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/* Tree lowering pass. This pass converts the GENERIC functions-as-trees
tree representation into the GIMPLE form.
Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
Major work done by Sebastian Pop <s.pop@laposte.net>,
Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "errors.h"
#include "varray.h"
#include "tree-gimple.h"
#include "tree-inline.h"
#include "diagnostic.h"
#include "langhooks.h"
#include "langhooks-def.h"
#include "tree-flow.h"
#include "timevar.h"
#include "except.h"
#include "hashtab.h"
#include "flags.h"
#include "real.h"
#include "function.h"
#include "output.h"
#include "expr.h"
#include "ggc.h"
static struct gimplify_ctx
{
tree current_bind_expr;
bool save_stack;
tree temps;
tree conditional_cleanups;
int conditions;
tree exit_label;
varray_type case_labels;
/* The formal temporary table. Should this be persistent? */
htab_t temp_htab;
} *gimplify_ctxp;
/* Formal (expression) temporary table handling: Multiple occurrences of
the same scalar expression are evaluated into the same temporary. */
typedef struct gimple_temp_hash_elt
{
tree val; /* Key */
tree temp; /* Value */
} elt_t;
/* Return a hash value for a formal temporary table entry. */
static hashval_t
gimple_tree_hash (const void *p)
{
tree t = ((const elt_t *)p)->val;
return iterative_hash_expr (t, 0);
}
/* Compare two formal temporary table entries. */
static int
gimple_tree_eq (const void *p1, const void *p2)
{
tree t1 = ((const elt_t *)p1)->val;
tree t2 = ((const elt_t *)p2)->val;
enum tree_code code = TREE_CODE (t1);
if (TREE_CODE (t2) != code
|| TREE_TYPE (t1) != TREE_TYPE (t2))
return 0;
if (!operand_equal_p (t1, t2, 0))
return 0;
/* Only allow them to compare equal if they also hash equal; otherwise
results are nondeterminate, and we fail bootstrap comparison. */
if (gimple_tree_hash (p1) != gimple_tree_hash (p2))
abort ();
return 1;
}
/* Set up a context for the gimplifier. */
void
push_gimplify_context (void)
{
if (gimplify_ctxp)
abort ();
gimplify_ctxp
= (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
gimplify_ctxp->temp_htab
= htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
}
/* Tear down a context for the gimplifier. If BODY is non-null, then
put the temporaries into the outer BIND_EXPR. Otherwise, put them
in the unexpanded_var_list. */
void
pop_gimplify_context (tree body)
{
if (!gimplify_ctxp || gimplify_ctxp->current_bind_expr)
abort ();
if (body)
declare_tmp_vars (gimplify_ctxp->temps, body);
else
record_vars (gimplify_ctxp->temps);
#if 0
if (!quiet_flag)
fprintf (stderr, " collisions: %f ",
htab_collisions (gimplify_ctxp->temp_htab));
#endif
htab_delete (gimplify_ctxp->temp_htab);
free (gimplify_ctxp);
gimplify_ctxp = NULL;
}
void
gimple_push_bind_expr (tree bind)
{
TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
gimplify_ctxp->current_bind_expr = bind;
}
void
gimple_pop_bind_expr (void)
{
gimplify_ctxp->current_bind_expr
= TREE_CHAIN (gimplify_ctxp->current_bind_expr);
}
tree
gimple_current_bind_expr (void)
{
return gimplify_ctxp->current_bind_expr;
}
/* Returns true iff there is a COND_EXPR between us and the innermost
CLEANUP_POINT_EXPR. This info is used by gimple_push_cleanup. */
static bool
gimple_conditional_context (void)
{
return gimplify_ctxp->conditions > 0;
}
/* Note that we've entered a COND_EXPR. */
static void
gimple_push_condition (void)
{
++(gimplify_ctxp->conditions);
}
/* Note that we've left a COND_EXPR. If we're back at unconditional scope
now, add any conditional cleanups we've seen to the prequeue. */
static void
gimple_pop_condition (tree *pre_p)
{
int conds = --(gimplify_ctxp->conditions);
if (conds == 0)
{
append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
gimplify_ctxp->conditional_cleanups = NULL_TREE;
}
else if (conds < 0)
abort ();
}
/* A subroutine of append_to_statement_list{,_force}. */
static void
append_to_statement_list_1 (tree t, tree *list_p, bool side_effects)
{
tree list = *list_p;
tree_stmt_iterator i;
if (!side_effects)
return;
if (!list)
{
if (t && TREE_CODE (t) == STATEMENT_LIST)
{
*list_p = t;
return;
}
*list_p = list = alloc_stmt_list ();
}
i = tsi_last (list);
tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
}
/* Add T to the end of the list container pointed by LIST_P.
If T is an expression with no effects, it is ignored. */
void
append_to_statement_list (tree t, tree *list_p)
{
append_to_statement_list_1 (t, list_p, t ? TREE_SIDE_EFFECTS (t) : false);
}
/* Similar, but the statement is always added, regardless of side effects. */
void
append_to_statement_list_force (tree t, tree *list_p)
{
append_to_statement_list_1 (t, list_p, t != NULL);
}
/* Add T to the end of a COMPOUND_EXPR pointed by LIST_P. The type
of the result is the type of T. */
void
append_to_compound_expr (tree t, tree *list_p)
{
if (!t)
return;
if (!*list_p)
*list_p = t;
else
*list_p = build (COMPOUND_EXPR, TREE_TYPE (t), *list_p, t);
}
/* Strip off a legitimate source ending from the input string NAME of
length LEN. Rather than having to know the names used by all of
our front ends, we strip off an ending of a period followed by
up to five characters. (Java uses ".class".) */
static inline void
remove_suffix (char *name, int len)
{
int i;
for (i = 2; i < 8 && len > i; i++)
{
if (name[len - i] == '.')
{
name[len - i] = '\0';
break;
}
}
}
/* Create a nameless artificial label and put it in the current function
context. Returns the newly created label. */
tree
create_artificial_label (void)
{
tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
DECL_ARTIFICIAL (lab) = 1;
DECL_CONTEXT (lab) = current_function_decl;
return lab;
}
/* Create a new temporary name with PREFIX. Returns an identifier. */
static GTY(()) unsigned int tmp_var_id_num;
tree
create_tmp_var_name (const char *prefix)
{
char *tmp_name;
if (prefix)
{
char *preftmp = ASTRDUP (prefix);
remove_suffix (preftmp, strlen (preftmp));
prefix = preftmp;
}
ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
return get_identifier (tmp_name);
}
/* Create a new temporary variable declaration of type TYPE.
Does NOT push it into the current binding. */
tree
create_tmp_var_raw (tree type, const char *prefix)
{
tree tmp_var;
tree new_type;
/* Make the type of the variable writable. */
new_type = build_type_variant (type, 0, 0);
TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
tmp_var = build_decl (VAR_DECL, create_tmp_var_name (prefix), type);
/* The variable was declared by the compiler. */
DECL_ARTIFICIAL (tmp_var) = 1;
/* And we don't want debug info for it. */
DECL_IGNORED_P (tmp_var) = 1;
/* Make the variable writable. */
TREE_READONLY (tmp_var) = 0;
DECL_EXTERNAL (tmp_var) = 0;
TREE_STATIC (tmp_var) = 0;
TREE_USED (tmp_var) = 1;
return tmp_var;
}
/* Create a new temporary variable declaration of type TYPE. DOES push the
variable into the current binding. Further, assume that this is called
only from gimplification or optimization, at which point the creation of
certain types are bugs. */
tree
create_tmp_var (tree type, const char *prefix)
{
tree tmp_var;
#if defined ENABLE_CHECKING
/* If the type is an array or a type which must be created by the
frontend, something is wrong. */
if (TREE_CODE (type) == ARRAY_TYPE || TREE_ADDRESSABLE (type))
abort ();
if (!COMPLETE_TYPE_P (type))
abort ();
/* Variable sized types require lots of machinery to create; the
optimizers shouldn't be doing anything of the sort. */
if (TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST)
abort ();
#endif
tmp_var = create_tmp_var_raw (type, prefix);
gimple_add_tmp_var (tmp_var);
return tmp_var;
}
/* Given a tree, try to return a useful variable name that we can use
to prefix a temporary that is being assigned the value of the tree.
I.E. given <temp> = &A, return A. */
const char *
get_name (tree t)
{
tree stripped_decl;
stripped_decl = t;
STRIP_NOPS (stripped_decl);
if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
else
{
switch (TREE_CODE (stripped_decl))
{
case ADDR_EXPR:
return get_name (TREE_OPERAND (stripped_decl, 0));
break;
default:
return NULL;
}
}
}
/* Create a temporary with a name derived from VAL. Subroutine of
lookup_tmp_var; nobody else should call this function. */
static inline tree
create_tmp_from_val (tree val)
{
return create_tmp_var (TREE_TYPE (val), get_name (val));
}
/* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
an existing expression temporary. */
static tree
lookup_tmp_var (tree val, bool is_formal)
{
if (!is_formal || TREE_SIDE_EFFECTS (val))
return create_tmp_from_val (val);
else
{
elt_t elt, *elt_p;
void **slot;
elt.val = val;
slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
if (*slot == NULL)
{
elt_p = xmalloc (sizeof (*elt_p));
elt_p->val = val;
elt_p->temp = create_tmp_from_val (val);
*slot = (void *)elt_p;
}
else
elt_p = (elt_t *) *slot;
return elt_p->temp;
}
}
/* Returns a formal temporary variable initialized with VAL. PRE_P is as
in gimplify_expr. Only use this function if:
1) The value of the unfactored expression represented by VAL will not
change between the initialization and use of the temporary, and
2) The temporary will not be otherwise modified.
For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
and #2 means it is inappropriate for && temps.
For other cases, use get_initialized_tmp_var instead. */
static tree
internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
{
tree t, mod;
char class;
gimplify_expr (&val, pre_p, post_p, is_gimple_rhs, fb_rvalue);
t = lookup_tmp_var (val, is_formal);
mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val);
class = TREE_CODE_CLASS (TREE_CODE (val));
if (EXPR_LOCUS (val))
SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
else
annotate_with_locus (mod, input_location);
/* gimplify_modify_expr might want to reduce this further. */
gimplify_stmt (&mod);
append_to_statement_list (mod, pre_p);
return t;
}
tree
get_formal_tmp_var (tree val, tree *pre_p)
{
return internal_get_tmp_var (val, pre_p, NULL, true);
}
/* Returns a temporary variable initialized with VAL. PRE_P and POST_P
are as in gimplify_expr. */
tree
get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
{
return internal_get_tmp_var (val, pre_p, post_p, false);
}
/* Returns true if T is a GIMPLE temporary variable, false otherwise. */
bool
is_gimple_tmp_var (tree t)
{
/* FIXME this could trigger for other local artificials, too. */
return (TREE_CODE (t) == VAR_DECL && DECL_ARTIFICIAL (t)
&& !TREE_STATIC (t) && !DECL_EXTERNAL (t));
}
/* Declares all the variables in VARS in SCOPE. Returns the last
DECL_STMT emitted. */
void
declare_tmp_vars (tree vars, tree scope)
{
tree last = vars;
if (last)
{
tree temps;
/* C99 mode puts the default 'return 0;' for main() outside the outer
braces. So drill down until we find an actual scope. */
while (TREE_CODE (scope) == COMPOUND_EXPR)
scope = TREE_OPERAND (scope, 0);
if (TREE_CODE (scope) != BIND_EXPR)
abort ();
temps = nreverse (last);
TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
BIND_EXPR_VARS (scope) = temps;
/* We don't add the temps to the block for this BIND_EXPR, as we're
not interested in debugging info for them. */
}
}
void
gimple_add_tmp_var (tree tmp)
{
if (TREE_CHAIN (tmp) || tmp->decl.seen_in_bind_expr)
abort ();
DECL_CONTEXT (tmp) = current_function_decl;
tmp->decl.seen_in_bind_expr = 1;
if (gimplify_ctxp)
{
TREE_CHAIN (tmp) = gimplify_ctxp->temps;
gimplify_ctxp->temps = tmp;
}
else if (cfun)
record_vars (tmp);
else
declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
}
/* Determines whether to assign a locus to the statement STMT. */
static bool
should_carry_locus_p (tree stmt)
{
/* Don't emit a line note for a label. We particularly don't want to
emit one for the break label, since it doesn't actually correspond
to the beginning of the loop/switch. */
if (TREE_CODE (stmt) == LABEL_EXPR)
return false;
/* Do not annotate empty statements, since it confuses gcov. */
if (!TREE_SIDE_EFFECTS (stmt))
return false;
return true;
}
void
annotate_all_with_locus (tree *stmt_p, location_t locus)
{
tree_stmt_iterator i;
if (!*stmt_p)
return;
for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
{
tree t = tsi_stmt (i);
#ifdef ENABLE_CHECKING
/* Assuming we've already been gimplified, we shouldn't
see nested chaining constructs anymore. */
if (TREE_CODE (t) == STATEMENT_LIST
|| TREE_CODE (t) == COMPOUND_EXPR)
abort ();
#endif
if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (t)))
&& ! EXPR_HAS_LOCATION (t)
&& should_carry_locus_p (t))
annotate_with_locus (t, locus);
}
}
/* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
These nodes model computations that should only be done once. If we
were to unshare something like SAVE_EXPR(i++), the gimplification
process would create wrong code. */
static tree
mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
{
enum tree_code code = TREE_CODE (*tp);
/* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
if (TREE_CODE_CLASS (code) == 't'
|| TREE_CODE_CLASS (code) == 'd'
|| TREE_CODE_CLASS (code) == 'c'
|| code == SAVE_EXPR || code == TARGET_EXPR
/* We can't do anything sensible with a BLOCK used as an expression,
but we also can't abort when we see it because of non-expression
uses. So just avert our eyes and cross our fingers. Silly Java. */
|| code == BLOCK)
*walk_subtrees = 0;
else if (code == BIND_EXPR)
abort ();
else
copy_tree_r (tp, walk_subtrees, data);
return NULL_TREE;
}
/* Mark all the _DECL nodes under *TP as volatile. FIXME: This must die
after VA_ARG_EXPRs are properly lowered. */
static tree
mark_decls_volatile_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED)
{
if (SSA_VAR_P (*tp))
TREE_THIS_VOLATILE (*tp) = 1;
return NULL_TREE;
}
/* Callback for walk_tree to unshare most of the shared trees rooted at
*TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
then *TP is deep copied by calling copy_tree_r.
This unshares the same trees as copy_tree_r with the exception of
SAVE_EXPR nodes. These nodes model computations that should only be
done once. If we were to unshare something like SAVE_EXPR(i++), the
gimplification process would create wrong code. */
static tree
copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED)
{
tree t = *tp;
enum tree_code code = TREE_CODE (t);
/* Skip types, decls, and constants. */
if (TREE_CODE_CLASS (code) == 't'
|| TREE_CODE_CLASS (code) == 'd'
|| TREE_CODE_CLASS (code) == 'c')
*walk_subtrees = 0;
/* Special-case BIND_EXPR. We should never be copying these, therefore
we can omit examining BIND_EXPR_VARS. Which also avoids problems with
double processing of the DECL_INITIAL, which could be seen via both
the BIND_EXPR_VARS and a DECL_STMT. */
else if (code == BIND_EXPR)
{
if (TREE_VISITED (t))
abort ();
TREE_VISITED (t) = 1;
*walk_subtrees = 0;
walk_tree (&BIND_EXPR_BODY (t), copy_if_shared_r, NULL, NULL);
}
/* If this node has been visited already, unshare it and don't look
any deeper. */
else if (TREE_VISITED (t))
{
walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
*walk_subtrees = 0;
}
/* Otherwise, mark the tree as visited and keep looking. */
else
TREE_VISITED (t) = 1;
return NULL_TREE;
}
static tree
unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED)
{
if (TREE_VISITED (*tp))
TREE_VISITED (*tp) = 0;
else
*walk_subtrees = 0;
return NULL_TREE;
}
/* Unshare T and all the trees reached from T via TREE_CHAIN. */
void
unshare_all_trees (tree t)
{
walk_tree (&t, copy_if_shared_r, NULL, NULL);
walk_tree (&t, unmark_visited_r, NULL, NULL);
}
/* Unconditionally make an unshared copy of EXPR. This is used when using
stored expressions which span multiple functions, such as BINFO_VTABLE,
as the normal unsharing process can't tell that they're shared. */
tree
unshare_expr (tree expr)
{
walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
return expr;
}
/* A terser interface for building a representation of a exception
specification. */
tree
gimple_build_eh_filter (tree body, tree allowed, tree failure)
{
tree t;
/* FIXME should the allowed types go in TREE_TYPE? */
t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
append_to_statement_list (body, &TREE_OPERAND (t, 0));
return t;
}
/* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
contain statements and have a value. Assign its value to a temporary
and give it void_type_node. Returns the temporary, or NULL_TREE if
WRAPPER was already void. */
tree
voidify_wrapper_expr (tree wrapper)
{
if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
{
tree *p;
tree temp;
/* Set p to point to the body of the wrapper. */
switch (TREE_CODE (wrapper))
{
case BIND_EXPR:
/* For a BIND_EXPR, the body is operand 1. */
p = &BIND_EXPR_BODY (wrapper);
break;
default:
p = &TREE_OPERAND (wrapper, 0);
break;
}
/* Advance to the last statement. Set all container types to void. */
if (TREE_CODE (*p) == STATEMENT_LIST)
{
tree_stmt_iterator i = tsi_last (*p);
p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
}
else
{
for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
{
TREE_SIDE_EFFECTS (*p) = 1;
TREE_TYPE (*p) = void_type_node;
}
}
if (p && TREE_CODE (*p) == INIT_EXPR)
{
/* The C++ frontend already did this for us. */;
temp = TREE_OPERAND (*p, 0);
}
else if (p && TREE_CODE (*p) == INDIRECT_REF)
{
/* If we're returning a dereference, move the dereference outside
the wrapper. */
tree ptr = TREE_OPERAND (*p, 0);
temp = create_tmp_var (TREE_TYPE (ptr), "retval");
*p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
/* If this is a BIND_EXPR for a const inline function, it might not
have TREE_SIDE_EFFECTS set. That is no longer accurate. */
TREE_SIDE_EFFECTS (wrapper) = 1;
}
else
{
temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
if (p && !IS_EMPTY_STMT (*p))
{
*p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
TREE_SIDE_EFFECTS (wrapper) = 1;
}
}
TREE_TYPE (wrapper) = void_type_node;
return temp;
}
return NULL_TREE;
}
/* Prepare calls to builtins to SAVE and RESTORE the stack as well as
a temporary through which they communicate. */
static void
build_stack_save_restore (tree *save, tree *restore)
{
tree save_call, tmp_var;
save_call =
build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
NULL_TREE);
tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
*save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
*restore =
build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
tree_cons (NULL_TREE, tmp_var, NULL_TREE));
}
/* Gimplify a BIND_EXPR. Just voidify and recurse. */
static enum gimplify_status
gimplify_bind_expr (tree *expr_p, tree *pre_p)
{
tree bind_expr = *expr_p;
tree temp = voidify_wrapper_expr (bind_expr);
bool old_save_stack = gimplify_ctxp->save_stack;
tree t;
/* Mark variables seen in this bind expr. */
for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
t->decl.seen_in_bind_expr = 1;
gimple_push_bind_expr (bind_expr);
gimplify_ctxp->save_stack = false;
gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
if (gimplify_ctxp->save_stack)
{
tree stack_save, stack_restore;
/* Save stack on entry and restore it on exit. Add a try_finally
block to achieve this. Note that mudflap depends on the
format of the emitted code: see mx_register_decls(). */
build_stack_save_restore (&stack_save, &stack_restore);
t = build (TRY_FINALLY_EXPR, void_type_node,
BIND_EXPR_BODY (bind_expr), NULL_TREE);
append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
BIND_EXPR_BODY (bind_expr) = NULL_TREE;
append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
}
gimplify_ctxp->save_stack = old_save_stack;
gimple_pop_bind_expr ();
if (temp)
{
*expr_p = temp;
append_to_statement_list (bind_expr, pre_p);
return GS_OK;
}
else
return GS_ALL_DONE;
}
/* Gimplify a RETURN_EXPR. If the expression to be returned is not a
GIMPLE value, it is assigned to a new temporary and the statement is
re-written to return the temporary.
PRE_P points to the list where side effects that must happen before
STMT should be stored. */
static enum gimplify_status
gimplify_return_expr (tree stmt, tree *pre_p)
{
tree ret_expr = TREE_OPERAND (stmt, 0);
tree result;
if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL)
return GS_ALL_DONE;
if (ret_expr == error_mark_node)
return GS_ERROR;
if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
result = NULL_TREE;
else
{
result = TREE_OPERAND (ret_expr, 0);
#ifdef ENABLE_CHECKING
if ((TREE_CODE (ret_expr) != MODIFY_EXPR
&& TREE_CODE (ret_expr) != INIT_EXPR)
|| TREE_CODE (result) != RESULT_DECL)
abort ();
#endif
}
/* We need to pass the full MODIFY_EXPR down so that special handling
can replace it with something else. */
gimplify_stmt (&ret_expr);
if (result == NULL_TREE)
TREE_OPERAND (stmt, 0) = NULL_TREE;
else if (ret_expr == TREE_OPERAND (stmt, 0))
/* It was already GIMPLE. */
return GS_ALL_DONE;
else
{
/* If there's still a MODIFY_EXPR of the RESULT_DECL after
gimplification, find it so we can put it in the RETURN_EXPR. */
tree ret = NULL_TREE;
if (TREE_CODE (ret_expr) == STATEMENT_LIST)
{
tree_stmt_iterator si;
for (si = tsi_start (ret_expr); !tsi_end_p (si); tsi_next (&si))
{
tree sub = tsi_stmt (si);
if (TREE_CODE (sub) == MODIFY_EXPR
&& TREE_OPERAND (sub, 0) == result)
{
ret = sub;
if (tsi_one_before_end_p (si))
tsi_delink (&si);
else
{
/* If there were posteffects after the MODIFY_EXPR,
we need a temporary. */
tree tmp = create_tmp_var (TREE_TYPE (result), "retval");
TREE_OPERAND (ret, 0) = tmp;
ret = build (MODIFY_EXPR, TREE_TYPE (result),
result, tmp);
}
break;
}
}
}
if (ret)
TREE_OPERAND (stmt, 0) = ret;
else
/* The return value must be set up some other way. Just tell
expand_return that we're returning the RESULT_DECL. */
TREE_OPERAND (stmt, 0) = result;
}
append_to_statement_list (ret_expr, pre_p);
return GS_ALL_DONE;
}
/* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
and replacing the LOOP_EXPR with goto, but if the loop contains an
EXIT_EXPR, we need to append a label for it to jump to. */
static enum gimplify_status
gimplify_loop_expr (tree *expr_p, tree *pre_p)
{
tree saved_label = gimplify_ctxp->exit_label;
tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
append_to_statement_list (start_label, pre_p);
gimplify_ctxp->exit_label = NULL_TREE;
gimplify_stmt (&LOOP_EXPR_BODY (*expr_p));
append_to_statement_list (LOOP_EXPR_BODY (*expr_p), pre_p);
if (gimplify_ctxp->exit_label)
{
append_to_statement_list (jump_stmt, pre_p);
*expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
}
else
*expr_p = jump_stmt;
gimplify_ctxp->exit_label = saved_label;
return GS_ALL_DONE;
}
/* Compare two case labels. Because the front end should already have
made sure that case ranges do not overlap, it is enough to only compare
the CASE_LOW values of each case label. */
static int
compare_case_labels (const void *p1, const void *p2)
{
tree case1 = *(tree *)p1;
tree case2 = *(tree *)p2;
return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
}
/* Sort the case labels in LABEL_VEC in ascending order. */
void
sort_case_labels (tree label_vec)
{
size_t len = TREE_VEC_LENGTH (label_vec);
tree default_case = TREE_VEC_ELT (label_vec, len - 1);
if (CASE_LOW (default_case))
{
size_t i;
/* The last label in the vector should be the default case
but it is not. */
for (i = 0; i < len; ++i)
{
tree t = TREE_VEC_ELT (label_vec, i);
if (!CASE_LOW (t))
{
default_case = t;
TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
TREE_VEC_ELT (label_vec, len - 1) = default_case;
break;
}
}
}
qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
compare_case_labels);
}
/* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
branch to. */
static enum gimplify_status
gimplify_switch_expr (tree *expr_p, tree *pre_p)
{
tree switch_expr = *expr_p;
enum gimplify_status ret;
ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
is_gimple_val, fb_rvalue);
if (SWITCH_BODY (switch_expr))
{
varray_type labels, saved_labels;
tree label_vec, default_case = NULL_TREE;
size_t i, len;
/* If someone can be bothered to fill in the labels, they can
be bothered to null out the body too. */
if (SWITCH_LABELS (switch_expr))
abort ();
saved_labels = gimplify_ctxp->case_labels;
VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
labels = gimplify_ctxp->case_labels;
gimplify_ctxp->case_labels = saved_labels;
len = VARRAY_ACTIVE_SIZE (labels);
for (i = 0; i < len; ++i)
{
tree t = VARRAY_TREE (labels, i);
if (!CASE_LOW (t))
{
/* The default case must be the last label in the list. */
default_case = t;
VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
len--;
break;
}
}
label_vec = make_tree_vec (len + 1);
SWITCH_LABELS (*expr_p) = label_vec;
append_to_statement_list (switch_expr, pre_p);
if (! default_case)
{
/* If the switch has no default label, add one, so that we jump
around the switch body. */
default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
NULL_TREE, create_artificial_label ());
append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
*expr_p = build (LABEL_EXPR, void_type_node,
CASE_LABEL (default_case));
}
else
*expr_p = SWITCH_BODY (switch_expr);
for (i = 0; i < len; ++i)
TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
TREE_VEC_ELT (label_vec, len) = default_case;
sort_case_labels (label_vec);
SWITCH_BODY (switch_expr) = NULL;
}
else if (!SWITCH_LABELS (switch_expr))
abort ();
return ret;
}
static enum gimplify_status
gimplify_case_label_expr (tree *expr_p)
{
tree expr = *expr_p;
if (gimplify_ctxp->case_labels)
VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
else
abort ();
*expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
return GS_ALL_DONE;
}
/* Gimplify a LABELED_BLOCK_EXPR into a LABEL_EXPR following
a (possibly empty) body. */
static enum gimplify_status
gimplify_labeled_block_expr (tree *expr_p)
{
tree body = LABELED_BLOCK_BODY (*expr_p);
tree label = LABELED_BLOCK_LABEL (*expr_p);
tree t;
DECL_CONTEXT (label) = current_function_decl;
t = build (LABEL_EXPR, void_type_node, label);
if (body != NULL_TREE)
t = build (COMPOUND_EXPR, void_type_node, body, t);
*expr_p = t;
return GS_OK;
}
/* Gimplify a EXIT_BLOCK_EXPR into a GOTO_EXPR. */
static enum gimplify_status
gimplify_exit_block_expr (tree *expr_p)
{
tree labeled_block = TREE_OPERAND (*expr_p, 0);
tree label;
/* First operand must be a LABELED_BLOCK_EXPR, which should
already be lowered (or partially lowered) when we get here. */
#if defined ENABLE_CHECKING
if (TREE_CODE (labeled_block) != LABELED_BLOCK_EXPR)
abort ();
#endif
label = LABELED_BLOCK_LABEL (labeled_block);
*expr_p = build1 (GOTO_EXPR, void_type_node, label);
return GS_OK;
}
/* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
if necessary. */
tree
build_and_jump (tree *label_p)
{
if (label_p == NULL)
/* If there's nowhere to jump, just fall through. */
return build_empty_stmt ();
if (*label_p == NULL_TREE)
{
tree label = create_artificial_label ();
*label_p = label;
}
return build1 (GOTO_EXPR, void_type_node, *label_p);
}
/* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
This also involves building a label to jump to and communicating it to
gimplify_loop_expr through gimplify_ctxp->exit_label. */
static enum gimplify_status
gimplify_exit_expr (tree *expr_p)
{
tree cond = TREE_OPERAND (*expr_p, 0);
tree expr;
expr = build_and_jump (&gimplify_ctxp->exit_label);
expr = build (COND_EXPR, void_type_node, cond, expr, build_empty_stmt ());
*expr_p = expr;
return GS_OK;
}
/* A helper function to be called via walk_tree. Mark all labels under *TP
as being forced. To be called for DECL_INITIAL of static variables. */
tree
force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
{
if (TYPE_P (*tp))
*walk_subtrees = 0;
if (TREE_CODE (*tp) == LABEL_DECL)
FORCED_LABEL (*tp) = 1;
return NULL_TREE;
}
/* Break out elements of a constructor used as an initializer into separate
MODIFY_EXPRs.
Note that we still need to clear any elements that don't have explicit
initializers, so if not all elements are initialized we keep the
original MODIFY_EXPR, we just remove all of the constructor elements. */
static enum gimplify_status
gimplify_init_constructor (tree *expr_p, tree *pre_p,
tree *post_p, int want_value)
{
tree object = TREE_OPERAND (*expr_p, 0);
tree ctor = TREE_OPERAND (*expr_p, 1);
tree type = TREE_TYPE (ctor);
enum gimplify_status ret;
tree elt_list;
if (TREE_CODE (ctor) != CONSTRUCTOR)
return GS_UNHANDLED;
elt_list = CONSTRUCTOR_ELTS (ctor);
ret = GS_ALL_DONE;
switch (TREE_CODE (type))
{
case RECORD_TYPE:
case UNION_TYPE:
case QUAL_UNION_TYPE:
case ARRAY_TYPE:
{
HOST_WIDE_INT i, num_elements, num_nonzero_elements;
HOST_WIDE_INT num_nonconstant_elements;
bool cleared;
/* Aggregate types must lower constructors to initialization of
individual elements. The exception is that a CONSTRUCTOR node
with no elements indicates zero-initialization of the whole. */
if (elt_list == NULL)
{
if (want_value)
{
*expr_p = object;
return GS_OK;
}
else
return GS_ALL_DONE;
}
categorize_ctor_elements (ctor, &num_nonzero_elements,
&num_nonconstant_elements);
num_elements = count_type_elements (TREE_TYPE (ctor));
/* If a const aggregate variable is being initialized, then it
should never be a lose to promote the variable to be static. */
if (num_nonconstant_elements == 0
&& TREE_READONLY (object)
&& TREE_CODE (object) == VAR_DECL)
{
DECL_INITIAL (object) = ctor;
TREE_STATIC (object) = 1;
if (!DECL_NAME (object))
DECL_NAME (object) = create_tmp_var_name ("C");
walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
/* ??? C++ doesn't automatically append a .<number> to the
assembler name, and even when it does, it looks a FE private
data structures to figure out what that number should be,
which are not set for this variable. I suppose this is
important for local statics for inline functions, which aren't
"local" in the object file sense. So in order to get a unique
TU-local symbol, we must invoke the lhd version now. */
lhd_set_decl_assembler_name (object);
*expr_p = build_empty_stmt ();
break;
}
/* If there are "lots" of initialized elements, and all of them
are valid address constants, then the entire initializer can
be dropped to memory, and then memcpy'd out. */
if (num_nonconstant_elements == 0)
{
HOST_WIDE_INT size = int_size_in_bytes (type);
unsigned int align;
/* ??? We can still get unbounded array types, at least
from the C++ front end. This seems wrong, but attempt
to work around it for now. */
if (size < 0)
{
size = int_size_in_bytes (TREE_TYPE (object));
if (size >= 0)
TREE_TYPE (ctor) = type = TREE_TYPE (object);
}
/* Find the maximum alignment we can assume for the object. */
/* ??? Make use of DECL_OFFSET_ALIGN. */
if (DECL_P (object))
align = DECL_ALIGN (object);
else
align = TYPE_ALIGN (type);
if (size > 0 && !can_move_by_pieces (size, align))
{
tree new = create_tmp_var_raw (type, "C");
gimple_add_tmp_var (new);
TREE_STATIC (new) = 1;
TREE_READONLY (new) = 1;
DECL_INITIAL (new) = ctor;
if (align > DECL_ALIGN (new))
{
DECL_ALIGN (new) = align;
DECL_USER_ALIGN (new) = 1;
}
walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
TREE_OPERAND (*expr_p, 1) = new;
break;
}
}
/* If there are "lots" of initialized elements, even discounting
those that are not address constants (and thus *must* be
computed at runtime), then partition the constructor into
constant and non-constant parts. Block copy the constant
parts in, then generate code for the non-constant parts. */
/* TODO. There's code in cp/typeck.c to do this. */
/* If there are "lots" of zeros, then block clear the object first. */
cleared = false;
if (num_elements - num_nonzero_elements > CLEAR_RATIO
&& num_nonzero_elements < num_elements/4)
cleared = true;
/* ??? This bit ought not be needed. For any element not present
in the initializer, we should simply set them to zero. Except
we'd need to *find* the elements that are not present, and that
requires trickery to avoid quadratic compile-time behavior in
large cases or excessive memory use in small cases. */
else
{
HOST_WIDE_INT len = list_length (elt_list);
if (TREE_CODE (type) == ARRAY_TYPE)
{
tree nelts = array_type_nelts (type);
if (!host_integerp (nelts, 1)
|| tree_low_cst (nelts, 1) != len)
cleared = 1;;
}
else if (len != fields_length (type))
cleared = 1;
}
if (cleared)
{
CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
append_to_statement_list (*expr_p, pre_p);
}
for (i = 0; elt_list; i++, elt_list = TREE_CHAIN (elt_list))
{
tree purpose, value, cref, init;
purpose = TREE_PURPOSE (elt_list);
value = TREE_VALUE (elt_list);
if (cleared && initializer_zerop (value))
continue;
if (TREE_CODE (type) == ARRAY_TYPE)
{
tree t = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
/* ??? Here's to hoping the front end fills in all of the
indicies, so we don't have to figure out what's missing
ourselves. */
if (!purpose)
abort ();
/* ??? Need to handle this. */
if (TREE_CODE (purpose) == RANGE_EXPR)
abort ();
cref = build (ARRAY_REF, t, object, purpose);
}
else
{
cref = build (COMPONENT_REF, TREE_TYPE (purpose),
object, purpose);
}
init = build (MODIFY_EXPR, TREE_TYPE (purpose), cref, value);
/* Each member initialization is a full-expression. */
gimplify_stmt (&init);
append_to_statement_list (init, pre_p);
}
*expr_p = build_empty_stmt ();
}
break;
case COMPLEX_TYPE:
{
tree r, i;
/* Extract the real and imaginary parts out of the ctor. */
r = i = NULL_TREE;
if (elt_list)
{
r = TREE_VALUE (elt_list);
elt_list = TREE_CHAIN (elt_list);
if (elt_list)
{
i = TREE_VALUE (elt_list);
if (TREE_CHAIN (elt_list))
abort ();
}
}
if (r == NULL || i == NULL)
{
tree zero = convert (TREE_TYPE (type), integer_zero_node);
if (r == NULL)
r = zero;
if (i == NULL)
i = zero;
}
/* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
represent creation of a complex value. */
if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
{
ctor = build_complex (type, r, i);
TREE_OPERAND (*expr_p, 1) = ctor;
}
else
{
ctor = build (COMPLEX_EXPR, type, r, i);
TREE_OPERAND (*expr_p, 1) = ctor;
ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
is_gimple_rhs, fb_rvalue);
}
}
break;
case VECTOR_TYPE:
/* Go ahead and simplify constant constructors to VECTOR_CST. */
if (TREE_CONSTANT (ctor))
TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
else
{
/* Vector types use CONSTRUCTOR all the way through gimple
compilation as a general initializer. */
for (; elt_list; elt_list = TREE_CHAIN (elt_list))
{
enum gimplify_status tret;
tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
is_gimple_constructor_elt, fb_rvalue);
if (tret == GS_ERROR)
ret = GS_ERROR;
}
}
break;
default:
/* So how did we get a CONSTRUCTOR for a scalar type? */
abort ();
}
if (ret == GS_ERROR)
return GS_ERROR;
else if (want_value)
{
append_to_statement_list (*expr_p, pre_p);
*expr_p = object;
return GS_OK;
}
else
return GS_ALL_DONE;
}
/* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
different from its canonical type, wrap the whole thing inside a
NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
type.
The canonical type of a COMPONENT_REF is the type of the field being
referenced--unless the field is a bit-field which can be read directly
in a smaller mode, in which case the canonical type is the
sign-appropriate type corresponding to that mode. */
static void
canonicalize_component_ref (tree *expr_p)
{
tree expr = *expr_p;
tree type;
if (TREE_CODE (expr) != COMPONENT_REF)
abort ();
if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
else
type = TREE_TYPE (TREE_OPERAND (expr, 1));
if (TREE_TYPE (expr) != type)
{
tree old_type = TREE_TYPE (expr);
/* Set the type of the COMPONENT_REF to the underlying type. */
TREE_TYPE (expr) = type;
/* And wrap the whole thing inside a NOP_EXPR. */
expr = build1 (NOP_EXPR, old_type, expr);
*expr_p = expr;
}
}
/* If a NOP conversion is changing a pointer to array of foo to a pointer
to foo, embed that change in the ADDR_EXPR. Lest we perturb the type
system too badly, we must take extra steps to ensure that the ADDR_EXPR
and the addressed object continue to agree on types. */
/* ??? We might could do better if we recognize
T array[N][M];
(T *)&array
==>
&array[0][0];
*/
static void
canonicalize_addr_expr (tree* expr_p)
{
tree expr = *expr_p;
tree ctype = TREE_TYPE (expr);
tree addr_expr = TREE_OPERAND (expr, 0);
tree atype = TREE_TYPE (addr_expr);
tree dctype, datype, ddatype, otype, obj_expr;
/* Both cast and addr_expr types should be pointers. */
if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
return;
/* The addr_expr type should be a pointer to an array. */
datype = TREE_TYPE (atype);
if (TREE_CODE (datype) != ARRAY_TYPE)
return;
/* Both cast and addr_expr types should address the same object type. */
dctype = TREE_TYPE (ctype);
ddatype = TREE_TYPE (datype);
if (!lang_hooks.types_compatible_p (ddatype, dctype))
return;
/* The addr_expr and the object type should match. */
obj_expr = TREE_OPERAND (addr_expr, 0);
otype = TREE_TYPE (obj_expr);
if (!lang_hooks.types_compatible_p (otype, datype))
return;
/* All checks succeeded. Build a new node to merge the cast. */
*expr_p = build1 (ADDR_EXPR, ctype, obj_expr);
}
/* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
underneath as appropriate. */
static enum gimplify_status
gimplify_conversion (tree *expr_p)
{
/* Strip away as many useless type conversions as possible
at the toplevel. */
STRIP_USELESS_TYPE_CONVERSION (*expr_p);
/* If we still have a conversion at the toplevel, then strip
away all but the outermost conversion. */
if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
{
STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
/* And remove the outermost conversion if it's useless. */
if (tree_ssa_useless_type_conversion (*expr_p))
*expr_p = TREE_OPERAND (*expr_p, 0);
}
/* If we still have a conversion at the toplevel,
then canonicalize some constructs. */
if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
{
tree sub = TREE_OPERAND (*expr_p, 0);
/* If a NOP conversion is changing the type of a COMPONENT_REF
expression, then canonicalize its type now in order to expose more
redundant conversions. */
if (TREE_CODE (sub) == COMPONENT_REF)
canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
/* If a NOP conversion is changing a pointer to array of foo
to a pointer to foo, embed that change in the ADDR_EXPR. */
else if (TREE_CODE (sub) == ADDR_EXPR)
canonicalize_addr_expr (expr_p);
}
return GS_OK;
}
/* Reduce MIN/MAX_EXPR to a COND_EXPR for further gimplification. */
static enum gimplify_status
gimplify_minimax_expr (tree *expr_p, tree *pre_p, tree *post_p)
{
tree op1 = TREE_OPERAND (*expr_p, 0);
tree op2 = TREE_OPERAND (*expr_p, 1);
enum tree_code code;
enum gimplify_status r0, r1;
if (TREE_CODE (*expr_p) == MIN_EXPR)
code = LE_EXPR;
else
code = GE_EXPR;
r0 = gimplify_expr (&op1, pre_p, post_p, is_gimple_val, fb_rvalue);
r1 = gimplify_expr (&op2, pre_p, post_p, is_gimple_val, fb_rvalue);
*expr_p = build (COND_EXPR, TREE_TYPE (*expr_p),
build (code, boolean_type_node, op1, op2),
op1, op2);
if (r0 == GS_ERROR || r1 == GS_ERROR)
return GS_ERROR;
else
return GS_OK;
}
/* Build an expression for the address of T. Folds away INDIRECT_REF to
avoid confusing the gimplify process. */
static tree
build_addr_expr_with_type (tree t, tree ptrtype)
{
if (TREE_CODE (t) == INDIRECT_REF)
{
t = TREE_OPERAND (t, 0);
if (TREE_TYPE (t) != ptrtype)
t = build1 (NOP_EXPR, ptrtype, t);
}
else
{
tree base = t;
while (TREE_CODE (base) == COMPONENT_REF
|| TREE_CODE (base) == ARRAY_REF)
base = TREE_OPERAND (base, 0);
if (DECL_P (base))
TREE_ADDRESSABLE (base) = 1;
t = build1 (ADDR_EXPR, ptrtype, t);
}
return t;
}
static tree
build_addr_expr (tree t)
{
return build_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
}
/* Subroutine of gimplify_compound_lval and gimplify_array_ref.
Converts an ARRAY_REF to the equivalent *(&array + offset) form. */
static enum gimplify_status
gimplify_array_ref_to_plus (tree *expr_p, tree *pre_p, tree *post_p)
{
tree array = TREE_OPERAND (*expr_p, 0);
tree arrtype = TREE_TYPE (array);
tree elttype = TREE_TYPE (arrtype);
tree size = size_in_bytes (elttype);
tree ptrtype = build_pointer_type (elttype);
enum tree_code add_code = PLUS_EXPR;
tree idx = TREE_OPERAND (*expr_p, 1);
tree minidx, offset, addr, result;
enum gimplify_status ret;
/* If the array domain does not start at zero, apply the offset. */
minidx = TYPE_DOMAIN (arrtype);
if (minidx)
{
minidx = TYPE_MIN_VALUE (minidx);
if (minidx && !integer_zerop (minidx))
{
idx = convert (TREE_TYPE (minidx), idx);
idx = fold (build (MINUS_EXPR, TREE_TYPE (minidx), idx, minidx));
}
}
/* If the index is negative -- a technically invalid situation now
that we've biased the index back to zero -- then casting it to
unsigned has ill effects. In particular, -1*4U/4U != -1.
Represent this as a subtraction of a positive rather than addition
of a negative. This will prevent any conversion back to ARRAY_REF
from getting the wrong results from the division. */
if (TREE_CODE (idx) == INTEGER_CST && tree_int_cst_sgn (idx) < 0)
{
idx = fold (build1 (NEGATE_EXPR, TREE_TYPE (idx), idx));
add_code = MINUS_EXPR;
}
/* Pointer arithmetic must be done in sizetype. */
idx = convert (sizetype, idx);
/* Convert the index to a byte offset. */
offset = size_binop (MULT_EXPR, size, idx);
ret = gimplify_expr (&array, pre_p, post_p, is_gimple_min_lval, fb_lvalue);
if (ret == GS_ERROR)
return ret;
addr = build_addr_expr_with_type (array, ptrtype);
result = fold (build (add_code, ptrtype, addr, offset));
*expr_p = build1 (INDIRECT_REF, elttype, result);
return GS_OK;
}
/* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
node pointed by EXPR_P.
compound_lval
: min_lval '[' val ']'
| min_lval '.' ID
| compound_lval '[' val ']'
| compound_lval '.' ID
This is not part of the original SIMPLE definition, which separates
array and member references, but it seems reasonable to handle them
together. Also, this way we don't run into problems with union
aliasing; gcc requires that for accesses through a union to alias, the
union reference must be explicit, which was not always the case when we
were splitting up array and member refs.
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored.
POST_P points to the list where side effects that must happen after
*EXPR_P should be stored. */
static enum gimplify_status
gimplify_compound_lval (tree *expr_p, tree *pre_p,
tree *post_p, int want_lvalue)
{
tree *p;
enum tree_code code;
varray_type stack;
enum gimplify_status ret;
#if defined ENABLE_CHECKING
if (TREE_CODE (*expr_p) != ARRAY_REF
&& TREE_CODE (*expr_p) != COMPONENT_REF
&& TREE_CODE (*expr_p) != REALPART_EXPR
&& TREE_CODE (*expr_p) != IMAGPART_EXPR)
abort ();
#endif
code = ERROR_MARK; /* [GIMPLE] Avoid uninitialized use warning. */
/* Create a stack of the subexpressions so later we can walk them in
order from inner to outer. */
VARRAY_TREE_INIT (stack, 10, "stack");
for (p = expr_p;
TREE_CODE (*p) == ARRAY_REF
|| TREE_CODE (*p) == COMPONENT_REF
|| TREE_CODE (*p) == REALPART_EXPR
|| TREE_CODE (*p) == IMAGPART_EXPR;
p = &TREE_OPERAND (*p, 0))
{
code = TREE_CODE (*p);
if (code == ARRAY_REF)
{
tree elttype = TREE_TYPE (TREE_TYPE (TREE_OPERAND (*p, 0)));
if (!TREE_CONSTANT (TYPE_SIZE_UNIT (elttype)))
/* If the size of the array elements is not constant,
computing the offset is non-trivial, so expose it. */
break;
}
VARRAY_PUSH_TREE (stack, *p);
}
/* Now 'p' points to the first bit that isn't a ref, 'code' is the
TREE_CODE of the last bit that was, and 'stack' is a stack of pointers
to all the refs we've walked through.
Gimplify the base, and then process each of the outer nodes from left
to right. */
ret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval,
code != ARRAY_REF ? fb_either : fb_lvalue);
for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
{
tree t = VARRAY_TOP_TREE (stack);
if (TREE_CODE (t) == ARRAY_REF)
{
/* Gimplify the dimension. */
enum gimplify_status tret;
/* Temporary fix for gcc.c-torture/execute/20040313-1.c.
Gimplify non-constant array indices into a temporary
variable.
FIXME - The real fix is to gimplify post-modify
expressions into a minimal gimple lvalue. However, that
exposes bugs in alias analysis. The alias analyzer does
not handle &PTR->FIELD very well. Will fix after the
branch is merged into mainline (dnovillo 2004-05-03). */
if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
{
tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
is_gimple_tmp_var, fb_rvalue);
if (tret == GS_ERROR)
ret = GS_ERROR;
}
}
recalculate_side_effects (t);
VARRAY_POP (stack);
}
/* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
if (!want_lvalue && TREE_CODE (*expr_p) == COMPONENT_REF)
{
canonicalize_component_ref (expr_p);
ret = MIN (ret, GS_OK);
}
return ret;
}
/* Re-write the ARRAY_REF node pointed by EXPR_P.
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored.
POST_P points to the list where side effects that must happen after
*EXPR_P should be stored.
FIXME: ARRAY_REF currently doesn't accept a pointer as the array
argument, so this gimplification uses an INDIRECT_REF of ARRAY_TYPE.
ARRAY_REF should be extended. */
static enum gimplify_status
gimplify_array_ref (tree *expr_p, tree *pre_p,
tree *post_p, int want_lvalue)
{
tree elttype = TREE_TYPE (TREE_TYPE (TREE_OPERAND (*expr_p, 0)));
if (!TREE_CONSTANT (TYPE_SIZE_UNIT (elttype)))
/* If the size of the array elements is not constant,
computing the offset is non-trivial, so expose it. */
return gimplify_array_ref_to_plus (expr_p, pre_p, post_p);
else
/* Handle array and member refs together for now. When alias analysis
improves, we may want to go back to handling them separately. */
return gimplify_compound_lval (expr_p, pre_p, post_p, want_lvalue);
}
/* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored.
POST_P points to the list where side effects that must happen after
*EXPR_P should be stored.
WANT_VALUE is nonzero iff we want to use the value of this expression
in another expression. */
static enum gimplify_status
gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
int want_value)
{
enum tree_code code;
tree lhs, lvalue, rhs, t1;
bool postfix;
enum tree_code arith_code;
enum gimplify_status ret;
code = TREE_CODE (*expr_p);
#if defined ENABLE_CHECKING
if (code != POSTINCREMENT_EXPR
&& code != POSTDECREMENT_EXPR
&& code != PREINCREMENT_EXPR
&& code != PREDECREMENT_EXPR)
abort ();
#endif
/* Prefix or postfix? */
if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
/* Faster to treat as prefix if result is not used. */
postfix = want_value;
else
postfix = false;
/* Add or subtract? */
if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
arith_code = PLUS_EXPR;
else
arith_code = MINUS_EXPR;
/* Gimplify the LHS into a GIMPLE lvalue. */
lvalue = TREE_OPERAND (*expr_p, 0);
ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
if (ret == GS_ERROR)
return ret;
/* Extract the operands to the arithmetic operation. */
lhs = lvalue;
rhs = TREE_OPERAND (*expr_p, 1);
/* For postfix operator, we evaluate the LHS to an rvalue and then use
that as the result value and in the postqueue operation. */
if (postfix)
{
ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
if (ret == GS_ERROR)
return ret;
}
t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
if (postfix)
{
gimplify_stmt (&t1);
append_to_statement_list (t1, post_p);
*expr_p = lhs;
return GS_ALL_DONE;
}
else
{
*expr_p = t1;
return GS_OK;
}
}
/* Gimplify the CALL_EXPR node pointed by EXPR_P.
call_expr
: ID '(' arglist ')'
arglist
: arglist ',' val
| val
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored. */
static enum gimplify_status
gimplify_call_expr (tree *expr_p, tree *pre_p, bool (*gimple_test_f) (tree))
{
tree decl;
tree arglist;
enum gimplify_status ret;
#if defined ENABLE_CHECKING
if (TREE_CODE (*expr_p) != CALL_EXPR)
abort ();
#endif
/* For reliable diagnostics during inlining, it is necessary that
every call_expr be annotated with file and line. */
if (!EXPR_LOCUS (*expr_p))
annotate_with_locus (*expr_p, input_location);
/* This may be a call to a builtin function.
Builtin function calls may be transformed into different
(and more efficient) builtin function calls under certain
circumstances. Unfortunately, gimplification can muck things
up enough that the builtin expanders are not aware that certain
transformations are still valid.
So we attempt transformation/gimplification of the call before
we gimplify the CALL_EXPR. At this time we do not manage to
transform all calls in the same manner as the expanders do, but
we do transform most of them. */
decl = get_callee_fndecl (*expr_p);
if (decl && DECL_BUILT_IN (decl))
{
tree new;
/* If it is allocation of stack, record the need to restore the memory
when the enclosing bind_expr is exited. */
if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_ALLOC)
gimplify_ctxp->save_stack = true;
/* If it is restore of the stack, reset it, since it means we are
regimplifying the bind_expr. Note that we use the fact that
for try_finally_expr, try part is processed first. */
if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_RESTORE)
gimplify_ctxp->save_stack = false;
new = simplify_builtin (*expr_p, gimple_test_f == is_gimple_stmt);
if (new && new != *expr_p)
{
/* There was a transformation of this call which computes the
same value, but in a more efficient way. Return and try
again. */
*expr_p = new;
return GS_OK;
}
}
/* There is a sequence point before the call, so any side effects in
the calling expression must occur before the actual call. Force
gimplify_expr to use an internal post queue. */
ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
is_gimple_val, fb_rvalue);
if (PUSH_ARGS_REVERSED)
TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
arglist = TREE_CHAIN (arglist))
{
enum gimplify_status t;
/* There is a sequence point before a function call. Side effects in
the argument list must occur before the actual call. So, when
gimplifying arguments, force gimplify_expr to use an internal
post queue which is then appended to the end of PRE_P. */
t = gimplify_expr (&TREE_VALUE (arglist), pre_p, NULL, is_gimple_val,
fb_rvalue);
if (t == GS_ERROR)
ret = GS_ERROR;
}
if (PUSH_ARGS_REVERSED)
TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
/* Try this again in case gimplification exposed something. */
if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
{
tree new = simplify_builtin (*expr_p, gimple_test_f == is_gimple_stmt);
if (new && new != *expr_p)
{
/* There was a transformation of this call which computes the
same value, but in a more efficient way. Return and try
again. */
*expr_p = new;
return GS_OK;
}
}
/* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
decl. This allows us to eliminate redundant or useless
calls to "const" functions. */
if (TREE_CODE (*expr_p) == CALL_EXPR
&& (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
TREE_SIDE_EFFECTS (*expr_p) = 0;
return ret;
}
/* Handle shortcut semantics in the predicate operand of a COND_EXPR by
rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
condition is true or false, respectively. If null, we should generate
our own to skip over the evaluation of this specific expression.
This function is the tree equivalent of do_jump.
shortcut_cond_r should only be called by shortcut_cond_expr. */
static tree
shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
{
tree local_label = NULL_TREE;
tree t, expr = NULL;
/* OK, it's not a simple case; we need to pull apart the COND_EXPR to
retain the shortcut semantics. Just insert the gotos here;
shortcut_cond_expr will append the real blocks later. */
if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
{
/* Turn if (a && b) into
if (a); else goto no;
if (b) goto yes; else goto no;
(no:) */
if (false_label_p == NULL)
false_label_p = &local_label;
t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
append_to_statement_list (t, &expr);
t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
false_label_p);
append_to_statement_list (t, &expr);
}
else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
{
/* Turn if (a || b) into
if (a) goto yes;
if (b) goto yes; else goto no;
(yes:) */
if (true_label_p == NULL)
true_label_p = &local_label;
t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
append_to_statement_list (t, &expr);
t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
false_label_p);
append_to_statement_list (t, &expr);
}
else if (TREE_CODE (pred) == COND_EXPR)
{
/* As long as we're messing with gotos, turn if (a ? b : c) into
if (a)
if (b) goto yes; else goto no;
else
if (c) goto yes; else goto no; */
expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
false_label_p),
shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
false_label_p));
}
else
{
expr = build (COND_EXPR, void_type_node, pred,
build_and_jump (true_label_p),
build_and_jump (false_label_p));
}
if (local_label)
{
t = build1 (LABEL_EXPR, void_type_node, local_label);
append_to_statement_list (t, &expr);
}
return expr;
}
static tree
shortcut_cond_expr (tree expr)
{
tree pred = TREE_OPERAND (expr, 0);
tree then_ = TREE_OPERAND (expr, 1);
tree else_ = TREE_OPERAND (expr, 2);
tree true_label, false_label, end_label, t;
tree *true_label_p;
tree *false_label_p;
bool emit_end, emit_false;
/* First do simple transformations. */
if (!TREE_SIDE_EFFECTS (else_))
{
/* If there is no 'else', turn (a && b) into if (a) if (b). */
while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
{
TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
then_ = shortcut_cond_expr (expr);
pred = TREE_OPERAND (pred, 0);
expr = build (COND_EXPR, void_type_node, pred, then_,
build_empty_stmt ());
}
}
if (!TREE_SIDE_EFFECTS (then_))
{
/* If there is no 'then', turn
if (a || b); else d
into
if (a); else if (b); else d. */
while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
{
TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
else_ = shortcut_cond_expr (expr);
pred = TREE_OPERAND (pred, 0);
expr = build (COND_EXPR, void_type_node, pred,
build_empty_stmt (), else_);
}
}
/* If we're done, great. */
if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
&& TREE_CODE (pred) != TRUTH_ORIF_EXPR)
return expr;
/* Otherwise we need to mess with gotos. Change
if (a) c; else d;
to
if (a); else goto no;
c; goto end;
no: d; end:
and recursively gimplify the condition. */
true_label = false_label = end_label = NULL_TREE;
/* If our arms just jump somewhere, hijack those labels so we don't
generate jumps to jumps. */
if (TREE_CODE (then_) == GOTO_EXPR
&& TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
{
true_label = GOTO_DESTINATION (then_);
then_ = build_empty_stmt ();
}
if (TREE_CODE (else_) == GOTO_EXPR
&& TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
{
false_label = GOTO_DESTINATION (else_);
else_ = build_empty_stmt ();
}
/* If we aren't hijacking a label for the 'then' branch, it falls through. */
if (true_label)
true_label_p = &true_label;
else
true_label_p = NULL;
/* The 'else' branch also needs a label if it contains interesting code. */
if (false_label || TREE_SIDE_EFFECTS (else_))
false_label_p = &false_label;
else
false_label_p = NULL;
/* If there was nothing else in our arms, just forward the label(s). */
if (!TREE_SIDE_EFFECTS (then_) && !TREE_SIDE_EFFECTS (else_))
return shortcut_cond_r (pred, true_label_p, false_label_p);
/* If our last subexpression already has a terminal label, reuse it. */
if (TREE_SIDE_EFFECTS (else_))
expr = expr_last (else_);
else
expr = expr_last (then_);
if (TREE_CODE (expr) == LABEL_EXPR)
end_label = LABEL_EXPR_LABEL (expr);
/* If we don't care about jumping to the 'else' branch, jump to the end
if the condition is false. */
if (!false_label_p)
false_label_p = &end_label;
/* We only want to emit these labels if we aren't hijacking them. */
emit_end = (end_label == NULL_TREE);
emit_false = (false_label == NULL_TREE);
pred = shortcut_cond_r (pred, true_label_p, false_label_p);
expr = NULL;
append_to_statement_list (pred, &expr);
append_to_statement_list (then_, &expr);
if (TREE_SIDE_EFFECTS (else_))
{
t = build_and_jump (&end_label);
append_to_statement_list (t, &expr);
if (emit_false)
{
t = build1 (LABEL_EXPR, void_type_node, false_label);
append_to_statement_list (t, &expr);
}
append_to_statement_list (else_, &expr);
}
if (emit_end && end_label)
{
t = build1 (LABEL_EXPR, void_type_node, end_label);
append_to_statement_list (t, &expr);
}
return expr;
}
/* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
static tree
gimple_boolify (tree expr)
{
tree type = TREE_TYPE (expr);
if (TREE_CODE (type) == BOOLEAN_TYPE)
return expr;
/* If this is the predicate of a COND_EXPR, it might not even be a
truthvalue yet. */
expr = lang_hooks.truthvalue_conversion (expr);
switch (TREE_CODE (expr))
{
case TRUTH_AND_EXPR:
case TRUTH_OR_EXPR:
case TRUTH_XOR_EXPR:
case TRUTH_ANDIF_EXPR:
case TRUTH_ORIF_EXPR:
/* Also boolify the arguments of truth exprs. */
TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
/* FALLTHRU */
case TRUTH_NOT_EXPR:
TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
/* FALLTHRU */
case EQ_EXPR: case NE_EXPR:
case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
/* These expressions always produce boolean results. */
TREE_TYPE (expr) = boolean_type_node;
return expr;
default:
/* Other expressions that get here must have boolean values, but
might need to be converted to the appropriate mode. */
return convert (boolean_type_node, expr);
}
}
/* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
into
if (p) if (p)
t1 = a; a;
else or else
t1 = b; b;
t1;
The second form is used when *EXPR_P is of type void.
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored. */
static enum gimplify_status
gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target)
{
tree expr = *expr_p;
tree tmp;
enum gimplify_status ret;
/* If this COND_EXPR has a value, copy the values into a temporary within
the arms. */
if (! VOID_TYPE_P (TREE_TYPE (expr)))
{
if (target)
{
tmp = target;
ret = GS_OK;
}
else
{
tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
ret = GS_ALL_DONE;
}
/* Build the then clause, 't1 = a;'. But don't build an assignment
if this branch is void; in C++ it can be, if it's a throw. */
if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
TREE_OPERAND (expr, 1)
= build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
/* Build the else clause, 't1 = b;'. */
if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
TREE_OPERAND (expr, 2)
= build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 2));
TREE_TYPE (expr) = void_type_node;
recalculate_side_effects (expr);
/* Move the COND_EXPR to the prequeue and use the temp in its place. */
gimplify_stmt (&expr);
append_to_statement_list (expr, pre_p);
*expr_p = tmp;
return ret;
}
/* Make sure the condition has BOOLEAN_TYPE. */
TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
/* Break apart && and || conditions. */
if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
|| TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
{
expr = shortcut_cond_expr (expr);
if (expr != *expr_p)
{
*expr_p = expr;
/* We can't rely on gimplify_expr to re-gimplify the expanded
form properly, as cleanups might cause the target labels to be
wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
set up a conditional context. */
gimple_push_condition ();
gimplify_stmt (expr_p);
gimple_pop_condition (pre_p);
return GS_ALL_DONE;
}
}
/* Now do the normal gimplification. */
ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
is_gimple_condexpr, fb_rvalue);
gimple_push_condition ();
gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
recalculate_side_effects (expr);
gimple_pop_condition (pre_p);
if (ret == GS_ERROR)
;
else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
ret = GS_ALL_DONE;
else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
/* Rewrite "if (a); else b" to "if (!a) b" */
{
TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
is_gimple_condexpr, fb_rvalue);
tmp = TREE_OPERAND (expr, 1);
TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
TREE_OPERAND (expr, 2) = tmp;
}
else
/* Both arms are empty; replace the COND_EXPR with its predicate. */
expr = TREE_OPERAND (expr, 0);
*expr_p = expr;
return ret;
}
/* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
modify_expr
: varname '=' rhs
| '*' ID '=' rhs
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored.
POST_P points to the list where side effects that must happen after
*EXPR_P should be stored.
WANT_VALUE is nonzero iff we want to use the value of this expression
in another expression. */
static enum gimplify_status
gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
{
tree *from_p = &TREE_OPERAND (*expr_p, 1);
tree *to_p = &TREE_OPERAND (*expr_p, 0);
enum gimplify_status ret;
#if defined ENABLE_CHECKING
if (TREE_CODE (*expr_p) != MODIFY_EXPR && TREE_CODE (*expr_p) != INIT_EXPR)
abort ();
#endif
/* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
if (TREE_CODE (*expr_p) == INIT_EXPR)
TREE_SET_CODE (*expr_p, MODIFY_EXPR);
ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
if (ret == GS_ERROR)
return ret;
/* If we are initializing something from a TARGET_EXPR, strip the
TARGET_EXPR and initialize it directly. */
/* What about code that pulls out the temp and uses it elsewhere? I
think that such code never uses the TARGET_EXPR as an initializer. If
I'm wrong, we'll abort because the temp won't have any RTL. In that
case, I guess we'll need to replace references somehow. */
if (TREE_CODE (*from_p) == TARGET_EXPR)
*from_p = TARGET_EXPR_INITIAL (*from_p);
/* If we're assigning from a ?: expression with ADDRESSABLE type, push
the assignment down into the branches, since we can't generate a
temporary of such a type. */
if (TREE_CODE (*from_p) == COND_EXPR
&& TREE_ADDRESSABLE (TREE_TYPE (*from_p)))
{
*expr_p = *from_p;
return gimplify_cond_expr (expr_p, pre_p, *to_p);
}
ret = gimplify_expr (from_p, pre_p, post_p, is_gimple_rhs, fb_rvalue);
if (ret == GS_ERROR)
return ret;
ret = gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
if (ret != GS_UNHANDLED)
return ret;
/* If the destination is already simple, nothing else needed. */
if (is_gimple_tmp_var (*to_p))
ret = GS_ALL_DONE;
else
{
/* If the RHS of the MODIFY_EXPR may throw or make a nonlocal goto and
the LHS is a user variable, then we need to introduce a temporary.
ie temp = RHS; LHS = temp.
This way the optimizers can determine that the user variable is
only modified if evaluation of the RHS does not throw.
FIXME this should be handled by the is_gimple_rhs predicate. */
if (TREE_CODE (*from_p) == CALL_EXPR
|| (flag_non_call_exceptions && tree_could_trap_p (*from_p))
/* If we're dealing with a renamable type, either source or dest
must be a renamed variable. */
|| (is_gimple_reg_type (TREE_TYPE (*from_p))
&& !is_gimple_reg (*to_p)))
gimplify_expr (from_p, pre_p, post_p, is_gimple_val, fb_rvalue);
/* If the value being copied is of variable width, expose the length
if the copy by converting the whole thing to a memcpy. */
/* ??? Except that we can't manage this with VA_ARG_EXPR. Yes, this
does leave us with an edge condition that doesn't work. The only
way out is to rearrange how VA_ARG_EXPR works. */
if (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (*to_p))) != INTEGER_CST
&& TREE_CODE (*from_p) != VA_ARG_EXPR)
{
tree args, t, dest;
t = TYPE_SIZE_UNIT (TREE_TYPE (*to_p));
t = unshare_expr (t);
args = tree_cons (NULL, t, NULL);
t = build_addr_expr (*from_p);
args = tree_cons (NULL, t, args);
dest = build_addr_expr (*to_p);
args = tree_cons (NULL, dest, args);
t = implicit_built_in_decls[BUILT_IN_MEMCPY];
t = build_function_call_expr (t, args);
if (want_value)
{
t = build1 (NOP_EXPR, TREE_TYPE (dest), t);
t = build1 (INDIRECT_REF, TREE_TYPE (*to_p), t);
}
*expr_p = t;
return GS_OK;
}
ret = want_value ? GS_OK : GS_ALL_DONE;
}
if (want_value)
{
append_to_statement_list (*expr_p, pre_p);
*expr_p = *to_p;
}
return ret;
}
/* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
points to the expression to gimplify.
Expressions of the form 'a && b' are gimplified to:
a && b ? true : false
gimplify_cond_expr will do the rest.
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored. */
static enum gimplify_status
gimplify_boolean_expr (tree *expr_p)
{
/* Preserve the original type of the expression. */
tree type = TREE_TYPE (*expr_p);
*expr_p = build (COND_EXPR, type, *expr_p,
convert (type, boolean_true_node),
convert (type, boolean_false_node));
return GS_OK;
}
/* Gimplifies an expression sequence. This function gimplifies each
expression and re-writes the original expression with the last
expression of the sequence in GIMPLE form.
PRE_P points to the list where the side effects for all the
expressions in the sequence will be emitted.
WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
/* ??? Should rearrange to share the pre-queue with all the indirect
invocations of gimplify_expr. Would probably save on creations
of statement_list nodes. */
static enum gimplify_status
gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
{
tree t = *expr_p;
do
{
tree *sub_p = &TREE_OPERAND (t, 0);
if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
gimplify_compound_expr (sub_p, pre_p, false);
else
gimplify_stmt (sub_p);
append_to_statement_list (*sub_p, pre_p);
t = TREE_OPERAND (t, 1);
}
while (TREE_CODE (t) == COMPOUND_EXPR);
*expr_p = t;
if (want_value)
return GS_OK;
else
{
gimplify_stmt (expr_p);
return GS_ALL_DONE;
}
}
/* Gimplifies a statement list. These may be created either by an
enlightened front-end, or by shortcut_cond_expr. */
static enum gimplify_status
gimplify_statement_list (tree *expr_p)
{
tree_stmt_iterator i = tsi_start (*expr_p);
while (!tsi_end_p (i))
{
tree t;
gimplify_stmt (tsi_stmt_ptr (i));
t = tsi_stmt (i);
if (TREE_CODE (t) == STATEMENT_LIST)
{
tsi_link_before (&i, t, TSI_SAME_STMT);
tsi_delink (&i);
}
else
tsi_next (&i);
}
return GS_ALL_DONE;
}
/* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
gimplify. After gimplification, EXPR_P will point to a new temporary
that holds the original value of the SAVE_EXPR node.
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored. */
static enum gimplify_status
gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
{
enum gimplify_status ret = GS_ALL_DONE;
tree val;
#if defined ENABLE_CHECKING
if (TREE_CODE (*expr_p) != SAVE_EXPR)
abort ();
#endif
val = TREE_OPERAND (*expr_p, 0);
/* If the operand is already a GIMPLE temporary, just re-write the
SAVE_EXPR node. */
if (is_gimple_tmp_var (val))
*expr_p = val;
/* The operand may be a void-valued expression such as SAVE_EXPRs
generated by the Java frontend for class initialization. It is
being executed only for its side-effects. */
else if (TREE_TYPE (val) == void_type_node)
{
tree body = TREE_OPERAND (*expr_p, 0);
ret = gimplify_expr (& body, pre_p, post_p, is_gimple_stmt, fb_none);
append_to_statement_list (body, pre_p);
*expr_p = build_empty_stmt ();
}
else
*expr_p = TREE_OPERAND (*expr_p, 0)
= get_initialized_tmp_var (val, pre_p, post_p);
return ret;
}
/* Re-write the ADDR_EXPR node pointed by EXPR_P
unary_expr
: ...
| '&' varname
...
PRE_P points to the list where side effects that must happen before
*EXPR_P should be stored.
POST_P points to the list where side effects that must happen after
*EXPR_P should be stored. */
static enum gimplify_status
gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
{
tree expr = *expr_p;
tree op0 = TREE_OPERAND (expr, 0);
enum gimplify_status ret;
switch (TREE_CODE (op0))
{
case INDIRECT_REF:
/* Check if we are dealing with an expression of the form '&*ptr'.
While the front end folds away '&*ptr' into 'ptr', these
expressions may be generated internally by the compiler (e.g.,
builtins like __builtin_va_end). */
*expr_p = TREE_OPERAND (op0, 0);
ret = GS_OK;
break;
case ARRAY_REF:
/* Fold &a[6] to (&a + 6). */
ret = gimplify_array_ref_to_plus (&TREE_OPERAND (expr, 0),
pre_p, post_p);
/* This added an INDIRECT_REF. Fold it away. */
op0 = TREE_OPERAND (TREE_OPERAND (expr, 0), 0);
*expr_p = op0;
break;
default:
/* We use fb_either here because the C frontend sometimes takes
the address of a call that returns a struct. */
ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
is_gimple_addr_expr_arg, fb_either);
if (ret != GS_ERROR)
{
/* At this point, the argument of the ADDR_EXPR should be
sufficiently simple that there are never side effects. */
/* ??? Could split out the decision code from build1 to verify. */
TREE_SIDE_EFFECTS (expr) = 0;
/* Make sure TREE_INVARIANT/TREE_CONSTANT is set properly. */
recompute_tree_invarant_for_addr_expr (expr);
/* Mark the RHS addressable. */
lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
}
break;
}
/* If the operand is gimplified into a _DECL, mark the address expression
as TREE_INVARIANT. */
if (DECL_P (TREE_OPERAND (expr, 0)))
TREE_INVARIANT (expr) = 1;
return ret;
}
/* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
value; output operands should be a gimple lvalue. */
static enum gimplify_status
gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
{
tree expr = *expr_p;
int noutputs = list_length (ASM_OUTPUTS (expr));
const char **oconstraints
= (const char **) alloca ((noutputs) * sizeof (const char *));
int i;
tree link;
const char *constraint;
bool allows_mem, allows_reg, is_inout;
enum gimplify_status ret, tret;
ASM_STRING (expr)
= resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr),
ASM_INPUTS (expr));
ret = GS_ALL_DONE;
for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
{
oconstraints[i] = constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
parse_output_constraint (&constraint, i, 0, 0,
&allows_mem, &allows_reg, &is_inout);
if (!allows_reg && allows_mem)
lang_hooks.mark_addressable (TREE_VALUE (link));
tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
is_inout ? is_gimple_min_lval : is_gimple_lvalue,
fb_lvalue | fb_mayfail);
if (tret == GS_ERROR)
{
error ("invalid lvalue in asm output %d", i);
ret = tret;
}
if (is_inout)
{
/* An input/output operand. To give the optimizers more
flexibility, split it into separate input and output
operands. */
tree input;
char buf[10];
size_t constraint_len = strlen (constraint);
/* Turn the in/out constraint into an output constraint. */
char *p = xstrdup (constraint);
p[0] = '=';
TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
free (p);
/* And add a matching input constraint. */
if (allows_reg)
{
sprintf (buf, "%d", i);
input = build_string (strlen (buf), buf);
}
else
input = build_string (constraint_len - 1, constraint + 1);
input = build_tree_list (build_tree_list (NULL_TREE, input),
unshare_expr (TREE_VALUE (link)));
ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
}
}
for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
{
constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
parse_input_constraint (&constraint, 0, 0, noutputs, 0,
oconstraints, &allows_mem, &allows_reg);
/* If the operand is a memory input, it should be an lvalue. */
if (!allows_reg && allows_mem)
{
lang_hooks.mark_addressable (TREE_VALUE (link));
tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
is_gimple_lvalue, fb_lvalue | fb_mayfail);
if (tret == GS_ERROR)
{
error ("memory input %d is not directly addressable", i);
ret = tret;
}
}
else
{
tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
is_gimple_val, fb_rvalue);
if (tret == GS_ERROR)
ret = tret;
}
}
return ret;
}
/* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
return to this function.
FIXME should we complexify the prequeue handling instead? Or use flags
for all the cleanups and let the optimizer tighten them up? The current
code seems pretty fragile; it will break on a cleanup within any
non-conditional nesting. But any such nesting would be broken, anyway;
we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
and continues out of it. We can do that at the RTL level, though, so
having an optimizer to tighten up try/finally regions would be a Good
Thing. */
static enum gimplify_status
gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
{
tree_stmt_iterator iter;
tree body;
tree temp = voidify_wrapper_expr (*expr_p);
/* We only care about the number of conditions between the innermost
CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
int old_conds = gimplify_ctxp->conditions;
gimplify_ctxp->conditions = 0;
body = TREE_OPERAND (*expr_p, 0);
gimplify_to_stmt_list (&body);
gimplify_ctxp->conditions = old_conds;
for (iter = tsi_start (body); !tsi_end_p (iter); )
{
tree *wce_p = tsi_stmt_ptr (iter);
tree wce = *wce_p;
if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
{
if (tsi_one_before_end_p (iter))
{
tsi_link_before (&iter, TREE_OPERAND (wce, 1), TSI_SAME_STMT);
tsi_delink (&iter);
break;
}
else
{
tree sl, tfe;
sl = tsi_split_statement_list_after (&iter);
tfe = build (TRY_FINALLY_EXPR, void_type_node, sl, NULL_TREE);
append_to_statement_list (TREE_OPERAND (wce, 1),
&TREE_OPERAND (tfe, 1));
*wce_p = tfe;
iter = tsi_start (sl);
}
}
else
tsi_next (&iter);
}
if (temp)
{
*expr_p = temp;
append_to_statement_list (body, pre_p);
return GS_OK;
}
else
{
*expr_p = body;
return GS_ALL_DONE;
}
}
/* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
is the cleanup action required. */
static void
gimple_push_cleanup (tree var, tree cleanup, tree *pre_p)
{
tree wce;
/* Errors can result in improperly nested cleanups. Which results in
confusion when trying to resolve the WITH_CLEANUP_EXPR. */
if (errorcount || sorrycount)
return;
if (gimple_conditional_context ())
{
/* If we're in a conditional context, this is more complex. We only
want to run the cleanup if we actually ran the initialization that
necessitates it, but we want to run it after the end of the
conditional context. So we wrap the try/finally around the
condition and use a flag to determine whether or not to actually
run the destructor. Thus
test ? f(A()) : 0
becomes (approximately)
flag = 0;
try {
if (test) { A::A(temp); flag = 1; val = f(temp); }
else { val = 0; }
} finally {
if (flag) A::~A(temp);
}
val
*/
tree flag = create_tmp_var (boolean_type_node, "cleanup");
tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
boolean_false_node);
tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
boolean_true_node);
cleanup = build (COND_EXPR, void_type_node, flag, cleanup,
build_empty_stmt ());
wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE,
cleanup, NULL_TREE);
append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
append_to_statement_list (ftrue, pre_p);
/* Because of this manipulation, and the EH edges that jump
threading cannot redirect, the temporary (VAR) will appear
to be used uninitialized. Don't warn. */
TREE_NO_WARNING (var) = 1;
}
else
{
wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE,
cleanup, NULL_TREE);
append_to_statement_list (wce, pre_p);
}
gimplify_stmt (&TREE_OPERAND (wce, 1));
}
/* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
static enum gimplify_status
gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
{
tree targ = *expr_p;
tree temp = TARGET_EXPR_SLOT (targ);
tree init = TARGET_EXPR_INITIAL (targ);
enum gimplify_status ret;
if (init)
{
/* TARGET_EXPR temps aren't part of the enclosing block, so add it to the
temps list. */
gimple_add_tmp_var (temp);
/* Build up the initialization and add it to pre_p. */
init = build (MODIFY_EXPR, void_type_node, temp, init);
ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
if (ret == GS_ERROR)
return GS_ERROR;
append_to_statement_list (init, pre_p);
/* If needed, push the cleanup for the temp. */
if (TARGET_EXPR_CLEANUP (targ))
{
gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ), pre_p);
}
/* Only expand this once. */
TREE_OPERAND (targ, 3) = init;
TARGET_EXPR_INITIAL (targ) = NULL_TREE;
}
else if (!temp->decl.seen_in_bind_expr)
/* We should have expanded this before. */
abort ();
*expr_p = temp;
return GS_OK;
}
/* Gimplification of expression trees. */
/* Gimplify an expression which appears at statement context; usually, this
means replacing it with a suitably gimple STATEMENT_LIST. */
void
gimplify_stmt (tree *stmt_p)
{
gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
if (!*stmt_p)
*stmt_p = alloc_stmt_list ();
}
/* Similarly, but force the result to be a STATEMENT_LIST. */
void
gimplify_to_stmt_list (tree *stmt_p)
{
gimplify_stmt (stmt_p);
if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
{
tree t = *stmt_p;
*stmt_p = alloc_stmt_list ();
append_to_statement_list (t, stmt_p);
}
}
/* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
gimplification failed.
PRE_P points to the list where side effects that must happen before
EXPR should be stored.
POST_P points to the list where side effects that must happen after
EXPR should be stored, or NULL if there is no suitable list. In
that case, we copy the result to a temporary, emit the
post-effects, and then return the temporary.
GIMPLE_TEST_F points to a function that takes a tree T and
returns nonzero if T is in the GIMPLE form requested by the
caller. The GIMPLE predicates are in tree-gimple.c.
This test is used twice. Before gimplification, the test is
invoked to determine whether *EXPR_P is already gimple enough. If
that fails, *EXPR_P is gimplified according to its code and
GIMPLE_TEST_F is called again. If the test still fails, then a new
temporary variable is created and assigned the value of the
gimplified expression.
FALLBACK tells the function what sort of a temporary we want. If the 1
bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
If both are set, either is OK, but an lvalue is preferable.
The return value is either GS_ERROR or GS_ALL_DONE, since this function
iterates until solution. */
enum gimplify_status
gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
bool (* gimple_test_f) (tree), fallback_t fallback)
{
tree tmp;
tree internal_pre = NULL_TREE;
tree internal_post = NULL_TREE;
tree save_expr;
int is_statement = (pre_p == NULL);
location_t *locus;
location_t saved_location;
enum gimplify_status ret;
save_expr = *expr_p;
if (save_expr == NULL_TREE)
return GS_ALL_DONE;
/* We used to check the predicate here and return immediately if it
succeeds. This is wrong; the design is for gimplification to be
idempotent, and for the predicates to only test for valid forms, not
whether they are fully simplified. */
/* Set up our internal queues if needed. */
if (pre_p == NULL)
pre_p = &internal_pre;
if (post_p == NULL)
post_p = &internal_post;
saved_location = input_location;
if (save_expr == error_mark_node)
locus = NULL;
else
locus = EXPR_LOCUS (save_expr);
if (locus)
input_location = *locus;
/* Loop over the specific gimplifiers until the toplevel node
remains the same. */
do
{
/* Strip any uselessness. */
STRIP_MAIN_TYPE_NOPS (*expr_p);
/* Remember the expr. */
save_expr = *expr_p;
/* Die, die, die, my darling. */
if (save_expr == error_mark_node
|| TREE_TYPE (save_expr) == error_mark_node)
{
ret = GS_ERROR;
break;
}
/* Do any language-specific gimplification. */
ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
if (ret == GS_OK)
{
if (*expr_p == NULL_TREE)
break;
if (*expr_p != save_expr)
continue;
}
else if (ret != GS_UNHANDLED)
break;
ret = GS_OK;
switch (TREE_CODE (*expr_p))
{
/* First deal with the special cases. */
case POSTINCREMENT_EXPR:
case POSTDECREMENT_EXPR:
case PREINCREMENT_EXPR:
case PREDECREMENT_EXPR:
ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
fallback != fb_none);
break;
case ARRAY_REF:
ret = gimplify_array_ref (expr_p, pre_p, post_p,
fallback & fb_lvalue);
break;
case COMPONENT_REF:
ret = gimplify_compound_lval (expr_p, pre_p, post_p,
fallback & fb_lvalue);
break;
case COND_EXPR:
ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE);
break;
case CALL_EXPR:
ret = gimplify_call_expr (expr_p, pre_p, gimple_test_f);
break;
case TREE_LIST:
abort ();
case COMPOUND_EXPR:
ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
break;
case REALPART_EXPR:
case IMAGPART_EXPR:
ret = gimplify_compound_lval (expr_p, pre_p, post_p,
fallback & fb_lvalue);
break;
case MODIFY_EXPR:
case INIT_EXPR:
ret = gimplify_modify_expr (expr_p, pre_p, post_p,
fallback != fb_none);
break;
case TRUTH_ANDIF_EXPR:
case TRUTH_ORIF_EXPR:
ret = gimplify_boolean_expr (expr_p);
break;
case TRUTH_NOT_EXPR:
TREE_OPERAND (*expr_p, 0)
= gimple_boolify (TREE_OPERAND (*expr_p, 0));
ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
is_gimple_val, fb_rvalue);
recalculate_side_effects (*expr_p);
break;
case ADDR_EXPR:
ret = gimplify_addr_expr (expr_p, pre_p, post_p);
break;
case VA_ARG_EXPR:
/* Mark any _DECL inside the operand as volatile to avoid the
optimizers messing around with it. FIXME: Remove this once
VA_ARG_EXPRs are properly lowered. */
walk_tree (&TREE_OPERAND (*expr_p, 0), mark_decls_volatile_r,
NULL, NULL);
/* va_arg expressions are in GIMPLE form already. */
ret = GS_ALL_DONE;
break;
case CONVERT_EXPR:
case NOP_EXPR:
if (IS_EMPTY_STMT (*expr_p))
{
ret = GS_ALL_DONE;
break;
}
if (VOID_TYPE_P (TREE_TYPE (*expr_p))
|| fallback == fb_none)
{
/* Just strip a conversion to void (or in void context) and
try again. */
*expr_p = TREE_OPERAND (*expr_p, 0);
break;
}
ret = gimplify_conversion (expr_p);
if (ret == GS_ERROR)
break;
if (*expr_p != save_expr)
break;
/* FALLTHRU */
case FIX_TRUNC_EXPR:
case FIX_CEIL_EXPR:
case FIX_FLOOR_EXPR:
case FIX_ROUND_EXPR:
/* unary_expr: ... | '(' cast ')' val | ... */
ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
is_gimple_val, fb_rvalue);
recalculate_side_effects (*expr_p);
break;
case INDIRECT_REF:
ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
is_gimple_reg, fb_rvalue);
recalculate_side_effects (*expr_p);
break;
/* Constants need not be gimplified. */
case INTEGER_CST:
case REAL_CST:
case STRING_CST:
case COMPLEX_CST:
case VECTOR_CST:
ret = GS_ALL_DONE;
break;
case CONST_DECL:
*expr_p = DECL_INITIAL (*expr_p);
break;
case EXC_PTR_EXPR:
/* FIXME make this a decl. */
ret = GS_ALL_DONE;
break;
case BIND_EXPR:
ret = gimplify_bind_expr (expr_p, pre_p);
break;
case LOOP_EXPR:
ret = gimplify_loop_expr (expr_p, pre_p);
break;
case SWITCH_EXPR:
ret = gimplify_switch_expr (expr_p, pre_p);
break;
case LABELED_BLOCK_EXPR:
ret = gimplify_labeled_block_expr (expr_p);
break;
case EXIT_BLOCK_EXPR:
ret = gimplify_exit_block_expr (expr_p);
break;
case EXIT_EXPR:
ret = gimplify_exit_expr (expr_p);
break;
case GOTO_EXPR:
/* If the target is not LABEL, then it is a computed jump
and the target needs to be gimplified. */
if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
NULL, is_gimple_val, fb_rvalue);
break;
case LABEL_EXPR:
ret = GS_ALL_DONE;
#ifdef ENABLE_CHECKING
if (decl_function_context (LABEL_EXPR_LABEL (*expr_p)) != current_function_decl)
abort ();
#endif
break;
case CASE_LABEL_EXPR:
ret = gimplify_case_label_expr (expr_p);
break;
case RETURN_EXPR:
ret = gimplify_return_expr (*expr_p, pre_p);
break;
case CONSTRUCTOR:
/* Don't reduce this in place; let gimplify_init_constructor work
its magic. */
ret = GS_ALL_DONE;
break;
/* The following are special cases that are not handled by the
original GIMPLE grammar. */
/* SAVE_EXPR nodes are converted into a GIMPLE identifier and
eliminated. */
case SAVE_EXPR:
ret = gimplify_save_expr (expr_p, pre_p, post_p);
break;
case BIT_FIELD_REF:
{
enum gimplify_status r0, r1, r2;
r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
is_gimple_min_lval, fb_either);
r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
is_gimple_val, fb_rvalue);
r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
is_gimple_val, fb_rvalue);
recalculate_side_effects (*expr_p);
ret = MIN (r0, MIN (r1, r2));
}
break;
case NON_LVALUE_EXPR:
/* This should have been stripped above. */
abort ();
break;
case ASM_EXPR:
ret = gimplify_asm_expr (expr_p, pre_p, post_p);
break;
case TRY_FINALLY_EXPR:
case TRY_CATCH_EXPR:
gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
ret = GS_ALL_DONE;
break;
case CLEANUP_POINT_EXPR:
ret = gimplify_cleanup_point_expr (expr_p, pre_p);
break;
case TARGET_EXPR:
ret = gimplify_target_expr (expr_p, pre_p, post_p);
break;
case CATCH_EXPR:
gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
ret = GS_ALL_DONE;
break;
case EH_FILTER_EXPR:
gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
ret = GS_ALL_DONE;
break;
case VTABLE_REF:
/* This moves much of the actual computation out of the
VTABLE_REF. Perhaps this should be revisited once we want to
do clever things with VTABLE_REFs. */
ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
is_gimple_min_lval, fb_lvalue);
break;
case MIN_EXPR:
case MAX_EXPR:
ret = gimplify_minimax_expr (expr_p, pre_p, post_p);
break;
case LABEL_DECL:
/* We get here when taking the address of a label. We mark
the label as "forced"; meaning it can never be removed and
it is a potential target for any computed goto. */
FORCED_LABEL (*expr_p) = 1;
ret = GS_ALL_DONE;
break;
case STATEMENT_LIST:
ret = gimplify_statement_list (expr_p);
break;
case VAR_DECL:
/* ??? If this is a local variable, and it has not been seen in any
outer BIND_EXPR, then it's probably the result of a duplicate
declaration, for which we've already issued an error. It would
be really nice if the front end wouldn't leak these at all.
Currently the only known culprit is C++ destructors, as seen
in g++.old-deja/g++.jason/binding.C. */
tmp = *expr_p;
if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
&& decl_function_context (tmp) == current_function_decl
&& !tmp->decl.seen_in_bind_expr)
{
#ifdef ENABLE_CHECKING
if (!errorcount && !sorrycount)
abort ();
#endif
ret = GS_ERROR;
}
else
ret = GS_ALL_DONE;
break;
default:
/* If *EXPR_P does not need to be special-cased, handle it
according to its class. */
if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '1')
ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
post_p, is_gimple_val, fb_rvalue);
else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '2'
|| TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '<'
|| TREE_CODE (*expr_p) == TRUTH_AND_EXPR
|| TREE_CODE (*expr_p) == TRUTH_OR_EXPR
|| TREE_CODE (*expr_p) == TRUTH_XOR_EXPR)
{
enum gimplify_status r0, r1;
r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
post_p, is_gimple_val, fb_rvalue);
r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
post_p, is_gimple_val, fb_rvalue);
ret = MIN (r0, r1);
}
else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'd'
|| TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'c')
{
ret = GS_ALL_DONE;
break;
}
else
/* Fail if we don't know how to handle this tree code. */
abort ();
recalculate_side_effects (*expr_p);
break;
}
/* If we replaced *expr_p, gimplify again. */
if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
ret = GS_ALL_DONE;
}
while (ret == GS_OK);
/* If we encountered an error_mark somewhere nested inside, either
stub out the statement or propagate the error back out. */
if (ret == GS_ERROR)
{
if (is_statement)
*expr_p = build_empty_stmt ();
goto out;
}
#ifdef ENABLE_CHECKING
/* This was only valid as a return value from the langhook, which
we handled. Make sure it doesn't escape from any other context. */
if (ret == GS_UNHANDLED)
abort ();
#endif
if (!*expr_p)
*expr_p = build_empty_stmt ();
if (fallback == fb_none && !is_gimple_stmt (*expr_p))
{
/* We aren't looking for a value, and we don't have a valid
statement. If it doesn't have side-effects, throw it away. */
if (!TREE_SIDE_EFFECTS (*expr_p))
*expr_p = build_empty_stmt ();
else if (!TREE_THIS_VOLATILE (*expr_p))
/* We only handle volatiles here; anything else with side-effects
must be converted to a valid statement before we get here. */
abort ();
else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
{
/* Historically, the compiler has treated a bare
reference to a volatile lvalue as forcing a load. */
tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
*expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
}
else
/* We can't do anything useful with a volatile reference to
incomplete type, so just throw it away. */
*expr_p = build_empty_stmt ();
}
/* If we are gimplifying at the statement level, we're done. Tack
everything together and replace the original statement with the
gimplified form. */
if (is_statement)
{
if (internal_pre || internal_post)
{
append_to_statement_list (*expr_p, &internal_pre);
append_to_statement_list (internal_post, &internal_pre);
annotate_all_with_locus (&internal_pre, input_location);
*expr_p = internal_pre;
}
goto out;
}
/* Otherwise we're gimplifying a subexpression, so the resulting value is
interesting. */
/* If it's sufficiently simple already, we're done. Unless we are
handling some post-effects internally; if that's the case, we need to
copy into a temp before adding the post-effects to the tree. */
if (!internal_post && (*gimple_test_f) (*expr_p))
goto out;
/* Otherwise, we need to create a new temporary for the gimplified
expression. */
/* We can't return an lvalue if we have an internal postqueue. The
object the lvalue refers to would (probably) be modified by the
postqueue; we need to copy the value out first, which means an
rvalue. */
if ((fallback & fb_lvalue) && !internal_post
&& is_gimple_addr_expr_arg (*expr_p))
{
/* An lvalue will do. Take the address of the expression, store it
in a temporary, and replace the expression with an INDIRECT_REF of
that temporary. */
tmp = build_addr_expr (*expr_p);
gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
*expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
}
else if ((fallback & fb_rvalue) && is_gimple_rhs (*expr_p))
{
#if defined ENABLE_CHECKING
if (VOID_TYPE_P (TREE_TYPE (*expr_p)))
abort ();
#endif
/* An rvalue will do. Assign the gimplified expression into a new
temporary TMP and replace the original expression with TMP. */
if (internal_post || (fallback & fb_lvalue))
/* The postqueue might change the value of the expression between
the initialization and use of the temporary, so we can't use a
formal temp. FIXME do we care? */
*expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
else
*expr_p = get_formal_tmp_var (*expr_p, pre_p);
}
else if (fallback & fb_mayfail)
{
/* If this is an asm statement, and the user asked for the impossible,
don't abort. Fail and let gimplify_asm_expr issue an error. */
ret = GS_ERROR;
goto out;
}
else
{
fprintf (stderr, "gimplification failed:\n");
print_generic_expr (stderr, *expr_p, 0);
debug_tree (*expr_p);
abort ();
}
#if defined ENABLE_CHECKING
/* Make sure the temporary matches our predicate. */
if (!(*gimple_test_f) (*expr_p))
abort ();
#endif
if (internal_post)
{
annotate_all_with_locus (&internal_post, input_location);
append_to_statement_list (internal_post, pre_p);
}
out:
input_location = saved_location;
return ret;
}
#ifdef ENABLE_CHECKING
/* Compare types A and B for a "close enough" match. */
static bool
cpt_same_type (tree a, tree b)
{
if (lang_hooks.types_compatible_p (a, b))
return true;
/* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
link them together. This routine is intended to catch type errors
that will affect the optimizers, and the optimizers don't add new
dereferences of function pointers, so ignore it. */
if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
&& (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
return true;
/* ??? The C FE pushes type qualifiers after the fact into the type of
the element from the type of the array. See build_unary_op's handling
of ADDR_EXPR. This seems wrong -- if we were going to do this, we
should have done it when creating the variable in the first place.
Alternately, why aren't the two array types made variants? */
if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
/* And because of those, we have to recurse down through pointers. */
if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
return false;
}
/* Check for some cases of the front end missing cast expressions.
The type of a dereference should correspond to the pointer type;
similarly the type of an address should match its object. */
static tree
check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED)
{
tree t = *tp;
tree ptype, otype, dtype;
switch (TREE_CODE (t))
{
case INDIRECT_REF:
case ARRAY_REF:
otype = TREE_TYPE (t);
ptype = TREE_TYPE (TREE_OPERAND (t, 0));
dtype = TREE_TYPE (ptype);
if (!cpt_same_type (otype, dtype))
abort ();
break;
case ADDR_EXPR:
ptype = TREE_TYPE (t);
otype = TREE_TYPE (TREE_OPERAND (t, 0));
dtype = TREE_TYPE (ptype);
if (!cpt_same_type (otype, dtype))
{
/* &array is allowed to produce a pointer to the element,
rather than a pointer to the array type. */
if (TREE_CODE (otype) == ARRAY_TYPE
&& POINTER_TYPE_P (ptype)
&& cpt_same_type (TREE_TYPE (otype), dtype))
break;
abort ();
}
break;
default:
return NULL_TREE;
}
return NULL_TREE;
}
#endif
/* Gimplify the body of statements pointed by BODY_P. FNDECL is the
function decl containing BODY. */
void
gimplify_body (tree *body_p, tree fndecl)
{
location_t saved_location = input_location;
tree body;
timevar_push (TV_TREE_GIMPLIFY);
push_gimplify_context ();
/* Unshare most shared trees in the body. */
unshare_all_trees (*body_p);
/* Make sure input_location isn't set to something wierd. */
input_location = DECL_SOURCE_LOCATION (fndecl);
/* Gimplify the function's body. */
gimplify_stmt (body_p);
body = *body_p;
/* Unshare again, in case gimplification was sloppy. */
unshare_all_trees (body);
/* If there isn't an outer BIND_EXPR, add one. */
if (TREE_CODE (body) == STATEMENT_LIST)
{
tree t = expr_only (*body_p);
if (t)
body = t;
}
if (TREE_CODE (body) != BIND_EXPR)
{
tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
NULL_TREE, NULL_TREE);
TREE_SIDE_EFFECTS (b) = 1;
append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
body = b;
}
*body_p = body;
pop_gimplify_context (body);
#ifdef ENABLE_CHECKING
walk_tree (body_p, check_pointer_types_r, NULL, NULL);
#endif
timevar_pop (TV_TREE_GIMPLIFY);
input_location = saved_location;
}
/* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
node for the function we want to gimplify. */
void
gimplify_function_tree (tree fndecl)
{
tree oldfn;
oldfn = current_function_decl;
current_function_decl = fndecl;
gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl);
/* If we're instrumenting function entry/exit, then prepend the call to
the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
catch the exit hook. */
/* ??? Add some way to ignore exceptions for this TFE. */
if (flag_instrument_function_entry_exit
&& ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
{
tree tf, x, bind;
tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
TREE_SIDE_EFFECTS (tf) = 1;
x = DECL_SAVED_TREE (fndecl);
append_to_statement_list (x, &TREE_OPERAND (tf, 0));
x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
x = build_function_call_expr (x, NULL);
append_to_statement_list (x, &TREE_OPERAND (tf, 1));
bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
TREE_SIDE_EFFECTS (bind) = 1;
x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
x = build_function_call_expr (x, NULL);
append_to_statement_list (x, &BIND_EXPR_BODY (bind));
append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
DECL_SAVED_TREE (fndecl) = bind;
}
current_function_decl = oldfn;
}
#include "gt-gimplify.h"
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