL),
|
||
GEN_INT (-(HOST_WIDE_INT)m_size),
|
||
NULL, true, OPTAB_LIB_WIDEN);
|
||
mark_reg_pointer (a1, m_bitsize);
|
||
v1 = gen_rtx_MEM (mode, a1);
|
||
set_mem_align (v1, m_bitsize);
|
||
v1 = force_reg (mode, validize_mem (v1));
|
||
|
||
a2 = plus_constant (base, GET_MODE_SIZE (mode) - 1);
|
||
a2 = expand_simple_binop (Pmode, AND, force_operand (a2, NULL),
|
||
GEN_INT (-(HOST_WIDE_INT)m_size),
|
||
NULL, true, OPTAB_LIB_WIDEN);
|
||
v2 = gen_rtx_MEM (mode, a2);
|
||
set_mem_align (v2, m_bitsize);
|
||
v2 = force_reg (mode, validize_mem (v2));
|
||
|
||
/* Combine these two values into a double-word value. */
|
||
if (m_bitsize == BITS_PER_WORD)
|
||
{
|
||
comb = gen_reg_rtx (dmode);
|
||
emit_insn (gen_rtx_CLOBBER (VOIDmode, comb));
|
||
emit_move_insn (gen_rtx_SUBREG (mode, comb, 0), v1);
|
||
emit_move_insn (gen_rtx_SUBREG (mode, comb, m_size), v2);
|
||
}
|
||
else
|
||
{
|
||
if (BYTES_BIG_ENDIAN)
|
||
comb = v1, v1 = v2, v2 = comb;
|
||
v1 = convert_modes (dmode, mode, v1, true);
|
||
if (v1 == NULL)
|
||
goto fail;
|
||
v2 = convert_modes (dmode, mode, v2, true);
|
||
v2 = expand_simple_binop (dmode, ASHIFT, v2, GEN_INT (m_bitsize),
|
||
NULL, true, OPTAB_LIB_WIDEN);
|
||
if (v2 == NULL)
|
||
goto fail;
|
||
comb = expand_simple_binop (dmode, IOR, v1, v2, NULL,
|
||
true, OPTAB_LIB_WIDEN);
|
||
if (comb == NULL)
|
||
goto fail;
|
||
}
|
||
|
||
shift = expand_simple_binop (Pmode, AND, base, GEN_INT (m_size - 1),
|
||
NULL, true, OPTAB_LIB_WIDEN);
|
||
shift = expand_mult (Pmode, shift, GEN_INT (BITS_PER_UNIT), NULL, 1);
|
||
|
||
if (bitpos != 0)
|
||
{
|
||
if (sign_shift_up <= bitpos)
|
||
bitpos -= sign_shift_up, sign_shift_up = 0;
|
||
shift = expand_simple_binop (Pmode, PLUS, shift, GEN_INT (bitpos),
|
||
NULL, true, OPTAB_LIB_WIDEN);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
unsigned HOST_WIDE_INT offset = bitpos / BITS_PER_UNIT;
|
||
bitpos %= BITS_PER_UNIT;
|
||
|
||
/* When strict alignment is not required, we can just load directly
|
||
from memory without masking. If the remaining BITPOS offset is
|
||
small enough, we may be able to do all operations in MODE as
|
||
opposed to DMODE. */
|
||
if (bitpos + bitsize <= m_bitsize)
|
||
dmode = mode;
|
||
comb = adjust_address (op0, dmode, offset);
|
||
|
||
if (sign_shift_up <= bitpos)
|
||
bitpos -= sign_shift_up, sign_shift_up = 0;
|
||
shift = GEN_INT (bitpos);
|
||
}
|
||
|
||
/* Shift down the double-word such that the requested value is at bit 0. */
|
||
if (shift != const0_rtx)
|
||
comb = expand_simple_binop (dmode, unsignedp ? LSHIFTRT : ASHIFTRT,
|
||
comb, shift, NULL, unsignedp, OPTAB_LIB_WIDEN);
|
||
if (comb == NULL)
|
||
goto fail;
|
||
|
||
/* If the field exactly matches MODE, then all we need to do is return the
|
||
lowpart. Otherwise, shift to get the sign bits set properly. */
|
||
result = force_reg (mode, gen_lowpart (mode, comb));
|
||
|
||
if (sign_shift_up)
|
||
result = expand_simple_binop (mode, ASHIFT, result,
|
||
GEN_INT (sign_shift_up),
|
||
NULL_RTX, 0, OPTAB_LIB_WIDEN);
|
||
if (sign_shift_dn)
|
||
result = expand_simple_binop (mode, unsignedp ? LSHIFTRT : ASHIFTRT,
|
||
result, GEN_INT (sign_shift_dn),
|
||
NULL_RTX, 0, OPTAB_LIB_WIDEN);
|
||
|
||
return result;
|
||
|
||
fail:
|
||
delete_insns_since (start);
|
||
return NULL;
|
||
}
|
||
|
||
/* Extract a bit field that is split across two words
|
||
and return an RTX for the result.
|
||
|
||
OP0 is the REG, SUBREG or MEM rtx for the first of the two words.
|
||
BITSIZE is the field width; BITPOS, position of its first bit, in the word.
|
||
UNSIGNEDP is 1 if should zero-extend the contents; else sign-extend. */
|
||
|
||
static rtx
|
||
extract_split_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize,
|
||
unsigned HOST_WIDE_INT bitpos, int unsignedp)
|
||
{
|
||
unsigned int unit;
|
||
unsigned int bitsdone = 0;
|
||
rtx result = NULL_RTX;
|
||
int first = 1;
|
||
|
||
/* Make sure UNIT isn't larger than BITS_PER_WORD, we can only handle that
|
||
much at a time. */
|
||
if (REG_P (op0) || GET_CODE (op0) == SUBREG)
|
||
unit = BITS_PER_WORD;
|
||
else
|
||
{
|
||
unit = MIN (MEM_ALIGN (op0), BITS_PER_WORD);
|
||
if (0 && bitsize / unit > 2)
|
||
{
|
||
rtx tmp = extract_force_align_mem_bit_field (op0, bitsize, bitpos,
|
||
unsignedp);
|
||
if (tmp)
|
||
return tmp;
|
||
}
|
||
}
|
||
|
||
while (bitsdone < bitsize)
|
||
{
|
||
unsigned HOST_WIDE_INT thissize;
|
||
rtx part, word;
|
||
unsigned HOST_WIDE_INT thispos;
|
||
unsigned HOST_WIDE_INT offset;
|
||
|
||
offset = (bitpos + bitsdone) / unit;
|
||
thispos = (bitpos + bitsdone) % unit;
|
||
|
||
/* THISSIZE must not overrun a word boundary. Otherwise,
|
||
extract_fixed_bit_field will call us again, and we will mutually
|
||
recurse forever. */
|
||
thissize = MIN (bitsize - bitsdone, BITS_PER_WORD);
|
||
thissize = MIN (thissize, unit - thispos);
|
||
|
||
/* If OP0 is a register, then handle OFFSET here.
|
||
|
||
When handling multiword bitfields, extract_bit_field may pass
|
||
down a word_mode SUBREG of a larger REG for a bitfield that actually
|
||
crosses a word boundary. Thus, for a SUBREG, we must find
|
||
the current word starting from the base register. */
|
||
if (GET_CODE (op0) == SUBREG)
|
||
{
|
||
int word_offset = (SUBREG_BYTE (op0) / UNITS_PER_WORD) + offset;
|
||
word = operand_subword_force (SUBREG_REG (op0), word_offset,
|
||
GET_MODE (SUBREG_REG (op0)));
|
||
offset = 0;
|
||
}
|
||
else if (REG_P (op0))
|
||
{
|
||
word = operand_subword_force (op0, offset, GET_MODE (op0));
|
||
offset = 0;
|
||
}
|
||
else
|
||
word = op0;
|
||
|
||
/* Extract the parts in bit-counting order,
|
||
whose meaning is determined by BYTES_PER_UNIT.
|
||
OFFSET is in UNITs, and UNIT is in bits.
|
||
extract_fixed_bit_field wants offset in bytes. */
|
||
part = extract_fixed_bit_field (word_mode, word,
|
||
offset * unit / BITS_PER_UNIT,
|
||
thissize, thispos, 0, 1);
|
||
bitsdone += thissize;
|
||
|
||
/* Shift this part into place for the result. */
|
||
if (BYTES_BIG_ENDIAN)
|
||
{
|
||
if (bitsize != bitsdone)
|
||
part = expand_shift (LSHIFT_EXPR, word_mode, part,
|
||
build_int_cst (NULL_TREE, bitsize - bitsdone),
|
||
0, 1);
|
||
}
|
||
else
|
||
{
|
||
if (bitsdone != thissize)
|
||
part = expand_shift (LSHIFT_EXPR, word_mode, part,
|
||
build_int_cst (NULL_TREE,
|
||
bitsdone - thissize), 0, 1);
|
||
}
|
||
|
||
if (first)
|
||
result = part;
|
||
else
|
||
/* Combine the parts with bitwise or. This works
|
||
because we extracted each part as an unsigned bit field. */
|
||
result = expand_binop (word_mode, ior_optab, part, result, NULL_RTX, 1,
|
||
OPTAB_LIB_WIDEN);
|
||
|
||
first = 0;
|
||
}
|
||
|
||
/* Unsigned bit field: we are done. */
|
||
if (unsignedp)
|
||
return result;
|
||
/* Signed bit field: sign-extend with two arithmetic shifts. */
|
||
result = expand_shift (LSHIFT_EXPR, word_mode, result,
|
||
build_int_cst (NULL_TREE, BITS_PER_WORD - bitsize),
|
||
NULL_RTX, 0);
|
||
return expand_shift (RSHIFT_EXPR, word_mode, result,
|
||
build_int_cst (NULL_TREE, BITS_PER_WORD - bitsize),
|
||
NULL_RTX, 0);
|
||
}
|
||
|
||
/* Add INC into TARGET. */
|
||
|
||
void
|
||
expand_inc (rtx target, rtx inc)
|
||
{
|
||
rtx value = expand_binop (GET_MODE (target), add_optab,
|
||
target, inc,
|
||
target, 0, OPTAB_LIB_WIDEN);
|
||
if (value != target)
|
||
emit_move_insn (target, value);
|
||
}
|
||
|
||
/* Subtract DEC from TARGET. */
|
||
|
||
void
|
||
expand_dec (rtx target, rtx dec)
|
||
{
|
||
rtx value = expand_binop (GET_MODE (target), sub_optab,
|
||
target, dec,
|
||
target, 0, OPTAB_LIB_WIDEN);
|
||
if (value != target)
|
||
emit_move_insn (target, value);
|
||
}
|
||
|
||
/* Output a shift instruction for expression code CODE,
|
||
with SHIFTED being the rtx for the value to shift,
|
||
and AMOUNT the tree for the amount to shift by.
|
||
Store the result in the rtx TARGET, if that is convenient.
|
||
If UNSIGNEDP is nonzero, do a logical shift; otherwise, arithmetic.
|
||
Return the rtx for where the value is. */
|
||
|
||
rtx
|
||
expand_shift (enum tree_code code, enum machine_mode mode, rtx shifted,
|
||
tree amount, rtx target, int unsignedp)
|
||
{
|
||
rtx op1, temp = 0;
|
||
int left = (code == LSHIFT_EXPR || code == LROTATE_EXPR);
|
||
int rotate = (code == LROTATE_EXPR || code == RROTATE_EXPR);
|
||
int try;
|
||
|
||
/* Previously detected shift-counts computed by NEGATE_EXPR
|
||
and shifted in the other direction; but that does not work
|
||
on all machines. */
|
||
|
||
op1 = expand_normal (amount);
|
||
|
||
if (SHIFT_COUNT_TRUNCATED)
|
||
{
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& ((unsigned HOST_WIDE_INT) INTVAL (op1) >=
|
||
(unsigned HOST_WIDE_INT) GET_MODE_BITSIZE (mode)))
|
||
op1 = GEN_INT ((unsigned HOST_WIDE_INT) INTVAL (op1)
|
||
% GET_MODE_BITSIZE (mode));
|
||
else if (GET_CODE (op1) == SUBREG
|
||
&& subreg_lowpart_p (op1))
|
||
op1 = SUBREG_REG (op1);
|
||
}
|
||
|
||
if (op1 == const0_rtx)
|
||
return shifted;
|
||
|
||
/* Check whether its cheaper to implement a left shift by a constant
|
||
bit count by a sequence of additions. */
|
||
if (code == LSHIFT_EXPR
|
||
&& GET_CODE (op1) == CONST_INT
|
||
&& INTVAL (op1) > 0
|
||
&& INTVAL (op1) < GET_MODE_BITSIZE (mode)
|
||
&& INTVAL (op1) < MAX_BITS_PER_WORD
|
||
&& shift_cost[mode][INTVAL (op1)] > INTVAL (op1) * add_cost[mode]
|
||
&& shift_cost[mode][INTVAL (op1)] != MAX_COST)
|
||
{
|
||
int i;
|
||
for (i = 0; i < INTVAL (op1); i++)
|
||
{
|
||
temp = force_reg (mode, shifted);
|
||
shifted = expand_binop (mode, add_optab, temp, temp, NULL_RTX,
|
||
unsignedp, OPTAB_LIB_WIDEN);
|
||
}
|
||
return shifted;
|
||
}
|
||
|
||
for (try = 0; temp == 0 && try < 3; try++)
|
||
{
|
||
enum optab_methods methods;
|
||
|
||
if (try == 0)
|
||
methods = OPTAB_DIRECT;
|
||
else if (try == 1)
|
||
methods = OPTAB_WIDEN;
|
||
else
|
||
methods = OPTAB_LIB_WIDEN;
|
||
|
||
if (rotate)
|
||
{
|
||
/* Widening does not work for rotation. */
|
||
if (methods == OPTAB_WIDEN)
|
||
continue;
|
||
else if (methods == OPTAB_LIB_WIDEN)
|
||
{
|
||
/* If we have been unable to open-code this by a rotation,
|
||
do it as the IOR of two shifts. I.e., to rotate A
|
||
by N bits, compute (A << N) | ((unsigned) A >> (C - N))
|
||
where C is the bitsize of A.
|
||
|
||
It is theoretically possible that the target machine might
|
||
not be able to perform either shift and hence we would
|
||
be making two libcalls rather than just the one for the
|
||
shift (similarly if IOR could not be done). We will allow
|
||
this extremely unlikely lossage to avoid complicating the
|
||
code below. */
|
||
|
||
rtx subtarget = target == shifted ? 0 : target;
|
||
tree new_amount, other_amount;
|
||
rtx temp1;
|
||
tree type = TREE_TYPE (amount);
|
||
if (GET_MODE (op1) != TYPE_MODE (type)
|
||
&& GET_MODE (op1) != VOIDmode)
|
||
op1 = convert_to_mode (TYPE_MODE (type), op1, 1);
|
||
new_amount = make_tree (type, op1);
|
||
other_amount
|
||
= fold_build2 (MINUS_EXPR, type,
|
||
build_int_cst (type, GET_MODE_BITSIZE (mode)),
|
||
new_amount);
|
||
|
||
shifted = force_reg (mode, shifted);
|
||
|
||
temp = expand_shift (left ? LSHIFT_EXPR : RSHIFT_EXPR,
|
||
mode, shifted, new_amount, 0, 1);
|
||
temp1 = expand_shift (left ? RSHIFT_EXPR : LSHIFT_EXPR,
|
||
mode, shifted, other_amount, subtarget, 1);
|
||
return expand_binop (mode, ior_optab, temp, temp1, target,
|
||
unsignedp, methods);
|
||
}
|
||
|
||
temp = expand_binop (mode,
|
||
left ? rotl_optab : rotr_optab,
|
||
shifted, op1, target, unsignedp, methods);
|
||
}
|
||
else if (unsignedp)
|
||
temp = expand_binop (mode,
|
||
left ? ashl_optab : lshr_optab,
|
||
shifted, op1, target, unsignedp, methods);
|
||
|
||
/* Do arithmetic shifts.
|
||
Also, if we are going to widen the operand, we can just as well
|
||
use an arithmetic right-shift instead of a logical one. */
|
||
if (temp == 0 && ! rotate
|
||
&& (! unsignedp || (! left && methods == OPTAB_WIDEN)))
|
||
{
|
||
enum optab_methods methods1 = methods;
|
||
|
||
/* If trying to widen a log shift to an arithmetic shift,
|
||
don't accept an arithmetic shift of the same size. */
|
||
if (unsignedp)
|
||
methods1 = OPTAB_MUST_WIDEN;
|
||
|
||
/* Arithmetic shift */
|
||
|
||
temp = expand_binop (mode,
|
||
left ? ashl_optab : ashr_optab,
|
||
shifted, op1, target, unsignedp, methods1);
|
||
}
|
||
|
||
/* We used to try extzv here for logical right shifts, but that was
|
||
only useful for one machine, the VAX, and caused poor code
|
||
generation there for lshrdi3, so the code was deleted and a
|
||
define_expand for lshrsi3 was added to vax.md. */
|
||
}
|
||
|
||
gcc_assert (temp);
|
||
return temp;
|
||
}
|
||
|
||
enum alg_code {
|
||
alg_unknown,
|
||
alg_zero,
|
||
alg_m, alg_shift,
|
||
alg_add_t_m2,
|
||
alg_sub_t_m2,
|
||
alg_add_factor,
|
||
alg_sub_factor,
|
||
alg_add_t2_m,
|
||
alg_sub_t2_m,
|
||
alg_impossible
|
||
};
|
||
|
||
/* This structure holds the "cost" of a multiply sequence. The
|
||
"cost" field holds the total rtx_cost of every operator in the
|
||
synthetic multiplication sequence, hence cost(a op b) is defined
|
||
as rtx_cost(op) + cost(a) + cost(b), where cost(leaf) is zero.
|
||
The "latency" field holds the minimum possible latency of the
|
||
synthetic multiply, on a hypothetical infinitely parallel CPU.
|
||
This is the critical path, or the maximum height, of the expression
|
||
tree which is the sum of rtx_costs on the most expensive path from
|
||
any leaf to the root. Hence latency(a op b) is defined as zero for
|
||
leaves and rtx_cost(op) + max(latency(a), latency(b)) otherwise. */
|
||
|
||
struct mult_cost {
|
||
short cost; /* Total rtx_cost of the multiplication sequence. */
|
||
short latency; /* The latency of the multiplication sequence. */
|
||
};
|
||
|
||
/* This macro is used to compare a pointer to a mult_cost against an
|
||
single integer "rtx_cost" value. This is equivalent to the macro
|
||
CHEAPER_MULT_COST(X,Z) where Z = {Y,Y}. */
|
||
#define MULT_COST_LESS(X,Y) ((X)->cost < (Y) \
|
||
|| ((X)->cost == (Y) && (X)->latency < (Y)))
|
||
|
||
/* This macro is used to compare two pointers to mult_costs against
|
||
each other. The macro returns true if X is cheaper than Y.
|
||
Currently, the cheaper of two mult_costs is the one with the
|
||
lower "cost". If "cost"s are tied, the lower latency is cheaper. */
|
||
#define CHEAPER_MULT_COST(X,Y) ((X)->cost < (Y)->cost \
|
||
|| ((X)->cost == (Y)->cost \
|
||
&& (X)->latency < (Y)->latency))
|
||
|
||
/* This structure records a sequence of operations.
|
||
`ops' is the number of operations recorded.
|
||
`cost' is their total cost.
|
||
The operations are stored in `op' and the corresponding
|
||
logarithms of the integer coefficients in `log'.
|
||
|
||
These are the operations:
|
||
alg_zero total := 0;
|
||
alg_m total := multiplicand;
|
||
alg_shift total := total * coeff
|
||
alg_add_t_m2 total := total + multiplicand * coeff;
|
||
alg_sub_t_m2 total := total - multiplicand * coeff;
|
||
alg_add_factor total := total * coeff + total;
|
||
alg_sub_factor total := total * coeff - total;
|
||
alg_add_t2_m total := total * coeff + multiplicand;
|
||
alg_sub_t2_m total := total * coeff - multiplicand;
|
||
|
||
The first operand must be either alg_zero or alg_m. */
|
||
|
||
struct algorithm
|
||
{
|
||
struct mult_cost cost;
|
||
short ops;
|
||
/* The size of the OP and LOG fields are not directly related to the
|
||
word size, but the worst-case algorithms will be if we have few
|
||
consecutive ones or zeros, i.e., a multiplicand like 10101010101...
|
||
In that case we will generate shift-by-2, add, shift-by-2, add,...,
|
||
in total wordsize operations. */
|
||
enum alg_code op[MAX_BITS_PER_WORD];
|
||
char log[MAX_BITS_PER_WORD];
|
||
};
|
||
|
||
/* The entry for our multiplication cache/hash table. */
|
||
struct alg_hash_entry {
|
||
/* The number we are multiplying by. */
|
||
unsigned HOST_WIDE_INT t;
|
||
|
||
/* The mode in which we are multiplying something by T. */
|
||
enum machine_mode mode;
|
||
|
||
/* The best multiplication algorithm for t. */
|
||
enum alg_code alg;
|
||
|
||
/* The cost of multiplication if ALG_CODE is not alg_impossible.
|
||
Otherwise, the cost within which multiplication by T is
|
||
impossible. */
|
||
struct mult_cost cost;
|
||
};
|
||
|
||
/* The number of cache/hash entries. */
|
||
#if HOST_BITS_PER_WIDE_INT == 64
|
||
#define NUM_ALG_HASH_ENTRIES 1031
|
||
#else
|
||
#define NUM_ALG_HASH_ENTRIES 307
|
||
#endif
|
||
|
||
/* Each entry of ALG_HASH caches alg_code for some integer. This is
|
||
actually a hash table. If we have a collision, that the older
|
||
entry is kicked out. */
|
||
static struct alg_hash_entry alg_hash[NUM_ALG_HASH_ENTRIES];
|
||
|
||
/* Indicates the type of fixup needed after a constant multiplication.
|
||
BASIC_VARIANT means no fixup is needed, NEGATE_VARIANT means that
|
||
the result should be negated, and ADD_VARIANT means that the
|
||
multiplicand should be added to the result. */
|
||
enum mult_variant {basic_variant, negate_variant, add_variant};
|
||
|
||
static void synth_mult (struct algorithm *, unsigned HOST_WIDE_INT,
|
||
const struct mult_cost *, enum machine_mode mode);
|
||
static bool choose_mult_variant (enum machine_mode, HOST_WIDE_INT,
|
||
struct algorithm *, enum mult_variant *, int);
|
||
static rtx expand_mult_const (enum machine_mode, rtx, HOST_WIDE_INT, rtx,
|
||
const struct algorithm *, enum mult_variant);
|
||
static unsigned HOST_WIDE_INT choose_multiplier (unsigned HOST_WIDE_INT, int,
|
||
int, rtx *, int *, int *);
|
||
static unsigned HOST_WIDE_INT invert_mod2n (unsigned HOST_WIDE_INT, int);
|
||
static rtx extract_high_half (enum machine_mode, rtx);
|
||
static rtx expand_mult_highpart (enum machine_mode, rtx, rtx, rtx, int, int);
|
||
static rtx expand_mult_highpart_optab (enum machine_mode, rtx, rtx, rtx,
|
||
int, int);
|
||
/* Compute and return the best algorithm for multiplying by T.
|
||
The algorithm must cost less than cost_limit
|
||
If retval.cost >= COST_LIMIT, no algorithm was found and all
|
||
other field of the returned struct are undefined.
|
||
MODE is the machine mode of the multiplication. */
|
||
|
||
static void
|
||
synth_mult (struct algorithm *alg_out, unsigned HOST_WIDE_INT t,
|
||
const struct mult_cost *cost_limit, enum machine_mode mode)
|
||
{
|
||
int m;
|
||
struct algorithm *alg_in, *best_alg;
|
||
struct mult_cost best_cost;
|
||
struct mult_cost new_limit;
|
||
int op_cost, op_latency;
|
||
unsigned HOST_WIDE_INT q;
|
||
int maxm = MIN (BITS_PER_WORD, GET_MODE_BITSIZE (mode));
|
||
int hash_index;
|
||
bool cache_hit = false;
|
||
enum alg_code cache_alg = alg_zero;
|
||
|
||
/* Indicate that no algorithm is yet found. If no algorithm
|
||
is found, this value will be returned and indicate failure. */
|
||
alg_out->cost.cost = cost_limit->cost + 1;
|
||
alg_out->cost.latency = cost_limit->latency + 1;
|
||
|
||
if (cost_limit->cost < 0
|
||
|| (cost_limit->cost == 0 && cost_limit->latency <= 0))
|
||
return;
|
||
|
||
/* Restrict the bits of "t" to the multiplication's mode. */
|
||
t &= GET_MODE_MASK (mode);
|
||
|
||
/* t == 1 can be done in zero cost. */
|
||
if (t == 1)
|
||
{
|
||
alg_out->ops = 1;
|
||
alg_out->cost.cost = 0;
|
||
alg_out->cost.latency = 0;
|
||
alg_out->op[0] = alg_m;
|
||
return;
|
||
}
|
||
|
||
/* t == 0 sometimes has a cost. If it does and it exceeds our limit,
|
||
fail now. */
|
||
if (t == 0)
|
||
{
|
||
if (MULT_COST_LESS (cost_limit, zero_cost))
|
||
return;
|
||
else
|
||
{
|
||
alg_out->ops = 1;
|
||
alg_out->cost.cost = zero_cost;
|
||
alg_out->cost.latency = zero_cost;
|
||
alg_out->op[0] = alg_zero;
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* We'll be needing a couple extra algorithm structures now. */
|
||
|
||
alg_in = alloca (sizeof (struct algorithm));
|
||
best_alg = alloca (sizeof (struct algorithm));
|
||
best_cost = *cost_limit;
|
||
|
||
/* Compute the hash index. */
|
||
hash_index = (t ^ (unsigned int) mode) % NUM_ALG_HASH_ENTRIES;
|
||
|
||
/* See if we already know what to do for T. */
|
||
if (alg_hash[hash_index].t == t
|
||
&& alg_hash[hash_index].mode == mode
|
||
&& alg_hash[hash_index].alg != alg_unknown)
|
||
{
|
||
cache_alg = alg_hash[hash_index].alg;
|
||
|
||
if (cache_alg == alg_impossible)
|
||
{
|
||
/* The cache tells us that it's impossible to synthesize
|
||
multiplication by T within alg_hash[hash_index].cost. */
|
||
if (!CHEAPER_MULT_COST (&alg_hash[hash_index].cost, cost_limit))
|
||
/* COST_LIMIT is at least as restrictive as the one
|
||
recorded in the hash table, in which case we have no
|
||
hope of synthesizing a multiplication. Just
|
||
return. */
|
||
return;
|
||
|
||
/* If we get here, COST_LIMIT is less restrictive than the
|
||
one recorded in the hash table, so we may be able to
|
||
synthesize a multiplication. Proceed as if we didn't
|
||
have the cache entry. */
|
||
}
|
||
else
|
||
{
|
||
if (CHEAPER_MULT_COST (cost_limit, &alg_hash[hash_index].cost))
|
||
/* The cached algorithm shows that this multiplication
|
||
requires more cost than COST_LIMIT. Just return. This
|
||
way, we don't clobber this cache entry with
|
||
alg_impossible but retain useful information. */
|
||
return;
|
||
|
||
cache_hit = true;
|
||
|
||
switch (cache_alg)
|
||
{
|
||
case alg_shift:
|
||
goto do_alg_shift;
|
||
|
||
case alg_add_t_m2:
|
||
case alg_sub_t_m2:
|
||
goto do_alg_addsub_t_m2;
|
||
|
||
case alg_add_factor:
|
||
case alg_sub_factor:
|
||
goto do_alg_addsub_factor;
|
||
|
||
case alg_add_t2_m:
|
||
goto do_alg_add_t2_m;
|
||
|
||
case alg_sub_t2_m:
|
||
goto do_alg_sub_t2_m;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If we have a group of zero bits at the low-order part of T, try
|
||
multiplying by the remaining bits and then doing a shift. */
|
||
|
||
if ((t & 1) == 0)
|
||
{
|
||
do_alg_shift:
|
||
m = floor_log2 (t & -t); /* m = number of low zero bits */
|
||
if (m < maxm)
|
||
{
|
||
q = t >> m;
|
||
/* The function expand_shift will choose between a shift and
|
||
a sequence of additions, so the observed cost is given as
|
||
MIN (m * add_cost[mode], shift_cost[mode][m]). */
|
||
op_cost = m * add_cost[mode];
|
||
if (shift_cost[mode][m] < op_cost)
|
||
op_cost = shift_cost[mode][m];
|
||
new_limit.cost = best_cost.cost - op_cost;
|
||
new_limit.latency = best_cost.latency - op_cost;
|
||
synth_mult (alg_in, q, &new_limit, mode);
|
||
|
||
alg_in->cost.cost += op_cost;
|
||
alg_in->cost.latency += op_cost;
|
||
if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost))
|
||
{
|
||
struct algorithm *x;
|
||
best_cost = alg_in->cost;
|
||
x = alg_in, alg_in = best_alg, best_alg = x;
|
||
best_alg->log[best_alg->ops] = m;
|
||
best_alg->op[best_alg->ops] = alg_shift;
|
||
}
|
||
}
|
||
if (cache_hit)
|
||
goto done;
|
||
}
|
||
|
||
/* If we have an odd number, add or subtract one. */
|
||
if ((t & 1) != 0)
|
||
{
|
||
unsigned HOST_WIDE_INT w;
|
||
|
||
do_alg_addsub_t_m2:
|
||
for (w = 1; (w & t) != 0; w <<= 1)
|
||
;
|
||
/* If T was -1, then W will be zero after the loop. This is another
|
||
case where T ends with ...111. Handling this with (T + 1) and
|
||
subtract 1 produces slightly better code and results in algorithm
|
||
selection much faster than treating it like the ...0111 case
|
||
below. */
|
||
if (w == 0
|
||
|| (w > 2
|
||
/* Reject the case where t is 3.
|
||
Thus we prefer addition in that case. */
|
||
&& t != 3))
|
||
{
|
||
/* T ends with ...111. Multiply by (T + 1) and subtract 1. */
|
||
|
||
op_cost = add_cost[mode];
|
||
new_limit.cost = best_cost.cost - op_cost;
|
||
new_limit.latency = best_cost.latency - op_cost;
|
||
synth_mult (alg_in, t + 1, &new_limit, mode);
|
||
|
||
alg_in->cost.cost += op_cost;
|
||
alg_in->cost.latency += op_cost;
|
||
if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost))
|
||
{
|
||
struct algorithm *x;
|
||
best_cost = alg_in->cost;
|
||
x = alg_in, alg_in = best_alg, best_alg = x;
|
||
best_alg->log[best_alg->ops] = 0;
|
||
best_alg->op[best_alg->ops] = alg_sub_t_m2;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* T ends with ...01 or ...011. Multiply by (T - 1) and add 1. */
|
||
|
||
op_cost = add_cost[mode];
|
||
new_limit.cost = best_cost.cost - op_cost;
|
||
new_limit.latency = best_cost.latency - op_cost;
|
||
synth_mult (alg_in, t - 1, &new_limit, mode);
|
||
|
||
alg_in->cost.cost += op_cost;
|
||
alg_in->cost.latency += op_cost;
|
||
if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost))
|
||
{
|
||
struct algorithm *x;
|
||
best_cost = alg_in->cost;
|
||
x = alg_in, alg_in = best_alg, best_alg = x;
|
||
best_alg->log[best_alg->ops] = 0;
|
||
best_alg->op[best_alg->ops] = alg_add_t_m2;
|
||
}
|
||
}
|
||
if (cache_hit)
|
||
goto done;
|
||
}
|
||
|
||
/* Look for factors of t of the form
|
||
t = q(2**m +- 1), 2 <= m <= floor(log2(t - 1)).
|
||
If we find such a factor, we can multiply by t using an algorithm that
|
||
multiplies by q, shift the result by m and add/subtract it to itself.
|
||
|
||
We search for large factors first and loop down, even if large factors
|
||
are less probable than small; if we find a large factor we will find a
|
||
good sequence quickly, and therefore be able to prune (by decreasing
|
||
COST_LIMIT) the search. */
|
||
|
||
do_alg_addsub_factor:
|
||
for (m = floor_log2 (t - 1); m >= 2; m--)
|
||
{
|
||
unsigned HOST_WIDE_INT d;
|
||
|
||
d = ((unsigned HOST_WIDE_INT) 1 << m) + 1;
|
||
if (t % d == 0 && t > d && m < maxm
|
||
&& (!cache_hit || cache_alg == alg_add_factor))
|
||
{
|
||
/* If the target has a cheap shift-and-add instruction use
|
||
that in preference to a shift insn followed by an add insn.
|
||
Assume that the shift-and-add is "atomic" with a latency
|
||
equal to its cost, otherwise assume that on superscalar
|
||
hardware the shift may be executed concurrently with the
|
||
earlier steps in the algorithm. */
|
||
op_cost = add_cost[mode] + shift_cost[mode][m];
|
||
if (shiftadd_cost[mode][m] < op_cost)
|
||
{
|
||
op_cost = shiftadd_cost[mode][m];
|
||
op_latency = op_cost;
|
||
}
|
||
else
|
||
op_latency = add_cost[mode];
|
||
|
||
new_limit.cost = best_cost.cost - op_cost;
|
||
new_limit.latency = best_cost.latency - op_latency;
|
||
synth_mult (alg_in, t / d, &new_limit, mode);
|
||
|
||
alg_in->cost.cost += op_cost;
|
||
alg_in->cost.latency += op_latency;
|
||
if (alg_in->cost.latency < op_cost)
|
||
alg_in->cost.latency = op_cost;
|
||
if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost))
|
||
{
|
||
struct algorithm *x;
|
||
best_cost = alg_in->cost;
|
||
x = alg_in, alg_in = best_alg, best_alg = x;
|
||
best_alg->log[best_alg->ops] = m;
|
||
best_alg->op[best_alg->ops] = alg_add_factor;
|
||
}
|
||
/* Other factors will have been taken care of in the recursion. */
|
||
break;
|
||
}
|
||
|
||
d = ((unsigned HOST_WIDE_INT) 1 << m) - 1;
|
||
if (t % d == 0 && t > d && m < maxm
|
||
&& (!cache_hit || cache_alg == alg_sub_factor))
|
||
{
|
||
/* If the target has a cheap shift-and-subtract insn use
|
||
that in preference to a shift insn followed by a sub insn.
|
||
Assume that the shift-and-sub is "atomic" with a latency
|
||
equal to it's cost, otherwise assume that on superscalar
|
||
hardware the shift may be executed concurrently with the
|
||
earlier steps in the algorithm. */
|
||
op_cost = add_cost[mode] + shift_cost[mode][m];
|
||
if (shiftsub_cost[mode][m] < op_cost)
|
||
{
|
||
op_cost = shiftsub_cost[mode][m];
|
||
op_latency = op_cost;
|
||
}
|
||
else
|
||
op_latency = add_cost[mode];
|
||
|
||
new_limit.cost = best_cost.cost - op_cost;
|
||
new_limit.latency = best_cost.latency - op_latency;
|
||
synth_mult (alg_in, t / d, &new_limit, mode);
|
||
|
||
alg_in->cost.cost += op_cost;
|
||
alg_in->cost.latency += op_latency;
|
||
if (alg_in->cost.latency < op_cost)
|
||
alg_in->cost.latency = op_cost;
|
||
if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost))
|
||
{
|
||
struct algorithm *x;
|
||
best_cost = alg_in->cost;
|
||
x = alg_in, alg_in = best_alg, best_alg = x;
|
||
best_alg->log[best_alg->ops] = m;
|
||
best_alg->op[best_alg->ops] = alg_sub_factor;
|
||
}
|
||
break;
|
||
}
|
||
}
|
||
if (cache_hit)
|
||
goto done;
|
||
|
||
/* Try shift-and-add (load effective address) instructions,
|
||
i.e. do a*3, a*5, a*9. */
|
||
if ((t & 1) != 0)
|
||
{
|
||
do_alg_add_t2_m:
|
||
q = t - 1;
|
||
q = q & -q;
|
||
m = exact_log2 (q);
|
||
if (m >= 0 && m < maxm)
|
||
{
|
||
op_cost = shiftadd_cost[mode][m];
|
||
new_limit.cost = best_cost.cost - op_cost;
|
||
new_limit.latency = best_cost.latency - op_cost;
|
||
synth_mult (alg_in, (t - 1) >> m, &new_limit, mode);
|
||
|
||
alg_in->cost.cost += op_cost;
|
||
alg_in->cost.latency += op_cost;
|
||
if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost))
|
||
{
|
||
struct algorithm *x;
|
||
best_cost = alg_in->cost;
|
||
x = alg_in, alg_in = best_alg, best_alg = x;
|
||
best_alg->log[best_alg->ops] = m;
|
||
best_alg->op[best_alg->ops] = alg_add_t2_m;
|
||
}
|
||
}
|
||
if (cache_hit)
|
||
goto done;
|
||
|
||
do_alg_sub_t2_m:
|
||
q = t + 1;
|
||
q = q & -q;
|
||
m = exact_log2 (q);
|
||
if (m >= 0 && m < maxm)
|
||
{
|
||
op_cost = shiftsub_cost[mode][m];
|
||
new_limit.cost = best_cost.cost - op_cost;
|
||
new_limit.latency = best_cost.latency - op_cost;
|
||
synth_mult (alg_in, (t + 1) >> m, &new_limit, mode);
|
||
|
||
alg_in->cost.cost += op_cost;
|
||
alg_in->cost.latency += op_cost;
|
||
if (CHEAPER_MULT_COST (&alg_in->cost, &best_cost))
|
||
{
|
||
struct algorithm *x;
|
||
best_cost = alg_in->cost;
|
||
x = alg_in, alg_in = best_alg, best_alg = x;
|
||
best_alg->log[best_alg->ops] = m;
|
||
best_alg->op[best_alg->ops] = alg_sub_t2_m;
|
||
}
|
||
}
|
||
if (cache_hit)
|
||
goto done;
|
||
}
|
||
|
||
done:
|
||
/* If best_cost has not decreased, we have not found any algorithm. */
|
||
if (!CHEAPER_MULT_COST (&best_cost, cost_limit))
|
||
{
|
||
/* We failed to find an algorithm. Record alg_impossible for
|
||
this case (that is, <T, MODE, COST_LIMIT>) so that next time
|
||
we are asked to find an algorithm for T within the same or
|
||
lower COST_LIMIT, we can immediately return to the
|
||
caller. */
|
||
alg_hash[hash_index].t = t;
|
||
alg_hash[hash_index].mode = mode;
|
||
alg_hash[hash_index].alg = alg_impossible;
|
||
alg_hash[hash_index].cost = *cost_limit;
|
||
return;
|
||
}
|
||
|
||
/* Cache the result. */
|
||
if (!cache_hit)
|
||
{
|
||
alg_hash[hash_index].t = t;
|
||
alg_hash[hash_index].mode = mode;
|
||
alg_hash[hash_index].alg = best_alg->op[best_alg->ops];
|
||
alg_hash[hash_index].cost.cost = best_cost.cost;
|
||
alg_hash[hash_index].cost.latency = best_cost.latency;
|
||
}
|
||
|
||
/* If we are getting a too long sequence for `struct algorithm'
|
||
to record, make this search fail. */
|
||
if (best_alg->ops == MAX_BITS_PER_WORD)
|
||
return;
|
||
|
||
/* Copy the algorithm from temporary space to the space at alg_out.
|
||
We avoid using structure assignment because the majority of
|
||
best_alg is normally undefined, and this is a critical function. */
|
||
alg_out->ops = best_alg->ops + 1;
|
||
alg_out->cost = best_cost;
|
||
memcpy (alg_out->op, best_alg->op,
|
||
alg_out->ops * sizeof *alg_out->op);
|
||
memcpy (alg_out->log, best_alg->log,
|
||
alg_out->ops * sizeof *alg_out->log);
|
||
}
|
||
|
||
/* Find the cheapest way of multiplying a value of mode MODE by VAL.
|
||
Try three variations:
|
||
|
||
- a shift/add sequence based on VAL itself
|
||
- a shift/add sequence based on -VAL, followed by a negation
|
||
- a shift/add sequence based on VAL - 1, followed by an addition.
|
||
|
||
Return true if the cheapest of these cost less than MULT_COST,
|
||
describing the algorithm in *ALG and final fixup in *VARIANT. */
|
||
|
||
static bool
|
||
choose_mult_variant (enum machine_mode mode, HOST_WIDE_INT val,
|
||
struct algorithm *alg, enum mult_variant *variant,
|
||
int mult_cost)
|
||
{
|
||
struct algorithm alg2;
|
||
struct mult_cost limit;
|
||
int op_cost;
|
||
|
||
/* Fail quickly for impossible bounds. */
|
||
if (mult_cost < 0)
|
||
return false;
|
||
|
||
/* Ensure that mult_cost provides a reasonable upper bound.
|
||
Any constant multiplication can be performed with less
|
||
than 2 * bits additions. */
|
||
op_cost = 2 * GET_MODE_BITSIZE (mode) * add_cost[mode];
|
||
if (mult_cost > op_cost)
|
||
mult_cost = op_cost;
|
||
|
||
*variant = basic_variant;
|
||
limit.cost = mult_cost;
|
||
limit.latency = mult_cost;
|
||
synth_mult (alg, val, &limit, mode);
|
||
|
||
/* This works only if the inverted value actually fits in an
|
||
`unsigned int' */
|
||
if (HOST_BITS_PER_INT >= GET_MODE_BITSIZE (mode))
|
||
{
|
||
op_cost = neg_cost[mode];
|
||
if (MULT_COST_LESS (&alg->cost, mult_cost))
|
||
{
|
||
limit.cost = alg->cost.cost - op_cost;
|
||
limit.latency = alg->cost.latency - op_cost;
|
||
}
|
||
else
|
||
{
|
||
limit.cost = mult_cost - op_cost;
|
||
limit.latency = mult_cost - op_cost;
|
||
}
|
||
|
||
synth_mult (&alg2, -val, &limit, mode);
|
||
alg2.cost.cost += op_cost;
|
||
alg2.cost.latency += op_cost;
|
||
if (CHEAPER_MULT_COST (&alg2.cost, &alg->cost))
|
||
*alg = alg2, *variant = negate_variant;
|
||
}
|
||
|
||
/* This proves very useful for division-by-constant. */
|
||
op_cost = add_cost[mode];
|
||
if (MULT_COST_LESS (&alg->cost, mult_cost))
|
||
{
|
||
limit.cost = alg->cost.cost - op_cost;
|
||
limit.latency = alg->cost.latency - op_cost;
|
||
}
|
||
else
|
||
{
|
||
limit.cost = mult_cost - op_cost;
|
||
limit.latency = mult_cost - op_cost;
|
||
}
|
||
|
||
synth_mult (&alg2, val - 1, &limit, mode);
|
||
alg2.cost.cost += op_cost;
|
||
alg2.cost.latency += op_cost;
|
||
if (CHEAPER_MULT_COST (&alg2.cost, &alg->cost))
|
||
*alg = alg2, *variant = add_variant;
|
||
|
||
return MULT_COST_LESS (&alg->cost, mult_cost);
|
||
}
|
||
|
||
/* A subroutine of expand_mult, used for constant multiplications.
|
||
Multiply OP0 by VAL in mode MODE, storing the result in TARGET if
|
||
convenient. Use the shift/add sequence described by ALG and apply
|
||
the final fixup specified by VARIANT. */
|
||
|
||
static rtx
|
||
expand_mult_const (enum machine_mode mode, rtx op0, HOST_WIDE_INT val,
|
||
rtx target, const struct algorithm *alg,
|
||
enum mult_variant variant)
|
||
{
|
||
HOST_WIDE_INT val_so_far;
|
||
rtx insn, accum, tem;
|
||
int opno;
|
||
enum machine_mode nmode;
|
||
|
||
/* Avoid referencing memory over and over.
|
||
For speed, but also for correctness when mem is volatile. */
|
||
if (MEM_P (op0))
|
||
op0 = force_reg (mode, op0);
|
||
|
||
/* ACCUM starts out either as OP0 or as a zero, depending on
|
||
the first operation. */
|
||
|
||
if (alg->op[0] == alg_zero)
|
||
{
|
||
accum = copy_to_mode_reg (mode, const0_rtx);
|
||
val_so_far = 0;
|
||
}
|
||
else if (alg->op[0] == alg_m)
|
||
{
|
||
accum = copy_to_mode_reg (mode, op0);
|
||
val_so_far = 1;
|
||
}
|
||
else
|
||
gcc_unreachable ();
|
||
|
||
for (opno = 1; opno < alg->ops; opno++)
|
||
{
|
||
int log = alg->log[opno];
|
||
rtx shift_subtarget = optimize ? 0 : accum;
|
||
rtx add_target
|
||
= (opno == alg->ops - 1 && target != 0 && variant != add_variant
|
||
&& !optimize)
|
||
? target : 0;
|
||
rtx accum_target = optimize ? 0 : accum;
|
||
|
||
switch (alg->op[opno])
|
||
{
|
||
case alg_shift:
|
||
accum = expand_shift (LSHIFT_EXPR, mode, accum,
|
||
build_int_cst (NULL_TREE, log),
|
||
NULL_RTX, 0);
|
||
val_so_far <<= log;
|
||
break;
|
||
|
||
case alg_add_t_m2:
|
||
tem = expand_shift (LSHIFT_EXPR, mode, op0,
|
||
build_int_cst (NULL_TREE, log),
|
||
NULL_RTX, 0);
|
||
accum = force_operand (gen_rtx_PLUS (mode, accum, tem),
|
||
add_target ? add_target : accum_target);
|
||
val_so_far += (HOST_WIDE_INT) 1 << log;
|
||
break;
|
||
|
||
case alg_sub_t_m2:
|
||
tem = expand_shift (LSHIFT_EXPR, mode, op0,
|
||
build_int_cst (NULL_TREE, log),
|
||
NULL_RTX, 0);
|
||
accum = force_operand (gen_rtx_MINUS (mode, accum, tem),
|
||
add_target ? add_target : accum_target);
|
||
val_so_far -= (HOST_WIDE_INT) 1 << log;
|
||
break;
|
||
|
||
case alg_add_t2_m:
|
||
accum = expand_shift (LSHIFT_EXPR, mode, accum,
|
||
build_int_cst (NULL_TREE, log),
|
||
shift_subtarget,
|
||
0);
|
||
accum = force_operand (gen_rtx_PLUS (mode, accum, op0),
|
||
add_target ? add_target : accum_target);
|
||
val_so_far = (val_so_far << log) + 1;
|
||
break;
|
||
|
||
case alg_sub_t2_m:
|
||
accum = expand_shift (LSHIFT_EXPR, mode, accum,
|
||
build_int_cst (NULL_TREE, log),
|
||
shift_subtarget, 0);
|
||
accum = force_operand (gen_rtx_MINUS (mode, accum, op0),
|
||
add_target ? add_target : accum_target);
|
||
val_so_far = (val_so_far << log) - 1;
|
||
break;
|
||
|
||
case alg_add_factor:
|
||
tem = expand_shift (LSHIFT_EXPR, mode, accum,
|
||
build_int_cst (NULL_TREE, log),
|
||
NULL_RTX, 0);
|
||
accum = force_operand (gen_rtx_PLUS (mode, accum, tem),
|
||
add_target ? add_target : accum_target);
|
||
val_so_far += val_so_far << log;
|
||
break;
|
||
|
||
case alg_sub_factor:
|
||
tem = expand_shift (LSHIFT_EXPR, mode, accum,
|
||
build_int_cst (NULL_TREE, log),
|
||
NULL_RTX, 0);
|
||
accum = force_operand (gen_rtx_MINUS (mode, tem, accum),
|
||
(add_target
|
||
? add_target : (optimize ? 0 : tem)));
|
||
val_so_far = (val_so_far << log) - val_so_far;
|
||
break;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
|
||
/* Write a REG_EQUAL note on the last insn so that we can cse
|
||
multiplication sequences. Note that if ACCUM is a SUBREG,
|
||
we've set the inner register and must properly indicate
|
||
that. */
|
||
|
||
tem = op0, nmode = mode;
|
||
if (GET_CODE (accum) == SUBREG)
|
||
{
|
||
nmode = GET_MODE (SUBREG_REG (accum));
|
||
tem = gen_lowpart (nmode, op0);
|
||
}
|
||
|
||
insn = get_last_insn ();
|
||
set_unique_reg_note (insn, REG_EQUAL,
|
||
gen_rtx_MULT (nmode, tem, GEN_INT (val_so_far)));
|
||
}
|
||
|
||
if (variant == negate_variant)
|
||
{
|
||
val_so_far = -val_so_far;
|
||
accum = expand_unop (mode, neg_optab, accum, target, 0);
|
||
}
|
||
else if (variant == add_variant)
|
||
{
|
||
val_so_far = val_so_far + 1;
|
||
accum = force_operand (gen_rtx_PLUS (mode, accum, op0), target);
|
||
}
|
||
|
||
/* Compare only the bits of val and val_so_far that are significant
|
||
in the result mode, to avoid sign-/zero-extension confusion. */
|
||
val &= GET_MODE_MASK (mode);
|
||
val_so_far &= GET_MODE_MASK (mode);
|
||
gcc_assert (val == val_so_far);
|
||
|
||
return accum;
|
||
}
|
||
|
||
/* Perform a multiplication and return an rtx for the result.
|
||
MODE is mode of value; OP0 and OP1 are what to multiply (rtx's);
|
||
TARGET is a suggestion for where to store the result (an rtx).
|
||
|
||
We check specially for a constant integer as OP1.
|
||
If you want this check for OP0 as well, then before calling
|
||
you should swap the two operands if OP0 would be constant. */
|
||
|
||
rtx
|
||
expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target,
|
||
int unsignedp)
|
||
{
|
||
enum mult_variant variant;
|
||
struct algorithm algorithm;
|
||
int max_cost;
|
||
|
||
/* Handling const0_rtx here allows us to use zero as a rogue value for
|
||
coeff below. */
|
||
if (op1 == const0_rtx)
|
||
return const0_rtx;
|
||
if (op1 == const1_rtx)
|
||
return op0;
|
||
if (op1 == constm1_rtx)
|
||
return expand_unop (mode,
|
||
GET_MODE_CLASS (mode) == MODE_INT
|
||
&& !unsignedp && flag_trapv
|
||
? negv_optab : neg_optab,
|
||
op0, target, 0);
|
||
|
||
/* These are the operations that are potentially turned into a sequence
|
||
of shifts and additions. */
|
||
if (SCALAR_INT_MODE_P (mode)
|
||
&& (unsignedp || !flag_trapv))
|
||
{
|
||
HOST_WIDE_INT coeff = 0;
|
||
rtx fake_reg = gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 1);
|
||
|
||
/* synth_mult does an `unsigned int' multiply. As long as the mode is
|
||
less than or equal in size to `unsigned int' this doesn't matter.
|
||
If the mode is larger than `unsigned int', then synth_mult works
|
||
only if the constant value exactly fits in an `unsigned int' without
|
||
any truncation. This means that multiplying by negative values does
|
||
not work; results are off by 2^32 on a 32 bit machine. */
|
||
|
||
if (GET_CODE (op1) == CONST_INT)
|
||
{
|
||
/* Attempt to handle multiplication of DImode values by negative
|
||
coefficients, by performing the multiplication by a positive
|
||
multiplier and then inverting the result. */
|
||
if (INTVAL (op1) < 0
|
||
&& GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
/* Its safe to use -INTVAL (op1) even for INT_MIN, as the
|
||
result is interpreted as an unsigned coefficient.
|
||
Exclude cost of op0 from max_cost to match the cost
|
||
calculation of the synth_mult. */
|
||
max_cost = rtx_cost (gen_rtx_MULT (mode, fake_reg, op1), SET)
|
||
- neg_cost[mode];
|
||
if (max_cost > 0
|
||
&& choose_mult_variant (mode, -INTVAL (op1), &algorithm,
|
||
&variant, max_cost))
|
||
{
|
||
rtx temp = expand_mult_const (mode, op0, -INTVAL (op1),
|
||
NULL_RTX, &algorithm,
|
||
variant);
|
||
return expand_unop (mode, neg_optab, temp, target, 0);
|
||
}
|
||
}
|
||
else coeff = INTVAL (op1);
|
||
}
|
||
else if (GET_CODE (op1) == CONST_DOUBLE)
|
||
{
|
||
/* If we are multiplying in DImode, it may still be a win
|
||
to try to work with shifts and adds. */
|
||
if (CONST_DOUBLE_HIGH (op1) == 0)
|
||
coeff = CONST_DOUBLE_LOW (op1);
|
||
else if (CONST_DOUBLE_LOW (op1) == 0
|
||
&& EXACT_POWER_OF_2_OR_ZERO_P (CONST_DOUBLE_HIGH (op1)))
|
||
{
|
||
int shift = floor_log2 (CONST_DOUBLE_HIGH (op1))
|
||
+ HOST_BITS_PER_WIDE_INT;
|
||
return expand_shift (LSHIFT_EXPR, mode, op0,
|
||
build_int_cst (NULL_TREE, shift),
|
||
target, unsignedp);
|
||
}
|
||
}
|
||
|
||
/* We used to test optimize here, on the grounds that it's better to
|
||
produce a smaller program when -O is not used. But this causes
|
||
such a terrible slowdown sometimes that it seems better to always
|
||
use synth_mult. */
|
||
if (coeff != 0)
|
||
{
|
||
/* Special case powers of two. */
|
||
if (EXACT_POWER_OF_2_OR_ZERO_P (coeff))
|
||
return expand_shift (LSHIFT_EXPR, mode, op0,
|
||
build_int_cst (NULL_TREE, floor_log2 (coeff)),
|
||
target, unsignedp);
|
||
|
||
/* Exclude cost of op0 from max_cost to match the cost
|
||
calculation of the synth_mult. */
|
||
max_cost = rtx_cost (gen_rtx_MULT (mode, fake_reg, op1), SET);
|
||
if (choose_mult_variant (mode, coeff, &algorithm, &variant,
|
||
max_cost))
|
||
return expand_mult_const (mode, op0, coeff, target,
|
||
&algorithm, variant);
|
||
}
|
||
}
|
||
|
||
if (GET_CODE (op0) == CONST_DOUBLE)
|
||
{
|
||
rtx temp = op0;
|
||
op0 = op1;
|
||
op1 = temp;
|
||
}
|
||
|
||
/* Expand x*2.0 as x+x. */
|
||
if (GET_CODE (op1) == CONST_DOUBLE
|
||
&& SCALAR_FLOAT_MODE_P (mode))
|
||
{
|
||
REAL_VALUE_TYPE d;
|
||
REAL_VALUE_FROM_CONST_DOUBLE (d, op1);
|
||
|
||
if (REAL_VALUES_EQUAL (d, dconst2))
|
||
{
|
||
op0 = force_reg (GET_MODE (op0), op0);
|
||
return expand_binop (mode, add_optab, op0, op0,
|
||
target, unsignedp, OPTAB_LIB_WIDEN);
|
||
}
|
||
}
|
||
|
||
/* This used to use umul_optab if unsigned, but for non-widening multiply
|
||
there is no difference between signed and unsigned. */
|
||
op0 = expand_binop (mode,
|
||
! unsignedp
|
||
&& flag_trapv && (GET_MODE_CLASS(mode) == MODE_INT)
|
||
? smulv_optab : smul_optab,
|
||
op0, op1, target, unsignedp, OPTAB_LIB_WIDEN);
|
||
gcc_assert (op0);
|
||
return op0;
|
||
}
|
||
|
||
/* Return the smallest n such that 2**n >= X. */
|
||
|
||
int
|
||
ceil_log2 (unsigned HOST_WIDE_INT x)
|
||
{
|
||
return floor_log2 (x - 1) + 1;
|
||
}
|
||
|
||
/* Choose a minimal N + 1 bit approximation to 1/D that can be used to
|
||
replace division by D, and put the least significant N bits of the result
|
||
in *MULTIPLIER_PTR and return the most significant bit.
|
||
|
||
The width of operations is N (should be <= HOST_BITS_PER_WIDE_INT), the
|
||
needed precision is in PRECISION (should be <= N).
|
||
|
||
PRECISION should be as small as possible so this function can choose
|
||
multiplier more freely.
|
||
|
||
The rounded-up logarithm of D is placed in *lgup_ptr. A shift count that
|
||
is to be used for a final right shift is placed in *POST_SHIFT_PTR.
|
||
|
||
Using this function, x/D will be equal to (x * m) >> (*POST_SHIFT_PTR),
|
||
where m is the full HOST_BITS_PER_WIDE_INT + 1 bit multiplier. */
|
||
|
||
static
|
||
unsigned HOST_WIDE_INT
|
||
choose_multiplier (unsigned HOST_WIDE_INT d, int n, int precision,
|
||
rtx *multiplier_ptr, int *post_shift_ptr, int *lgup_ptr)
|
||
{
|
||
HOST_WIDE_INT mhigh_hi, mlow_hi;
|
||
unsigned HOST_WIDE_INT mhigh_lo, mlow_lo;
|
||
int lgup, post_shift;
|
||
int pow, pow2;
|
||
unsigned HOST_WIDE_INT nl, dummy1;
|
||
HOST_WIDE_INT nh, dummy2;
|
||
|
||
/* lgup = ceil(log2(divisor)); */
|
||
lgup = ceil_log2 (d);
|
||
|
||
gcc_assert (lgup <= n);
|
||
|
||
pow = n + lgup;
|
||
pow2 = n + lgup - precision;
|
||
|
||
/* We could handle this with some effort, but this case is much
|
||
better handled directly with a scc insn, so rely on caller using
|
||
that. */
|
||
gcc_assert (pow != 2 * HOST_BITS_PER_WIDE_INT);
|
||
|
||
/* mlow = 2^(N + lgup)/d */
|
||
if (pow >= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
nh = (HOST_WIDE_INT) 1 << (pow - HOST_BITS_PER_WIDE_INT);
|
||
nl = 0;
|
||
}
|
||
else
|
||
{
|
||
nh = 0;
|
||
nl = (unsigned HOST_WIDE_INT) 1 << pow;
|
||
}
|
||
div_and_round_double (TRUNC_DIV_EXPR, 1, nl, nh, d, (HOST_WIDE_INT) 0,
|
||
&mlow_lo, &mlow_hi, &dummy1, &dummy2);
|
||
|
||
/* mhigh = (2^(N + lgup) + 2^N + lgup - precision)/d */
|
||
if (pow2 >= HOST_BITS_PER_WIDE_INT)
|
||
nh |= (HOST_WIDE_INT) 1 << (pow2 - HOST_BITS_PER_WIDE_INT);
|
||
else
|
||
nl |= (unsigned HOST_WIDE_INT) 1 << pow2;
|
||
div_and_round_double (TRUNC_DIV_EXPR, 1, nl, nh, d, (HOST_WIDE_INT) 0,
|
||
&mhigh_lo, &mhigh_hi, &dummy1, &dummy2);
|
||
|
||
gcc_assert (!mhigh_hi || nh - d < d);
|
||
gcc_assert (mhigh_hi <= 1 && mlow_hi <= 1);
|
||
/* Assert that mlow < mhigh. */
|
||
gcc_assert (mlow_hi < mhigh_hi
|
||
|| (mlow_hi == mhigh_hi && mlow_lo < mhigh_lo));
|
||
|
||
/* If precision == N, then mlow, mhigh exceed 2^N
|
||
(but they do not exceed 2^(N+1)). */
|
||
|
||
/* Reduce to lowest terms. */
|
||
for (post_shift = lgup; post_shift > 0; post_shift--)
|
||
{
|
||
unsigned HOST_WIDE_INT ml_lo = (mlow_hi << (HOST_BITS_PER_WIDE_INT - 1)) | (mlow_lo >> 1);
|
||
unsigned HOST_WIDE_INT mh_lo = (mhigh_hi << (HOST_BITS_PER_WIDE_INT - 1)) | (mhigh_lo >> 1);
|
||
if (ml_lo >= mh_lo)
|
||
break;
|
||
|
||
mlow_hi = 0;
|
||
mlow_lo = ml_lo;
|
||
mhigh_hi = 0;
|
||
mhigh_lo = mh_lo;
|
||
}
|
||
|
||
*post_shift_ptr = post_shift;
|
||
*lgup_ptr = lgup;
|
||
if (n < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
unsigned HOST_WIDE_INT mask = ((unsigned HOST_WIDE_INT) 1 << n) - 1;
|
||
*multiplier_ptr = GEN_INT (mhigh_lo & mask);
|
||
return mhigh_lo >= mask;
|
||
}
|
||
else
|
||
{
|
||
*multiplier_ptr = GEN_INT (mhigh_lo);
|
||
return mhigh_hi;
|
||
}
|
||
}
|
||
|
||
/* Compute the inverse of X mod 2**n, i.e., find Y such that X * Y is
|
||
congruent to 1 (mod 2**N). */
|
||
|
||
static unsigned HOST_WIDE_INT
|
||
invert_mod2n (unsigned HOST_WIDE_INT x, int n)
|
||
{
|
||
/* Solve x*y == 1 (mod 2^n), where x is odd. Return y. */
|
||
|
||
/* The algorithm notes that the choice y = x satisfies
|
||
x*y == 1 mod 2^3, since x is assumed odd.
|
||
Each iteration doubles the number of bits of significance in y. */
|
||
|
||
unsigned HOST_WIDE_INT mask;
|
||
unsigned HOST_WIDE_INT y = x;
|
||
int nbit = 3;
|
||
|
||
mask = (n == HOST_BITS_PER_WIDE_INT
|
||
? ~(unsigned HOST_WIDE_INT) 0
|
||
: ((unsigned HOST_WIDE_INT) 1 << n) - 1);
|
||
|
||
while (nbit < n)
|
||
{
|
||
y = y * (2 - x*y) & mask; /* Modulo 2^N */
|
||
nbit *= 2;
|
||
}
|
||
return y;
|
||
}
|
||
|
||
/* Emit code to adjust ADJ_OPERAND after multiplication of wrong signedness
|
||
flavor of OP0 and OP1. ADJ_OPERAND is already the high half of the
|
||
product OP0 x OP1. If UNSIGNEDP is nonzero, adjust the signed product
|
||
to become unsigned, if UNSIGNEDP is zero, adjust the unsigned product to
|
||
become signed.
|
||
|
||
The result is put in TARGET if that is convenient.
|
||
|
||
MODE is the mode of operation. */
|
||
|
||
rtx
|
||
expand_mult_highpart_adjust (enum machine_mode mode, rtx adj_operand, rtx op0,
|
||
rtx op1, rtx target, int unsignedp)
|
||
{
|
||
rtx tem;
|
||
enum rtx_code adj_code = unsignedp ? PLUS : MINUS;
|
||
|
||
tem = expand_shift (RSHIFT_EXPR, mode, op0,
|
||
build_int_cst (NULL_TREE, GET_MODE_BITSIZE (mode) - 1),
|
||
NULL_RTX, 0);
|
||
tem = expand_and (mode, tem, op1, NULL_RTX);
|
||
adj_operand
|
||
= force_operand (gen_rtx_fmt_ee (adj_code, mode, adj_operand, tem),
|
||
adj_operand);
|
||
|
||
tem = expand_shift (RSHIFT_EXPR, mode, op1,
|
||
build_int_cst (NULL_TREE, GET_MODE_BITSIZE (mode) - 1),
|
||
NULL_RTX, 0);
|
||
tem = expand_and (mode, tem, op0, NULL_RTX);
|
||
target = force_operand (gen_rtx_fmt_ee (adj_code, mode, adj_operand, tem),
|
||
target);
|
||
|
||
return target;
|
||
}
|
||
|
||
/* Subroutine of expand_mult_highpart. Return the MODE high part of OP. */
|
||
|
||
static rtx
|
||
extract_high_half (enum machine_mode mode, rtx op)
|
||
{
|
||
enum machine_mode wider_mode;
|
||
|
||
if (mode == word_mode)
|
||
return gen_highpart (mode, op);
|
||
|
||
gcc_assert (!SCALAR_FLOAT_MODE_P (mode));
|
||
|
||
wider_mode = GET_MODE_WIDER_MODE (mode);
|
||
op = expand_shift (RSHIFT_EXPR, wider_mode, op,
|
||
build_int_cst (NULL_TREE, GET_MODE_BITSIZE (mode)), 0, 1);
|
||
return convert_modes (mode, wider_mode, op, 0);
|
||
}
|
||
|
||
/* Like expand_mult_highpart, but only consider using a multiplication
|
||
optab. OP1 is an rtx for the constant operand. */
|
||
|
||
static rtx
|
||
expand_mult_highpart_optab (enum machine_mode mode, rtx op0, rtx op1,
|
||
rtx target, int unsignedp, int max_cost)
|
||
{
|
||
rtx narrow_op1 = gen_int_mode (INTVAL (op1), mode);
|
||
enum machine_mode wider_mode;
|
||
optab moptab;
|
||
rtx tem;
|
||
int size;
|
||
|
||
gcc_assert (!SCALAR_FLOAT_MODE_P (mode));
|
||
|
||
wider_mode = GET_MODE_WIDER_MODE (mode);
|
||
size = GET_MODE_BITSIZE (mode);
|
||
|
||
/* Firstly, try using a multiplication insn that only generates the needed
|
||
high part of the product, and in the sign flavor of unsignedp. */
|
||
if (mul_highpart_cost[mode] < max_cost)
|
||
{
|
||
moptab = unsignedp ? umul_highpart_optab : smul_highpart_optab;
|
||
tem = expand_binop (mode, moptab, op0, narrow_op1, target,
|
||
unsignedp, OPTAB_DIRECT);
|
||
if (tem)
|
||
return tem;
|
||
}
|
||
|
||
/* Secondly, same as above, but use sign flavor opposite of unsignedp.
|
||
Need to adjust the result after the multiplication. */
|
||
if (size - 1 < BITS_PER_WORD
|
||
&& (mul_highpart_cost[mode] + 2 * shift_cost[mode][size-1]
|
||
+ 4 * add_cost[mode] < max_cost))
|
||
{
|
||
moptab = unsignedp ? smul_highpart_optab : umul_highpart_optab;
|
||
tem = expand_binop (mode, moptab, op0, narrow_op1, target,
|
||
unsignedp, OPTAB_DIRECT);
|
||
if (tem)
|
||
/* We used the wrong signedness. Adjust the result. */
|
||
return expand_mult_highpart_adjust (mode, tem, op0, narrow_op1,
|
||
tem, unsignedp);
|
||
}
|
||
|
||
/* Try widening multiplication. */
|
||
moptab = unsignedp ? umul_widen_optab : smul_widen_optab;
|
||
if (moptab->handlers[wider_mode].insn_code != CODE_FOR_nothing
|
||
&& mul_widen_cost[wider_mode] < max_cost)
|
||
{
|
||
tem = expand_binop (wider_mode, moptab, op0, narrow_op1, 0,
|
||
unsignedp, OPTAB_WIDEN);
|
||
if (tem)
|
||
return extract_high_half (mode, tem);
|
||
}
|
||
|
||
/* Try widening the mode and perform a non-widening multiplication. */
|
||
if (smul_optab->handlers[wider_mode].insn_code != CODE_FOR_nothing
|
||
&& size - 1 < BITS_PER_WORD
|
||
&& mul_cost[wider_mode] + shift_cost[mode][size-1] < max_cost)
|
||
{
|
||
rtx insns, wop0, wop1;
|
||
|
||
/* We need to widen the operands, for example to ensure the
|
||
constant multiplier is correctly sign or zero extended.
|
||
Use a sequence to clean-up any instructions emitted by
|
||
the conversions if things don't work out. */
|
||
start_sequence ();
|
||
wop0 = convert_modes (wider_mode, mode, op0, unsignedp);
|
||
wop1 = convert_modes (wider_mode, mode, op1, unsignedp);
|
||
tem = expand_binop (wider_mode, smul_optab, wop0, wop1, 0,
|
||
unsignedp, OPTAB_WIDEN);
|
||
insns = get_insns ();
|
||
end_sequence ();
|
||
|
||
if (tem)
|
||
{
|
||
emit_insn (insns);
|
||
return extract_high_half (mode, tem);
|
||
}
|
||
}
|
||
|
||
/* Try widening multiplication of opposite signedness, and adjust. */
|
||
moptab = unsignedp ? smul_widen_optab : umul_widen_optab;
|
||
if (moptab->handlers[wider_mode].insn_code != CODE_FOR_nothing
|
||
&& size - 1 < BITS_PER_WORD
|
||
&& (mul_widen_cost[wider_mode] + 2 * shift_cost[mode][size-1]
|
||
+ 4 * add_cost[mode] < max_cost))
|
||
{
|
||
tem = expand_binop (wider_mode, moptab, op0, narrow_op1,
|
||
NULL_RTX, ! unsignedp, OPTAB_WIDEN);
|
||
if (tem != 0)
|
||
{
|
||
tem = extract_high_half (mode, tem);
|
||
/* We used the wrong signedness. Adjust the result. */
|
||
return expand_mult_highpart_adjust (mode, tem, op0, narrow_op1,
|
||
target, unsignedp);
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Emit code to multiply OP0 and OP1 (where OP1 is an integer constant),
|
||
putting the high half of the result in TARGET if that is convenient,
|
||
and return where the result is. If the operation can not be performed,
|
||
0 is returned.
|
||
|
||
MODE is the mode of operation and result.
|
||
|
||
UNSIGNEDP nonzero means unsigned multiply.
|
||
|
||
MAX_COST is the total allowed cost for the expanded RTL. */
|
||
|
||
static rtx
|
||
expand_mult_highpart (enum machine_mode mode, rtx op0, rtx op1,
|
||
rtx target, int unsignedp, int max_cost)
|
||
{
|
||
enum machine_mode wider_mode = GET_MODE_WIDER_MODE (mode);
|
||
unsigned HOST_WIDE_INT cnst1;
|
||
int extra_cost;
|
||
bool sign_adjust = false;
|
||
enum mult_variant variant;
|
||
struct algorithm alg;
|
||
rtx tem;
|
||
|
||
gcc_assert (!SCALAR_FLOAT_MODE_P (mode));
|
||
/* We can't support modes wider than HOST_BITS_PER_INT. */
|
||
gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT);
|
||
|
||
cnst1 = INTVAL (op1) & GET_MODE_MASK (mode);
|
||
|
||
/* We can't optimize modes wider than BITS_PER_WORD.
|
||
??? We might be able to perform double-word arithmetic if
|
||
mode == word_mode, however all the cost calculations in
|
||
synth_mult etc. assume single-word operations. */
|
||
if (GET_MODE_BITSIZE (wider_mode) > BITS_PER_WORD)
|
||
return expand_mult_highpart_optab (mode, op0, op1, target,
|
||
unsignedp, max_cost);
|
||
|
||
extra_cost = shift_cost[mode][GET_MODE_BITSIZE (mode) - 1];
|
||
|
||
/* Check whether we try to multiply by a negative constant. */
|
||
if (!unsignedp && ((cnst1 >> (GET_MODE_BITSIZE (mode) - 1)) & 1))
|
||
{
|
||
sign_adjust = true;
|
||
extra_cost += add_cost[mode];
|
||
}
|
||
|
||
/* See whether shift/add multiplication is cheap enough. */
|
||
if (choose_mult_variant (wider_mode, cnst1, &alg, &variant,
|
||
max_cost - extra_cost))
|
||
{
|
||
/* See whether the specialized multiplication optabs are
|
||
cheaper than the shift/add version. */
|
||
tem = expand_mult_highpart_optab (mode, op0, op1, target, unsignedp,
|
||
alg.cost.cost + extra_cost);
|
||
if (tem)
|
||
return tem;
|
||
|
||
tem = convert_to_mode (wider_mode, op0, unsignedp);
|
||
tem = expand_mult_const (wider_mode, tem, cnst1, 0, &alg, variant);
|
||
tem = extract_high_half (mode, tem);
|
||
|
||
/* Adjust result for signedness. */
|
||
if (sign_adjust)
|
||
tem = force_operand (gen_rtx_MINUS (mode, tem, op0), tem);
|
||
|
||
return tem;
|
||
}
|
||
return expand_mult_highpart_optab (mode, op0, op1, target,
|
||
unsignedp, max_cost);
|
||
}
|
||
|
||
|
||
/* Expand signed modulus of OP0 by a power of two D in mode MODE. */
|
||
|
||
static rtx
|
||
expand_smod_pow2 (enum machine_mode mode, rtx op0, HOST_WIDE_INT d)
|
||
{
|
||
unsigned HOST_WIDE_INT masklow, maskhigh;
|
||
rtx result, temp, shift, label;
|
||
int logd;
|
||
|
||
logd = floor_log2 (d);
|
||
result = gen_reg_rtx (mode);
|
||
|
||
/* Avoid conditional branches when they're expensive. */
|
||
if (BRANCH_COST >= 2
|
||
&& !optimize_size)
|
||
{
|
||
rtx signmask = emit_store_flag (result, LT, op0, const0_rtx,
|
||
mode, 0, -1);
|
||
if (signmask)
|
||
{
|
||
signmask = force_reg (mode, signmask);
|
||
masklow = ((HOST_WIDE_INT) 1 << logd) - 1;
|
||
shift = GEN_INT (GET_MODE_BITSIZE (mode) - logd);
|
||
|
||
/* Use the rtx_cost of a LSHIFTRT instruction to determine
|
||
which instruction sequence to use. If logical right shifts
|
||
are expensive the use 2 XORs, 2 SUBs and an AND, otherwise
|
||
use a LSHIFTRT, 1 ADD, 1 SUB and an AND. */
|
||
|
||
temp = gen_rtx_LSHIFTRT (mode, result, shift);
|
||
if (lshr_optab->handlers[mode].insn_code == CODE_FOR_nothing
|
||
|| rtx_cost (temp, SET) > COSTS_N_INSNS (2))
|
||
{
|
||
temp = expand_binop (mode, xor_optab, op0, signmask,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = expand_binop (mode, sub_optab, temp, signmask,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = expand_binop (mode, and_optab, temp, GEN_INT (masklow),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = expand_binop (mode, xor_optab, temp, signmask,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = expand_binop (mode, sub_optab, temp, signmask,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
}
|
||
else
|
||
{
|
||
signmask = expand_binop (mode, lshr_optab, signmask, shift,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
signmask = force_reg (mode, signmask);
|
||
|
||
temp = expand_binop (mode, add_optab, op0, signmask,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = expand_binop (mode, and_optab, temp, GEN_INT (masklow),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
temp = expand_binop (mode, sub_optab, temp, signmask,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
}
|
||
return temp;
|
||
}
|
||
}
|
||
|
||
/* Mask contains the mode's signbit and the significant bits of the
|
||
modulus. By including the signbit in the operation, many targets
|
||
can avoid an explicit compare operation in the following comparison
|
||
against zero. */
|
||
|
||
masklow = ((HOST_WIDE_INT) 1 << logd) - 1;
|
||
if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
masklow |= (HOST_WIDE_INT) -1 << (GET_MODE_BITSIZE (mode) - 1);
|
||
maskhigh = -1;
|
||
}
|
||
else
|
||
maskhigh = (HOST_WIDE_INT) -1
|
||
<< (GET_MODE_BITSIZE (mode) - HOST_BITS_PER_WIDE_INT - 1);
|
||
|
||
temp = expand_binop (mode, and_optab, op0,
|
||
immed_double_const (masklow, maskhigh, mode),
|
||
result, 1, OPTAB_LIB_WIDEN);
|
||
if (temp != result)
|
||
emit_move_insn (result, temp);
|
||
|
||
label = gen_label_rtx ();
|
||
do_cmp_and_jump (result, const0_rtx, GE, mode, label);
|
||
|
||
temp = expand_binop (mode, sub_optab, result, const1_rtx, result,
|
||
0, OPTAB_LIB_WIDEN);
|
||
masklow = (HOST_WIDE_INT) -1 << logd;
|
||
maskhigh = -1;
|
||
temp = expand_binop (mode, ior_optab, temp,
|
||
immed_double_const (masklow, maskhigh, mode),
|
||
result, 1, OPTAB_LIB_WIDEN);
|
||
temp = expand_binop (mode, add_optab, temp, const1_rtx, result,
|
||
0, OPTAB_LIB_WIDEN);
|
||
if (temp != result)
|
||
emit_move_insn (result, temp);
|
||
emit_label (label);
|
||
return result;
|
||
}
|
||
|
||
/* Expand signed division of OP0 by a power of two D in mode MODE.
|
||
This routine is only called for positive values of D. */
|
||
|
||
static rtx
|
||
expand_sdiv_pow2 (enum machine_mode mode, rtx op0, HOST_WIDE_INT d)
|
||
{
|
||
rtx temp, label;
|
||
tree shift;
|
||
int logd;
|
||
|
||
logd = floor_log2 (d);
|
||
shift = build_int_cst (NULL_TREE, logd);
|
||
|
||
if (d == 2 && BRANCH_COST >= 1)
|
||
{
|
||
temp = gen_reg_rtx (mode);
|
||
temp = emit_store_flag (temp, LT, op0, const0_rtx, mode, 0, 1);
|
||
temp = expand_binop (mode, add_optab, temp, op0, NULL_RTX,
|
||
0, OPTAB_LIB_WIDEN);
|
||
return expand_shift (RSHIFT_EXPR, mode, temp, shift, NULL_RTX, 0);
|
||
}
|
||
|
||
#ifdef HAVE_conditional_move
|
||
if (BRANCH_COST >= 2)
|
||
{
|
||
rtx temp2;
|
||
|
||
/* ??? emit_conditional_move forces a stack adjustment via
|
||
compare_from_rtx so, if the sequence is discarded, it will
|
||
be lost. Do it now instead. */
|
||
do_pending_stack_adjust ();
|
||
|
||
start_sequence ();
|
||
temp2 = copy_to_mode_reg (mode, op0);
|
||
temp = expand_binop (mode, add_optab, temp2, GEN_INT (d-1),
|
||
NULL_RTX, 0, OPTAB_LIB_WIDEN);
|
||
temp = force_reg (mode, temp);
|
||
|
||
/* Construct "temp2 = (temp2 < 0) ? temp : temp2". */
|
||
temp2 = emit_conditional_move (temp2, LT, temp2, const0_rtx,
|
||
mode, temp, temp2, mode, 0);
|
||
if (temp2)
|
||
{
|
||
rtx seq = get_insns ();
|
||
end_sequence ();
|
||
emit_insn (seq);
|
||
return expand_shift (RSHIFT_EXPR, mode, temp2, shift, NULL_RTX, 0);
|
||
}
|
||
end_sequence ();
|
||
}
|
||
#endif
|
||
|
||
if (BRANCH_COST >= 2)
|
||
{
|
||
int ushift = GET_MODE_BITSIZE (mode) - logd;
|
||
|
||
temp = gen_reg_rtx (mode);
|
||
temp = emit_store_flag (temp, LT, op0, const0_rtx, mode, 0, -1);
|
||
if (shift_cost[mode][ushift] > COSTS_N_INSNS (1))
|
||
temp = expand_binop (mode, and_optab, temp, GEN_INT (d - 1),
|
||
NULL_RTX, 0, OPTAB_LIB_WIDEN);
|
||
else
|
||
temp = expand_shift (RSHIFT_EXPR, mode, temp,
|
||
build_int_cst (NULL_TREE, ushift),
|
||
NULL_RTX, 1);
|
||
temp = expand_binop (mode, add_optab, temp, op0, NULL_RTX,
|
||
0, OPTAB_LIB_WIDEN);
|
||
return expand_shift (RSHIFT_EXPR, mode, temp, shift, NULL_RTX, 0);
|
||
}
|
||
|
||
label = gen_label_rtx ();
|
||
temp = copy_to_mode_reg (mode, op0);
|
||
do_cmp_and_jump (temp, const0_rtx, GE, mode, label);
|
||
expand_inc (temp, GEN_INT (d - 1));
|
||
emit_label (label);
|
||
return expand_shift (RSHIFT_EXPR, mode, temp, shift, NULL_RTX, 0);
|
||
}
|
||
|
||
/* Emit the code to divide OP0 by OP1, putting the result in TARGET
|
||
if that is convenient, and returning where the result is.
|
||
You may request either the quotient or the remainder as the result;
|
||
specify REM_FLAG nonzero to get the remainder.
|
||
|
||
CODE is the expression code for which kind of division this is;
|
||
it controls how rounding is done. MODE is the machine mode to use.
|
||
UNSIGNEDP nonzero means do unsigned division. */
|
||
|
||
/* ??? For CEIL_MOD_EXPR, can compute incorrect remainder with ANDI
|
||
and then correct it by or'ing in missing high bits
|
||
if result of ANDI is nonzero.
|
||
For ROUND_MOD_EXPR, can use ANDI and then sign-extend the result.
|
||
This could optimize to a bfexts instruction.
|
||
But C doesn't use these operations, so their optimizations are
|
||
left for later. */
|
||
/* ??? For modulo, we don't actually need the highpart of the first product,
|
||
the low part will do nicely. And for small divisors, the second multiply
|
||
can also be a low-part only multiply or even be completely left out.
|
||
E.g. to calculate the remainder of a division by 3 with a 32 bit
|
||
multiply, multiply with 0x55555556 and extract the upper two bits;
|
||
the result is exact for inputs up to 0x1fffffff.
|
||
The input range can be reduced by using cross-sum rules.
|
||
For odd divisors >= 3, the following table gives right shift counts
|
||
so that if a number is shifted by an integer multiple of the given
|
||
amount, the remainder stays the same:
|
||
2, 4, 3, 6, 10, 12, 4, 8, 18, 6, 11, 20, 18, 0, 5, 10, 12, 0, 12, 20,
|
||
14, 12, 23, 21, 8, 0, 20, 18, 0, 0, 6, 12, 0, 22, 0, 18, 20, 30, 0, 0,
|
||
0, 8, 0, 11, 12, 10, 36, 0, 30, 0, 0, 12, 0, 0, 0, 0, 44, 12, 24, 0,
|
||
20, 0, 7, 14, 0, 18, 36, 0, 0, 46, 60, 0, 42, 0, 15, 24, 20, 0, 0, 33,
|
||
0, 20, 0, 0, 18, 0, 60, 0, 0, 0, 0, 0, 40, 18, 0, 0, 12
|
||
|
||
Cross-sum rules for even numbers can be derived by leaving as many bits
|
||
to the right alone as the divisor has zeros to the right.
|
||
E.g. if x is an unsigned 32 bit number:
|
||
(x mod 12) == (((x & 1023) + ((x >> 8) & ~3)) * 0x15555558 >> 2 * 3) >> 28
|
||
*/
|
||
|
||
rtx
|
||
expand_divmod (int rem_flag, enum tree_code code, enum machine_mode mode,
|
||
rtx op0, rtx op1, rtx target, int unsignedp)
|
||
{
|
||
enum machine_mode compute_mode;
|
||
rtx tquotient;
|
||
rtx quotient = 0, remainder = 0;
|
||
rtx last;
|
||
int size;
|
||
rtx insn, set;
|
||
optab optab1, optab2;
|
||
int op1_is_constant, op1_is_pow2 = 0;
|
||
int max_cost, extra_cost;
|
||
static HOST_WIDE_INT last_div_const = 0;
|
||
static HOST_WIDE_INT ext_op1;
|
||
|
||
op1_is_constant = GET_CODE (op1) == CONST_INT;
|
||
if (op1_is_constant)
|
||
{
|
||
ext_op1 = INTVAL (op1);
|
||
if (unsignedp)
|
||
ext_op1 &= GET_MODE_MASK (mode);
|
||
op1_is_pow2 = ((EXACT_POWER_OF_2_OR_ZERO_P (ext_op1)
|
||
|| (! unsignedp && EXACT_POWER_OF_2_OR_ZERO_P (-ext_op1))));
|
||
}
|
||
|
||
/*
|
||
This is the structure of expand_divmod:
|
||
|
||
First comes code to fix up the operands so we can perform the operations
|
||
correctly and efficiently.
|
||
|
||
Second comes a switch statement with code specific for each rounding mode.
|
||
For some special operands this code emits all RTL for the desired
|
||
operation, for other cases, it generates only a quotient and stores it in
|
||
QUOTIENT. The case for trunc division/remainder might leave quotient = 0,
|
||
to indicate that it has not done anything.
|
||
|
||
Last comes code that finishes the operation. If QUOTIENT is set and
|
||
REM_FLAG is set, the remainder is computed as OP0 - QUOTIENT * OP1. If
|
||
QUOTIENT is not set, it is computed using trunc rounding.
|
||
|
||
We try to generate special code for division and remainder when OP1 is a
|
||
constant. If |OP1| = 2**n we can use shifts and some other fast
|
||
operations. For other values of OP1, we compute a carefully selected
|
||
fixed-point approximation m = 1/OP1, and generate code that multiplies OP0
|
||
by m.
|
||
|
||
In all cases but EXACT_DIV_EXPR, this multiplication requires the upper
|
||
half of the product. Different strategies for generating the product are
|
||
implemented in expand_mult_highpart.
|
||
|
||
If what we actually want is the remainder, we generate that by another
|
||
by-constant multiplication and a subtraction. */
|
||
|
||
/* We shouldn't be called with OP1 == const1_rtx, but some of the
|
||
code below will malfunction if we are, so check here and handle
|
||
the special case if so. */
|
||
if (op1 == const1_rtx)
|
||
return rem_flag ? const0_rtx : op0;
|
||
|
||
/* When dividing by -1, we could get an overflow.
|
||
negv_optab can handle overflows. */
|
||
if (! unsignedp && op1 == constm1_rtx)
|
||
{
|
||
if (rem_flag)
|
||
return const0_rtx;
|
||
return expand_unop (mode, flag_trapv && GET_MODE_CLASS(mode) == MODE_INT
|
||
? negv_optab : neg_optab, op0, target, 0);
|
||
}
|
||
|
||
if (target
|
||
/* Don't use the function value register as a target
|
||
since we have to read it as well as write it,
|
||
and function-inlining gets confused by this. */
|
||
&& ((REG_P (target) && REG_FUNCTION_VALUE_P (target))
|
||
/* Don't clobber an operand while doing a multi-step calculation. */
|
||
|| ((rem_flag || op1_is_constant)
|
||
&& (reg_mentioned_p (target, op0)
|
||
|| (MEM_P (op0) && MEM_P (target))))
|
||
|| reg_mentioned_p (target, op1)
|
||
|| (MEM_P (op1) && MEM_P (target))))
|
||
target = 0;
|
||
|
||
/* Get the mode in which to perform this computation. Normally it will
|
||
be MODE, but sometimes we can't do the desired operation in MODE.
|
||
If so, pick a wider mode in which we can do the operation. Convert
|
||
to that mode at the start to avoid repeated conversions.
|
||
|
||
First see what operations we need. These depend on the expression
|
||
we are evaluating. (We assume that divxx3 insns exist under the
|
||
same conditions that modxx3 insns and that these insns don't normally
|
||
fail. If these assumptions are not correct, we may generate less
|
||
efficient code in some cases.)
|
||
|
||
Then see if we find a mode in which we can open-code that operation
|
||
(either a division, modulus, or shift). Finally, check for the smallest
|
||
mode for which we can do the operation with a library call. */
|
||
|
||
/* We might want to refine this now that we have division-by-constant
|
||
optimization. Since expand_mult_highpart tries so many variants, it is
|
||
not straightforward to generalize this. Maybe we should make an array
|
||
of possible modes in init_expmed? Save this for GCC 2.7. */
|
||
|
||
optab1 = ((op1_is_pow2 && op1 != const0_rtx)
|
||
? (unsignedp ? lshr_optab : ashr_optab)
|
||
: (unsignedp ? udiv_optab : sdiv_optab));
|
||
optab2 = ((op1_is_pow2 && op1 != const0_rtx)
|
||
? optab1
|
||
: (unsignedp ? udivmod_optab : sdivmod_optab));
|
||
|
||
for (compute_mode = mode; compute_mode != VOIDmode;
|
||
compute_mode = GET_MODE_WIDER_MODE (compute_mode))
|
||
if (optab1->handlers[compute_mode].insn_code != CODE_FOR_nothing
|
||
|| optab2->handlers[compute_mode].insn_code != CODE_FOR_nothing)
|
||
break;
|
||
|
||
if (compute_mode == VOIDmode)
|
||
for (compute_mode = mode; compute_mode != VOIDmode;
|
||
compute_mode = GET_MODE_WIDER_MODE (compute_mode))
|
||
if (optab1->handlers[compute_mode].libfunc
|
||
|| optab2->handlers[compute_mode].libfunc)
|
||
break;
|
||
|
||
/* If we still couldn't find a mode, use MODE, but expand_binop will
|
||
probably die. */
|
||
if (compute_mode == VOIDmode)
|
||
compute_mode = mode;
|
||
|
||
if (target && GET_MODE (target) == compute_mode)
|
||
tquotient = target;
|
||
else
|
||
tquotient = gen_reg_rtx (compute_mode);
|
||
|
||
size = GET_MODE_BITSIZE (compute_mode);
|
||
#if 0
|
||
/* It should be possible to restrict the precision to GET_MODE_BITSIZE
|
||
(mode), and thereby get better code when OP1 is a constant. Do that
|
||
later. It will require going over all usages of SIZE below. */
|
||
size = GET_MODE_BITSIZE (mode);
|
||
#endif
|
||
|
||
/* Only deduct something for a REM if the last divide done was
|
||
for a different constant. Then set the constant of the last
|
||
divide. */
|
||
max_cost = unsignedp ? udiv_cost[compute_mode] : sdiv_cost[compute_mode];
|
||
if (rem_flag && ! (last_div_const != 0 && op1_is_constant
|
||
&& INTVAL (op1) == last_div_const))
|
||
max_cost -= mul_cost[compute_mode] + add_cost[compute_mode];
|
||
|
||
last_div_const = ! rem_flag && op1_is_constant ? INTVAL (op1) : 0;
|
||
|
||
/* Now convert to the best mode to use. */
|
||
if (compute_mode != mode)
|
||
{
|
||
op0 = convert_modes (compute_mode, mode, op0, unsignedp);
|
||
op1 = convert_modes (compute_mode, mode, op1, unsignedp);
|
||
|
||
/* convert_modes may have placed op1 into a register, so we
|
||
must recompute the following. */
|
||
op1_is_constant = GET_CODE (op1) == CONST_INT;
|
||
op1_is_pow2 = (op1_is_constant
|
||
&& ((EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1))
|
||
|| (! unsignedp
|
||
&& EXACT_POWER_OF_2_OR_ZERO_P (-INTVAL (op1)))))) ;
|
||
}
|
||
|
||
/* If one of the operands is a volatile MEM, copy it into a register. */
|
||
|
||
if (MEM_P (op0) && MEM_VOLATILE_P (op0))
|
||
op0 = force_reg (compute_mode, op0);
|
||
if (MEM_P (op1) && MEM_VOLATILE_P (op1))
|
||
op1 = force_reg (compute_mode, op1);
|
||
|
||
/* If we need the remainder or if OP1 is constant, we need to
|
||
put OP0 in a register in case it has any queued subexpressions. */
|
||
if (rem_flag || op1_is_constant)
|
||
op0 = force_reg (compute_mode, op0);
|
||
|
||
last = get_last_insn ();
|
||
|
||
/* Promote floor rounding to trunc rounding for unsigned operations. */
|
||
if (unsignedp)
|
||
{
|
||
if (code == FLOOR_DIV_EXPR)
|
||
code = TRUNC_DIV_EXPR;
|
||
if (code == FLOOR_MOD_EXPR)
|
||
code = TRUNC_MOD_EXPR;
|
||
if (code == EXACT_DIV_EXPR && op1_is_pow2)
|
||
code = TRUNC_DIV_EXPR;
|
||
}
|
||
|
||
if (op1 != const0_rtx)
|
||
switch (code)
|
||
{
|
||
case TRUNC_MOD_EXPR:
|
||
case TRUNC_DIV_EXPR:
|
||
if (op1_is_constant)
|
||
{
|
||
if (unsignedp)
|
||
{
|
||
unsigned HOST_WIDE_INT mh;
|
||
int pre_shift, post_shift;
|
||
int dummy;
|
||
rtx ml;
|
||
unsigned HOST_WIDE_INT d = (INTVAL (op1)
|
||
& GET_MODE_MASK (compute_mode));
|
||
|
||
if (EXACT_POWER_OF_2_OR_ZERO_P (d))
|
||
{
|
||
pre_shift = floor_log2 (d);
|
||
if (rem_flag)
|
||
{
|
||
remainder
|
||
= expand_binop (compute_mode, and_optab, op0,
|
||
GEN_INT (((HOST_WIDE_INT) 1 << pre_shift) - 1),
|
||
remainder, 1,
|
||
OPTAB_LIB_WIDEN);
|
||
if (remainder)
|
||
return gen_lowpart (mode, remainder);
|
||
}
|
||
quotient = expand_shift (RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE,
|
||
pre_shift),
|
||
tquotient, 1);
|
||
}
|
||
else if (size <= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
if (d >= ((unsigned HOST_WIDE_INT) 1 << (size - 1)))
|
||
{
|
||
/* Most significant bit of divisor is set; emit an scc
|
||
insn. */
|
||
quotient = emit_store_flag (tquotient, GEU, op0, op1,
|
||
compute_mode, 1, 1);
|
||
if (quotient == 0)
|
||
goto fail1;
|
||
}
|
||
else
|
||
{
|
||
/* Find a suitable multiplier and right shift count
|
||
instead of multiplying with D. */
|
||
|
||
mh = choose_multiplier (d, size, size,
|
||
&ml, &post_shift, &dummy);
|
||
|
||
/* If the suggested multiplier is more than SIZE bits,
|
||
we can do better for even divisors, using an
|
||
initial right shift. */
|
||
if (mh != 0 && (d & 1) == 0)
|
||
{
|
||
pre_shift = floor_log2 (d & -d);
|
||
mh = choose_multiplier (d >> pre_shift, size,
|
||
size - pre_shift,
|
||
&ml, &post_shift, &dummy);
|
||
gcc_assert (!mh);
|
||
}
|
||
else
|
||
pre_shift = 0;
|
||
|
||
if (mh != 0)
|
||
{
|
||
rtx t1, t2, t3, t4;
|
||
|
||
if (post_shift - 1 >= BITS_PER_WORD)
|
||
goto fail1;
|
||
|
||
extra_cost
|
||
= (shift_cost[compute_mode][post_shift - 1]
|
||
+ shift_cost[compute_mode][1]
|
||
+ 2 * add_cost[compute_mode]);
|
||
t1 = expand_mult_highpart (compute_mode, op0, ml,
|
||
NULL_RTX, 1,
|
||
max_cost - extra_cost);
|
||
if (t1 == 0)
|
||
goto fail1;
|
||
t2 = force_operand (gen_rtx_MINUS (compute_mode,
|
||
op0, t1),
|
||
NULL_RTX);
|
||
t3 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, t2,
|
||
build_int_cst (NULL_TREE, 1),
|
||
NULL_RTX,1);
|
||
t4 = force_operand (gen_rtx_PLUS (compute_mode,
|
||
t1, t3),
|
||
NULL_RTX);
|
||
quotient = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, t4,
|
||
build_int_cst (NULL_TREE, post_shift - 1),
|
||
tquotient, 1);
|
||
}
|
||
else
|
||
{
|
||
rtx t1, t2;
|
||
|
||
if (pre_shift >= BITS_PER_WORD
|
||
|| post_shift >= BITS_PER_WORD)
|
||
goto fail1;
|
||
|
||
t1 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, pre_shift),
|
||
NULL_RTX, 1);
|
||
extra_cost
|
||
= (shift_cost[compute_mode][pre_shift]
|
||
+ shift_cost[compute_mode][post_shift]);
|
||
t2 = expand_mult_highpart (compute_mode, t1, ml,
|
||
NULL_RTX, 1,
|
||
max_cost - extra_cost);
|
||
if (t2 == 0)
|
||
goto fail1;
|
||
quotient = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, t2,
|
||
build_int_cst (NULL_TREE, post_shift),
|
||
tquotient, 1);
|
||
}
|
||
}
|
||
}
|
||
else /* Too wide mode to use tricky code */
|
||
break;
|
||
|
||
insn = get_last_insn ();
|
||
if (insn != last
|
||
&& (set = single_set (insn)) != 0
|
||
&& SET_DEST (set) == quotient)
|
||
set_unique_reg_note (insn,
|
||
REG_EQUAL,
|
||
gen_rtx_UDIV (compute_mode, op0, op1));
|
||
}
|
||
else /* TRUNC_DIV, signed */
|
||
{
|
||
unsigned HOST_WIDE_INT ml;
|
||
int lgup, post_shift;
|
||
rtx mlr;
|
||
HOST_WIDE_INT d = INTVAL (op1);
|
||
unsigned HOST_WIDE_INT abs_d = d >= 0 ? d : -d;
|
||
|
||
/* n rem d = n rem -d */
|
||
if (rem_flag && d < 0)
|
||
{
|
||
d = abs_d;
|
||
op1 = gen_int_mode (abs_d, compute_mode);
|
||
}
|
||
|
||
if (d == 1)
|
||
quotient = op0;
|
||
else if (d == -1)
|
||
quotient = expand_unop (compute_mode, neg_optab, op0,
|
||
tquotient, 0);
|
||
else if (abs_d == (unsigned HOST_WIDE_INT) 1 << (size - 1))
|
||
{
|
||
/* This case is not handled correctly below. */
|
||
quotient = emit_store_flag (tquotient, EQ, op0, op1,
|
||
compute_mode, 1, 1);
|
||
if (quotient == 0)
|
||
goto fail1;
|
||
}
|
||
else if (EXACT_POWER_OF_2_OR_ZERO_P (d)
|
||
&& (rem_flag ? smod_pow2_cheap[compute_mode]
|
||
: sdiv_pow2_cheap[compute_mode])
|
||
/* We assume that cheap metric is true if the
|
||
optab has an expander for this mode. */
|
||
&& (((rem_flag ? smod_optab : sdiv_optab)
|
||
->handlers[compute_mode].insn_code
|
||
!= CODE_FOR_nothing)
|
||
|| (sdivmod_optab->handlers[compute_mode]
|
||
.insn_code != CODE_FOR_nothing)))
|
||
;
|
||
else if (EXACT_POWER_OF_2_OR_ZERO_P (abs_d))
|
||
{
|
||
if (rem_flag)
|
||
{
|
||
remainder = expand_smod_pow2 (compute_mode, op0, d);
|
||
if (remainder)
|
||
return gen_lowpart (mode, remainder);
|
||
}
|
||
|
||
if (sdiv_pow2_cheap[compute_mode]
|
||
&& ((sdiv_optab->handlers[compute_mode].insn_code
|
||
!= CODE_FOR_nothing)
|
||
|| (sdivmod_optab->handlers[compute_mode].insn_code
|
||
!= CODE_FOR_nothing)))
|
||
quotient = expand_divmod (0, TRUNC_DIV_EXPR,
|
||
compute_mode, op0,
|
||
gen_int_mode (abs_d,
|
||
compute_mode),
|
||
NULL_RTX, 0);
|
||
else
|
||
quotient = expand_sdiv_pow2 (compute_mode, op0, abs_d);
|
||
|
||
/* We have computed OP0 / abs(OP1). If OP1 is negative,
|
||
negate the quotient. */
|
||
if (d < 0)
|
||
{
|
||
insn = get_last_insn ();
|
||
if (insn != last
|
||
&& (set = single_set (insn)) != 0
|
||
&& SET_DEST (set) == quotient
|
||
&& abs_d < ((unsigned HOST_WIDE_INT) 1
|
||
<< (HOST_BITS_PER_WIDE_INT - 1)))
|
||
set_unique_reg_note (insn,
|
||
REG_EQUAL,
|
||
gen_rtx_DIV (compute_mode,
|
||
op0,
|
||
GEN_INT
|
||
(trunc_int_for_mode
|
||
(abs_d,
|
||
compute_mode))));
|
||
|
||
quotient = expand_unop (compute_mode, neg_optab,
|
||
quotient, quotient, 0);
|
||
}
|
||
}
|
||
else if (size <= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
choose_multiplier (abs_d, size, size - 1,
|
||
&mlr, &post_shift, &lgup);
|
||
ml = (unsigned HOST_WIDE_INT) INTVAL (mlr);
|
||
if (ml < (unsigned HOST_WIDE_INT) 1 << (size - 1))
|
||
{
|
||
rtx t1, t2, t3;
|
||
|
||
if (post_shift >= BITS_PER_WORD
|
||
|| size - 1 >= BITS_PER_WORD)
|
||
goto fail1;
|
||
|
||
extra_cost = (shift_cost[compute_mode][post_shift]
|
||
+ shift_cost[compute_mode][size - 1]
|
||
+ add_cost[compute_mode]);
|
||
t1 = expand_mult_highpart (compute_mode, op0, mlr,
|
||
NULL_RTX, 0,
|
||
max_cost - extra_cost);
|
||
if (t1 == 0)
|
||
goto fail1;
|
||
t2 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, t1,
|
||
build_int_cst (NULL_TREE, post_shift),
|
||
NULL_RTX, 0);
|
||
t3 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, size - 1),
|
||
NULL_RTX, 0);
|
||
if (d < 0)
|
||
quotient
|
||
= force_operand (gen_rtx_MINUS (compute_mode,
|
||
t3, t2),
|
||
tquotient);
|
||
else
|
||
quotient
|
||
= force_operand (gen_rtx_MINUS (compute_mode,
|
||
t2, t3),
|
||
tquotient);
|
||
}
|
||
else
|
||
{
|
||
rtx t1, t2, t3, t4;
|
||
|
||
if (post_shift >= BITS_PER_WORD
|
||
|| size - 1 >= BITS_PER_WORD)
|
||
goto fail1;
|
||
|
||
ml |= (~(unsigned HOST_WIDE_INT) 0) << (size - 1);
|
||
mlr = gen_int_mode (ml, compute_mode);
|
||
extra_cost = (shift_cost[compute_mode][post_shift]
|
||
+ shift_cost[compute_mode][size - 1]
|
||
+ 2 * add_cost[compute_mode]);
|
||
t1 = expand_mult_highpart (compute_mode, op0, mlr,
|
||
NULL_RTX, 0,
|
||
max_cost - extra_cost);
|
||
if (t1 == 0)
|
||
goto fail1;
|
||
t2 = force_operand (gen_rtx_PLUS (compute_mode,
|
||
t1, op0),
|
||
NULL_RTX);
|
||
t3 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, t2,
|
||
build_int_cst (NULL_TREE, post_shift),
|
||
NULL_RTX, 0);
|
||
t4 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, size - 1),
|
||
NULL_RTX, 0);
|
||
if (d < 0)
|
||
quotient
|
||
= force_operand (gen_rtx_MINUS (compute_mode,
|
||
t4, t3),
|
||
tquotient);
|
||
else
|
||
quotient
|
||
= force_operand (gen_rtx_MINUS (compute_mode,
|
||
t3, t4),
|
||
tquotient);
|
||
}
|
||
}
|
||
else /* Too wide mode to use tricky code */
|
||
break;
|
||
|
||
insn = get_last_insn ();
|
||
if (insn != last
|
||
&& (set = single_set (insn)) != 0
|
||
&& SET_DEST (set) == quotient)
|
||
set_unique_reg_note (insn,
|
||
REG_EQUAL,
|
||
gen_rtx_DIV (compute_mode, op0, op1));
|
||
}
|
||
break;
|
||
}
|
||
fail1:
|
||
delete_insns_since (last);
|
||
break;
|
||
|
||
case FLOOR_DIV_EXPR:
|
||
case FLOOR_MOD_EXPR:
|
||
/* We will come here only for signed operations. */
|
||
if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size)
|
||
{
|
||
unsigned HOST_WIDE_INT mh;
|
||
int pre_shift, lgup, post_shift;
|
||
HOST_WIDE_INT d = INTVAL (op1);
|
||
rtx ml;
|
||
|
||
if (d > 0)
|
||
{
|
||
/* We could just as easily deal with negative constants here,
|
||
but it does not seem worth the trouble for GCC 2.6. */
|
||
if (EXACT_POWER_OF_2_OR_ZERO_P (d))
|
||
{
|
||
pre_shift = floor_log2 (d);
|
||
if (rem_flag)
|
||
{
|
||
remainder = expand_binop (compute_mode, and_optab, op0,
|
||
GEN_INT (((HOST_WIDE_INT) 1 << pre_shift) - 1),
|
||
remainder, 0, OPTAB_LIB_WIDEN);
|
||
if (remainder)
|
||
return gen_lowpart (mode, remainder);
|
||
}
|
||
quotient = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, pre_shift),
|
||
tquotient, 0);
|
||
}
|
||
else
|
||
{
|
||
rtx t1, t2, t3, t4;
|
||
|
||
mh = choose_multiplier (d, size, size - 1,
|
||
&ml, &post_shift, &lgup);
|
||
gcc_assert (!mh);
|
||
|
||
if (post_shift < BITS_PER_WORD
|
||
&& size - 1 < BITS_PER_WORD)
|
||
{
|
||
t1 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, size - 1),
|
||
NULL_RTX, 0);
|
||
t2 = expand_binop (compute_mode, xor_optab, op0, t1,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
extra_cost = (shift_cost[compute_mode][post_shift]
|
||
+ shift_cost[compute_mode][size - 1]
|
||
+ 2 * add_cost[compute_mode]);
|
||
t3 = expand_mult_highpart (compute_mode, t2, ml,
|
||
NULL_RTX, 1,
|
||
max_cost - extra_cost);
|
||
if (t3 != 0)
|
||
{
|
||
t4 = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, t3,
|
||
build_int_cst (NULL_TREE, post_shift),
|
||
NULL_RTX, 1);
|
||
quotient = expand_binop (compute_mode, xor_optab,
|
||
t4, t1, tquotient, 0,
|
||
OPTAB_WIDEN);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
rtx nsign, t1, t2, t3, t4;
|
||
t1 = force_operand (gen_rtx_PLUS (compute_mode,
|
||
op0, constm1_rtx), NULL_RTX);
|
||
t2 = expand_binop (compute_mode, ior_optab, op0, t1, NULL_RTX,
|
||
0, OPTAB_WIDEN);
|
||
nsign = expand_shift
|
||
(RSHIFT_EXPR, compute_mode, t2,
|
||
build_int_cst (NULL_TREE, size - 1),
|
||
NULL_RTX, 0);
|
||
t3 = force_operand (gen_rtx_MINUS (compute_mode, t1, nsign),
|
||
NULL_RTX);
|
||
t4 = expand_divmod (0, TRUNC_DIV_EXPR, compute_mode, t3, op1,
|
||
NULL_RTX, 0);
|
||
if (t4)
|
||
{
|
||
rtx t5;
|
||
t5 = expand_unop (compute_mode, one_cmpl_optab, nsign,
|
||
NULL_RTX, 0);
|
||
quotient = force_operand (gen_rtx_PLUS (compute_mode,
|
||
t4, t5),
|
||
tquotient);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (quotient != 0)
|
||
break;
|
||
delete_insns_since (last);
|
||
|
||
/* Try using an instruction that produces both the quotient and
|
||
remainder, using truncation. We can easily compensate the quotient
|
||
or remainder to get floor rounding, once we have the remainder.
|
||
Notice that we compute also the final remainder value here,
|
||
and return the result right away. */
|
||
if (target == 0 || GET_MODE (target) != compute_mode)
|
||
target = gen_reg_rtx (compute_mode);
|
||
|
||
if (rem_flag)
|
||
{
|
||
remainder
|
||
= REG_P (target) ? target : gen_reg_rtx (compute_mode);
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
}
|
||
else
|
||
{
|
||
quotient
|
||
= REG_P (target) ? target : gen_reg_rtx (compute_mode);
|
||
remainder = gen_reg_rtx (compute_mode);
|
||
}
|
||
|
||
if (expand_twoval_binop (sdivmod_optab, op0, op1,
|
||
quotient, remainder, 0))
|
||
{
|
||
/* This could be computed with a branch-less sequence.
|
||
Save that for later. */
|
||
rtx tem;
|
||
rtx label = gen_label_rtx ();
|
||
do_cmp_and_jump (remainder, const0_rtx, EQ, compute_mode, label);
|
||
tem = expand_binop (compute_mode, xor_optab, op0, op1,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
do_cmp_and_jump (tem, const0_rtx, GE, compute_mode, label);
|
||
expand_dec (quotient, const1_rtx);
|
||
expand_inc (remainder, op1);
|
||
emit_label (label);
|
||
return gen_lowpart (mode, rem_flag ? remainder : quotient);
|
||
}
|
||
|
||
/* No luck with division elimination or divmod. Have to do it
|
||
by conditionally adjusting op0 *and* the result. */
|
||
{
|
||
rtx label1, label2, label3, label4, label5;
|
||
rtx adjusted_op0;
|
||
rtx tem;
|
||
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
adjusted_op0 = copy_to_mode_reg (compute_mode, op0);
|
||
label1 = gen_label_rtx ();
|
||
label2 = gen_label_rtx ();
|
||
label3 = gen_label_rtx ();
|
||
label4 = gen_label_rtx ();
|
||
label5 = gen_label_rtx ();
|
||
do_cmp_and_jump (op1, const0_rtx, LT, compute_mode, label2);
|
||
do_cmp_and_jump (adjusted_op0, const0_rtx, LT, compute_mode, label1);
|
||
tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1,
|
||
quotient, 0, OPTAB_LIB_WIDEN);
|
||
if (tem != quotient)
|
||
emit_move_insn (quotient, tem);
|
||
emit_jump_insn (gen_jump (label5));
|
||
emit_barrier ();
|
||
emit_label (label1);
|
||
expand_inc (adjusted_op0, const1_rtx);
|
||
emit_jump_insn (gen_jump (label4));
|
||
emit_barrier ();
|
||
emit_label (label2);
|
||
do_cmp_and_jump (adjusted_op0, const0_rtx, GT, compute_mode, label3);
|
||
tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1,
|
||
quotient, 0, OPTAB_LIB_WIDEN);
|
||
if (tem != quotient)
|
||
emit_move_insn (quotient, tem);
|
||
emit_jump_insn (gen_jump (label5));
|
||
emit_barrier ();
|
||
emit_label (label3);
|
||
expand_dec (adjusted_op0, const1_rtx);
|
||
emit_label (label4);
|
||
tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1,
|
||
quotient, 0, OPTAB_LIB_WIDEN);
|
||
if (tem != quotient)
|
||
emit_move_insn (quotient, tem);
|
||
expand_dec (quotient, const1_rtx);
|
||
emit_label (label5);
|
||
}
|
||
break;
|
||
|
||
case CEIL_DIV_EXPR:
|
||
case CEIL_MOD_EXPR:
|
||
if (unsignedp)
|
||
{
|
||
if (op1_is_constant && EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1)))
|
||
{
|
||
rtx t1, t2, t3;
|
||
unsigned HOST_WIDE_INT d = INTVAL (op1);
|
||
t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, floor_log2 (d)),
|
||
tquotient, 1);
|
||
t2 = expand_binop (compute_mode, and_optab, op0,
|
||
GEN_INT (d - 1),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
t3 = gen_reg_rtx (compute_mode);
|
||
t3 = emit_store_flag (t3, NE, t2, const0_rtx,
|
||
compute_mode, 1, 1);
|
||
if (t3 == 0)
|
||
{
|
||
rtx lab;
|
||
lab = gen_label_rtx ();
|
||
do_cmp_and_jump (t2, const0_rtx, EQ, compute_mode, lab);
|
||
expand_inc (t1, const1_rtx);
|
||
emit_label (lab);
|
||
quotient = t1;
|
||
}
|
||
else
|
||
quotient = force_operand (gen_rtx_PLUS (compute_mode,
|
||
t1, t3),
|
||
tquotient);
|
||
break;
|
||
}
|
||
|
||
/* Try using an instruction that produces both the quotient and
|
||
remainder, using truncation. We can easily compensate the
|
||
quotient or remainder to get ceiling rounding, once we have the
|
||
remainder. Notice that we compute also the final remainder
|
||
value here, and return the result right away. */
|
||
if (target == 0 || GET_MODE (target) != compute_mode)
|
||
target = gen_reg_rtx (compute_mode);
|
||
|
||
if (rem_flag)
|
||
{
|
||
remainder = (REG_P (target)
|
||
? target : gen_reg_rtx (compute_mode));
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
}
|
||
else
|
||
{
|
||
quotient = (REG_P (target)
|
||
? target : gen_reg_rtx (compute_mode));
|
||
remainder = gen_reg_rtx (compute_mode);
|
||
}
|
||
|
||
if (expand_twoval_binop (udivmod_optab, op0, op1, quotient,
|
||
remainder, 1))
|
||
{
|
||
/* This could be computed with a branch-less sequence.
|
||
Save that for later. */
|
||
rtx label = gen_label_rtx ();
|
||
do_cmp_and_jump (remainder, const0_rtx, EQ,
|
||
compute_mode, label);
|
||
expand_inc (quotient, const1_rtx);
|
||
expand_dec (remainder, op1);
|
||
emit_label (label);
|
||
return gen_lowpart (mode, rem_flag ? remainder : quotient);
|
||
}
|
||
|
||
/* No luck with division elimination or divmod. Have to do it
|
||
by conditionally adjusting op0 *and* the result. */
|
||
{
|
||
rtx label1, label2;
|
||
rtx adjusted_op0, tem;
|
||
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
adjusted_op0 = copy_to_mode_reg (compute_mode, op0);
|
||
label1 = gen_label_rtx ();
|
||
label2 = gen_label_rtx ();
|
||
do_cmp_and_jump (adjusted_op0, const0_rtx, NE,
|
||
compute_mode, label1);
|
||
emit_move_insn (quotient, const0_rtx);
|
||
emit_jump_insn (gen_jump (label2));
|
||
emit_barrier ();
|
||
emit_label (label1);
|
||
expand_dec (adjusted_op0, const1_rtx);
|
||
tem = expand_binop (compute_mode, udiv_optab, adjusted_op0, op1,
|
||
quotient, 1, OPTAB_LIB_WIDEN);
|
||
if (tem != quotient)
|
||
emit_move_insn (quotient, tem);
|
||
expand_inc (quotient, const1_rtx);
|
||
emit_label (label2);
|
||
}
|
||
}
|
||
else /* signed */
|
||
{
|
||
if (op1_is_constant && EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1))
|
||
&& INTVAL (op1) >= 0)
|
||
{
|
||
/* This is extremely similar to the code for the unsigned case
|
||
above. For 2.7 we should merge these variants, but for
|
||
2.6.1 I don't want to touch the code for unsigned since that
|
||
get used in C. The signed case will only be used by other
|
||
languages (Ada). */
|
||
|
||
rtx t1, t2, t3;
|
||
unsigned HOST_WIDE_INT d = INTVAL (op1);
|
||
t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, floor_log2 (d)),
|
||
tquotient, 0);
|
||
t2 = expand_binop (compute_mode, and_optab, op0,
|
||
GEN_INT (d - 1),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
t3 = gen_reg_rtx (compute_mode);
|
||
t3 = emit_store_flag (t3, NE, t2, const0_rtx,
|
||
compute_mode, 1, 1);
|
||
if (t3 == 0)
|
||
{
|
||
rtx lab;
|
||
lab = gen_label_rtx ();
|
||
do_cmp_and_jump (t2, const0_rtx, EQ, compute_mode, lab);
|
||
expand_inc (t1, const1_rtx);
|
||
emit_label (lab);
|
||
quotient = t1;
|
||
}
|
||
else
|
||
quotient = force_operand (gen_rtx_PLUS (compute_mode,
|
||
t1, t3),
|
||
tquotient);
|
||
break;
|
||
}
|
||
|
||
/* Try using an instruction that produces both the quotient and
|
||
remainder, using truncation. We can easily compensate the
|
||
quotient or remainder to get ceiling rounding, once we have the
|
||
remainder. Notice that we compute also the final remainder
|
||
value here, and return the result right away. */
|
||
if (target == 0 || GET_MODE (target) != compute_mode)
|
||
target = gen_reg_rtx (compute_mode);
|
||
if (rem_flag)
|
||
{
|
||
remainder= (REG_P (target)
|
||
? target : gen_reg_rtx (compute_mode));
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
}
|
||
else
|
||
{
|
||
quotient = (REG_P (target)
|
||
? target : gen_reg_rtx (compute_mode));
|
||
remainder = gen_reg_rtx (compute_mode);
|
||
}
|
||
|
||
if (expand_twoval_binop (sdivmod_optab, op0, op1, quotient,
|
||
remainder, 0))
|
||
{
|
||
/* This could be computed with a branch-less sequence.
|
||
Save that for later. */
|
||
rtx tem;
|
||
rtx label = gen_label_rtx ();
|
||
do_cmp_and_jump (remainder, const0_rtx, EQ,
|
||
compute_mode, label);
|
||
tem = expand_binop (compute_mode, xor_optab, op0, op1,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
do_cmp_and_jump (tem, const0_rtx, LT, compute_mode, label);
|
||
expand_inc (quotient, const1_rtx);
|
||
expand_dec (remainder, op1);
|
||
emit_label (label);
|
||
return gen_lowpart (mode, rem_flag ? remainder : quotient);
|
||
}
|
||
|
||
/* No luck with division elimination or divmod. Have to do it
|
||
by conditionally adjusting op0 *and* the result. */
|
||
{
|
||
rtx label1, label2, label3, label4, label5;
|
||
rtx adjusted_op0;
|
||
rtx tem;
|
||
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
adjusted_op0 = copy_to_mode_reg (compute_mode, op0);
|
||
label1 = gen_label_rtx ();
|
||
label2 = gen_label_rtx ();
|
||
label3 = gen_label_rtx ();
|
||
label4 = gen_label_rtx ();
|
||
label5 = gen_label_rtx ();
|
||
do_cmp_and_jump (op1, const0_rtx, LT, compute_mode, label2);
|
||
do_cmp_and_jump (adjusted_op0, const0_rtx, GT,
|
||
compute_mode, label1);
|
||
tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1,
|
||
quotient, 0, OPTAB_LIB_WIDEN);
|
||
if (tem != quotient)
|
||
emit_move_insn (quotient, tem);
|
||
emit_jump_insn (gen_jump (label5));
|
||
emit_barrier ();
|
||
emit_label (label1);
|
||
expand_dec (adjusted_op0, const1_rtx);
|
||
emit_jump_insn (gen_jump (label4));
|
||
emit_barrier ();
|
||
emit_label (label2);
|
||
do_cmp_and_jump (adjusted_op0, const0_rtx, LT,
|
||
compute_mode, label3);
|
||
tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1,
|
||
quotient, 0, OPTAB_LIB_WIDEN);
|
||
if (tem != quotient)
|
||
emit_move_insn (quotient, tem);
|
||
emit_jump_insn (gen_jump (label5));
|
||
emit_barrier ();
|
||
emit_label (label3);
|
||
expand_inc (adjusted_op0, const1_rtx);
|
||
emit_label (label4);
|
||
tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1,
|
||
quotient, 0, OPTAB_LIB_WIDEN);
|
||
if (tem != quotient)
|
||
emit_move_insn (quotient, tem);
|
||
expand_inc (quotient, const1_rtx);
|
||
emit_label (label5);
|
||
}
|
||
}
|
||
break;
|
||
|
||
case EXACT_DIV_EXPR:
|
||
if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size)
|
||
{
|
||
HOST_WIDE_INT d = INTVAL (op1);
|
||
unsigned HOST_WIDE_INT ml;
|
||
int pre_shift;
|
||
rtx t1;
|
||
|
||
pre_shift = floor_log2 (d & -d);
|
||
ml = invert_mod2n (d >> pre_shift, size);
|
||
t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0,
|
||
build_int_cst (NULL_TREE, pre_shift),
|
||
NULL_RTX, unsignedp);
|
||
quotient = expand_mult (compute_mode, t1,
|
||
gen_int_mode (ml, compute_mode),
|
||
NULL_RTX, 1);
|
||
|
||
insn = get_last_insn ();
|
||
set_unique_reg_note (insn,
|
||
REG_EQUAL,
|
||
gen_rtx_fmt_ee (unsignedp ? UDIV : DIV,
|
||
compute_mode,
|
||
op0, op1));
|
||
}
|
||
break;
|
||
|
||
case ROUND_DIV_EXPR:
|
||
case ROUND_MOD_EXPR:
|
||
if (unsignedp)
|
||
{
|
||
rtx tem;
|
||
rtx label;
|
||
label = gen_label_rtx ();
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
remainder = gen_reg_rtx (compute_mode);
|
||
if (expand_twoval_binop (udivmod_optab, op0, op1, quotient, remainder, 1) == 0)
|
||
{
|
||
rtx tem;
|
||
quotient = expand_binop (compute_mode, udiv_optab, op0, op1,
|
||
quotient, 1, OPTAB_LIB_WIDEN);
|
||
tem = expand_mult (compute_mode, quotient, op1, NULL_RTX, 1);
|
||
remainder = expand_binop (compute_mode, sub_optab, op0, tem,
|
||
remainder, 1, OPTAB_LIB_WIDEN);
|
||
}
|
||
tem = plus_constant (op1, -1);
|
||
tem = expand_shift (RSHIFT_EXPR, compute_mode, tem,
|
||
build_int_cst (NULL_TREE, 1),
|
||
NULL_RTX, 1);
|
||
do_cmp_and_jump (remainder, tem, LEU, compute_mode, label);
|
||
expand_inc (quotient, const1_rtx);
|
||
expand_dec (remainder, op1);
|
||
emit_label (label);
|
||
}
|
||
else
|
||
{
|
||
rtx abs_rem, abs_op1, tem, mask;
|
||
rtx label;
|
||
label = gen_label_rtx ();
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
remainder = gen_reg_rtx (compute_mode);
|
||
if (expand_twoval_binop (sdivmod_optab, op0, op1, quotient, remainder, 0) == 0)
|
||
{
|
||
rtx tem;
|
||
quotient = expand_binop (compute_mode, sdiv_optab, op0, op1,
|
||
quotient, 0, OPTAB_LIB_WIDEN);
|
||
tem = expand_mult (compute_mode, quotient, op1, NULL_RTX, 0);
|
||
remainder = expand_binop (compute_mode, sub_optab, op0, tem,
|
||
remainder, 0, OPTAB_LIB_WIDEN);
|
||
}
|
||
abs_rem = expand_abs (compute_mode, remainder, NULL_RTX, 1, 0);
|
||
abs_op1 = expand_abs (compute_mode, op1, NULL_RTX, 1, 0);
|
||
tem = expand_shift (LSHIFT_EXPR, compute_mode, abs_rem,
|
||
build_int_cst (NULL_TREE, 1),
|
||
NULL_RTX, 1);
|
||
do_cmp_and_jump (tem, abs_op1, LTU, compute_mode, label);
|
||
tem = expand_binop (compute_mode, xor_optab, op0, op1,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
mask = expand_shift (RSHIFT_EXPR, compute_mode, tem,
|
||
build_int_cst (NULL_TREE, size - 1),
|
||
NULL_RTX, 0);
|
||
tem = expand_binop (compute_mode, xor_optab, mask, const1_rtx,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
tem = expand_binop (compute_mode, sub_optab, tem, mask,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
expand_inc (quotient, tem);
|
||
tem = expand_binop (compute_mode, xor_optab, mask, op1,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
tem = expand_binop (compute_mode, sub_optab, tem, mask,
|
||
NULL_RTX, 0, OPTAB_WIDEN);
|
||
expand_dec (remainder, tem);
|
||
emit_label (label);
|
||
}
|
||
return gen_lowpart (mode, rem_flag ? remainder : quotient);
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
|
||
if (quotient == 0)
|
||
{
|
||
if (target && GET_MODE (target) != compute_mode)
|
||
target = 0;
|
||
|
||
if (rem_flag)
|
||
{
|
||
/* Try to produce the remainder without producing the quotient.
|
||
If we seem to have a divmod pattern that does not require widening,
|
||
don't try widening here. We should really have a WIDEN argument
|
||
to expand_twoval_binop, since what we'd really like to do here is
|
||
1) try a mod insn in compute_mode
|
||
2) try a divmod insn in compute_mode
|
||
3) try a div insn in compute_mode and multiply-subtract to get
|
||
remainder
|
||
4) try the same things with widening allowed. */
|
||
remainder
|
||
= sign_expand_binop (compute_mode, umod_optab, smod_optab,
|
||
op0, op1, target,
|
||
unsignedp,
|
||
((optab2->handlers[compute_mode].insn_code
|
||
!= CODE_FOR_nothing)
|
||
? OPTAB_DIRECT : OPTAB_WIDEN));
|
||
if (remainder == 0)
|
||
{
|
||
/* No luck there. Can we do remainder and divide at once
|
||
without a library call? */
|
||
remainder = gen_reg_rtx (compute_mode);
|
||
if (! expand_twoval_binop ((unsignedp
|
||
? udivmod_optab
|
||
: sdivmod_optab),
|
||
op0, op1,
|
||
NULL_RTX, remainder, unsignedp))
|
||
remainder = 0;
|
||
}
|
||
|
||
if (remainder)
|
||
return gen_lowpart (mode, remainder);
|
||
}
|
||
|
||
/* Produce the quotient. Try a quotient insn, but not a library call.
|
||
If we have a divmod in this mode, use it in preference to widening
|
||
the div (for this test we assume it will not fail). Note that optab2
|
||
is set to the one of the two optabs that the call below will use. */
|
||
quotient
|
||
= sign_expand_binop (compute_mode, udiv_optab, sdiv_optab,
|
||
op0, op1, rem_flag ? NULL_RTX : target,
|
||
unsignedp,
|
||
((optab2->handlers[compute_mode].insn_code
|
||
!= CODE_FOR_nothing)
|
||
? OPTAB_DIRECT : OPTAB_WIDEN));
|
||
|
||
if (quotient == 0)
|
||
{
|
||
/* No luck there. Try a quotient-and-remainder insn,
|
||
keeping the quotient alone. */
|
||
quotient = gen_reg_rtx (compute_mode);
|
||
if (! expand_twoval_binop (unsignedp ? udivmod_optab : sdivmod_optab,
|
||
op0, op1,
|
||
quotient, NULL_RTX, unsignedp))
|
||
{
|
||
quotient = 0;
|
||
if (! rem_flag)
|
||
/* Still no luck. If we are not computing the remainder,
|
||
use a library call for the quotient. */
|
||
quotient = sign_expand_binop (compute_mode,
|
||
udiv_optab, sdiv_optab,
|
||
op0, op1, target,
|
||
unsignedp, OPTAB_LIB_WIDEN);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (rem_flag)
|
||
{
|
||
if (target && GET_MODE (target) != compute_mode)
|
||
target = 0;
|
||
|
||
if (quotient == 0)
|
||
{
|
||
/* No divide instruction either. Use library for remainder. */
|
||
remainder = sign_expand_binop (compute_mode, umod_optab, smod_optab,
|
||
op0, op1, target,
|
||
unsignedp, OPTAB_LIB_WIDEN);
|
||
/* No remainder function. Try a quotient-and-remainder
|
||
function, keeping the remainder. */
|
||
if (!remainder)
|
||
{
|
||
remainder = gen_reg_rtx (compute_mode);
|
||
if (!expand_twoval_binop_libfunc
|
||
(unsignedp ? udivmod_optab : sdivmod_optab,
|
||
op0, op1,
|
||
NULL_RTX, remainder,
|
||
unsignedp ? UMOD : MOD))
|
||
remainder = NULL_RTX;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* We divided. Now finish doing X - Y * (X / Y). */
|
||
remainder = expand_mult (compute_mode, quotient, op1,
|
||
NULL_RTX, unsignedp);
|
||
remainder = expand_binop (compute_mode, sub_optab, op0,
|
||
remainder, target, unsignedp,
|
||
OPTAB_LIB_WIDEN);
|
||
}
|
||
}
|
||
|
||
return gen_lowpart (mode, rem_flag ? remainder : quotient);
|
||
}
|
||
|
||
/* Return a tree node with data type TYPE, describing the value of X.
|
||
Usually this is an VAR_DECL, if there is no obvious better choice.
|
||
X may be an expression, however we only support those expressions
|
||
generated by loop.c. */
|
||
|
||
tree
|
||
make_tree (tree type, rtx x)
|
||
{
|
||
tree t;
|
||
|
||
switch (GET_CODE (x))
|
||
{
|
||
case CONST_INT:
|
||
{
|
||
HOST_WIDE_INT hi = 0;
|
||
|
||
if (INTVAL (x) < 0
|
||
&& !(TYPE_UNSIGNED (type)
|
||
&& (GET_MODE_BITSIZE (TYPE_MODE (type))
|
||
< HOST_BITS_PER_WIDE_INT)))
|
||
hi = -1;
|
||
|
||
t = build_int_cst_wide (type, INTVAL (x), hi);
|
||
|
||
return t;
|
||
}
|
||
|
||
case CONST_DOUBLE:
|
||
if (GET_MODE (x) == VOIDmode)
|
||
t = build_int_cst_wide (type,
|
||
CONST_DOUBLE_LOW (x), CONST_DOUBLE_HIGH (x));
|
||
else
|
||
{
|
||
REAL_VALUE_TYPE d;
|
||
|
||
REAL_VALUE_FROM_CONST_DOUBLE (d, x);
|
||
t = build_real (type, d);
|
||
}
|
||
|
||
return t;
|
||
|
||
case CONST_VECTOR:
|
||
{
|
||
int units = CONST_VECTOR_NUNITS (x);
|
||
tree itype = TREE_TYPE (type);
|
||
tree t = NULL_TREE;
|
||
int i;
|
||
|
||
|
||
/* Build a tree with vector elements. */
|
||
for (i = units - 1; i >= 0; --i)
|
||
{
|
||
rtx elt = CONST_VECTOR_ELT (x, i);
|
||
t = tree_cons (NULL_TREE, make_tree (itype, elt), t);
|
||
}
|
||
|
||
return build_vector (type, t);
|
||
}
|
||
|
||
case PLUS:
|
||
return fold_build2 (PLUS_EXPR, type, make_tree (type, XEXP (x, 0)),
|
||
make_tree (type, XEXP (x, 1)));
|
||
|
||
case MINUS:
|
||
return fold_build2 (MINUS_EXPR, type, make_tree (type, XEXP (x, 0)),
|
||
make_tree (type, XEXP (x, 1)));
|
||
|
||
case NEG:
|
||
return fold_build1 (NEGATE_EXPR, type, make_tree (type, XEXP (x, 0)));
|
||
|
||
case MULT:
|
||
return fold_build2 (MULT_EXPR, type, make_tree (type, XEXP (x, 0)),
|
||
make_tree (type, XEXP (x, 1)));
|
||
|
||
case ASHIFT:
|
||
return fold_build2 (LSHIFT_EXPR, type, make_tree (type, XEXP (x, 0)),
|
||
make_tree (type, XEXP (x, 1)));
|
||
|
||
case LSHIFTRT:
|
||
t = lang_hooks.types.unsigned_type (type);
|
||
return fold_convert (type, build2 (RSHIFT_EXPR, t,
|
||
make_tree (t, XEXP (x, 0)),
|
||
make_tree (type, XEXP (x, 1))));
|
||
|
||
case ASHIFTRT:
|
||
t = lang_hooks.types.signed_type (type);
|
||
return fold_convert (type, build2 (RSHIFT_EXPR, t,
|
||
make_tree (t, XEXP (x, 0)),
|
||
make_tree (type, XEXP (x, 1))));
|
||
|
||
case DIV:
|
||
if (TREE_CODE (type) != REAL_TYPE)
|
||
t = lang_hooks.types.signed_type (type);
|
||
else
|
||
t = type;
|
||
|
||
return fold_convert (type, build2 (TRUNC_DIV_EXPR, t,
|
||
make_tree (t, XEXP (x, 0)),
|
||
make_tree (t, XEXP (x, 1))));
|
||
case UDIV:
|
||
t = lang_hooks.types.unsigned_type (type);
|
||
return fold_convert (type, build2 (TRUNC_DIV_EXPR, t,
|
||
make_tree (t, XEXP (x, 0)),
|
||
make_tree (t, XEXP (x, 1))));
|
||
|
||
case SIGN_EXTEND:
|
||
case ZERO_EXTEND:
|
||
t = lang_hooks.types.type_for_mode (GET_MODE (XEXP (x, 0)),
|
||
GET_CODE (x) == ZERO_EXTEND);
|
||
return fold_convert (type, make_tree (t, XEXP (x, 0)));
|
||
|
||
case CONST:
|
||
return make_tree (type, XEXP (x, 0));
|
||
|
||
case SYMBOL_REF:
|
||
t = SYMBOL_REF_DECL (x);
|
||
if (t)
|
||
return fold_convert (type, build_fold_addr_expr (t));
|
||
/* else fall through. */
|
||
|
||
default:
|
||
t = build_decl (VAR_DECL, NULL_TREE, type);
|
||
|
||
/* If TYPE is a POINTER_TYPE, X might be Pmode with TYPE_MODE being
|
||
ptr_mode. So convert. */
|
||
if (POINTER_TYPE_P (type))
|
||
x = convert_memory_address (TYPE_MODE (type), x);
|
||
|
||
/* Note that we do *not* use SET_DECL_RTL here, because we do not
|
||
want set_decl_rtl to go adjusting REG_ATTRS for this temporary. */
|
||
t->decl_with_rtl.rtl = x;
|
||
|
||
return t;
|
||
}
|
||
}
|
||
|
||
/* Compute the logical-and of OP0 and OP1, storing it in TARGET
|
||
and returning TARGET.
|
||
|
||
If TARGET is 0, a pseudo-register or constant is returned. */
|
||
|
||
rtx
|
||
expand_and (enum machine_mode mode, rtx op0, rtx op1, rtx target)
|
||
{
|
||
rtx tem = 0;
|
||
|
||
if (GET_MODE (op0) == VOIDmode && GET_MODE (op1) == VOIDmode)
|
||
tem = simplify_binary_operation (AND, mode, op0, op1);
|
||
if (tem == 0)
|
||
tem = expand_binop (mode, and_optab, op0, op1, target, 0, OPTAB_LIB_WIDEN);
|
||
|
||
if (target == 0)
|
||
target = tem;
|
||
else if (tem != target)
|
||
emit_move_insn (target, tem);
|
||
return target;
|
||
}
|
||
|
||
/* Emit a store-flags instruction for comparison CODE on OP0 and OP1
|
||
and storing in TARGET. Normally return TARGET.
|
||
Return 0 if that cannot be done.
|
||
|
||
MODE is the mode to use for OP0 and OP1 should they be CONST_INTs. If
|
||
it is VOIDmode, they cannot both be CONST_INT.
|
||
|
||
UNSIGNEDP is for the case where we have to widen the operands
|
||
to perform the operation. It says to use zero-extension.
|
||
|
||
NORMALIZEP is 1 if we should convert the result to be either zero
|
||
or one. Normalize is -1 if we should convert the result to be
|
||
either zero or -1. If NORMALIZEP is zero, the result will be left
|
||
"raw" out of the scc insn. */
|
||
|
||
rtx
|
||
emit_store_flag (rtx target, enum rtx_code code, rtx op0, rtx op1,
|
||
enum machine_mode mode, int unsignedp, int normalizep)
|
||
{
|
||
rtx subtarget;
|
||
enum insn_code icode;
|
||
enum machine_mode compare_mode;
|
||
enum machine_mode target_mode = GET_MODE (target);
|
||
rtx tem;
|
||
rtx last = get_last_insn ();
|
||
rtx pattern, comparison;
|
||
|
||
if (unsignedp)
|
||
code = unsigned_condition (code);
|
||
|
||
/* If one operand is constant, make it the second one. Only do this
|
||
if the other operand is not constant as well. */
|
||
|
||
if (swap_commutative_operands_p (op0, op1))
|
||
{
|
||
tem = op0;
|
||
op0 = op1;
|
||
op1 = tem;
|
||
code = swap_condition (code);
|
||
}
|
||
|
||
if (mode == VOIDmode)
|
||
mode = GET_MODE (op0);
|
||
|
||
/* For some comparisons with 1 and -1, we can convert this to
|
||
comparisons with zero. This will often produce more opportunities for
|
||
store-flag insns. */
|
||
|
||
switch (code)
|
||
{
|
||
case LT:
|
||
if (op1 == const1_rtx)
|
||
op1 = const0_rtx, code = LE;
|
||
break;
|
||
case LE:
|
||
if (op1 == constm1_rtx)
|
||
op1 = const0_rtx, code = LT;
|
||
break;
|
||
case GE:
|
||
if (op1 == const1_rtx)
|
||
op1 = const0_rtx, code = GT;
|
||
break;
|
||
case GT:
|
||
if (op1 == constm1_rtx)
|
||
op1 = const0_rtx, code = GE;
|
||
break;
|
||
case GEU:
|
||
if (op1 == const1_rtx)
|
||
op1 = const0_rtx, code = NE;
|
||
break;
|
||
case LTU:
|
||
if (op1 == const1_rtx)
|
||
op1 = const0_rtx, code = EQ;
|
||
break;
|
||
default:
|
||
break;
|
||
}
|
||
|
||
/* If we are comparing a double-word integer with zero or -1, we can
|
||
convert the comparison into one involving a single word. */
|
||
if (GET_MODE_BITSIZE (mode) == BITS_PER_WORD * 2
|
||
&& GET_MODE_CLASS (mode) == MODE_INT
|
||
&& (!MEM_P (op0) || ! MEM_VOLATILE_P (op0)))
|
||
{
|
||
if ((code == EQ || code == NE)
|
||
&& (op1 == const0_rtx || op1 == constm1_rtx))
|
||
{
|
||
rtx op00, op01, op0both;
|
||
|
||
/* Do a logical OR or AND of the two words and compare the result. */
|
||
op00 = simplify_gen_subreg (word_mode, op0, mode, 0);
|
||
op01 = simplify_gen_subreg (word_mode, op0, mode, UNITS_PER_WORD);
|
||
op0both = expand_binop (word_mode,
|
||
op1 == const0_rtx ? ior_optab : and_optab,
|
||
op00, op01, NULL_RTX, unsignedp, OPTAB_DIRECT);
|
||
|
||
if (op0both != 0)
|
||
return emit_store_flag (target, code, op0both, op1, word_mode,
|
||
unsignedp, normalizep);
|
||
}
|
||
else if ((code == LT || code == GE) && op1 == const0_rtx)
|
||
{
|
||
rtx op0h;
|
||
|
||
/* If testing the sign bit, can just test on high word. */
|
||
op0h = simplify_gen_subreg (word_mode, op0, mode,
|
||
subreg_highpart_offset (word_mode, mode));
|
||
return emit_store_flag (target, code, op0h, op1, word_mode,
|
||
unsignedp, normalizep);
|
||
}
|
||
}
|
||
|
||
/* From now on, we won't change CODE, so set ICODE now. */
|
||
icode = setcc_gen_code[(int) code];
|
||
|
||
/* If this is A < 0 or A >= 0, we can do this by taking the ones
|
||
complement of A (for GE) and shifting the sign bit to the low bit. */
|
||
if (op1 == const0_rtx && (code == LT || code == GE)
|
||
&& GET_MODE_CLASS (mode) == MODE_INT
|
||
&& (normalizep || STORE_FLAG_VALUE == 1
|
||
|| (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
|
||
&& ((STORE_FLAG_VALUE & GET_MODE_MASK (mode))
|
||
== (unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1)))))
|
||
{
|
||
subtarget = target;
|
||
|
||
/* If the result is to be wider than OP0, it is best to convert it
|
||
first. If it is to be narrower, it is *incorrect* to convert it
|
||
first. */
|
||
if (GET_MODE_SIZE (target_mode) > GET_MODE_SIZE (mode))
|
||
{
|
||
op0 = convert_modes (target_mode, mode, op0, 0);
|
||
mode = target_mode;
|
||
}
|
||
|
||
if (target_mode != mode)
|
||
subtarget = 0;
|
||
|
||
if (code == GE)
|
||
op0 = expand_unop (mode, one_cmpl_optab, op0,
|
||
((STORE_FLAG_VALUE == 1 || normalizep)
|
||
? 0 : subtarget), 0);
|
||
|
||
if (STORE_FLAG_VALUE == 1 || normalizep)
|
||
/* If we are supposed to produce a 0/1 value, we want to do
|
||
a logical shift from the sign bit to the low-order bit; for
|
||
a -1/0 value, we do an arithmetic shift. */
|
||
op0 = expand_shift (RSHIFT_EXPR, mode, op0,
|
||
size_int (GET_MODE_BITSIZE (mode) - 1),
|
||
subtarget, normalizep != -1);
|
||
|
||
if (mode != target_mode)
|
||
op0 = convert_modes (target_mode, mode, op0, 0);
|
||
|
||
return op0;
|
||
}
|
||
|
||
if (icode != CODE_FOR_nothing)
|
||
{
|
||
insn_operand_predicate_fn pred;
|
||
|
||
/* We think we may be able to do this with a scc insn. Emit the
|
||
comparison and then the scc insn. */
|
||
|
||
do_pending_stack_adjust ();
|
||
last = get_last_insn ();
|
||
|
||
comparison
|
||
= compare_from_rtx (op0, op1, code, unsignedp, mode, NULL_RTX);
|
||
if (CONSTANT_P (comparison))
|
||
{
|
||
switch (GET_CODE (comparison))
|
||
{
|
||
case CONST_INT:
|
||
if (comparison == const0_rtx)
|
||
return const0_rtx;
|
||
break;
|
||
|
||
#ifdef FLOAT_STORE_FLAG_VALUE
|
||
case CONST_DOUBLE:
|
||
if (comparison == CONST0_RTX (GET_MODE (comparison)))
|
||
return const0_rtx;
|
||
break;
|
||
#endif
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
|
||
if (normalizep == 1)
|
||
return const1_rtx;
|
||
if (normalizep == -1)
|
||
return constm1_rtx;
|
||
return const_true_rtx;
|
||
}
|
||
|
||
/* The code of COMPARISON may not match CODE if compare_from_rtx
|
||
decided to swap its operands and reverse the original code.
|
||
|
||
We know that compare_from_rtx returns either a CONST_INT or
|
||
a new comparison code, so it is safe to just extract the
|
||
code from COMPARISON. */
|
||
code = GET_CODE (comparison);
|
||
|
||
/* Get a reference to the target in the proper mode for this insn. */
|
||
compare_mode = insn_data[(int) icode].operand[0].mode;
|
||
subtarget = target;
|
||
pred = insn_data[(int) icode].operand[0].predicate;
|
||
if (optimize || ! (*pred) (subtarget, compare_mode))
|
||
subtarget = gen_reg_rtx (compare_mode);
|
||
|
||
pattern = GEN_FCN (icode) (subtarget);
|
||
if (pattern)
|
||
{
|
||
emit_insn (pattern);
|
||
|
||
/* If we are converting to a wider mode, first convert to
|
||
TARGET_MODE, then normalize. This produces better combining
|
||
opportunities on machines that have a SIGN_EXTRACT when we are
|
||
testing a single bit. This mostly benefits the 68k.
|
||
|
||
If STORE_FLAG_VALUE does not have the sign bit set when
|
||
interpreted in COMPARE_MODE, we can do this conversion as
|
||
unsigned, which is usually more efficient. */
|
||
if (GET_MODE_SIZE (target_mode) > GET_MODE_SIZE (compare_mode))
|
||
{
|
||
convert_move (target, subtarget,
|
||
(GET_MODE_BITSIZE (compare_mode)
|
||
<= HOST_BITS_PER_WIDE_INT)
|
||
&& 0 == (STORE_FLAG_VALUE
|
||
& ((HOST_WIDE_INT) 1
|
||
<< (GET_MODE_BITSIZE (compare_mode) -1))));
|
||
op0 = target;
|
||
compare_mode = target_mode;
|
||
}
|
||
else
|
||
op0 = subtarget;
|
||
|
||
/* If we want to keep subexpressions around, don't reuse our
|
||
last target. */
|
||
|
||
if (optimize)
|
||
subtarget = 0;
|
||
|
||
/* Now normalize to the proper value in COMPARE_MODE. Sometimes
|
||
we don't have to do anything. */
|
||
if (normalizep == 0 || normalizep == STORE_FLAG_VALUE)
|
||
;
|
||
/* STORE_FLAG_VALUE might be the most negative number, so write
|
||
the comparison this way to avoid a compiler-time warning. */
|
||
else if (- normalizep == STORE_FLAG_VALUE)
|
||
op0 = expand_unop (compare_mode, neg_optab, op0, subtarget, 0);
|
||
|
||
/* We don't want to use STORE_FLAG_VALUE < 0 below since this
|
||
makes it hard to use a value of just the sign bit due to
|
||
ANSI integer constant typing rules. */
|
||
else if (GET_MODE_BITSIZE (compare_mode) <= HOST_BITS_PER_WIDE_INT
|
||
&& (STORE_FLAG_VALUE
|
||
& ((HOST_WIDE_INT) 1
|
||
<< (GET_MODE_BITSIZE (compare_mode) - 1))))
|
||
op0 = expand_shift (RSHIFT_EXPR, compare_mode, op0,
|
||
size_int (GET_MODE_BITSIZE (compare_mode) - 1),
|
||
subtarget, normalizep == 1);
|
||
else
|
||
{
|
||
gcc_assert (STORE_FLAG_VALUE & 1);
|
||
|
||
op0 = expand_and (compare_mode, op0, const1_rtx, subtarget);
|
||
if (normalizep == -1)
|
||
op0 = expand_unop (compare_mode, neg_optab, op0, op0, 0);
|
||
}
|
||
|
||
/* If we were converting to a smaller mode, do the
|
||
conversion now. */
|
||
if (target_mode != compare_mode)
|
||
{
|
||
convert_move (target, op0, 0);
|
||
return target;
|
||
}
|
||
else
|
||
return op0;
|
||
}
|
||
}
|
||
|
||
delete_insns_since (last);
|
||
|
||
/* If optimizing, use different pseudo registers for each insn, instead
|
||
of reusing the same pseudo. This leads to better CSE, but slows
|
||
down the compiler, since there are more pseudos */
|
||
subtarget = (!optimize
|
||
&& (target_mode == mode)) ? target : NULL_RTX;
|
||
|
||
/* If we reached here, we can't do this with a scc insn. However, there
|
||
are some comparisons that can be done directly. For example, if
|
||
this is an equality comparison of integers, we can try to exclusive-or
|
||
(or subtract) the two operands and use a recursive call to try the
|
||
comparison with zero. Don't do any of these cases if branches are
|
||
very cheap. */
|
||
|
||
if (BRANCH_COST > 0
|
||
&& GET_MODE_CLASS (mode) == MODE_INT && (code == EQ || code == NE)
|
||
&& op1 != const0_rtx)
|
||
{
|
||
tem = expand_binop (mode, xor_optab, op0, op1, subtarget, 1,
|
||
OPTAB_WIDEN);
|
||
|
||
if (tem == 0)
|
||
tem = expand_binop (mode, sub_optab, op0, op1, subtarget, 1,
|
||
OPTAB_WIDEN);
|
||
if (tem != 0)
|
||
tem = emit_store_flag (target, code, tem, const0_rtx,
|
||
mode, unsignedp, normalizep);
|
||
if (tem == 0)
|
||
delete_insns_since (last);
|
||
return tem;
|
||
}
|
||
|
||
/* Some other cases we can do are EQ, NE, LE, and GT comparisons with
|
||
the constant zero. Reject all other comparisons at this point. Only
|
||
do LE and GT if branches are expensive since they are expensive on
|
||
2-operand machines. */
|
||
|
||
if (BRANCH_COST == 0
|
||
|| GET_MODE_CLASS (mode) != MODE_INT || op1 != const0_rtx
|
||
|| (code != EQ && code != NE
|
||
&& (BRANCH_COST <= 1 || (code != LE && code != GT))))
|
||
return 0;
|
||
|
||
/* See what we need to return. We can only return a 1, -1, or the
|
||
sign bit. */
|
||
|
||
if (normalizep == 0)
|
||
{
|
||
if (STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1)
|
||
normalizep = STORE_FLAG_VALUE;
|
||
|
||
else if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
|
||
&& ((STORE_FLAG_VALUE & GET_MODE_MASK (mode))
|
||
== (unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1)))
|
||
;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* Try to put the result of the comparison in the sign bit. Assume we can't
|
||
do the necessary operation below. */
|
||
|
||
tem = 0;
|
||
|
||
/* To see if A <= 0, compute (A | (A - 1)). A <= 0 iff that result has
|
||
the sign bit set. */
|
||
|
||
if (code == LE)
|
||
{
|
||
/* This is destructive, so SUBTARGET can't be OP0. */
|
||
if (rtx_equal_p (subtarget, op0))
|
||
subtarget = 0;
|
||
|
||
tem = expand_binop (mode, sub_optab, op0, const1_rtx, subtarget, 0,
|
||
OPTAB_WIDEN);
|
||
if (tem)
|
||
tem = expand_binop (mode, ior_optab, op0, tem, subtarget, 0,
|
||
OPTAB_WIDEN);
|
||
}
|
||
|
||
/* To see if A > 0, compute (((signed) A) << BITS) - A, where BITS is the
|
||
number of bits in the mode of OP0, minus one. */
|
||
|
||
if (code == GT)
|
||
{
|
||
if (rtx_equal_p (subtarget, op0))
|
||
subtarget = 0;
|
||
|
||
tem = expand_shift (RSHIFT_EXPR, mode, op0,
|
||
size_int (GET_MODE_BITSIZE (mode) - 1),
|
||
subtarget, 0);
|
||
tem = expand_binop (mode, sub_optab, tem, op0, subtarget, 0,
|
||
OPTAB_WIDEN);
|
||
}
|
||
|
||
if (code == EQ || code == NE)
|
||
{
|
||
/* For EQ or NE, one way to do the comparison is to apply an operation
|
||
that converts the operand into a positive number if it is nonzero
|
||
or zero if it was originally zero. Then, for EQ, we subtract 1 and
|
||
for NE we negate. This puts the result in the sign bit. Then we
|
||
normalize with a shift, if needed.
|
||
|
||
Two operations that can do the above actions are ABS and FFS, so try
|
||
them. If that doesn't work, and MODE is smaller than a full word,
|
||
we can use zero-extension to the wider mode (an unsigned conversion)
|
||
as the operation. */
|
||
|
||
/* Note that ABS doesn't yield a positive number for INT_MIN, but
|
||
that is compensated by the subsequent overflow when subtracting
|
||
one / negating. */
|
||
|
||
if (abs_optab->handlers[mode].insn_code != CODE_FOR_nothing)
|
||
tem = expand_unop (mode, abs_optab, op0, subtarget, 1);
|
||
else if (ffs_optab->handlers[mode].insn_code != CODE_FOR_nothing)
|
||
tem = expand_unop (mode, ffs_optab, op0, subtarget, 1);
|
||
else if (GET_MODE_SIZE (mode) < UNITS_PER_WORD)
|
||
{
|
||
tem = convert_modes (word_mode, mode, op0, 1);
|
||
mode = word_mode;
|
||
}
|
||
|
||
if (tem != 0)
|
||
{
|
||
if (code == EQ)
|
||
tem = expand_binop (mode, sub_optab, tem, const1_rtx, subtarget,
|
||
0, OPTAB_WIDEN);
|
||
else
|
||
tem = expand_unop (mode, neg_optab, tem, subtarget, 0);
|
||
}
|
||
|
||
/* If we couldn't do it that way, for NE we can "or" the two's complement
|
||
of the value with itself. For EQ, we take the one's complement of
|
||
that "or", which is an extra insn, so we only handle EQ if branches
|
||
are expensive. */
|
||
|
||
if (tem == 0 && (code == NE || BRANCH_COST > 1))
|
||
{
|
||
if (rtx_equal_p (subtarget, op0))
|
||
subtarget = 0;
|
||
|
||
tem = expand_unop (mode, neg_optab, op0, subtarget, 0);
|
||
tem = expand_binop (mode, ior_optab, tem, op0, subtarget, 0,
|
||
OPTAB_WIDEN);
|
||
|
||
if (tem && code == EQ)
|
||
tem = expand_unop (mode, one_cmpl_optab, tem, subtarget, 0);
|
||
}
|
||
}
|
||
|
||
if (tem && normalizep)
|
||
tem = expand_shift (RSHIFT_EXPR, mode, tem,
|
||
size_int (GET_MODE_BITSIZE (mode) - 1),
|
||
subtarget, normalizep == 1);
|
||
|
||
if (tem)
|
||
{
|
||
if (GET_MODE (tem) != target_mode)
|
||
{
|
||
convert_move (target, tem, 0);
|
||
tem = target;
|
||
}
|
||
else if (!subtarget)
|
||
{
|
||
emit_move_insn (target, tem);
|
||
tem = target;
|
||
}
|
||
}
|
||
else
|
||
delete_insns_since (last);
|
||
|
||
return tem;
|
||
}
|
||
|
||
/* Like emit_store_flag, but always succeeds. */
|
||
|
||
rtx
|
||
emit_store_flag_force (rtx target, enum rtx_code code, rtx op0, rtx op1,
|
||
enum machine_mode mode, int unsignedp, int normalizep)
|
||
{
|
||
rtx tem, label;
|
||
|
||
/* First see if emit_store_flag can do the job. */
|
||
tem = emit_store_flag (target, code, op0, op1, mode, unsignedp, normalizep);
|
||
if (tem != 0)
|
||
return tem;
|
||
|
||
if (normalizep == 0)
|
||
normalizep = 1;
|
||
|
||
/* If this failed, we have to do this with set/compare/jump/set code. */
|
||
|
||
if (!REG_P (target)
|
||
|| reg_mentioned_p (target, op0) || reg_mentioned_p (target, op1))
|
||
target = gen_reg_rtx (GET_MODE (target));
|
||
|
||
emit_move_insn (target, const1_rtx);
|
||
label = gen_label_rtx ();
|
||
do_compare_rtx_and_jump (op0, op1, code, unsignedp, mode, NULL_RTX,
|
||
NULL_RTX, label);
|
||
|
||
emit_move_insn (target, const0_rtx);
|
||
emit_label (label);
|
||
|
||
return target;
|
||
}
|
||
|
||
/* Perform possibly multi-word comparison and conditional jump to LABEL
|
||
if ARG1 OP ARG2 true where ARG1 and ARG2 are of mode MODE. This is
|
||
now a thin wrapper around do_compare_rtx_and_jump. */
|
||
|
||
static void
|
||
do_cmp_and_jump (rtx arg1, rtx arg2, enum rtx_code op, enum machine_mode mode,
|
||
rtx label)
|
||
{
|
||
int unsignedp = (op == LTU || op == LEU || op == GTU || op == GEU);
|
||
do_compare_rtx_and_jump (arg1, arg2, op, unsignedp, mode,
|
||
NULL_RTX, NULL_RTX, label);
|
||
}
|