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freebsd/contrib/gcc/tree-inline.c
David E. O'Brien 45fc31f8dd Gcc 3.2.1 release virgin vendor import. (19-Nov-2002)
2002-12-04 15:42:16 +00:00

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/* Control and data flow functions for trees.
Copyright 2001, 2002 Free Software Foundation, Inc.
Contributed by Alexandre Oliva <aoliva@redhat.com>
This file is part of GNU CC.
GNU CC 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.
GNU CC 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 GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "toplev.h"
#include "tree.h"
#include "tree-inline.h"
#include "rtl.h"
#include "expr.h"
#include "flags.h"
#include "params.h"
#include "input.h"
#include "insn-config.h"
#include "integrate.h"
#include "varray.h"
#include "hashtab.h"
#include "splay-tree.h"
#include "langhooks.h"
/* This should be eventually be generalized to other languages, but
this would require a shared function-as-trees infrastructure. */
#include "c-common.h"
/* 0 if we should not perform inlining.
1 if we should expand functions calls inline at the tree level.
2 if we should consider *all* functions to be inline
candidates. */
int flag_inline_trees = 0;
/* To Do:
o In order to make inlining-on-trees work, we pessimized
function-local static constants. In particular, they are now
always output, even when not addressed. Fix this by treating
function-local static constants just like global static
constants; the back-end already knows not to output them if they
are not needed.
o Provide heuristics to clamp inlining of recursive template
calls? */
/* Data required for function inlining. */
typedef struct inline_data
{
/* A stack of the functions we are inlining. For example, if we are
compiling `f', which calls `g', which calls `h', and we are
inlining the body of `h', the stack will contain, `h', followed
by `g', followed by `f'. The first few elements of the stack may
contain other functions that we know we should not recurse into,
even though they are not directly being inlined. */
varray_type fns;
/* The index of the first element of FNS that really represents an
inlined function. */
unsigned first_inlined_fn;
/* The label to jump to when a return statement is encountered. If
this value is NULL, then return statements will simply be
remapped as return statements, rather than as jumps. */
tree ret_label;
/* The map from local declarations in the inlined function to
equivalents in the function into which it is being inlined. */
splay_tree decl_map;
/* Nonzero if we are currently within the cleanup for a
TARGET_EXPR. */
int in_target_cleanup_p;
/* A stack of the TARGET_EXPRs that we are currently processing. */
varray_type target_exprs;
/* A list of the functions current function has inlined. */
varray_type inlined_fns;
/* The approximate number of statements we have inlined in the
current call stack. */
int inlined_stmts;
/* We use the same mechanism to build clones that we do to perform
inlining. However, there are a few places where we need to
distinguish between those two situations. This flag is true if
we are cloning, rather than inlining. */
bool cloning_p;
/* Hash table used to prevent walk_tree from visiting the same node
umpteen million times. */
htab_t tree_pruner;
} inline_data;
/* Prototypes. */
static tree initialize_inlined_parameters PARAMS ((inline_data *, tree, tree));
static tree declare_return_variable PARAMS ((inline_data *, tree *));
static tree copy_body_r PARAMS ((tree *, int *, void *));
static tree copy_body PARAMS ((inline_data *));
static tree expand_call_inline PARAMS ((tree *, int *, void *));
static void expand_calls_inline PARAMS ((tree *, inline_data *));
static int inlinable_function_p PARAMS ((tree, inline_data *));
static tree remap_decl PARAMS ((tree, inline_data *));
static void remap_block PARAMS ((tree, tree, inline_data *));
static void copy_scope_stmt PARAMS ((tree *, int *, inline_data *));
/* The approximate number of instructions per statement. This number
need not be particularly accurate; it is used only to make
decisions about when a function is too big to inline. */
#define INSNS_PER_STMT (10)
/* Remap DECL during the copying of the BLOCK tree for the function. */
static tree
remap_decl (decl, id)
tree decl;
inline_data *id;
{
splay_tree_node n;
tree fn;
/* We only remap local variables in the current function. */
fn = VARRAY_TOP_TREE (id->fns);
if (! (*lang_hooks.tree_inlining.auto_var_in_fn_p) (decl, fn))
return NULL_TREE;
/* See if we have remapped this declaration. */
n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
/* If we didn't already have an equivalent for this declaration,
create one now. */
if (!n)
{
tree t;
/* Make a copy of the variable or label. */
t = copy_decl_for_inlining (decl, fn,
VARRAY_TREE (id->fns, 0));
/* The decl T could be a dynamic array or other variable size type,
in which case some fields need to be remapped because they may
contain SAVE_EXPRs. */
if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE
&& TYPE_DOMAIN (TREE_TYPE (t)))
{
TREE_TYPE (t) = copy_node (TREE_TYPE (t));
TYPE_DOMAIN (TREE_TYPE (t))
= copy_node (TYPE_DOMAIN (TREE_TYPE (t)));
walk_tree (&TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t))),
copy_body_r, id, NULL);
}
if (! DECL_NAME (t) && TREE_TYPE (t)
&& (*lang_hooks.tree_inlining.anon_aggr_type_p) (TREE_TYPE (t)))
{
/* For a VAR_DECL of anonymous type, we must also copy the
member VAR_DECLS here and rechain the
DECL_ANON_UNION_ELEMS. */
tree members = NULL;
tree src;
for (src = DECL_ANON_UNION_ELEMS (t); src;
src = TREE_CHAIN (src))
{
tree member = remap_decl (TREE_VALUE (src), id);
if (TREE_PURPOSE (src))
abort ();
members = tree_cons (NULL, member, members);
}
DECL_ANON_UNION_ELEMS (t) = nreverse (members);
}
/* Remember it, so that if we encounter this local entity
again we can reuse this copy. */
n = splay_tree_insert (id->decl_map,
(splay_tree_key) decl,
(splay_tree_value) t);
}
return (tree) n->value;
}
/* Copy the SCOPE_STMT_BLOCK associated with SCOPE_STMT to contain
remapped versions of the variables therein. And hook the new block
into the block-tree. If non-NULL, the DECLS are declarations to
add to use instead of the BLOCK_VARS in the old block. */
static void
remap_block (scope_stmt, decls, id)
tree scope_stmt;
tree decls;
inline_data *id;
{
/* We cannot do this in the cleanup for a TARGET_EXPR since we do
not know whether or not expand_expr will actually write out the
code we put there. If it does not, then we'll have more BLOCKs
than block-notes, and things will go awry. At some point, we
should make the back-end handle BLOCK notes in a tidier way,
without requiring a strict correspondence to the block-tree; then
this check can go. */
if (id->in_target_cleanup_p)
{
SCOPE_STMT_BLOCK (scope_stmt) = NULL_TREE;
return;
}
/* If this is the beginning of a scope, remap the associated BLOCK. */
if (SCOPE_BEGIN_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
{
tree old_block;
tree new_block;
tree old_var;
tree fn;
/* Make the new block. */
old_block = SCOPE_STMT_BLOCK (scope_stmt);
new_block = make_node (BLOCK);
TREE_USED (new_block) = TREE_USED (old_block);
BLOCK_ABSTRACT_ORIGIN (new_block) = old_block;
SCOPE_STMT_BLOCK (scope_stmt) = new_block;
/* Remap its variables. */
for (old_var = decls ? decls : BLOCK_VARS (old_block);
old_var;
old_var = TREE_CHAIN (old_var))
{
tree new_var;
/* Remap the variable. */
new_var = remap_decl (old_var, id);
/* If we didn't remap this variable, so we can't mess with
its TREE_CHAIN. If we remapped this variable to
something other than a declaration (say, if we mapped it
to a constant), then we must similarly omit any mention
of it here. */
if (!new_var || !DECL_P (new_var))
;
else
{
TREE_CHAIN (new_var) = BLOCK_VARS (new_block);
BLOCK_VARS (new_block) = new_var;
}
}
/* We put the BLOCK_VARS in reverse order; fix that now. */
BLOCK_VARS (new_block) = nreverse (BLOCK_VARS (new_block));
fn = VARRAY_TREE (id->fns, 0);
if (id->cloning_p)
/* We're building a clone; DECL_INITIAL is still
error_mark_node, and current_binding_level is the parm
binding level. */
insert_block (new_block);
else
{
/* Attach this new block after the DECL_INITIAL block for the
function into which this block is being inlined. In
rest_of_compilation we will straighten out the BLOCK tree. */
tree *first_block;
if (DECL_INITIAL (fn))
first_block = &BLOCK_CHAIN (DECL_INITIAL (fn));
else
first_block = &DECL_INITIAL (fn);
BLOCK_CHAIN (new_block) = *first_block;
*first_block = new_block;
}
/* Remember the remapped block. */
splay_tree_insert (id->decl_map,
(splay_tree_key) old_block,
(splay_tree_value) new_block);
}
/* If this is the end of a scope, set the SCOPE_STMT_BLOCK to be the
remapped block. */
else if (SCOPE_END_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
{
splay_tree_node n;
/* Find this block in the table of remapped things. */
n = splay_tree_lookup (id->decl_map,
(splay_tree_key) SCOPE_STMT_BLOCK (scope_stmt));
if (! n)
abort ();
SCOPE_STMT_BLOCK (scope_stmt) = (tree) n->value;
}
}
/* Copy the SCOPE_STMT pointed to by TP. */
static void
copy_scope_stmt (tp, walk_subtrees, id)
tree *tp;
int *walk_subtrees;
inline_data *id;
{
tree block;
/* Remember whether or not this statement was nullified. When
making a copy, copy_tree_r always sets SCOPE_NULLIFIED_P (and
doesn't copy the SCOPE_STMT_BLOCK) to free callers from having to
deal with copying BLOCKs if they do not wish to do so. */
block = SCOPE_STMT_BLOCK (*tp);
/* Copy (and replace) the statement. */
copy_tree_r (tp, walk_subtrees, NULL);
/* Restore the SCOPE_STMT_BLOCK. */
SCOPE_STMT_BLOCK (*tp) = block;
/* Remap the associated block. */
remap_block (*tp, NULL_TREE, id);
}
/* Called from copy_body via walk_tree. DATA is really an
`inline_data *'. */
static tree
copy_body_r (tp, walk_subtrees, data)
tree *tp;
int *walk_subtrees;
void *data;
{
inline_data* id;
tree fn;
/* Set up. */
id = (inline_data *) data;
fn = VARRAY_TOP_TREE (id->fns);
#if 0
/* All automatic variables should have a DECL_CONTEXT indicating
what function they come from. */
if ((TREE_CODE (*tp) == VAR_DECL || TREE_CODE (*tp) == LABEL_DECL)
&& DECL_NAMESPACE_SCOPE_P (*tp))
if (! DECL_EXTERNAL (*tp) && ! TREE_STATIC (*tp))
abort ();
#endif
/* If this is a RETURN_STMT, change it into an EXPR_STMT and a
GOTO_STMT with the RET_LABEL as its target. */
if (TREE_CODE (*tp) == RETURN_STMT && id->ret_label)
{
tree return_stmt = *tp;
tree goto_stmt;
/* Build the GOTO_STMT. */
goto_stmt = build_stmt (GOTO_STMT, id->ret_label);
TREE_CHAIN (goto_stmt) = TREE_CHAIN (return_stmt);
GOTO_FAKE_P (goto_stmt) = 1;
/* If we're returning something, just turn that into an
assignment into the equivalent of the original
RESULT_DECL. */
if (RETURN_EXPR (return_stmt))
{
*tp = build_stmt (EXPR_STMT,
RETURN_EXPR (return_stmt));
STMT_IS_FULL_EXPR_P (*tp) = 1;
/* And then jump to the end of the function. */
TREE_CHAIN (*tp) = goto_stmt;
}
/* If we're not returning anything just do the jump. */
else
*tp = goto_stmt;
}
/* Local variables and labels need to be replaced by equivalent
variables. We don't want to copy static variables; there's only
one of those, no matter how many times we inline the containing
function. */
else if ((*lang_hooks.tree_inlining.auto_var_in_fn_p) (*tp, fn))
{
tree new_decl;
/* Remap the declaration. */
new_decl = remap_decl (*tp, id);
if (! new_decl)
abort ();
/* Replace this variable with the copy. */
STRIP_TYPE_NOPS (new_decl);
*tp = new_decl;
}
#if 0
else if (nonstatic_local_decl_p (*tp)
&& DECL_CONTEXT (*tp) != VARRAY_TREE (id->fns, 0))
abort ();
#endif
else if (TREE_CODE (*tp) == SAVE_EXPR)
remap_save_expr (tp, id->decl_map, VARRAY_TREE (id->fns, 0),
walk_subtrees);
else if (TREE_CODE (*tp) == UNSAVE_EXPR)
/* UNSAVE_EXPRs should not be generated until expansion time. */
abort ();
/* For a SCOPE_STMT, we must copy the associated block so that we
can write out debugging information for the inlined variables. */
else if (TREE_CODE (*tp) == SCOPE_STMT && !id->in_target_cleanup_p)
copy_scope_stmt (tp, walk_subtrees, id);
/* Otherwise, just copy the node. Note that copy_tree_r already
knows not to copy VAR_DECLs, etc., so this is safe. */
else
{
copy_tree_r (tp, walk_subtrees, NULL);
/* The copied TARGET_EXPR has never been expanded, even if the
original node was expanded already. */
if (TREE_CODE (*tp) == TARGET_EXPR && TREE_OPERAND (*tp, 3))
{
TREE_OPERAND (*tp, 1) = TREE_OPERAND (*tp, 3);
TREE_OPERAND (*tp, 3) = NULL_TREE;
}
else if (TREE_CODE (*tp) == MODIFY_EXPR
&& TREE_OPERAND (*tp, 0) == TREE_OPERAND (*tp, 1)
&& ((*lang_hooks.tree_inlining.auto_var_in_fn_p)
(TREE_OPERAND (*tp, 0), fn)))
{
/* Some assignments VAR = VAR; don't generate any rtl code
and thus don't count as variable modification. Avoid
keeping bogosities like 0 = 0. */
tree decl = TREE_OPERAND (*tp, 0), value;
splay_tree_node n;
n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
if (n)
{
value = (tree) n->value;
STRIP_TYPE_NOPS (value);
if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value))
*tp = value;
}
}
}
/* Keep iterating. */
return NULL_TREE;
}
/* Make a copy of the body of FN so that it can be inserted inline in
another function. */
static tree
copy_body (id)
inline_data *id;
{
tree body;
body = DECL_SAVED_TREE (VARRAY_TOP_TREE (id->fns));
walk_tree (&body, copy_body_r, id, NULL);
return body;
}
/* Generate code to initialize the parameters of the function at the
top of the stack in ID from the ARGS (presented as a TREE_LIST). */
static tree
initialize_inlined_parameters (id, args, fn)
inline_data *id;
tree args;
tree fn;
{
tree init_stmts;
tree parms;
tree a;
tree p;
/* Figure out what the parameters are. */
parms = DECL_ARGUMENTS (fn);
/* Start with no initializations whatsoever. */
init_stmts = NULL_TREE;
/* Loop through the parameter declarations, replacing each with an
equivalent VAR_DECL, appropriately initialized. */
for (p = parms, a = args; p;
a = a ? TREE_CHAIN (a) : a, p = TREE_CHAIN (p))
{
tree init_stmt;
tree var;
tree value;
tree cleanup;
/* Find the initializer. */
value = (*lang_hooks.tree_inlining.convert_parm_for_inlining)
(p, a ? TREE_VALUE (a) : NULL_TREE, fn);
/* If the parameter is never assigned to, we may not need to
create a new variable here at all. Instead, we may be able
to just use the argument value. */
if (TREE_READONLY (p)
&& !TREE_ADDRESSABLE (p)
&& value && !TREE_SIDE_EFFECTS (value))
{
/* Simplify the value, if possible. */
value = fold (DECL_P (value) ? decl_constant_value (value) : value);
/* We can't risk substituting complex expressions. They
might contain variables that will be assigned to later.
Theoretically, we could check the expression to see if
all of the variables that determine its value are
read-only, but we don't bother. */
if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value))
{
/* If this is a declaration, wrap it a NOP_EXPR so that
we don't try to put the VALUE on the list of
BLOCK_VARS. */
if (DECL_P (value))
value = build1 (NOP_EXPR, TREE_TYPE (value), value);
splay_tree_insert (id->decl_map,
(splay_tree_key) p,
(splay_tree_value) value);
continue;
}
}
/* Make an equivalent VAR_DECL. */
var = copy_decl_for_inlining (p, fn, VARRAY_TREE (id->fns, 0));
/* Register the VAR_DECL as the equivalent for the PARM_DECL;
that way, when the PARM_DECL is encountered, it will be
automatically replaced by the VAR_DECL. */
splay_tree_insert (id->decl_map,
(splay_tree_key) p,
(splay_tree_value) var);
/* Declare this new variable. */
init_stmt = build_stmt (DECL_STMT, var);
TREE_CHAIN (init_stmt) = init_stmts;
init_stmts = init_stmt;
/* Initialize this VAR_DECL from the equivalent argument. If
the argument is an object, created via a constructor or copy,
this will not result in an extra copy: the TARGET_EXPR
representing the argument will be bound to VAR, and the
object will be constructed in VAR. */
if (! TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (p)))
DECL_INITIAL (var) = value;
else
{
/* Even if P was TREE_READONLY, the new VAR should not be.
In the original code, we would have constructed a
temporary, and then the function body would have never
changed the value of P. However, now, we will be
constructing VAR directly. The constructor body may
change its value multiple times as it is being
constructed. Therefore, it must not be TREE_READONLY;
the back-end assumes that TREE_READONLY variable is
assigned to only once. */
TREE_READONLY (var) = 0;
/* Build a run-time initialization. */
init_stmt = build_stmt (EXPR_STMT,
build (INIT_EXPR, TREE_TYPE (p),
var, value));
/* Add this initialization to the list. Note that we want the
declaration *after* the initialization because we are going
to reverse all the initialization statements below. */
TREE_CHAIN (init_stmt) = init_stmts;
init_stmts = init_stmt;
}
/* See if we need to clean up the declaration. */
cleanup = maybe_build_cleanup (var);
if (cleanup)
{
tree cleanup_stmt;
/* Build the cleanup statement. */
cleanup_stmt = build_stmt (CLEANUP_STMT, var, cleanup);
/* Add it to the *front* of the list; the list will be
reversed below. */
TREE_CHAIN (cleanup_stmt) = init_stmts;
init_stmts = cleanup_stmt;
}
}
/* Evaluate trailing arguments. */
for (; a; a = TREE_CHAIN (a))
{
tree init_stmt;
tree value = TREE_VALUE (a);
if (! value || ! TREE_SIDE_EFFECTS (value))
continue;
init_stmt = build_stmt (EXPR_STMT, value);
TREE_CHAIN (init_stmt) = init_stmts;
init_stmts = init_stmt;
}
/* The initialization statements have been built up in reverse
order. Straighten them out now. */
return nreverse (init_stmts);
}
/* Declare a return variable to replace the RESULT_DECL for the
function we are calling. An appropriate DECL_STMT is returned.
The USE_STMT is filled in to contain a use of the declaration to
indicate the return value of the function. */
static tree
declare_return_variable (id, use_stmt)
struct inline_data *id;
tree *use_stmt;
{
tree fn = VARRAY_TOP_TREE (id->fns);
tree result = DECL_RESULT (fn);
tree var;
int need_return_decl = 1;
/* We don't need to do anything for functions that don't return
anything. */
if (!result || VOID_TYPE_P (TREE_TYPE (result)))
{
*use_stmt = NULL_TREE;
return NULL_TREE;
}
var = ((*lang_hooks.tree_inlining.copy_res_decl_for_inlining)
(result, fn, VARRAY_TREE (id->fns, 0), id->decl_map,
&need_return_decl, &id->target_exprs));
/* Register the VAR_DECL as the equivalent for the RESULT_DECL; that
way, when the RESULT_DECL is encountered, it will be
automatically replaced by the VAR_DECL. */
splay_tree_insert (id->decl_map,
(splay_tree_key) result,
(splay_tree_value) var);
/* Build the USE_STMT. If the return type of the function was
promoted, convert it back to the expected type. */
if (TREE_TYPE (var) == TREE_TYPE (TREE_TYPE (fn)))
*use_stmt = build_stmt (EXPR_STMT, var);
else
*use_stmt = build_stmt (EXPR_STMT,
build1 (NOP_EXPR, TREE_TYPE (TREE_TYPE (fn)),
var));
TREE_ADDRESSABLE (*use_stmt) = 1;
/* Build the declaration statement if FN does not return an
aggregate. */
if (need_return_decl)
return build_stmt (DECL_STMT, var);
/* If FN does return an aggregate, there's no need to declare the
return variable; we're using a variable in our caller's frame. */
else
return NULL_TREE;
}
/* Returns non-zero if a function can be inlined as a tree. */
int
tree_inlinable_function_p (fn)
tree fn;
{
return inlinable_function_p (fn, NULL);
}
/* Returns non-zero if FN is a function that can be inlined into the
inlining context ID_. If ID_ is NULL, check whether the function
can be inlined at all. */
static int
inlinable_function_p (fn, id)
tree fn;
inline_data *id;
{
int inlinable;
/* If we've already decided this function shouldn't be inlined,
there's no need to check again. */
if (DECL_UNINLINABLE (fn))
return 0;
/* Assume it is not inlinable. */
inlinable = 0;
/* If we're not inlining things, then nothing is inlinable. */
if (! flag_inline_trees)
;
/* If we're not inlining all functions and the function was not
declared `inline', we don't inline it. Don't think of
disregarding DECL_INLINE when flag_inline_trees == 2; it's the
front-end that must set DECL_INLINE in this case, because
dwarf2out loses if a function is inlined that doesn't have
DECL_INLINE set. */
else if (! DECL_INLINE (fn))
;
/* We can't inline functions that are too big. Only allow a single
function to eat up half of our budget. Make special allowance
for extern inline functions, though. */
else if (! (*lang_hooks.tree_inlining.disregard_inline_limits) (fn)
&& DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS / 2)
;
/* All is well. We can inline this function. Traditionally, GCC
has refused to inline functions using alloca, or functions whose
values are returned in a PARALLEL, and a few other such obscure
conditions. We are not equally constrained at the tree level. */
else
inlinable = 1;
/* Squirrel away the result so that we don't have to check again. */
DECL_UNINLINABLE (fn) = ! inlinable;
/* Even if this function is not itself too big to inline, it might
be that we've done so much inlining already that we don't want to
risk too much inlining any more and thus halve the acceptable
size. */
if (! (*lang_hooks.tree_inlining.disregard_inline_limits) (fn)
&& ((DECL_NUM_STMTS (fn) + (id ? id->inlined_stmts : 0)) * INSNS_PER_STMT
> MAX_INLINE_INSNS)
&& DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS / 4)
inlinable = 0;
if (inlinable && (*lang_hooks.tree_inlining.cannot_inline_tree_fn) (&fn))
inlinable = 0;
/* If we don't have the function body available, we can't inline
it. */
if (! DECL_SAVED_TREE (fn))
inlinable = 0;
/* Check again, language hooks may have modified it. */
if (! inlinable || DECL_UNINLINABLE (fn))
return 0;
/* Don't do recursive inlining, either. We don't record this in
DECL_UNINLINABLE; we may be able to inline this function later. */
if (id)
{
size_t i;
for (i = 0; i < VARRAY_ACTIVE_SIZE (id->fns); ++i)
if (VARRAY_TREE (id->fns, i) == fn)
return 0;
if (DECL_INLINED_FNS (fn))
{
int j;
tree inlined_fns = DECL_INLINED_FNS (fn);
for (j = 0; j < TREE_VEC_LENGTH (inlined_fns); ++j)
if (TREE_VEC_ELT (inlined_fns, j) == VARRAY_TREE (id->fns, 0))
return 0;
}
}
/* Return the result. */
return inlinable;
}
/* If *TP is a CALL_EXPR, replace it with its inline expansion. */
static tree
expand_call_inline (tp, walk_subtrees, data)
tree *tp;
int *walk_subtrees;
void *data;
{
inline_data *id;
tree t;
tree expr;
tree stmt;
tree chain;
tree fn;
tree scope_stmt;
tree use_stmt;
tree arg_inits;
tree *inlined_body;
splay_tree st;
/* See what we've got. */
id = (inline_data *) data;
t = *tp;
/* Recurse, but letting recursive invocations know that we are
inside the body of a TARGET_EXPR. */
if (TREE_CODE (*tp) == TARGET_EXPR)
{
int i, len = first_rtl_op (TARGET_EXPR);
/* We're walking our own subtrees. */
*walk_subtrees = 0;
/* Push *TP on the stack of pending TARGET_EXPRs. */
VARRAY_PUSH_TREE (id->target_exprs, *tp);
/* Actually walk over them. This loop is the body of
walk_trees, omitting the case where the TARGET_EXPR
itself is handled. */
for (i = 0; i < len; ++i)
{
if (i == 2)
++id->in_target_cleanup_p;
walk_tree (&TREE_OPERAND (*tp, i), expand_call_inline, data,
id->tree_pruner);
if (i == 2)
--id->in_target_cleanup_p;
}
/* We're done with this TARGET_EXPR now. */
VARRAY_POP (id->target_exprs);
return NULL_TREE;
}
if (TYPE_P (t))
/* Because types were not copied in copy_body, CALL_EXPRs beneath
them should not be expanded. This can happen if the type is a
dynamic array type, for example. */
*walk_subtrees = 0;
/* From here on, we're only interested in CALL_EXPRs. */
if (TREE_CODE (t) != CALL_EXPR)
return NULL_TREE;
/* First, see if we can figure out what function is being called.
If we cannot, then there is no hope of inlining the function. */
fn = get_callee_fndecl (t);
if (!fn)
return NULL_TREE;
/* If fn is a declaration of a function in a nested scope that was
globally declared inline, we don't set its DECL_INITIAL.
However, we can't blindly follow DECL_ABSTRACT_ORIGIN because the
C++ front-end uses it for cdtors to refer to their internal
declarations, that are not real functions. Fortunately those
don't have trees to be saved, so we can tell by checking their
DECL_SAVED_TREE. */
if (! DECL_INITIAL (fn)
&& DECL_ABSTRACT_ORIGIN (fn)
&& DECL_SAVED_TREE (DECL_ABSTRACT_ORIGIN (fn)))
fn = DECL_ABSTRACT_ORIGIN (fn);
/* Don't try to inline functions that are not well-suited to
inlining. */
if (!inlinable_function_p (fn, id))
return NULL_TREE;
if (! (*lang_hooks.tree_inlining.start_inlining) (fn))
return NULL_TREE;
/* Set the current filename and line number to the function we are
inlining so that when we create new _STMT nodes here they get
line numbers corresponding to the function we are calling. We
wrap the whole inlined body in an EXPR_WITH_FILE_AND_LINE as well
because individual statements don't record the filename. */
push_srcloc (fn->decl.filename, fn->decl.linenum);
/* Build a statement-expression containing code to initialize the
arguments, the actual inline expansion of the body, and a label
for the return statements within the function to jump to. The
type of the statement expression is the return type of the
function call. */
expr = build1 (STMT_EXPR, TREE_TYPE (TREE_TYPE (fn)), make_node (COMPOUND_STMT));
/* There is no scope associated with the statement-expression. */
STMT_EXPR_NO_SCOPE (expr) = 1;
stmt = STMT_EXPR_STMT (expr);
/* Local declarations will be replaced by their equivalents in this
map. */
st = id->decl_map;
id->decl_map = splay_tree_new (splay_tree_compare_pointers,
NULL, NULL);
/* Initialize the parameters. */
arg_inits = initialize_inlined_parameters (id, TREE_OPERAND (t, 1), fn);
/* Expand any inlined calls in the initializers. Do this before we
push FN on the stack of functions we are inlining; we want to
inline calls to FN that appear in the initializers for the
parameters. */
expand_calls_inline (&arg_inits, id);
/* And add them to the tree. */
COMPOUND_BODY (stmt) = chainon (COMPOUND_BODY (stmt), arg_inits);
/* Record the function we are about to inline so that we can avoid
recursing into it. */
VARRAY_PUSH_TREE (id->fns, fn);
/* Record the function we are about to inline if optimize_function
has not been called on it yet and we don't have it in the list. */
if (! DECL_INLINED_FNS (fn))
{
int i;
for (i = VARRAY_ACTIVE_SIZE (id->inlined_fns) - 1; i >= 0; i--)
if (VARRAY_TREE (id->inlined_fns, i) == fn)
break;
if (i < 0)
VARRAY_PUSH_TREE (id->inlined_fns, fn);
}
/* Return statements in the function body will be replaced by jumps
to the RET_LABEL. */
id->ret_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
DECL_CONTEXT (id->ret_label) = VARRAY_TREE (id->fns, 0);
if (! DECL_INITIAL (fn)
|| TREE_CODE (DECL_INITIAL (fn)) != BLOCK)
abort ();
/* Create a block to put the parameters in. We have to do this
after the parameters have been remapped because remapping
parameters is different from remapping ordinary variables. */
scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
SCOPE_BEGIN_P (scope_stmt) = 1;
SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
remap_block (scope_stmt, DECL_ARGUMENTS (fn), id);
TREE_CHAIN (scope_stmt) = COMPOUND_BODY (stmt);
COMPOUND_BODY (stmt) = scope_stmt;
/* Tell the debugging backends that this block represents the
outermost scope of the inlined function. */
if (SCOPE_STMT_BLOCK (scope_stmt))
BLOCK_ABSTRACT_ORIGIN (SCOPE_STMT_BLOCK (scope_stmt)) = DECL_ORIGIN (fn);
/* Declare the return variable for the function. */
COMPOUND_BODY (stmt)
= chainon (COMPOUND_BODY (stmt),
declare_return_variable (id, &use_stmt));
/* After we've initialized the parameters, we insert the body of the
function itself. */
inlined_body = &COMPOUND_BODY (stmt);
while (*inlined_body)
inlined_body = &TREE_CHAIN (*inlined_body);
*inlined_body = copy_body (id);
/* After the body of the function comes the RET_LABEL. This must come
before we evaluate the returned value below, because that evalulation
may cause RTL to be generated. */
COMPOUND_BODY (stmt)
= chainon (COMPOUND_BODY (stmt),
build_stmt (LABEL_STMT, id->ret_label));
/* Finally, mention the returned value so that the value of the
statement-expression is the returned value of the function. */
COMPOUND_BODY (stmt) = chainon (COMPOUND_BODY (stmt), use_stmt);
/* Close the block for the parameters. */
scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
remap_block (scope_stmt, NULL_TREE, id);
COMPOUND_BODY (stmt)
= chainon (COMPOUND_BODY (stmt), scope_stmt);
/* Clean up. */
splay_tree_delete (id->decl_map);
id->decl_map = st;
/* The new expression has side-effects if the old one did. */
TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (t);
/* Replace the call by the inlined body. Wrap it in an
EXPR_WITH_FILE_LOCATION so that we'll get debugging line notes
pointing to the right place. */
chain = TREE_CHAIN (*tp);
*tp = build_expr_wfl (expr, DECL_SOURCE_FILE (fn), DECL_SOURCE_LINE (fn),
/*col=*/0);
EXPR_WFL_EMIT_LINE_NOTE (*tp) = 1;
TREE_CHAIN (*tp) = chain;
pop_srcloc ();
/* If the value of the new expression is ignored, that's OK. We
don't warn about this for CALL_EXPRs, so we shouldn't warn about
the equivalent inlined version either. */
TREE_USED (*tp) = 1;
/* Our function now has more statements than it did before. */
DECL_NUM_STMTS (VARRAY_TREE (id->fns, 0)) += DECL_NUM_STMTS (fn);
id->inlined_stmts += DECL_NUM_STMTS (fn);
/* Recurse into the body of the just inlined function. */
expand_calls_inline (inlined_body, id);
VARRAY_POP (id->fns);
/* If we've returned to the top level, clear out the record of how
much inlining has been done. */
if (VARRAY_ACTIVE_SIZE (id->fns) == id->first_inlined_fn)
id->inlined_stmts = 0;
/* Don't walk into subtrees. We've already handled them above. */
*walk_subtrees = 0;
(*lang_hooks.tree_inlining.end_inlining) (fn);
/* Keep iterating. */
return NULL_TREE;
}
/* Walk over the entire tree *TP, replacing CALL_EXPRs with inline
expansions as appropriate. */
static void
expand_calls_inline (tp, id)
tree *tp;
inline_data *id;
{
/* Search through *TP, replacing all calls to inline functions by
appropriate equivalents. Use walk_tree in no-duplicates mode
to avoid exponential time complexity. (We can't just use
walk_tree_without_duplicates, because of the special TARGET_EXPR
handling in expand_calls. The hash table is set up in
optimize_function. */
walk_tree (tp, expand_call_inline, id, id->tree_pruner);
}
/* Expand calls to inline functions in the body of FN. */
void
optimize_inline_calls (fn)
tree fn;
{
inline_data id;
tree prev_fn;
/* Clear out ID. */
memset (&id, 0, sizeof (id));
/* Don't allow recursion into FN. */
VARRAY_TREE_INIT (id.fns, 32, "fns");
VARRAY_PUSH_TREE (id.fns, fn);
/* Or any functions that aren't finished yet. */
prev_fn = NULL_TREE;
if (current_function_decl)
{
VARRAY_PUSH_TREE (id.fns, current_function_decl);
prev_fn = current_function_decl;
}
prev_fn = ((*lang_hooks.tree_inlining.add_pending_fn_decls)
(&id.fns, prev_fn));
/* Create the stack of TARGET_EXPRs. */
VARRAY_TREE_INIT (id.target_exprs, 32, "target_exprs");
/* Create the list of functions this call will inline. */
VARRAY_TREE_INIT (id.inlined_fns, 32, "inlined_fns");
/* Keep track of the low-water mark, i.e., the point where the first
real inlining is represented in ID.FNS. */
id.first_inlined_fn = VARRAY_ACTIVE_SIZE (id.fns);
/* Replace all calls to inline functions with the bodies of those
functions. */
id.tree_pruner = htab_create (37, htab_hash_pointer,
htab_eq_pointer, NULL);
expand_calls_inline (&DECL_SAVED_TREE (fn), &id);
/* Clean up. */
htab_delete (id.tree_pruner);
VARRAY_FREE (id.fns);
VARRAY_FREE (id.target_exprs);
if (DECL_LANG_SPECIFIC (fn))
{
tree ifn = make_tree_vec (VARRAY_ACTIVE_SIZE (id.inlined_fns));
memcpy (&TREE_VEC_ELT (ifn, 0), &VARRAY_TREE (id.inlined_fns, 0),
VARRAY_ACTIVE_SIZE (id.inlined_fns) * sizeof (tree));
DECL_INLINED_FNS (fn) = ifn;
}
VARRAY_FREE (id.inlined_fns);
}
/* FN is a function that has a complete body, and CLONE is a function
whose body is to be set to a copy of FN, mapping argument
declarations according to the ARG_MAP splay_tree. */
void
clone_body (clone, fn, arg_map)
tree clone, fn;
void *arg_map;
{
inline_data id;
/* Clone the body, as if we were making an inline call. But, remap
the parameters in the callee to the parameters of caller. If
there's an in-charge parameter, map it to an appropriate
constant. */
memset (&id, 0, sizeof (id));
VARRAY_TREE_INIT (id.fns, 2, "fns");
VARRAY_PUSH_TREE (id.fns, clone);
VARRAY_PUSH_TREE (id.fns, fn);
id.decl_map = (splay_tree)arg_map;
/* Cloning is treated slightly differently from inlining. Set
CLONING_P so that it's clear which operation we're performing. */
id.cloning_p = true;
/* Actually copy the body. */
TREE_CHAIN (DECL_SAVED_TREE (clone)) = copy_body (&id);
/* Clean up. */
VARRAY_FREE (id.fns);
}
/* Apply FUNC to all the sub-trees of TP in a pre-order traversal.
FUNC is called with the DATA and the address of each sub-tree. If
FUNC returns a non-NULL value, the traversal is aborted, and the
value returned by FUNC is returned. If HTAB is non-NULL it is used
to record the nodes visited, and to avoid visiting a node more than
once. */
tree
walk_tree (tp, func, data, htab_)
tree *tp;
walk_tree_fn func;
void *data;
void *htab_;
{
htab_t htab = (htab_t) htab_;
enum tree_code code;
int walk_subtrees;
tree result;
#define WALK_SUBTREE(NODE) \
do \
{ \
result = walk_tree (&(NODE), func, data, htab); \
if (result) \
return result; \
} \
while (0)
#define WALK_SUBTREE_TAIL(NODE) \
do \
{ \
tp = & (NODE); \
goto tail_recurse; \
} \
while (0)
tail_recurse:
/* Skip empty subtrees. */
if (!*tp)
return NULL_TREE;
if (htab)
{
void **slot;
/* Don't walk the same tree twice, if the user has requested
that we avoid doing so. */
if (htab_find (htab, *tp))
return NULL_TREE;
/* If we haven't already seen this node, add it to the table. */
slot = htab_find_slot (htab, *tp, INSERT);
*slot = *tp;
}
/* Call the function. */
walk_subtrees = 1;
result = (*func) (tp, &walk_subtrees, data);
/* If we found something, return it. */
if (result)
return result;
code = TREE_CODE (*tp);
/* Even if we didn't, FUNC may have decided that there was nothing
interesting below this point in the tree. */
if (!walk_subtrees)
{
if (statement_code_p (code) || code == TREE_LIST
|| (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp))
/* But we still need to check our siblings. */
WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
else
return NULL_TREE;
}
/* Handle common cases up front. */
if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
|| TREE_CODE_CLASS (code) == 'r'
|| TREE_CODE_CLASS (code) == 's')
{
int i, len;
/* Set lineno here so we get the right instantiation context
if we call instantiate_decl from inlinable_function_p. */
if (statement_code_p (code) && !STMT_LINENO_FOR_FN_P (*tp))
lineno = STMT_LINENO (*tp);
/* Walk over all the sub-trees of this operand. */
len = first_rtl_op (code);
/* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
But, we only want to walk once. */
if (code == TARGET_EXPR
&& TREE_OPERAND (*tp, 3) == TREE_OPERAND (*tp, 1))
--len;
/* Go through the subtrees. We need to do this in forward order so
that the scope of a FOR_EXPR is handled properly. */
for (i = 0; i < len; ++i)
WALK_SUBTREE (TREE_OPERAND (*tp, i));
/* For statements, we also walk the chain so that we cover the
entire statement tree. */
if (statement_code_p (code))
{
if (code == DECL_STMT
&& DECL_STMT_DECL (*tp)
&& DECL_P (DECL_STMT_DECL (*tp)))
{
/* Walk the DECL_INITIAL and DECL_SIZE. We don't want to walk
into declarations that are just mentioned, rather than
declared; they don't really belong to this part of the tree.
And, we can see cycles: the initializer for a declaration can
refer to the declaration itself. */
WALK_SUBTREE (DECL_INITIAL (DECL_STMT_DECL (*tp)));
WALK_SUBTREE (DECL_SIZE (DECL_STMT_DECL (*tp)));
WALK_SUBTREE (DECL_SIZE_UNIT (DECL_STMT_DECL (*tp)));
}
/* This can be tail-recursion optimized if we write it this way. */
WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
}
/* We didn't find what we were looking for. */
return NULL_TREE;
}
else if (TREE_CODE_CLASS (code) == 'd')
{
WALK_SUBTREE_TAIL (TREE_TYPE (*tp));
}
else if (TREE_CODE_CLASS (code) == 't')
{
WALK_SUBTREE (TYPE_SIZE (*tp));
WALK_SUBTREE (TYPE_SIZE_UNIT (*tp));
/* Also examine various special fields, below. */
}
result = (*lang_hooks.tree_inlining.walk_subtrees) (tp, &walk_subtrees, func,
data, htab);
if (result || ! walk_subtrees)
return result;
/* Not one of the easy cases. We must explicitly go through the
children. */
switch (code)
{
case ERROR_MARK:
case IDENTIFIER_NODE:
case INTEGER_CST:
case REAL_CST:
case VECTOR_CST:
case STRING_CST:
case REAL_TYPE:
case COMPLEX_TYPE:
case VECTOR_TYPE:
case VOID_TYPE:
case BOOLEAN_TYPE:
case UNION_TYPE:
case ENUMERAL_TYPE:
case BLOCK:
case RECORD_TYPE:
/* None of thse have subtrees other than those already walked
above. */
break;
case POINTER_TYPE:
case REFERENCE_TYPE:
WALK_SUBTREE_TAIL (TREE_TYPE (*tp));
break;
case TREE_LIST:
WALK_SUBTREE (TREE_VALUE (*tp));
WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
break;
case TREE_VEC:
{
int len = TREE_VEC_LENGTH (*tp);
if (len == 0)
break;
/* Walk all elements but the first. */
while (--len)
WALK_SUBTREE (TREE_VEC_ELT (*tp, len));
/* Now walk the first one as a tail call. */
WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp, 0));
}
case COMPLEX_CST:
WALK_SUBTREE (TREE_REALPART (*tp));
WALK_SUBTREE_TAIL (TREE_IMAGPART (*tp));
case CONSTRUCTOR:
WALK_SUBTREE_TAIL (CONSTRUCTOR_ELTS (*tp));
case METHOD_TYPE:
WALK_SUBTREE (TYPE_METHOD_BASETYPE (*tp));
/* Fall through. */
case FUNCTION_TYPE:
WALK_SUBTREE (TREE_TYPE (*tp));
{
tree arg = TYPE_ARG_TYPES (*tp);
/* We never want to walk into default arguments. */
for (; arg; arg = TREE_CHAIN (arg))
WALK_SUBTREE (TREE_VALUE (arg));
}
break;
case ARRAY_TYPE:
WALK_SUBTREE (TREE_TYPE (*tp));
WALK_SUBTREE_TAIL (TYPE_DOMAIN (*tp));
case INTEGER_TYPE:
WALK_SUBTREE (TYPE_MIN_VALUE (*tp));
WALK_SUBTREE_TAIL (TYPE_MAX_VALUE (*tp));
case OFFSET_TYPE:
WALK_SUBTREE (TREE_TYPE (*tp));
WALK_SUBTREE_TAIL (TYPE_OFFSET_BASETYPE (*tp));
default:
abort ();
}
/* We didn't find what we were looking for. */
return NULL_TREE;
#undef WALK_SUBTREE
#undef WALK_SUBTREE_TAIL
}
/* Like walk_tree, but does not walk duplicate nodes more than
once. */
tree
walk_tree_without_duplicates (tp, func, data)
tree *tp;
walk_tree_fn func;
void *data;
{
tree result;
htab_t htab;
htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL);
result = walk_tree (tp, func, data, htab);
htab_delete (htab);
return result;
}
/* Passed to walk_tree. Copies the node pointed to, if appropriate. */
tree
copy_tree_r (tp, walk_subtrees, data)
tree *tp;
int *walk_subtrees;
void *data ATTRIBUTE_UNUSED;
{
enum tree_code code = TREE_CODE (*tp);
/* We make copies of most nodes. */
if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
|| TREE_CODE_CLASS (code) == 'r'
|| TREE_CODE_CLASS (code) == 'c'
|| TREE_CODE_CLASS (code) == 's'
|| code == TREE_LIST
|| code == TREE_VEC
|| (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp))
{
/* Because the chain gets clobbered when we make a copy, we save it
here. */
tree chain = TREE_CHAIN (*tp);
/* Copy the node. */
*tp = copy_node (*tp);
/* Now, restore the chain, if appropriate. That will cause
walk_tree to walk into the chain as well. */
if (code == PARM_DECL || code == TREE_LIST
|| (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp)
|| statement_code_p (code))
TREE_CHAIN (*tp) = chain;
/* For now, we don't update BLOCKs when we make copies. So, we
have to nullify all scope-statements. */
if (TREE_CODE (*tp) == SCOPE_STMT)
SCOPE_STMT_BLOCK (*tp) = NULL_TREE;
}
else if (TREE_CODE_CLASS (code) == 't' && !variably_modified_type_p (*tp))
/* Types only need to be copied if they are variably modified. */
*walk_subtrees = 0;
return NULL_TREE;
}
/* The SAVE_EXPR pointed to by TP is being copied. If ST contains
information indicating to what new SAVE_EXPR this one should be
mapped, use that one. Otherwise, create a new node and enter it in
ST. FN is the function into which the copy will be placed. */
void
remap_save_expr (tp, st_, fn, walk_subtrees)
tree *tp;
void *st_;
tree fn;
int *walk_subtrees;
{
splay_tree st = (splay_tree) st_;
splay_tree_node n;
/* See if we already encountered this SAVE_EXPR. */
n = splay_tree_lookup (st, (splay_tree_key) *tp);
/* If we didn't already remap this SAVE_EXPR, do so now. */
if (!n)
{
tree t = copy_node (*tp);
/* The SAVE_EXPR is now part of the function into which we
are inlining this body. */
SAVE_EXPR_CONTEXT (t) = fn;
/* And we haven't evaluated it yet. */
SAVE_EXPR_RTL (t) = NULL_RTX;
/* Remember this SAVE_EXPR. */
n = splay_tree_insert (st,
(splay_tree_key) *tp,
(splay_tree_value) t);
/* Make sure we don't remap an already-remapped SAVE_EXPR. */
splay_tree_insert (st, (splay_tree_key) t,
(splay_tree_value) error_mark_node);
}
else
/* We've already walked into this SAVE_EXPR, so we needn't do it
again. */
*walk_subtrees = 0;
/* Replace this SAVE_EXPR with the copy. */
*tp = (tree) n->value;
}
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