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1306 lines
39 KiB
C
1306 lines
39 KiB
C
/* Definitions for computing resource usage of specific insns.
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Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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#include "config.h"
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#include "system.h"
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#include "toplev.h"
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#include "rtl.h"
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#include "tm_p.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "function.h"
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#include "regs.h"
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#include "flags.h"
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#include "output.h"
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#include "resource.h"
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#include "except.h"
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#include "insn-attr.h"
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#include "params.h"
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/* This structure is used to record liveness information at the targets or
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fallthrough insns of branches. We will most likely need the information
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at targets again, so save them in a hash table rather than recomputing them
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each time. */
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struct target_info
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{
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int uid; /* INSN_UID of target. */
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struct target_info *next; /* Next info for same hash bucket. */
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HARD_REG_SET live_regs; /* Registers live at target. */
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int block; /* Basic block number containing target. */
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int bb_tick; /* Generation count of basic block info. */
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};
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#define TARGET_HASH_PRIME 257
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/* Indicates what resources are required at the beginning of the epilogue. */
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static struct resources start_of_epilogue_needs;
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/* Indicates what resources are required at function end. */
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static struct resources end_of_function_needs;
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/* Define the hash table itself. */
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static struct target_info **target_hash_table = NULL;
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/* For each basic block, we maintain a generation number of its basic
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block info, which is updated each time we move an insn from the
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target of a jump. This is the generation number indexed by block
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number. */
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static int *bb_ticks;
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/* Marks registers possibly live at the current place being scanned by
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mark_target_live_regs. Also used by update_live_status. */
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static HARD_REG_SET current_live_regs;
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/* Marks registers for which we have seen a REG_DEAD note but no assignment.
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Also only used by the next two functions. */
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static HARD_REG_SET pending_dead_regs;
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static void update_live_status PARAMS ((rtx, rtx, void *));
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static int find_basic_block PARAMS ((rtx, int));
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static rtx next_insn_no_annul PARAMS ((rtx));
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static rtx find_dead_or_set_registers PARAMS ((rtx, struct resources*,
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rtx*, int, struct resources,
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struct resources));
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/* Utility function called from mark_target_live_regs via note_stores.
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It deadens any CLOBBERed registers and livens any SET registers. */
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static void
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update_live_status (dest, x, data)
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rtx dest;
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rtx x;
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void *data ATTRIBUTE_UNUSED;
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{
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int first_regno, last_regno;
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int i;
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if (GET_CODE (dest) != REG
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&& (GET_CODE (dest) != SUBREG || GET_CODE (SUBREG_REG (dest)) != REG))
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return;
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if (GET_CODE (dest) == SUBREG)
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first_regno = subreg_regno (dest);
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else
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first_regno = REGNO (dest);
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last_regno = first_regno + HARD_REGNO_NREGS (first_regno, GET_MODE (dest));
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if (GET_CODE (x) == CLOBBER)
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for (i = first_regno; i < last_regno; i++)
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CLEAR_HARD_REG_BIT (current_live_regs, i);
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else
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for (i = first_regno; i < last_regno; i++)
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{
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SET_HARD_REG_BIT (current_live_regs, i);
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CLEAR_HARD_REG_BIT (pending_dead_regs, i);
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}
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}
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/* Find the number of the basic block with correct live register
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information that starts closest to INSN. Return -1 if we couldn't
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find such a basic block or the beginning is more than
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SEARCH_LIMIT instructions before INSN. Use SEARCH_LIMIT = -1 for
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an unlimited search.
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The delay slot filling code destroys the control-flow graph so,
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instead of finding the basic block containing INSN, we search
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backwards toward a BARRIER where the live register information is
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correct. */
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static int
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find_basic_block (insn, search_limit)
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rtx insn;
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int search_limit;
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{
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int i;
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/* Scan backwards to the previous BARRIER. Then see if we can find a
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label that starts a basic block. Return the basic block number. */
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for (insn = prev_nonnote_insn (insn);
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insn && GET_CODE (insn) != BARRIER && search_limit != 0;
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insn = prev_nonnote_insn (insn), --search_limit)
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;
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/* The closest BARRIER is too far away. */
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if (search_limit == 0)
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return -1;
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/* The start of the function is basic block zero. */
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else if (insn == 0)
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return 0;
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/* See if any of the upcoming CODE_LABELs start a basic block. If we reach
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anything other than a CODE_LABEL or note, we can't find this code. */
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for (insn = next_nonnote_insn (insn);
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insn && GET_CODE (insn) == CODE_LABEL;
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insn = next_nonnote_insn (insn))
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{
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for (i = 0; i < n_basic_blocks; i++)
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if (insn == BLOCK_HEAD (i))
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return i;
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}
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return -1;
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}
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/* Similar to next_insn, but ignores insns in the delay slots of
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an annulled branch. */
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static rtx
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next_insn_no_annul (insn)
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rtx insn;
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{
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if (insn)
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{
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/* If INSN is an annulled branch, skip any insns from the target
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of the branch. */
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if (INSN_ANNULLED_BRANCH_P (insn)
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&& NEXT_INSN (PREV_INSN (insn)) != insn)
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while (INSN_FROM_TARGET_P (NEXT_INSN (insn)))
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insn = NEXT_INSN (insn);
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insn = NEXT_INSN (insn);
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if (insn && GET_CODE (insn) == INSN
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&& GET_CODE (PATTERN (insn)) == SEQUENCE)
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insn = XVECEXP (PATTERN (insn), 0, 0);
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}
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return insn;
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}
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/* Given X, some rtl, and RES, a pointer to a `struct resource', mark
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which resources are referenced by the insn. If INCLUDE_DELAYED_EFFECTS
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is TRUE, resources used by the called routine will be included for
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CALL_INSNs. */
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void
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mark_referenced_resources (x, res, include_delayed_effects)
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rtx x;
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struct resources *res;
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int include_delayed_effects;
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{
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enum rtx_code code = GET_CODE (x);
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int i, j;
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unsigned int r;
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const char *format_ptr;
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/* Handle leaf items for which we set resource flags. Also, special-case
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CALL, SET and CLOBBER operators. */
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switch (code)
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{
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case CONST:
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case CONST_INT:
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case CONST_DOUBLE:
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case CONST_VECTOR:
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case PC:
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case SYMBOL_REF:
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case LABEL_REF:
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return;
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case SUBREG:
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if (GET_CODE (SUBREG_REG (x)) != REG)
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mark_referenced_resources (SUBREG_REG (x), res, 0);
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else
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{
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unsigned int regno = subreg_regno (x);
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unsigned int last_regno
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= regno + HARD_REGNO_NREGS (regno, GET_MODE (x));
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if (last_regno > FIRST_PSEUDO_REGISTER)
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abort ();
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for (r = regno; r < last_regno; r++)
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SET_HARD_REG_BIT (res->regs, r);
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}
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return;
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case REG:
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{
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unsigned int regno = REGNO (x);
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unsigned int last_regno
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= regno + HARD_REGNO_NREGS (regno, GET_MODE (x));
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if (last_regno > FIRST_PSEUDO_REGISTER)
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abort ();
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for (r = regno; r < last_regno; r++)
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SET_HARD_REG_BIT (res->regs, r);
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}
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return;
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case MEM:
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/* If this memory shouldn't change, it really isn't referencing
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memory. */
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if (RTX_UNCHANGING_P (x))
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res->unch_memory = 1;
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else
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res->memory = 1;
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res->volatil |= MEM_VOLATILE_P (x);
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/* Mark registers used to access memory. */
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mark_referenced_resources (XEXP (x, 0), res, 0);
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return;
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case CC0:
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res->cc = 1;
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return;
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case UNSPEC_VOLATILE:
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case ASM_INPUT:
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/* Traditional asm's are always volatile. */
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res->volatil = 1;
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return;
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case TRAP_IF:
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res->volatil = 1;
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break;
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case ASM_OPERANDS:
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res->volatil |= MEM_VOLATILE_P (x);
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/* For all ASM_OPERANDS, we must traverse the vector of input operands.
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We can not just fall through here since then we would be confused
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by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate
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traditional asms unlike their normal usage. */
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for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++)
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mark_referenced_resources (ASM_OPERANDS_INPUT (x, i), res, 0);
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return;
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case CALL:
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/* The first operand will be a (MEM (xxx)) but doesn't really reference
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memory. The second operand may be referenced, though. */
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mark_referenced_resources (XEXP (XEXP (x, 0), 0), res, 0);
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mark_referenced_resources (XEXP (x, 1), res, 0);
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return;
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case SET:
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/* Usually, the first operand of SET is set, not referenced. But
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registers used to access memory are referenced. SET_DEST is
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also referenced if it is a ZERO_EXTRACT or SIGN_EXTRACT. */
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mark_referenced_resources (SET_SRC (x), res, 0);
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x = SET_DEST (x);
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if (GET_CODE (x) == SIGN_EXTRACT
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|| GET_CODE (x) == ZERO_EXTRACT
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|| GET_CODE (x) == STRICT_LOW_PART)
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mark_referenced_resources (x, res, 0);
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else if (GET_CODE (x) == SUBREG)
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x = SUBREG_REG (x);
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if (GET_CODE (x) == MEM)
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mark_referenced_resources (XEXP (x, 0), res, 0);
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return;
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case CLOBBER:
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return;
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case CALL_INSN:
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if (include_delayed_effects)
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{
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/* A CALL references memory, the frame pointer if it exists, the
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stack pointer, any global registers and any registers given in
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USE insns immediately in front of the CALL.
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However, we may have moved some of the parameter loading insns
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into the delay slot of this CALL. If so, the USE's for them
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don't count and should be skipped. */
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rtx insn = PREV_INSN (x);
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rtx sequence = 0;
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int seq_size = 0;
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int i;
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/* If we are part of a delay slot sequence, point at the SEQUENCE. */
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if (NEXT_INSN (insn) != x)
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{
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sequence = PATTERN (NEXT_INSN (insn));
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seq_size = XVECLEN (sequence, 0);
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if (GET_CODE (sequence) != SEQUENCE)
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abort ();
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}
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res->memory = 1;
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SET_HARD_REG_BIT (res->regs, STACK_POINTER_REGNUM);
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if (frame_pointer_needed)
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{
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SET_HARD_REG_BIT (res->regs, FRAME_POINTER_REGNUM);
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#if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
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SET_HARD_REG_BIT (res->regs, HARD_FRAME_POINTER_REGNUM);
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#endif
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}
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for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
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if (global_regs[i])
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SET_HARD_REG_BIT (res->regs, i);
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/* Check for a REG_SETJMP. If it exists, then we must
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assume that this call can need any register.
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This is done to be more conservative about how we handle setjmp.
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We assume that they both use and set all registers. Using all
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registers ensures that a register will not be considered dead
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just because it crosses a setjmp call. A register should be
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considered dead only if the setjmp call returns non-zero. */
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if (find_reg_note (x, REG_SETJMP, NULL))
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SET_HARD_REG_SET (res->regs);
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{
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rtx link;
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for (link = CALL_INSN_FUNCTION_USAGE (x);
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link;
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link = XEXP (link, 1))
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if (GET_CODE (XEXP (link, 0)) == USE)
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{
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for (i = 1; i < seq_size; i++)
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{
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rtx slot_pat = PATTERN (XVECEXP (sequence, 0, i));
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if (GET_CODE (slot_pat) == SET
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&& rtx_equal_p (SET_DEST (slot_pat),
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XEXP (XEXP (link, 0), 0)))
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break;
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}
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if (i >= seq_size)
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mark_referenced_resources (XEXP (XEXP (link, 0), 0),
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res, 0);
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}
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}
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}
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/* ... fall through to other INSN processing ... */
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case INSN:
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case JUMP_INSN:
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#ifdef INSN_REFERENCES_ARE_DELAYED
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if (! include_delayed_effects
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&& INSN_REFERENCES_ARE_DELAYED (x))
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return;
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#endif
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/* No special processing, just speed up. */
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mark_referenced_resources (PATTERN (x), res, include_delayed_effects);
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return;
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default:
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break;
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}
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/* Process each sub-expression and flag what it needs. */
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format_ptr = GET_RTX_FORMAT (code);
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for (i = 0; i < GET_RTX_LENGTH (code); i++)
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switch (*format_ptr++)
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{
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case 'e':
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mark_referenced_resources (XEXP (x, i), res, include_delayed_effects);
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break;
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case 'E':
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for (j = 0; j < XVECLEN (x, i); j++)
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mark_referenced_resources (XVECEXP (x, i, j), res,
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include_delayed_effects);
|
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break;
|
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}
|
||
}
|
||
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||
/* A subroutine of mark_target_live_regs. Search forward from TARGET
|
||
looking for registers that are set before they are used. These are dead.
|
||
Stop after passing a few conditional jumps, and/or a small
|
||
number of unconditional branches. */
|
||
|
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static rtx
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find_dead_or_set_registers (target, res, jump_target, jump_count, set, needed)
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rtx target;
|
||
struct resources *res;
|
||
rtx *jump_target;
|
||
int jump_count;
|
||
struct resources set, needed;
|
||
{
|
||
HARD_REG_SET scratch;
|
||
rtx insn, next;
|
||
rtx jump_insn = 0;
|
||
int i;
|
||
|
||
for (insn = target; insn; insn = next)
|
||
{
|
||
rtx this_jump_insn = insn;
|
||
|
||
next = NEXT_INSN (insn);
|
||
|
||
/* If this instruction can throw an exception, then we don't
|
||
know where we might end up next. That means that we have to
|
||
assume that whatever we have already marked as live really is
|
||
live. */
|
||
if (can_throw_internal (insn))
|
||
break;
|
||
|
||
switch (GET_CODE (insn))
|
||
{
|
||
case CODE_LABEL:
|
||
/* After a label, any pending dead registers that weren't yet
|
||
used can be made dead. */
|
||
AND_COMPL_HARD_REG_SET (pending_dead_regs, needed.regs);
|
||
AND_COMPL_HARD_REG_SET (res->regs, pending_dead_regs);
|
||
CLEAR_HARD_REG_SET (pending_dead_regs);
|
||
|
||
continue;
|
||
|
||
case BARRIER:
|
||
case NOTE:
|
||
continue;
|
||
|
||
case INSN:
|
||
if (GET_CODE (PATTERN (insn)) == USE)
|
||
{
|
||
/* If INSN is a USE made by update_block, we care about the
|
||
underlying insn. Any registers set by the underlying insn
|
||
are live since the insn is being done somewhere else. */
|
||
if (INSN_P (XEXP (PATTERN (insn), 0)))
|
||
mark_set_resources (XEXP (PATTERN (insn), 0), res, 0,
|
||
MARK_SRC_DEST_CALL);
|
||
|
||
/* All other USE insns are to be ignored. */
|
||
continue;
|
||
}
|
||
else if (GET_CODE (PATTERN (insn)) == CLOBBER)
|
||
continue;
|
||
else if (GET_CODE (PATTERN (insn)) == SEQUENCE)
|
||
{
|
||
/* An unconditional jump can be used to fill the delay slot
|
||
of a call, so search for a JUMP_INSN in any position. */
|
||
for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
|
||
{
|
||
this_jump_insn = XVECEXP (PATTERN (insn), 0, i);
|
||
if (GET_CODE (this_jump_insn) == JUMP_INSN)
|
||
break;
|
||
}
|
||
}
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
if (GET_CODE (this_jump_insn) == JUMP_INSN)
|
||
{
|
||
if (jump_count++ < 10)
|
||
{
|
||
if (any_uncondjump_p (this_jump_insn)
|
||
|| GET_CODE (PATTERN (this_jump_insn)) == RETURN)
|
||
{
|
||
next = JUMP_LABEL (this_jump_insn);
|
||
if (jump_insn == 0)
|
||
{
|
||
jump_insn = insn;
|
||
if (jump_target)
|
||
*jump_target = JUMP_LABEL (this_jump_insn);
|
||
}
|
||
}
|
||
else if (any_condjump_p (this_jump_insn))
|
||
{
|
||
struct resources target_set, target_res;
|
||
struct resources fallthrough_res;
|
||
|
||
/* We can handle conditional branches here by following
|
||
both paths, and then IOR the results of the two paths
|
||
together, which will give us registers that are dead
|
||
on both paths. Since this is expensive, we give it
|
||
a much higher cost than unconditional branches. The
|
||
cost was chosen so that we will follow at most 1
|
||
conditional branch. */
|
||
|
||
jump_count += 4;
|
||
if (jump_count >= 10)
|
||
break;
|
||
|
||
mark_referenced_resources (insn, &needed, 1);
|
||
|
||
/* For an annulled branch, mark_set_resources ignores slots
|
||
filled by instructions from the target. This is correct
|
||
if the branch is not taken. Since we are following both
|
||
paths from the branch, we must also compute correct info
|
||
if the branch is taken. We do this by inverting all of
|
||
the INSN_FROM_TARGET_P bits, calling mark_set_resources,
|
||
and then inverting the INSN_FROM_TARGET_P bits again. */
|
||
|
||
if (GET_CODE (PATTERN (insn)) == SEQUENCE
|
||
&& INSN_ANNULLED_BRANCH_P (this_jump_insn))
|
||
{
|
||
for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++)
|
||
INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i))
|
||
= ! INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i));
|
||
|
||
target_set = set;
|
||
mark_set_resources (insn, &target_set, 0,
|
||
MARK_SRC_DEST_CALL);
|
||
|
||
for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++)
|
||
INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i))
|
||
= ! INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i));
|
||
|
||
mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL);
|
||
}
|
||
else
|
||
{
|
||
mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL);
|
||
target_set = set;
|
||
}
|
||
|
||
target_res = *res;
|
||
COPY_HARD_REG_SET (scratch, target_set.regs);
|
||
AND_COMPL_HARD_REG_SET (scratch, needed.regs);
|
||
AND_COMPL_HARD_REG_SET (target_res.regs, scratch);
|
||
|
||
fallthrough_res = *res;
|
||
COPY_HARD_REG_SET (scratch, set.regs);
|
||
AND_COMPL_HARD_REG_SET (scratch, needed.regs);
|
||
AND_COMPL_HARD_REG_SET (fallthrough_res.regs, scratch);
|
||
|
||
find_dead_or_set_registers (JUMP_LABEL (this_jump_insn),
|
||
&target_res, 0, jump_count,
|
||
target_set, needed);
|
||
find_dead_or_set_registers (next,
|
||
&fallthrough_res, 0, jump_count,
|
||
set, needed);
|
||
IOR_HARD_REG_SET (fallthrough_res.regs, target_res.regs);
|
||
AND_HARD_REG_SET (res->regs, fallthrough_res.regs);
|
||
break;
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
else
|
||
{
|
||
/* Don't try this optimization if we expired our jump count
|
||
above, since that would mean there may be an infinite loop
|
||
in the function being compiled. */
|
||
jump_insn = 0;
|
||
break;
|
||
}
|
||
}
|
||
|
||
mark_referenced_resources (insn, &needed, 1);
|
||
mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL);
|
||
|
||
COPY_HARD_REG_SET (scratch, set.regs);
|
||
AND_COMPL_HARD_REG_SET (scratch, needed.regs);
|
||
AND_COMPL_HARD_REG_SET (res->regs, scratch);
|
||
}
|
||
|
||
return jump_insn;
|
||
}
|
||
|
||
/* Given X, a part of an insn, and a pointer to a `struct resource',
|
||
RES, indicate which resources are modified by the insn. If
|
||
MARK_TYPE is MARK_SRC_DEST_CALL, also mark resources potentially
|
||
set by the called routine. If MARK_TYPE is MARK_DEST, only mark SET_DESTs
|
||
|
||
If IN_DEST is nonzero, it means we are inside a SET. Otherwise,
|
||
objects are being referenced instead of set.
|
||
|
||
We never mark the insn as modifying the condition code unless it explicitly
|
||
SETs CC0 even though this is not totally correct. The reason for this is
|
||
that we require a SET of CC0 to immediately precede the reference to CC0.
|
||
So if some other insn sets CC0 as a side-effect, we know it cannot affect
|
||
our computation and thus may be placed in a delay slot. */
|
||
|
||
void
|
||
mark_set_resources (x, res, in_dest, mark_type)
|
||
rtx x;
|
||
struct resources *res;
|
||
int in_dest;
|
||
enum mark_resource_type mark_type;
|
||
{
|
||
enum rtx_code code;
|
||
int i, j;
|
||
unsigned int r;
|
||
const char *format_ptr;
|
||
|
||
restart:
|
||
|
||
code = GET_CODE (x);
|
||
|
||
switch (code)
|
||
{
|
||
case NOTE:
|
||
case BARRIER:
|
||
case CODE_LABEL:
|
||
case USE:
|
||
case CONST_INT:
|
||
case CONST_DOUBLE:
|
||
case CONST_VECTOR:
|
||
case LABEL_REF:
|
||
case SYMBOL_REF:
|
||
case CONST:
|
||
case PC:
|
||
/* These don't set any resources. */
|
||
return;
|
||
|
||
case CC0:
|
||
if (in_dest)
|
||
res->cc = 1;
|
||
return;
|
||
|
||
case CALL_INSN:
|
||
/* Called routine modifies the condition code, memory, any registers
|
||
that aren't saved across calls, global registers and anything
|
||
explicitly CLOBBERed immediately after the CALL_INSN. */
|
||
|
||
if (mark_type == MARK_SRC_DEST_CALL)
|
||
{
|
||
rtx link;
|
||
|
||
res->cc = res->memory = 1;
|
||
for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
|
||
if (call_used_regs[r] || global_regs[r])
|
||
SET_HARD_REG_BIT (res->regs, r);
|
||
|
||
for (link = CALL_INSN_FUNCTION_USAGE (x);
|
||
link; link = XEXP (link, 1))
|
||
if (GET_CODE (XEXP (link, 0)) == CLOBBER)
|
||
mark_set_resources (SET_DEST (XEXP (link, 0)), res, 1,
|
||
MARK_SRC_DEST);
|
||
|
||
/* Check for a REG_SETJMP. If it exists, then we must
|
||
assume that this call can clobber any register. */
|
||
if (find_reg_note (x, REG_SETJMP, NULL))
|
||
SET_HARD_REG_SET (res->regs);
|
||
}
|
||
|
||
/* ... and also what its RTL says it modifies, if anything. */
|
||
|
||
case JUMP_INSN:
|
||
case INSN:
|
||
|
||
/* An insn consisting of just a CLOBBER (or USE) is just for flow
|
||
and doesn't actually do anything, so we ignore it. */
|
||
|
||
#ifdef INSN_SETS_ARE_DELAYED
|
||
if (mark_type != MARK_SRC_DEST_CALL
|
||
&& INSN_SETS_ARE_DELAYED (x))
|
||
return;
|
||
#endif
|
||
|
||
x = PATTERN (x);
|
||
if (GET_CODE (x) != USE && GET_CODE (x) != CLOBBER)
|
||
goto restart;
|
||
return;
|
||
|
||
case SET:
|
||
/* If the source of a SET is a CALL, this is actually done by
|
||
the called routine. So only include it if we are to include the
|
||
effects of the calling routine. */
|
||
|
||
mark_set_resources (SET_DEST (x), res,
|
||
(mark_type == MARK_SRC_DEST_CALL
|
||
|| GET_CODE (SET_SRC (x)) != CALL),
|
||
mark_type);
|
||
|
||
if (mark_type != MARK_DEST)
|
||
mark_set_resources (SET_SRC (x), res, 0, MARK_SRC_DEST);
|
||
return;
|
||
|
||
case CLOBBER:
|
||
mark_set_resources (XEXP (x, 0), res, 1, MARK_SRC_DEST);
|
||
return;
|
||
|
||
case SEQUENCE:
|
||
for (i = 0; i < XVECLEN (x, 0); i++)
|
||
if (! (INSN_ANNULLED_BRANCH_P (XVECEXP (x, 0, 0))
|
||
&& INSN_FROM_TARGET_P (XVECEXP (x, 0, i))))
|
||
mark_set_resources (XVECEXP (x, 0, i), res, 0, mark_type);
|
||
return;
|
||
|
||
case POST_INC:
|
||
case PRE_INC:
|
||
case POST_DEC:
|
||
case PRE_DEC:
|
||
mark_set_resources (XEXP (x, 0), res, 1, MARK_SRC_DEST);
|
||
return;
|
||
|
||
case PRE_MODIFY:
|
||
case POST_MODIFY:
|
||
mark_set_resources (XEXP (x, 0), res, 1, MARK_SRC_DEST);
|
||
mark_set_resources (XEXP (XEXP (x, 1), 0), res, 0, MARK_SRC_DEST);
|
||
mark_set_resources (XEXP (XEXP (x, 1), 1), res, 0, MARK_SRC_DEST);
|
||
return;
|
||
|
||
case SIGN_EXTRACT:
|
||
case ZERO_EXTRACT:
|
||
if (! (mark_type == MARK_DEST && in_dest))
|
||
{
|
||
mark_set_resources (XEXP (x, 0), res, in_dest, MARK_SRC_DEST);
|
||
mark_set_resources (XEXP (x, 1), res, 0, MARK_SRC_DEST);
|
||
mark_set_resources (XEXP (x, 2), res, 0, MARK_SRC_DEST);
|
||
}
|
||
return;
|
||
|
||
case MEM:
|
||
if (in_dest)
|
||
{
|
||
res->memory = 1;
|
||
res->unch_memory |= RTX_UNCHANGING_P (x);
|
||
res->volatil |= MEM_VOLATILE_P (x);
|
||
}
|
||
|
||
mark_set_resources (XEXP (x, 0), res, 0, MARK_SRC_DEST);
|
||
return;
|
||
|
||
case SUBREG:
|
||
if (in_dest)
|
||
{
|
||
if (GET_CODE (SUBREG_REG (x)) != REG)
|
||
mark_set_resources (SUBREG_REG (x), res, in_dest, mark_type);
|
||
else
|
||
{
|
||
unsigned int regno = subreg_regno (x);
|
||
unsigned int last_regno
|
||
= regno + HARD_REGNO_NREGS (regno, GET_MODE (x));
|
||
|
||
if (last_regno > FIRST_PSEUDO_REGISTER)
|
||
abort ();
|
||
for (r = regno; r < last_regno; r++)
|
||
SET_HARD_REG_BIT (res->regs, r);
|
||
}
|
||
}
|
||
return;
|
||
|
||
case REG:
|
||
if (in_dest)
|
||
{
|
||
unsigned int regno = REGNO (x);
|
||
unsigned int last_regno
|
||
= regno + HARD_REGNO_NREGS (regno, GET_MODE (x));
|
||
|
||
if (last_regno > FIRST_PSEUDO_REGISTER)
|
||
abort ();
|
||
for (r = regno; r < last_regno; r++)
|
||
SET_HARD_REG_BIT (res->regs, r);
|
||
}
|
||
return;
|
||
|
||
case STRICT_LOW_PART:
|
||
if (! (mark_type == MARK_DEST && in_dest))
|
||
{
|
||
mark_set_resources (XEXP (x, 0), res, 0, MARK_SRC_DEST);
|
||
return;
|
||
}
|
||
|
||
case UNSPEC_VOLATILE:
|
||
case ASM_INPUT:
|
||
/* Traditional asm's are always volatile. */
|
||
res->volatil = 1;
|
||
return;
|
||
|
||
case TRAP_IF:
|
||
res->volatil = 1;
|
||
break;
|
||
|
||
case ASM_OPERANDS:
|
||
res->volatil |= MEM_VOLATILE_P (x);
|
||
|
||
/* For all ASM_OPERANDS, we must traverse the vector of input operands.
|
||
We can not just fall through here since then we would be confused
|
||
by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate
|
||
traditional asms unlike their normal usage. */
|
||
|
||
for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++)
|
||
mark_set_resources (ASM_OPERANDS_INPUT (x, i), res, in_dest,
|
||
MARK_SRC_DEST);
|
||
return;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
/* Process each sub-expression and flag what it needs. */
|
||
format_ptr = GET_RTX_FORMAT (code);
|
||
for (i = 0; i < GET_RTX_LENGTH (code); i++)
|
||
switch (*format_ptr++)
|
||
{
|
||
case 'e':
|
||
mark_set_resources (XEXP (x, i), res, in_dest, mark_type);
|
||
break;
|
||
|
||
case 'E':
|
||
for (j = 0; j < XVECLEN (x, i); j++)
|
||
mark_set_resources (XVECEXP (x, i, j), res, in_dest, mark_type);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Set the resources that are live at TARGET.
|
||
|
||
If TARGET is zero, we refer to the end of the current function and can
|
||
return our precomputed value.
|
||
|
||
Otherwise, we try to find out what is live by consulting the basic block
|
||
information. This is tricky, because we must consider the actions of
|
||
reload and jump optimization, which occur after the basic block information
|
||
has been computed.
|
||
|
||
Accordingly, we proceed as follows::
|
||
|
||
We find the previous BARRIER and look at all immediately following labels
|
||
(with no intervening active insns) to see if any of them start a basic
|
||
block. If we hit the start of the function first, we use block 0.
|
||
|
||
Once we have found a basic block and a corresponding first insns, we can
|
||
accurately compute the live status from basic_block_live_regs and
|
||
reg_renumber. (By starting at a label following a BARRIER, we are immune
|
||
to actions taken by reload and jump.) Then we scan all insns between
|
||
that point and our target. For each CLOBBER (or for call-clobbered regs
|
||
when we pass a CALL_INSN), mark the appropriate registers are dead. For
|
||
a SET, mark them as live.
|
||
|
||
We have to be careful when using REG_DEAD notes because they are not
|
||
updated by such things as find_equiv_reg. So keep track of registers
|
||
marked as dead that haven't been assigned to, and mark them dead at the
|
||
next CODE_LABEL since reload and jump won't propagate values across labels.
|
||
|
||
If we cannot find the start of a basic block (should be a very rare
|
||
case, if it can happen at all), mark everything as potentially live.
|
||
|
||
Next, scan forward from TARGET looking for things set or clobbered
|
||
before they are used. These are not live.
|
||
|
||
Because we can be called many times on the same target, save our results
|
||
in a hash table indexed by INSN_UID. This is only done if the function
|
||
init_resource_info () was invoked before we are called. */
|
||
|
||
void
|
||
mark_target_live_regs (insns, target, res)
|
||
rtx insns;
|
||
rtx target;
|
||
struct resources *res;
|
||
{
|
||
int b = -1;
|
||
unsigned int i;
|
||
struct target_info *tinfo = NULL;
|
||
rtx insn;
|
||
rtx jump_insn = 0;
|
||
rtx jump_target;
|
||
HARD_REG_SET scratch;
|
||
struct resources set, needed;
|
||
|
||
/* Handle end of function. */
|
||
if (target == 0)
|
||
{
|
||
*res = end_of_function_needs;
|
||
return;
|
||
}
|
||
|
||
/* We have to assume memory is needed, but the CC isn't. */
|
||
res->memory = 1;
|
||
res->volatil = res->unch_memory = 0;
|
||
res->cc = 0;
|
||
|
||
/* See if we have computed this value already. */
|
||
if (target_hash_table != NULL)
|
||
{
|
||
for (tinfo = target_hash_table[INSN_UID (target) % TARGET_HASH_PRIME];
|
||
tinfo; tinfo = tinfo->next)
|
||
if (tinfo->uid == INSN_UID (target))
|
||
break;
|
||
|
||
/* Start by getting the basic block number. If we have saved
|
||
information, we can get it from there unless the insn at the
|
||
start of the basic block has been deleted. */
|
||
if (tinfo && tinfo->block != -1
|
||
&& ! INSN_DELETED_P (BLOCK_HEAD (tinfo->block)))
|
||
b = tinfo->block;
|
||
}
|
||
|
||
if (b == -1)
|
||
b = find_basic_block (target, MAX_DELAY_SLOT_LIVE_SEARCH);
|
||
|
||
if (target_hash_table != NULL)
|
||
{
|
||
if (tinfo)
|
||
{
|
||
/* If the information is up-to-date, use it. Otherwise, we will
|
||
update it below. */
|
||
if (b == tinfo->block && b != -1 && tinfo->bb_tick == bb_ticks[b])
|
||
{
|
||
COPY_HARD_REG_SET (res->regs, tinfo->live_regs);
|
||
return;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Allocate a place to put our results and chain it into the
|
||
hash table. */
|
||
tinfo = (struct target_info *) xmalloc (sizeof (struct target_info));
|
||
tinfo->uid = INSN_UID (target);
|
||
tinfo->block = b;
|
||
tinfo->next
|
||
= target_hash_table[INSN_UID (target) % TARGET_HASH_PRIME];
|
||
target_hash_table[INSN_UID (target) % TARGET_HASH_PRIME] = tinfo;
|
||
}
|
||
}
|
||
|
||
CLEAR_HARD_REG_SET (pending_dead_regs);
|
||
|
||
/* If we found a basic block, get the live registers from it and update
|
||
them with anything set or killed between its start and the insn before
|
||
TARGET. Otherwise, we must assume everything is live. */
|
||
if (b != -1)
|
||
{
|
||
regset regs_live = BASIC_BLOCK (b)->global_live_at_start;
|
||
unsigned int j;
|
||
unsigned int regno;
|
||
rtx start_insn, stop_insn;
|
||
|
||
/* Compute hard regs live at start of block -- this is the real hard regs
|
||
marked live, plus live pseudo regs that have been renumbered to
|
||
hard regs. */
|
||
|
||
REG_SET_TO_HARD_REG_SET (current_live_regs, regs_live);
|
||
|
||
EXECUTE_IF_SET_IN_REG_SET
|
||
(regs_live, FIRST_PSEUDO_REGISTER, i,
|
||
{
|
||
if (reg_renumber[i] >= 0)
|
||
{
|
||
regno = reg_renumber[i];
|
||
for (j = regno;
|
||
j < regno + HARD_REGNO_NREGS (regno,
|
||
PSEUDO_REGNO_MODE (i));
|
||
j++)
|
||
SET_HARD_REG_BIT (current_live_regs, j);
|
||
}
|
||
});
|
||
|
||
/* Get starting and ending insn, handling the case where each might
|
||
be a SEQUENCE. */
|
||
start_insn = (b == 0 ? insns : BLOCK_HEAD (b));
|
||
stop_insn = target;
|
||
|
||
if (GET_CODE (start_insn) == INSN
|
||
&& GET_CODE (PATTERN (start_insn)) == SEQUENCE)
|
||
start_insn = XVECEXP (PATTERN (start_insn), 0, 0);
|
||
|
||
if (GET_CODE (stop_insn) == INSN
|
||
&& GET_CODE (PATTERN (stop_insn)) == SEQUENCE)
|
||
stop_insn = next_insn (PREV_INSN (stop_insn));
|
||
|
||
for (insn = start_insn; insn != stop_insn;
|
||
insn = next_insn_no_annul (insn))
|
||
{
|
||
rtx link;
|
||
rtx real_insn = insn;
|
||
|
||
/* If this insn is from the target of a branch, it isn't going to
|
||
be used in the sequel. If it is used in both cases, this
|
||
test will not be true. */
|
||
if (INSN_FROM_TARGET_P (insn))
|
||
continue;
|
||
|
||
/* If this insn is a USE made by update_block, we care about the
|
||
underlying insn. */
|
||
if (GET_CODE (insn) == INSN && GET_CODE (PATTERN (insn)) == USE
|
||
&& INSN_P (XEXP (PATTERN (insn), 0)))
|
||
real_insn = XEXP (PATTERN (insn), 0);
|
||
|
||
if (GET_CODE (real_insn) == CALL_INSN)
|
||
{
|
||
/* CALL clobbers all call-used regs that aren't fixed except
|
||
sp, ap, and fp. Do this before setting the result of the
|
||
call live. */
|
||
AND_COMPL_HARD_REG_SET (current_live_regs,
|
||
regs_invalidated_by_call);
|
||
|
||
/* A CALL_INSN sets any global register live, since it may
|
||
have been modified by the call. */
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
if (global_regs[i])
|
||
SET_HARD_REG_BIT (current_live_regs, i);
|
||
}
|
||
|
||
/* Mark anything killed in an insn to be deadened at the next
|
||
label. Ignore USE insns; the only REG_DEAD notes will be for
|
||
parameters. But they might be early. A CALL_INSN will usually
|
||
clobber registers used for parameters. It isn't worth bothering
|
||
with the unlikely case when it won't. */
|
||
if ((GET_CODE (real_insn) == INSN
|
||
&& GET_CODE (PATTERN (real_insn)) != USE
|
||
&& GET_CODE (PATTERN (real_insn)) != CLOBBER)
|
||
|| GET_CODE (real_insn) == JUMP_INSN
|
||
|| GET_CODE (real_insn) == CALL_INSN)
|
||
{
|
||
for (link = REG_NOTES (real_insn); link; link = XEXP (link, 1))
|
||
if (REG_NOTE_KIND (link) == REG_DEAD
|
||
&& GET_CODE (XEXP (link, 0)) == REG
|
||
&& REGNO (XEXP (link, 0)) < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
unsigned int first_regno = REGNO (XEXP (link, 0));
|
||
unsigned int last_regno
|
||
= (first_regno
|
||
+ HARD_REGNO_NREGS (first_regno,
|
||
GET_MODE (XEXP (link, 0))));
|
||
|
||
for (i = first_regno; i < last_regno; i++)
|
||
SET_HARD_REG_BIT (pending_dead_regs, i);
|
||
}
|
||
|
||
note_stores (PATTERN (real_insn), update_live_status, NULL);
|
||
|
||
/* If any registers were unused after this insn, kill them.
|
||
These notes will always be accurate. */
|
||
for (link = REG_NOTES (real_insn); link; link = XEXP (link, 1))
|
||
if (REG_NOTE_KIND (link) == REG_UNUSED
|
||
&& GET_CODE (XEXP (link, 0)) == REG
|
||
&& REGNO (XEXP (link, 0)) < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
unsigned int first_regno = REGNO (XEXP (link, 0));
|
||
unsigned int last_regno
|
||
= (first_regno
|
||
+ HARD_REGNO_NREGS (first_regno,
|
||
GET_MODE (XEXP (link, 0))));
|
||
|
||
for (i = first_regno; i < last_regno; i++)
|
||
CLEAR_HARD_REG_BIT (current_live_regs, i);
|
||
}
|
||
}
|
||
|
||
else if (GET_CODE (real_insn) == CODE_LABEL)
|
||
{
|
||
/* A label clobbers the pending dead registers since neither
|
||
reload nor jump will propagate a value across a label. */
|
||
AND_COMPL_HARD_REG_SET (current_live_regs, pending_dead_regs);
|
||
CLEAR_HARD_REG_SET (pending_dead_regs);
|
||
}
|
||
|
||
/* The beginning of the epilogue corresponds to the end of the
|
||
RTL chain when there are no epilogue insns. Certain resources
|
||
are implicitly required at that point. */
|
||
else if (GET_CODE (real_insn) == NOTE
|
||
&& NOTE_LINE_NUMBER (real_insn) == NOTE_INSN_EPILOGUE_BEG)
|
||
IOR_HARD_REG_SET (current_live_regs, start_of_epilogue_needs.regs);
|
||
}
|
||
|
||
COPY_HARD_REG_SET (res->regs, current_live_regs);
|
||
if (tinfo != NULL)
|
||
{
|
||
tinfo->block = b;
|
||
tinfo->bb_tick = bb_ticks[b];
|
||
}
|
||
}
|
||
else
|
||
/* We didn't find the start of a basic block. Assume everything
|
||
in use. This should happen only extremely rarely. */
|
||
SET_HARD_REG_SET (res->regs);
|
||
|
||
CLEAR_RESOURCE (&set);
|
||
CLEAR_RESOURCE (&needed);
|
||
|
||
jump_insn = find_dead_or_set_registers (target, res, &jump_target, 0,
|
||
set, needed);
|
||
|
||
/* If we hit an unconditional branch, we have another way of finding out
|
||
what is live: we can see what is live at the branch target and include
|
||
anything used but not set before the branch. We add the live
|
||
resources found using the test below to those found until now. */
|
||
|
||
if (jump_insn)
|
||
{
|
||
struct resources new_resources;
|
||
rtx stop_insn = next_active_insn (jump_insn);
|
||
|
||
mark_target_live_regs (insns, next_active_insn (jump_target),
|
||
&new_resources);
|
||
CLEAR_RESOURCE (&set);
|
||
CLEAR_RESOURCE (&needed);
|
||
|
||
/* Include JUMP_INSN in the needed registers. */
|
||
for (insn = target; insn != stop_insn; insn = next_active_insn (insn))
|
||
{
|
||
mark_referenced_resources (insn, &needed, 1);
|
||
|
||
COPY_HARD_REG_SET (scratch, needed.regs);
|
||
AND_COMPL_HARD_REG_SET (scratch, set.regs);
|
||
IOR_HARD_REG_SET (new_resources.regs, scratch);
|
||
|
||
mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL);
|
||
}
|
||
|
||
IOR_HARD_REG_SET (res->regs, new_resources.regs);
|
||
}
|
||
|
||
if (tinfo != NULL)
|
||
{
|
||
COPY_HARD_REG_SET (tinfo->live_regs, res->regs);
|
||
}
|
||
}
|
||
|
||
/* Initialize the resources required by mark_target_live_regs ().
|
||
This should be invoked before the first call to mark_target_live_regs. */
|
||
|
||
void
|
||
init_resource_info (epilogue_insn)
|
||
rtx epilogue_insn;
|
||
{
|
||
int i;
|
||
|
||
/* Indicate what resources are required to be valid at the end of the current
|
||
function. The condition code never is and memory always is. If the
|
||
frame pointer is needed, it is and so is the stack pointer unless
|
||
EXIT_IGNORE_STACK is non-zero. If the frame pointer is not needed, the
|
||
stack pointer is. Registers used to return the function value are
|
||
needed. Registers holding global variables are needed. */
|
||
|
||
end_of_function_needs.cc = 0;
|
||
end_of_function_needs.memory = 1;
|
||
end_of_function_needs.unch_memory = 0;
|
||
CLEAR_HARD_REG_SET (end_of_function_needs.regs);
|
||
|
||
if (frame_pointer_needed)
|
||
{
|
||
SET_HARD_REG_BIT (end_of_function_needs.regs, FRAME_POINTER_REGNUM);
|
||
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
|
||
SET_HARD_REG_BIT (end_of_function_needs.regs, HARD_FRAME_POINTER_REGNUM);
|
||
#endif
|
||
#ifdef EXIT_IGNORE_STACK
|
||
if (! EXIT_IGNORE_STACK
|
||
|| current_function_sp_is_unchanging)
|
||
#endif
|
||
SET_HARD_REG_BIT (end_of_function_needs.regs, STACK_POINTER_REGNUM);
|
||
}
|
||
else
|
||
SET_HARD_REG_BIT (end_of_function_needs.regs, STACK_POINTER_REGNUM);
|
||
|
||
if (current_function_return_rtx != 0)
|
||
mark_referenced_resources (current_function_return_rtx,
|
||
&end_of_function_needs, 1);
|
||
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
if (global_regs[i]
|
||
#ifdef EPILOGUE_USES
|
||
|| EPILOGUE_USES (i)
|
||
#endif
|
||
)
|
||
SET_HARD_REG_BIT (end_of_function_needs.regs, i);
|
||
|
||
/* The registers required to be live at the end of the function are
|
||
represented in the flow information as being dead just prior to
|
||
reaching the end of the function. For example, the return of a value
|
||
might be represented by a USE of the return register immediately
|
||
followed by an unconditional jump to the return label where the
|
||
return label is the end of the RTL chain. The end of the RTL chain
|
||
is then taken to mean that the return register is live.
|
||
|
||
This sequence is no longer maintained when epilogue instructions are
|
||
added to the RTL chain. To reconstruct the original meaning, the
|
||
start of the epilogue (NOTE_INSN_EPILOGUE_BEG) is regarded as the
|
||
point where these registers become live (start_of_epilogue_needs).
|
||
If epilogue instructions are present, the registers set by those
|
||
instructions won't have been processed by flow. Thus, those
|
||
registers are additionally required at the end of the RTL chain
|
||
(end_of_function_needs). */
|
||
|
||
start_of_epilogue_needs = end_of_function_needs;
|
||
|
||
while ((epilogue_insn = next_nonnote_insn (epilogue_insn)))
|
||
mark_set_resources (epilogue_insn, &end_of_function_needs, 0,
|
||
MARK_SRC_DEST_CALL);
|
||
|
||
/* Allocate and initialize the tables used by mark_target_live_regs. */
|
||
target_hash_table = (struct target_info **)
|
||
xcalloc (TARGET_HASH_PRIME, sizeof (struct target_info *));
|
||
bb_ticks = (int *) xcalloc (n_basic_blocks, sizeof (int));
|
||
}
|
||
|
||
/* Free up the resources allcated to mark_target_live_regs (). This
|
||
should be invoked after the last call to mark_target_live_regs (). */
|
||
|
||
void
|
||
free_resource_info ()
|
||
{
|
||
if (target_hash_table != NULL)
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < TARGET_HASH_PRIME; ++i)
|
||
{
|
||
struct target_info *ti = target_hash_table[i];
|
||
|
||
while (ti)
|
||
{
|
||
struct target_info *next = ti->next;
|
||
free (ti);
|
||
ti = next;
|
||
}
|
||
}
|
||
|
||
free (target_hash_table);
|
||
target_hash_table = NULL;
|
||
}
|
||
|
||
if (bb_ticks != NULL)
|
||
{
|
||
free (bb_ticks);
|
||
bb_ticks = NULL;
|
||
}
|
||
}
|
||
|
||
/* Clear any hashed information that we have stored for INSN. */
|
||
|
||
void
|
||
clear_hashed_info_for_insn (insn)
|
||
rtx insn;
|
||
{
|
||
struct target_info *tinfo;
|
||
|
||
if (target_hash_table != NULL)
|
||
{
|
||
for (tinfo = target_hash_table[INSN_UID (insn) % TARGET_HASH_PRIME];
|
||
tinfo; tinfo = tinfo->next)
|
||
if (tinfo->uid == INSN_UID (insn))
|
||
break;
|
||
|
||
if (tinfo)
|
||
tinfo->block = -1;
|
||
}
|
||
}
|
||
|
||
/* Increment the tick count for the basic block that contains INSN. */
|
||
|
||
void
|
||
incr_ticks_for_insn (insn)
|
||
rtx insn;
|
||
{
|
||
int b = find_basic_block (insn, MAX_DELAY_SLOT_LIVE_SEARCH);
|
||
|
||
if (b != -1)
|
||
bb_ticks[b]++;
|
||
}
|
||
|
||
/* Add TRIAL to the set of resources used at the end of the current
|
||
function. */
|
||
void
|
||
mark_end_of_function_resources (trial, include_delayed_effects)
|
||
rtx trial;
|
||
int include_delayed_effects;
|
||
{
|
||
mark_referenced_resources (trial, &end_of_function_needs,
|
||
include_delayed_effects);
|
||
}
|