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Commit 02075bb2 by Diego Novillo
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tree-ssa-operands.c: Cleanup whitespace. 


	* tree-ssa-operands.c: Cleanup whitespace.
	(get_asm_expr_operands): Move before first invocation.
	(get_indirect_ref_operands): Likewise.
	(get_tmr_operands): Likewise.
	(get_call_expr_operands): Likewise.
	(append_def): Likewise.
	(append_use): Likewise.
	(append_v_may_def): Likewise.
	(append_v_must_def): Likewise.
	(add_call_clobber_ops): Likewise.
	(add_call_read_ops): Likewise.
	(add_stmt_operand): Likewise.
	(add_virtual_operand): Likewise.
	(build_ssa_operands): Likewise.

From-SVN: r111604
parent 2bb6e0ce
Showing with 1044 additions and 1028 deletions
gcc/ChangeLog
2006-01-23 Andrew Pinski <pinskia@physics.uc.edu> 2006-03-01 Diego Novillo <dnovillo@redhat.com>
* tree-ssa-operands.c: Cleanup whitespace.
(get_asm_expr_operands): Move before first invocation.
(get_indirect_ref_operands): Likewise.
(get_tmr_operands): Likewise.
(get_call_expr_operands): Likewise.
(append_def): Likewise.
(append_use): Likewise.
(append_v_may_def): Likewise.
(append_v_must_def): Likewise.
(add_call_clobber_ops): Likewise.
(add_call_read_ops): Likewise.
(add_stmt_operand): Likewise.
(add_virtual_operand): Likewise.
(build_ssa_operands): Likewise.
2006-03-01 Andrew Pinski <pinskia@physics.uc.edu>
PR middle-end/26022 PR middle-end/26022
Revert: Revert:
......
gcc/tree-ssa-operands.c
...@@ -74,10 +74,7 @@ Boston, MA 02110-1301, USA. */ ...@@ -74,10 +74,7 @@ Boston, MA 02110-1301, USA. */
i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new operand i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new operand
vector for VUSE, then the new vector will also be modified such that vector for VUSE, then the new vector will also be modified such that
it contains 'a_5' rather than 'a'. it contains 'a_5' rather than 'a'. */
*/
/* Flags to describe operand properties in helpers. */ /* Flags to describe operand properties in helpers. */
...@@ -103,7 +100,6 @@ Boston, MA 02110-1301, USA. */ ...@@ -103,7 +100,6 @@ Boston, MA 02110-1301, USA. */
to distinguish "reset the world" events from explicit MODIFY_EXPRs. */ to distinguish "reset the world" events from explicit MODIFY_EXPRs. */
#define opf_non_specific (1 << 3) #define opf_non_specific (1 << 3)
/* Array for building all the def operands. */ /* Array for building all the def operands. */
static VEC(tree,heap) *build_defs; static VEC(tree,heap) *build_defs;
...@@ -119,7 +115,6 @@ static VEC(tree,heap) *build_vuses; ...@@ -119,7 +115,6 @@ static VEC(tree,heap) *build_vuses;
/* Array for building all the v_must_def operands. */ /* Array for building all the v_must_def operands. */
static VEC(tree,heap) *build_v_must_defs; static VEC(tree,heap) *build_v_must_defs;
/* These arrays are the cached operand vectors for call clobbered calls. */ /* These arrays are the cached operand vectors for call clobbered calls. */
static bool ops_active = false; static bool ops_active = false;
...@@ -127,22 +122,6 @@ static GTY (()) struct ssa_operand_memory_d *operand_memory = NULL; ...@@ -127,22 +122,6 @@ static GTY (()) struct ssa_operand_memory_d *operand_memory = NULL;
static unsigned operand_memory_index; static unsigned operand_memory_index;
static void get_expr_operands (tree, tree *, int); static void get_expr_operands (tree, tree *, int);
static void get_asm_expr_operands (tree);
static void get_indirect_ref_operands (tree, tree, int, tree, HOST_WIDE_INT,
HOST_WIDE_INT, bool);
static void get_tmr_operands (tree, tree, int);
static void get_call_expr_operands (tree, tree);
static inline void append_def (tree *);
static inline void append_use (tree *);
static void append_v_may_def (tree);
static void append_v_must_def (tree);
static void add_call_clobber_ops (tree, tree);
static void add_call_read_ops (tree, tree);
static void add_stmt_operand (tree *, stmt_ann_t, int);
static void add_virtual_operand (tree, stmt_ann_t, int, tree,
HOST_WIDE_INT, HOST_WIDE_INT,
bool);
static void build_ssa_operands (tree stmt);
static def_optype_p free_defs = NULL; static def_optype_p free_defs = NULL;
static use_optype_p free_uses = NULL; static use_optype_p free_uses = NULL;
...@@ -162,6 +141,7 @@ get_name_decl (tree t) ...@@ -162,6 +141,7 @@ get_name_decl (tree t)
return DECL_UID (SSA_NAME_VAR (t)); return DECL_UID (SSA_NAME_VAR (t));
} }
/* Comparison function for qsort used in operand_build_sort_virtual. */ /* Comparison function for qsort used in operand_build_sort_virtual. */
static int static int
...@@ -181,6 +161,7 @@ operand_build_cmp (const void *p, const void *q) ...@@ -181,6 +161,7 @@ operand_build_cmp (const void *p, const void *q)
return (u1 > u2 ? 1 : -1); return (u1 > u2 ? 1 : -1);
} }
/* Sort the virtual operands in LIST from lowest DECL_UID to highest. */ /* Sort the virtual operands in LIST from lowest DECL_UID to highest. */
static inline void static inline void
...@@ -209,7 +190,6 @@ operand_build_sort_virtual (VEC(tree,heap) *list) ...@@ -209,7 +190,6 @@ operand_build_sort_virtual (VEC(tree,heap) *list)
} }
/* Return true if the ssa operands cache is active. */ /* Return true if the ssa operands cache is active. */
bool bool
...@@ -218,8 +198,10 @@ ssa_operands_active (void) ...@@ -218,8 +198,10 @@ ssa_operands_active (void)
return ops_active; return ops_active;
} }
/* Structure storing statistics on how many call clobbers we have, and /* Structure storing statistics on how many call clobbers we have, and
how many where avoided. */ how many where avoided. */
static struct static struct
{ {
/* Number of call-clobbered ops we attempt to add to calls in /* Number of call-clobbered ops we attempt to add to calls in
...@@ -246,6 +228,7 @@ static struct ...@@ -246,6 +228,7 @@ static struct
unsigned int static_readonly_clobbers_avoided; unsigned int static_readonly_clobbers_avoided;
} clobber_stats; } clobber_stats;
/* Initialize the operand cache routines. */ /* Initialize the operand cache routines. */
void void
...@@ -291,12 +274,18 @@ fini_ssa_operands (void) ...@@ -291,12 +274,18 @@ fini_ssa_operands (void)
if (dump_file && (dump_flags & TDF_STATS)) if (dump_file && (dump_flags & TDF_STATS))
{ {
fprintf (dump_file, "Original clobbered vars:%d\n", clobber_stats.clobbered_vars); fprintf (dump_file, "Original clobbered vars:%d\n",
fprintf (dump_file, "Static write clobbers avoided:%d\n", clobber_stats.static_write_clobbers_avoided); clobber_stats.clobbered_vars);
fprintf (dump_file, "Static read clobbers avoided:%d\n", clobber_stats.static_read_clobbers_avoided); fprintf (dump_file, "Static write clobbers avoided:%d\n",
fprintf (dump_file, "Unescapable clobbers avoided:%d\n", clobber_stats.unescapable_clobbers_avoided); clobber_stats.static_write_clobbers_avoided);
fprintf (dump_file, "Original readonly clobbers:%d\n", clobber_stats.readonly_clobbers); fprintf (dump_file, "Static read clobbers avoided:%d\n",
fprintf (dump_file, "Static readonly clobbers avoided:%d\n", clobber_stats.static_readonly_clobbers_avoided); clobber_stats.static_read_clobbers_avoided);
fprintf (dump_file, "Unescapable clobbers avoided:%d\n",
clobber_stats.unescapable_clobbers_avoided);
fprintf (dump_file, "Original readonly clobbers:%d\n",
clobber_stats.readonly_clobbers);
fprintf (dump_file, "Static readonly clobbers avoided:%d\n",
clobber_stats.static_readonly_clobbers_avoided);
} }
} }
...@@ -352,7 +341,8 @@ correct_use_link (use_operand_p ptr, tree stmt) ...@@ -352,7 +341,8 @@ correct_use_link (use_operand_p ptr, tree stmt)
if (root == *(ptr->use)) if (root == *(ptr->use))
return; return;
} }
/* Its in the wrong list if we reach here. */
/* It is in the wrong list if we reach here. */
delink_imm_use (ptr); delink_imm_use (ptr);
link_imm_use (ptr, *(ptr->use)); link_imm_use (ptr, *(ptr->use));
} }
...@@ -362,6 +352,7 @@ correct_use_link (use_operand_p ptr, tree stmt) ...@@ -362,6 +352,7 @@ correct_use_link (use_operand_p ptr, tree stmt)
sure the stmt pointer is set to the current stmt. Virtual uses do not need sure the stmt pointer is set to the current stmt. Virtual uses do not need
the overhead of correct_use_link since they cannot be directly manipulated the overhead of correct_use_link since they cannot be directly manipulated
like a real use can be. (They don't exist in the TREE_OPERAND nodes.) */ like a real use can be. (They don't exist in the TREE_OPERAND nodes.) */
static inline void static inline void
set_virtual_use_link (use_operand_p ptr, tree stmt) set_virtual_use_link (use_operand_p ptr, tree stmt)
{ {
...@@ -375,7 +366,6 @@ set_virtual_use_link (use_operand_p ptr, tree stmt) ...@@ -375,7 +366,6 @@ set_virtual_use_link (use_operand_p ptr, tree stmt)
} }
#define FINALIZE_OPBUILD build_defs #define FINALIZE_OPBUILD build_defs
#define FINALIZE_OPBUILD_BASE(I) (tree *)VEC_index (tree, \ #define FINALIZE_OPBUILD_BASE(I) (tree *)VEC_index (tree, \
build_defs, (I)) build_defs, (I))
...@@ -400,12 +390,12 @@ static void ...@@ -400,12 +390,12 @@ static void
finalize_ssa_defs (tree stmt) finalize_ssa_defs (tree stmt)
{ {
unsigned int num = VEC_length (tree, build_defs); unsigned int num = VEC_length (tree, build_defs);
/* There should only be a single real definition per assignment. */ /* There should only be a single real definition per assignment. */
gcc_assert ((stmt && TREE_CODE (stmt) != MODIFY_EXPR) || num <= 1); gcc_assert ((stmt && TREE_CODE (stmt) != MODIFY_EXPR) || num <= 1);
/* If there is an old list, often the new list is identical, or close, so /* If there is an old list, often the new list is identical, or close, so
find the elements at the beginning that are the same as the vector. */ find the elements at the beginning that are the same as the vector. */
finalize_ssa_def_ops (stmt); finalize_ssa_def_ops (stmt);
VEC_truncate (tree, build_defs, 0); VEC_truncate (tree, build_defs, 0);
} }
...@@ -630,7 +620,6 @@ finalize_ssa_v_must_defs (tree stmt) ...@@ -630,7 +620,6 @@ finalize_ssa_v_must_defs (tree stmt)
all must-defs in a statement belong to subvars if there is more than one all must-defs in a statement belong to subvars if there is more than one
MUST-def, so we don't do it. Suffice to say, if you reach here without MUST-def, so we don't do it. Suffice to say, if you reach here without
having subvars, and have num >1, you have hit a bug. */ having subvars, and have num >1, you have hit a bug. */
finalize_ssa_v_must_def_ops (stmt); finalize_ssa_v_must_def_ops (stmt);
VEC_truncate (tree, build_v_must_defs, 0); VEC_truncate (tree, build_v_must_defs, 0);
} }
...@@ -735,600 +724,644 @@ append_v_must_def (tree var) ...@@ -735,600 +724,644 @@ append_v_must_def (tree var)
} }
/* Parse STMT looking for operands. OLD_OPS is the original stmt operand /* REF is a tree that contains the entire pointer dereference
cache for STMT, if it existed before. When finished, the various build_* expression, if available, or NULL otherwise. ALIAS is the variable
operand vectors will have potential operands. in them. */ we are asking if REF can access. OFFSET and SIZE come from the
memory access expression that generated this virtual operand.
FOR_CLOBBER is true is this is adding a virtual operand for a call
clobber. */
static void static bool
parse_ssa_operands (tree stmt) access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
HOST_WIDE_INT size)
{ {
enum tree_code code; bool offsetgtz = offset > 0;
unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset;
tree base = ref ? get_base_address (ref) : NULL;
code = TREE_CODE (stmt); /* If ALIAS is an SFT, it can't be touched if the offset
switch (code) and size of the access is not overlapping with the SFT offset and
{ size. This is only true if we are accessing through a pointer
case MODIFY_EXPR: to a type that is the same as SFT_PARENT_VAR. Otherwise, we may
/* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if be accessing through a pointer to some substruct of the
either only part of LHS is modified or if the RHS might throw, structure, and if we try to prune there, we will have the wrong
otherwise, use V_MUST_DEF. offset, and get the wrong answer.
i.e., we can't prune without more work if we have something like
??? If it might throw, we should represent somehow that it is killed struct gcc_target
on the fallthrough path. */
{ {
tree lhs = TREE_OPERAND (stmt, 0); struct asm_out
int lhs_flags = opf_is_def; {
const char *byte_op;
get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none); struct asm_int_op
{
/* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether const char *hi;
or not the entire LHS is modified; that depends on what's } aligned_op;
inside the VIEW_CONVERT_EXPR. */ } asm_out;
if (TREE_CODE (lhs) == VIEW_CONVERT_EXPR) } targetm;
lhs = TREE_OPERAND (lhs, 0);
if (TREE_CODE (lhs) != ARRAY_RANGE_REF foo = &targetm.asm_out.aligned_op;
&& TREE_CODE (lhs) != BIT_FIELD_REF) return foo->hi;
lhs_flags |= opf_kill_def;
get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), lhs_flags); SFT.1, which represents hi, will have SFT_OFFSET=32 because in
terms of SFT_PARENT_VAR, that is where it is.
However, the access through the foo pointer will be at offset 0. */
if (size != -1
&& TREE_CODE (alias) == STRUCT_FIELD_TAG
&& base
&& TREE_TYPE (base) == TREE_TYPE (SFT_PARENT_VAR (alias))
&& !overlap_subvar (offset, size, alias, NULL))
{
#ifdef ACCESS_DEBUGGING
fprintf (stderr, "Access to ");
print_generic_expr (stderr, ref, 0);
fprintf (stderr, " may not touch ");
print_generic_expr (stderr, alias, 0);
fprintf (stderr, " in function %s\n", get_name (current_function_decl));
#endif
return false;
} }
break;
case COND_EXPR:
get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none);
break;
case SWITCH_EXPR:
get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none);
break;
case ASM_EXPR: /* Without strict aliasing, it is impossible for a component access
get_asm_expr_operands (stmt); through a pointer to touch a random variable, unless that
break; variable *is* a structure or a pointer.
case RETURN_EXPR: That is, given p->c, and some random global variable b,
get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_none); there is no legal way that p->c could be an access to b.
break;
case GOTO_EXPR: Without strict aliasing on, we consider it legal to do something
get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_none); like:
break;
case LABEL_EXPR: struct foos { int l; };
get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_none); int foo;
break; static struct foos *getfoo(void);
int main (void)
{
struct foos *f = getfoo();
f->l = 1;
foo = 2;
if (f->l == 1)
abort();
exit(0);
}
static struct foos *getfoo(void)
{ return (struct foos *)&foo; }
/* These nodes contain no variable references. */ (taken from 20000623-1.c)
case BIND_EXPR: */
case CASE_LABEL_EXPR: else if (ref
case TRY_CATCH_EXPR: && flag_strict_aliasing
case TRY_FINALLY_EXPR: && TREE_CODE (ref) != INDIRECT_REF
case EH_FILTER_EXPR: && !MTAG_P (alias)
case CATCH_EXPR: && !AGGREGATE_TYPE_P (TREE_TYPE (alias))
case RESX_EXPR: && TREE_CODE (TREE_TYPE (alias)) != COMPLEX_TYPE
break; && !POINTER_TYPE_P (TREE_TYPE (alias)))
{
#ifdef ACCESS_DEBUGGING
fprintf (stderr, "Access to ");
print_generic_expr (stderr, ref, 0);
fprintf (stderr, " may not touch ");
print_generic_expr (stderr, alias, 0);
fprintf (stderr, " in function %s\n", get_name (current_function_decl));
#endif
return false;
}
default: /* If the offset of the access is greater than the size of one of
/* Notice that if get_expr_operands tries to use &STMT as the operand the possible aliases, it can't be touching that alias, because it
pointer (which may only happen for USE operands), we will fail in would be past the end of the structure. */
append_use. This default will handle statements like empty else if (ref
statements, or CALL_EXPRs that may appear on the RHS of a statement && flag_strict_aliasing
or as statements themselves. */ && TREE_CODE (ref) != INDIRECT_REF
get_expr_operands (stmt, &stmt, opf_none); && !MTAG_P (alias)
break; && !POINTER_TYPE_P (TREE_TYPE (alias))
&& offsetgtz
&& DECL_SIZE (alias)
&& TREE_CODE (DECL_SIZE (alias)) == INTEGER_CST
&& uoffset > TREE_INT_CST_LOW (DECL_SIZE (alias)))
{
#ifdef ACCESS_DEBUGGING
fprintf (stderr, "Access to ");
print_generic_expr (stderr, ref, 0);
fprintf (stderr, " may not touch ");
print_generic_expr (stderr, alias, 0);
fprintf (stderr, " in function %s\n", get_name (current_function_decl));
#endif
return false;
} }
return true;
} }
/* Create an operands cache for STMT. */
/* Add VAR to the virtual operands array. FLAGS is as in
get_expr_operands. FULL_REF is a tree that contains the entire
pointer dereference expression, if available, or NULL otherwise.
OFFSET and SIZE come from the memory access expression that
generated this virtual operand. FOR_CLOBBER is true is this is
adding a virtual operand for a call clobber. */
static void static void
build_ssa_operands (tree stmt) add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
tree full_ref, HOST_WIDE_INT offset,
HOST_WIDE_INT size, bool for_clobber)
{ {
stmt_ann_t ann = get_stmt_ann (stmt); VEC(tree,gc) *aliases;
tree sym;
var_ann_t v_ann;
/* Initially assume that the statement has no volatile operands. */ sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
if (ann) v_ann = var_ann (sym);
ann->has_volatile_ops = false;
start_ssa_stmt_operands (); /* Mark statements with volatile operands. Optimizers should back
off from statements having volatile operands. */
if (TREE_THIS_VOLATILE (sym) && s_ann)
s_ann->has_volatile_ops = true;
parse_ssa_operands (stmt); /* If the variable cannot be modified and this is a V_MAY_DEF change
operand_build_sort_virtual (build_vuses); it into a VUSE. This happens when read-only variables are marked
operand_build_sort_virtual (build_v_may_defs); call-clobbered and/or aliased to writable variables. So we only
operand_build_sort_virtual (build_v_must_defs); check that this only happens on non-specific stores.
finalize_ssa_stmt_operands (stmt); Note that if this is a specific store, i.e. associated with a
} modify_expr, then we can't suppress the V_MAY_DEF, lest we run
into validation problems.
This can happen when programs cast away const, leaving us with a
store to read-only memory. If the statement is actually executed
at runtime, then the program is ill formed. If the statement is
not executed then all is well. At the very least, we cannot ICE. */
if ((flags & opf_non_specific) && unmodifiable_var_p (var))
flags &= ~(opf_is_def | opf_kill_def);
/* Free any operands vectors in OPS. */ /* The variable is not a GIMPLE register. Add it (or its aliases) to
void virtual operands, unless the caller has specifically requested
free_ssa_operands (stmt_operands_p ops) not to add virtual operands (used when adding operands inside an
{ ADDR_EXPR expression). */
ops->def_ops = NULL; if (flags & opf_no_vops)
ops->use_ops = NULL; return;
ops->maydef_ops = NULL;
ops->mustdef_ops = NULL;
ops->vuse_ops = NULL;
}
aliases = v_ann->may_aliases;
if (aliases == NULL)
{
/* The variable is not aliased or it is an alias tag. */
if (flags & opf_is_def)
{
if (flags & opf_kill_def)
{
/* V_MUST_DEF for non-aliased, non-GIMPLE register
variable definitions. */
gcc_assert (!MTAG_P (var)
|| TREE_CODE (var) == STRUCT_FIELD_TAG);
append_v_must_def (var);
}
else
{
/* Add a V_MAY_DEF for call-clobbered variables and
memory tags. */
append_v_may_def (var);
}
}
else
append_vuse (var);
}
else
{
unsigned i;
tree al;
/* Get the operands of statement STMT. Note that repeated calls to /* The variable is aliased. Add its aliases to the virtual
get_stmt_operands for the same statement will do nothing until the operands. */
statement is marked modified by a call to mark_stmt_modified(). */ gcc_assert (VEC_length (tree, aliases) != 0);
void if (flags & opf_is_def)
update_stmt_operands (tree stmt) {
{
stmt_ann_t ann = get_stmt_ann (stmt);
/* If get_stmt_operands is called before SSA is initialized, dont
do anything. */
if (!ssa_operands_active ())
return;
/* The optimizers cannot handle statements that are nothing but a
_DECL. This indicates a bug in the gimplifier. */
gcc_assert (!SSA_VAR_P (stmt));
gcc_assert (ann->modified); bool none_added = true;
timevar_push (TV_TREE_OPS); for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
{
if (!access_can_touch_variable (full_ref, al, offset, size))
continue;
build_ssa_operands (stmt); none_added = false;
append_v_may_def (al);
}
/* Clear the modified bit for STMT. Subsequent calls to /* If the variable is also an alias tag, add a virtual
get_stmt_operands for this statement will do nothing until the operand for it, otherwise we will miss representing
statement is marked modified by a call to mark_stmt_modified(). */ references to the members of the variable's alias set.
ann->modified = 0; This fixes the bug in gcc.c-torture/execute/20020503-1.c.
timevar_pop (TV_TREE_OPS); It is also necessary to add bare defs on clobbers for
TMT's, so that bare TMT uses caused by pruning all the
aliases will link up properly with calls. In order to
keep the number of these bare defs we add down to the
minimum necessary, we keep track of which TMT's were used
alone in statement defs or vuses. */
if (v_ann->is_aliased
|| none_added
|| (TREE_CODE (var) == TYPE_MEMORY_TAG && for_clobber
&& TMT_USED_ALONE (var)))
{
/* Every bare tmt def we add should have TMT_USED_ALONE
set on it, or else we will get the wrong answer on
clobbers. */
if (none_added && !updating_used_alone && aliases_computed_p
&& TREE_CODE (var) == TYPE_MEMORY_TAG)
gcc_assert (TMT_USED_ALONE (var));
append_v_may_def (var);
}
}
else
{
bool none_added = true;
for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
{
if (!access_can_touch_variable (full_ref, al, offset, size))
continue;
none_added = false;
append_vuse (al);
}
/* Similarly, append a virtual uses for VAR itself, when
it is an alias tag. */
if (v_ann->is_aliased || none_added)
append_vuse (var);
}
}
} }
/* Copies virtual operands from SRC to DST. */ /* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in
get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to
the statement's real operands, otherwise it is added to virtual
operands. */
void static void
copy_virtual_operands (tree dest, tree src) add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags)
{ {
tree t; bool is_real_op;
ssa_op_iter iter, old_iter; tree var, sym;
use_operand_p use_p, u2; var_ann_t v_ann;
def_operand_p def_p, d2;
build_ssa_operands (dest);
/* Copy all the virtual fields. */ var = *var_p;
FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VUSE) gcc_assert (SSA_VAR_P (var));
append_vuse (t);
FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMAYDEF)
append_v_may_def (t);
FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMUSTDEF)
append_v_must_def (t);
if (VEC_length (tree, build_vuses) == 0 is_real_op = is_gimple_reg (var);
&& VEC_length (tree, build_v_may_defs) == 0
&& VEC_length (tree, build_v_must_defs) == 0)
return;
/* Now commit the virtual operands to this stmt. */ /* If this is a real operand, the operand is either an SSA name or a
finalize_ssa_v_must_defs (dest); decl. Virtual operands may only be decls. */
finalize_ssa_v_may_defs (dest); gcc_assert (is_real_op || DECL_P (var));
finalize_ssa_vuses (dest);
/* Finally, set the field to the same values as then originals. */ sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
v_ann = var_ann (sym);
/* Mark statements with volatile operands. Optimizers should back
off from statements having volatile operands. */
if (TREE_THIS_VOLATILE (sym) && s_ann)
s_ann->has_volatile_ops = true;
t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE); if (is_real_op)
FOR_EACH_SSA_USE_OPERAND (use_p, dest, iter, SSA_OP_VUSE)
{ {
gcc_assert (!op_iter_done (&old_iter)); /* The variable is a GIMPLE register. Add it to real operands. */
SET_USE (use_p, t); if (flags & opf_is_def)
t = op_iter_next_tree (&old_iter); append_def (var_p);
else
append_use (var_p);
} }
gcc_assert (op_iter_done (&old_iter)); else
add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false);
}
op_iter_init_maydef (&old_iter, src, &u2, &d2);
FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, dest, iter)
{
gcc_assert (!op_iter_done (&old_iter));
SET_USE (use_p, USE_FROM_PTR (u2));
SET_DEF (def_p, DEF_FROM_PTR (d2));
op_iter_next_maymustdef (&u2, &d2, &old_iter);
}
gcc_assert (op_iter_done (&old_iter));
op_iter_init_mustdef (&old_iter, src, &u2, &d2); /* A subroutine of get_expr_operands to handle INDIRECT_REF,
FOR_EACH_SSA_MUSTDEF_OPERAND (def_p, use_p, dest, iter) ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
{
gcc_assert (!op_iter_done (&old_iter));
SET_USE (use_p, USE_FROM_PTR (u2));
SET_DEF (def_p, DEF_FROM_PTR (d2));
op_iter_next_maymustdef (&u2, &d2, &old_iter);
}
gcc_assert (op_iter_done (&old_iter));
} STMT is the statement being processed, EXPR is the INDIRECT_REF
that got us here.
FLAGS is as in get_expr_operands.
/* Specifically for use in DOM's expression analysis. Given a store, we FULL_REF contains the full pointer dereference expression, if we
create an artificial stmt which looks like a load from the store, this can have it, or NULL otherwise.
be used to eliminate redundant loads. OLD_OPS are the operands from the
store stmt, and NEW_STMT is the new load which represents a load of the
values stored. */
void OFFSET and SIZE are the location of the access inside the
create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt) dereferenced pointer, if known.
{
stmt_ann_t ann;
tree op;
ssa_op_iter iter;
use_operand_p use_p;
unsigned x;
ann = get_stmt_ann (new_stmt); RECURSE_ON_BASE should be set to true if we want to continue
calling get_expr_operands on the base pointer, and false if
something else will do it for us. */
/* process the stmt looking for operands. */ static void
start_ssa_stmt_operands (); get_indirect_ref_operands (tree stmt, tree expr, int flags,
parse_ssa_operands (new_stmt); tree full_ref,
HOST_WIDE_INT offset, HOST_WIDE_INT size,
bool recurse_on_base)
{
tree *pptr = &TREE_OPERAND (expr, 0);
tree ptr = *pptr;
stmt_ann_t s_ann = stmt_ann (stmt);
for (x = 0; x < VEC_length (tree, build_vuses); x++) /* Stores into INDIRECT_REF operands are never killing definitions. */
flags &= ~opf_kill_def;
if (SSA_VAR_P (ptr))
{ {
tree t = VEC_index (tree, build_vuses, x); struct ptr_info_def *pi = NULL;
if (TREE_CODE (t) != SSA_NAME)
/* If PTR has flow-sensitive points-to information, use it. */
if (TREE_CODE (ptr) == SSA_NAME
&& (pi = SSA_NAME_PTR_INFO (ptr)) != NULL
&& pi->name_mem_tag)
{ {
var_ann_t ann = var_ann (t); /* PTR has its own memory tag. Use it. */
ann->in_vuse_list = 0; add_virtual_operand (pi->name_mem_tag, s_ann, flags,
} full_ref, offset, size, false);
} }
else
{
/* If PTR is not an SSA_NAME or it doesn't have a name
tag, use its type memory tag. */
var_ann_t v_ann;
for (x = 0; x < VEC_length (tree, build_v_may_defs); x++) /* If we are emitting debugging dumps, display a warning if
PTR is an SSA_NAME with no flow-sensitive alias
information. That means that we may need to compute
aliasing again. */
if (dump_file
&& TREE_CODE (ptr) == SSA_NAME
&& pi == NULL)
{ {
tree t = VEC_index (tree, build_v_may_defs, x); fprintf (dump_file,
if (TREE_CODE (t) != SSA_NAME) "NOTE: no flow-sensitive alias info for ");
{ print_generic_expr (dump_file, ptr, dump_flags);
var_ann_t ann = var_ann (t); fprintf (dump_file, " in ");
ann->in_v_may_def_list = 0; print_generic_stmt (dump_file, stmt, dump_flags);
}
} }
/* Remove any virtual operands that were found. */
VEC_truncate (tree, build_v_may_defs, 0);
VEC_truncate (tree, build_v_must_defs, 0);
VEC_truncate (tree, build_vuses, 0);
/* For each VDEF on the original statement, we want to create a
VUSE of the V_MAY_DEF result or V_MUST_DEF op on the new
statement. */
FOR_EACH_SSA_TREE_OPERAND (op, old_stmt, iter,
(SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF))
append_vuse (op);
/* Now build the operands for this new stmt. */
finalize_ssa_stmt_operands (new_stmt);
/* All uses in this fake stmt must not be in the immediate use lists. */
FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES)
delink_imm_use (use_p);
}
void if (TREE_CODE (ptr) == SSA_NAME)
swap_tree_operands (tree stmt, tree *exp0, tree *exp1) ptr = SSA_NAME_VAR (ptr);
{ v_ann = var_ann (ptr);
tree op0, op1;
op0 = *exp0;
op1 = *exp1;
/* If the operand cache is active, attempt to preserve the relative positions if (v_ann->type_mem_tag)
of these two operands in their respective immediate use lists. */ add_virtual_operand (v_ann->type_mem_tag, s_ann, flags,
if (ssa_operands_active () && op0 != op1) full_ref, offset, size, false);
{
use_optype_p use0, use1, ptr;
use0 = use1 = NULL;
/* Find the 2 operands in the cache, if they are there. */
for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
if (USE_OP_PTR (ptr)->use == exp0)
{
use0 = ptr;
break;
} }
for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
if (USE_OP_PTR (ptr)->use == exp1)
{
use1 = ptr;
break;
} }
/* If both uses don't have operand entries, there isn't much we can do else if (TREE_CODE (ptr) == INTEGER_CST)
at this point. Presumably we dont need to worry about it. */
if (use0 && use1)
{ {
tree *tmp = USE_OP_PTR (use1)->use; /* If a constant is used as a pointer, we can't generate a real
USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use; operand for it but we mark the statement volatile to prevent
USE_OP_PTR (use0)->use = tmp; optimizations from messing things up. */
if (s_ann)
s_ann->has_volatile_ops = true;
return;
} }
else
{
/* Ok, this isn't even is_gimple_min_invariant. Something's broke. */
gcc_unreachable ();
} }
/* Now swap the data. */ /* If requested, add a USE operand for the base pointer. */
*exp0 = op1; if (recurse_on_base)
*exp1 = op0; get_expr_operands (stmt, pptr, opf_none);
} }
/* Recursively scan the expression pointed to by EXPR_P in statement /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */
referred to by INFO. FLAGS is one of the OPF_* constants modifying
how to interpret the operands found. */
static void static void
get_expr_operands (tree stmt, tree *expr_p, int flags) get_tmr_operands (tree stmt, tree expr, int flags)
{ {
enum tree_code code; tree tag = TMR_TAG (expr), ref;
enum tree_code_class class; HOST_WIDE_INT offset, size, maxsize;
tree expr = *expr_p; subvar_t svars, sv;
stmt_ann_t s_ann = stmt_ann (stmt); stmt_ann_t s_ann = stmt_ann (stmt);
if (expr == NULL) /* First record the real operands. */
return; get_expr_operands (stmt, &TMR_BASE (expr), opf_none);
get_expr_operands (stmt, &TMR_INDEX (expr), opf_none);
code = TREE_CODE (expr);
class = TREE_CODE_CLASS (code);
switch (code)
{
case ADDR_EXPR:
/* Taking the address of a variable does not represent a
reference to it, but the fact that the statement takes its
address will be of interest to some passes (e.g. alias
resolution). */
add_to_addressable_set (TREE_OPERAND (expr, 0), &s_ann->addresses_taken);
/* If the address is invariant, there may be no interesting
variable references inside. */
if (is_gimple_min_invariant (expr))
return;
/* Otherwise, there may be variables referenced inside but there
should be no VUSEs created, since the referenced objects are
not really accessed. The only operands that we should find
here are ARRAY_REF indices which will always be real operands
(GIMPLE does not allow non-registers as array indices). */
flags |= opf_no_vops;
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
return;
case SSA_NAME:
case STRUCT_FIELD_TAG:
case TYPE_MEMORY_TAG:
case NAME_MEMORY_TAG:
add_stmt_operand (expr_p, s_ann, flags);
return;
case VAR_DECL: /* MEM_REFs should never be killing. */
case PARM_DECL: flags &= ~opf_kill_def;
case RESULT_DECL:
{
subvar_t svars;
/* Add the subvars for a variable if it has subvars, to DEFS if (TMR_SYMBOL (expr))
or USES. Otherwise, add the variable itself. Whether it
goes to USES or DEFS depends on the operand flags. */
if (var_can_have_subvars (expr)
&& (svars = get_subvars_for_var (expr)))
{ {
subvar_t sv; stmt_ann_t ann = stmt_ann (stmt);
for (sv = svars; sv; sv = sv->next) add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken);
add_stmt_operand (&sv->var, s_ann, flags);
} }
else
add_stmt_operand (expr_p, s_ann, flags);
if (!tag)
{
/* Something weird, so ensure that we will be careful. */
stmt_ann (stmt)->has_volatile_ops = true;
return; return;
} }
case MISALIGNED_INDIRECT_REF: if (DECL_P (tag))
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
/* fall through */
case ALIGN_INDIRECT_REF:
case INDIRECT_REF:
get_indirect_ref_operands (stmt, expr, flags, NULL_TREE,
0, -1, true);
return;
case TARGET_MEM_REF:
get_tmr_operands (stmt, expr, flags);
return;
case ARRAY_RANGE_REF:
/* Treat array references as references to the virtual variable
representing the array. The virtual variable for an ARRAY_REF
is the VAR_DECL for the array. */
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_none);
return;
case ARRAY_REF:
case COMPONENT_REF:
case REALPART_EXPR:
case IMAGPART_EXPR:
{
tree ref;
HOST_WIDE_INT offset, size, maxsize;
bool none = true;
/* This component reference becomes an access to all of the
subvariables it can touch, if we can determine that, but
*NOT* the real one. If we can't determine which fields we
could touch, the recursion will eventually get to a
variable and add *all* of its subvars, or whatever is the
minimum correct subset. */
ref = get_ref_base_and_extent (expr, &offset, &size, &maxsize);
if (SSA_VAR_P (ref) && get_subvars_for_var (ref))
{ {
subvar_t sv; get_expr_operands (stmt, &tag, flags);
subvar_t svars = get_subvars_for_var (ref); return;
}
ref = get_ref_base_and_extent (tag, &offset, &size, &maxsize);
gcc_assert (ref != NULL_TREE);
svars = get_subvars_for_var (ref);
for (sv = svars; sv; sv = sv->next) for (sv = svars; sv; sv = sv->next)
{ {
bool exact; bool exact;
if (overlap_subvar (offset, maxsize, sv->var, &exact)) if (overlap_subvar (offset, maxsize, sv->var, &exact))
{ {
int subvar_flags = flags; int subvar_flags = flags;
none = false;
if (!exact || size != maxsize) if (!exact || size != maxsize)
subvar_flags &= ~opf_kill_def; subvar_flags &= ~opf_kill_def;
add_stmt_operand (&sv->var, s_ann, subvar_flags); add_stmt_operand (&sv->var, s_ann, subvar_flags);
} }
} }
}
if (!none)
flags |= opf_no_vops;
}
else if (TREE_CODE (ref) == INDIRECT_REF)
{
get_indirect_ref_operands (stmt, ref, flags, expr,
offset, maxsize, false);
flags |= opf_no_vops;
}
/* Even if we found subvars above we need to ensure to see /* Add clobbering definitions for .GLOBAL_VAR or for each of the call
immediate uses for d in s.a[d]. In case of s.a having clobbered variables in the function. */
a subvar we'd miss it otherwise. */
get_expr_operands (stmt, &TREE_OPERAND (expr, 0),
flags & ~opf_kill_def);
if (code == COMPONENT_REF) static void
{ add_call_clobber_ops (tree stmt, tree callee)
if (s_ann && TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1))) {
s_ann->has_volatile_ops = true; unsigned u;
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); bitmap_iterator bi;
} stmt_ann_t s_ann = stmt_ann (stmt);
else if (code == ARRAY_REF) bitmap not_read_b, not_written_b;
{
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); /* Functions that are not const, pure or never return may clobber
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); call-clobbered variables. */
get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_none); if (s_ann)
} s_ann->makes_clobbering_call = true;
/* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases
for the heuristic used to decide whether to create .GLOBAL_VAR or not. */
if (global_var)
{
add_stmt_operand (&global_var, s_ann, opf_is_def);
return; return;
} }
case WITH_SIZE_EXPR: /* Get info for local and module level statics. There is a bit
/* WITH_SIZE_EXPR is a pass-through reference to its first argument, set for each static if the call being processed does not read
and an rvalue reference to its second argument. */ or write that variable. */
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); not_written_b = callee ? ipa_reference_get_not_written_global (callee) : NULL;
return; /* Add a V_MAY_DEF operand for every call clobbered variable. */
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
{
tree var = referenced_var_lookup (u);
unsigned int escape_mask = var_ann (var)->escape_mask;
tree real_var = var;
bool not_read;
bool not_written;
case CALL_EXPR: /* Not read and not written are computed on regular vars, not
get_call_expr_operands (stmt, expr); subvars, so look at the parent var if this is an SFT. */
return; if (TREE_CODE (var) == STRUCT_FIELD_TAG)
real_var = SFT_PARENT_VAR (var);
case COND_EXPR: not_read = not_read_b ? bitmap_bit_p (not_read_b,
case VEC_COND_EXPR: DECL_UID (real_var)) : false;
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none); not_written = not_written_b ? bitmap_bit_p (not_written_b,
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); DECL_UID (real_var)) : false;
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); gcc_assert (!unmodifiable_var_p (var));
return;
case MODIFY_EXPR: clobber_stats.clobbered_vars++;
{
int subflags;
tree op;
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); /* See if this variable is really clobbered by this function. */
op = TREE_OPERAND (expr, 0); /* Trivial case: Things escaping only to pure/const are not
if (TREE_CODE (op) == WITH_SIZE_EXPR) clobbered by non-pure-const, and only read by pure/const. */
op = TREE_OPERAND (expr, 0); if ((escape_mask & ~(ESCAPE_TO_PURE_CONST)) == 0)
if (TREE_CODE (op) == ARRAY_RANGE_REF {
|| TREE_CODE (op) == REALPART_EXPR tree call = get_call_expr_in (stmt);
|| TREE_CODE (op) == IMAGPART_EXPR) if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
subflags = opf_is_def; {
add_stmt_operand (&var, s_ann, opf_none);
clobber_stats.unescapable_clobbers_avoided++;
continue;
}
else else
subflags = opf_is_def | opf_kill_def; {
clobber_stats.unescapable_clobbers_avoided++;
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), subflags); continue;
return; }
} }
case CONSTRUCTOR: if (not_written)
{ {
/* General aggregate CONSTRUCTORs have been decomposed, but they clobber_stats.static_write_clobbers_avoided++;
are still in use as the COMPLEX_EXPR equivalent for vectors. */ if (!not_read)
constructor_elt *ce; add_stmt_operand (&var, s_ann, opf_none);
unsigned HOST_WIDE_INT idx; else
clobber_stats.static_read_clobbers_avoided++;
}
else
add_virtual_operand (var, s_ann, opf_is_def,
NULL, 0, -1, true);
}
for (idx = 0; }
VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (expr), idx, ce);
idx++)
get_expr_operands (stmt, &ce->value, opf_none);
return;
}
case TRUTH_NOT_EXPR: /* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the
case BIT_FIELD_REF: function. */
case VIEW_CONVERT_EXPR:
do_unary:
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
return;
case TRUTH_AND_EXPR: static void
case TRUTH_OR_EXPR: add_call_read_ops (tree stmt, tree callee)
case TRUTH_XOR_EXPR: {
case COMPOUND_EXPR: unsigned u;
case OBJ_TYPE_REF: bitmap_iterator bi;
case ASSERT_EXPR: stmt_ann_t s_ann = stmt_ann (stmt);
do_binary: bitmap not_read_b;
/* if the function is not pure, it may reference memory. Add
a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var
for the heuristic used to decide whether to create .GLOBAL_VAR. */
if (global_var)
{ {
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); add_stmt_operand (&global_var, s_ann, opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
return; return;
} }
case DOT_PROD_EXPR: not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
case REALIGN_LOAD_EXPR:
/* Add a VUSE for each call-clobbered variable. */
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
{ {
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); tree var = referenced_var (u);
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags); tree real_var = var;
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), flags); bool not_read;
return;
clobber_stats.readonly_clobbers++;
/* Not read and not written are computed on regular vars, not
subvars, so look at the parent var if this is an SFT. */
if (TREE_CODE (var) == STRUCT_FIELD_TAG)
real_var = SFT_PARENT_VAR (var);
not_read = not_read_b ? bitmap_bit_p (not_read_b,
DECL_UID (real_var)) : false;
if (not_read)
{
clobber_stats.static_readonly_clobbers_avoided++;
continue;
} }
case BLOCK: add_stmt_operand (&var, s_ann, opf_none | opf_non_specific);
case FUNCTION_DECL: }
case EXC_PTR_EXPR: }
case FILTER_EXPR:
case LABEL_DECL:
case CONST_DECL:
case OMP_PARALLEL:
case OMP_SECTIONS:
case OMP_FOR:
case OMP_RETURN_EXPR:
case OMP_SINGLE:
case OMP_MASTER:
case OMP_ORDERED:
case OMP_CRITICAL:
/* Expressions that make no memory references. */
return;
default:
if (class == tcc_unary) /* A subroutine of get_expr_operands to handle CALL_EXPR. */
goto do_unary;
if (class == tcc_binary || class == tcc_comparison) static void
goto do_binary; get_call_expr_operands (tree stmt, tree expr)
if (class == tcc_constant || class == tcc_type) {
return; tree op;
int call_flags = call_expr_flags (expr);
/* If aliases have been computed already, add V_MAY_DEF or V_USE
operands for all the symbols that have been found to be
call-clobbered.
Note that if aliases have not been computed, the global effects
of calls will not be included in the SSA web. This is fine
because no optimizer should run before aliases have been
computed. By not bothering with virtual operands for CALL_EXPRs
we avoid adding superfluous virtual operands, which can be a
significant compile time sink (See PR 15855). */
if (aliases_computed_p
&& !bitmap_empty_p (call_clobbered_vars)
&& !(call_flags & ECF_NOVOPS))
{
/* A 'pure' or a 'const' function never call-clobbers anything.
A 'noreturn' function might, but since we don't return anyway
there is no point in recording that. */
if (TREE_SIDE_EFFECTS (expr)
&& !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN)))
add_call_clobber_ops (stmt, get_callee_fndecl (expr));
else if (!(call_flags & ECF_CONST))
add_call_read_ops (stmt, get_callee_fndecl (expr));
} }
/* If we get here, something has gone wrong. */ /* Find uses in the called function. */
#ifdef ENABLE_CHECKING get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none);
fprintf (stderr, "unhandled expression in get_expr_operands():\n");
debug_tree (expr); for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op))
fputs ("\n", stderr); get_expr_operands (stmt, &TREE_VALUE (op), opf_none);
internal_error ("internal error");
#endif get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
gcc_unreachable ();
} }
...@@ -1427,507 +1460,611 @@ get_asm_expr_operands (tree stmt) ...@@ -1427,507 +1460,611 @@ get_asm_expr_operands (tree stmt)
} }
} }
/* A subroutine of get_expr_operands to handle INDIRECT_REF,
ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
STMT is the statement being processed, EXPR is the INDIRECT_REF
that got us here.
FLAGS is as in get_expr_operands.
FULL_REF contains the full pointer dereference expression, if we
have it, or NULL otherwise.
OFFSET and SIZE are the location of the access inside the
dereferenced pointer, if known.
RECURSE_ON_BASE should be set to true if we want to continue /* Recursively scan the expression pointed to by EXPR_P in statement
calling get_expr_operands on the base pointer, and false if referred to by INFO. FLAGS is one of the OPF_* constants modifying
something else will do it for us. */ how to interpret the operands found. */
static void static void
get_indirect_ref_operands (tree stmt, tree expr, int flags, get_expr_operands (tree stmt, tree *expr_p, int flags)
tree full_ref,
HOST_WIDE_INT offset, HOST_WIDE_INT size,
bool recurse_on_base)
{ {
tree *pptr = &TREE_OPERAND (expr, 0); enum tree_code code;
tree ptr = *pptr; enum tree_code_class class;
tree expr = *expr_p;
stmt_ann_t s_ann = stmt_ann (stmt); stmt_ann_t s_ann = stmt_ann (stmt);
/* Stores into INDIRECT_REF operands are never killing definitions. */ if (expr == NULL)
flags &= ~opf_kill_def; return;
if (SSA_VAR_P (ptr)) code = TREE_CODE (expr);
{ class = TREE_CODE_CLASS (code);
struct ptr_info_def *pi = NULL;
/* If PTR has flow-sensitive points-to information, use it. */ switch (code)
if (TREE_CODE (ptr) == SSA_NAME
&& (pi = SSA_NAME_PTR_INFO (ptr)) != NULL
&& pi->name_mem_tag)
{
/* PTR has its own memory tag. Use it. */
add_virtual_operand (pi->name_mem_tag, s_ann, flags,
full_ref, offset, size, false);
}
else
{ {
/* If PTR is not an SSA_NAME or it doesn't have a name case ADDR_EXPR:
tag, use its type memory tag. */ /* Taking the address of a variable does not represent a
var_ann_t v_ann; reference to it, but the fact that the statement takes its
address will be of interest to some passes (e.g. alias
resolution). */
add_to_addressable_set (TREE_OPERAND (expr, 0), &s_ann->addresses_taken);
/* If we are emitting debugging dumps, display a warning if /* If the address is invariant, there may be no interesting
PTR is an SSA_NAME with no flow-sensitive alias variable references inside. */
information. That means that we may need to compute if (is_gimple_min_invariant (expr))
aliasing again. */ return;
if (dump_file
&& TREE_CODE (ptr) == SSA_NAME
&& pi == NULL)
{
fprintf (dump_file,
"NOTE: no flow-sensitive alias info for ");
print_generic_expr (dump_file, ptr, dump_flags);
fprintf (dump_file, " in ");
print_generic_stmt (dump_file, stmt, dump_flags);
}
if (TREE_CODE (ptr) == SSA_NAME) /* Otherwise, there may be variables referenced inside but there
ptr = SSA_NAME_VAR (ptr); should be no VUSEs created, since the referenced objects are
v_ann = var_ann (ptr); not really accessed. The only operands that we should find
here are ARRAY_REF indices which will always be real operands
(GIMPLE does not allow non-registers as array indices). */
flags |= opf_no_vops;
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
return;
if (v_ann->type_mem_tag) case SSA_NAME:
add_virtual_operand (v_ann->type_mem_tag, s_ann, flags, case STRUCT_FIELD_TAG:
full_ref, offset, size, false); case TYPE_MEMORY_TAG:
} case NAME_MEMORY_TAG:
} add_stmt_operand (expr_p, s_ann, flags);
else if (TREE_CODE (ptr) == INTEGER_CST)
{
/* If a constant is used as a pointer, we can't generate a real
operand for it but we mark the statement volatile to prevent
optimizations from messing things up. */
if (s_ann)
s_ann->has_volatile_ops = true;
return; return;
}
else
{
/* Ok, this isn't even is_gimple_min_invariant. Something's broke. */
gcc_unreachable ();
}
/* If requested, add a USE operand for the base pointer. */ case VAR_DECL:
if (recurse_on_base) case PARM_DECL:
get_expr_operands (stmt, pptr, opf_none); case RESULT_DECL:
} {
subvar_t svars;
/* Add the subvars for a variable if it has subvars, to DEFS
or USES. Otherwise, add the variable itself. Whether it
goes to USES or DEFS depends on the operand flags. */
if (var_can_have_subvars (expr)
&& (svars = get_subvars_for_var (expr)))
{
subvar_t sv;
for (sv = svars; sv; sv = sv->next)
add_stmt_operand (&sv->var, s_ann, flags);
}
else
add_stmt_operand (expr_p, s_ann, flags);
/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ return;
}
static void case MISALIGNED_INDIRECT_REF:
get_tmr_operands (tree stmt, tree expr, int flags) get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
{ /* fall through */
tree tag = TMR_TAG (expr), ref;
HOST_WIDE_INT offset, size, maxsize;
subvar_t svars, sv;
stmt_ann_t s_ann = stmt_ann (stmt);
/* First record the real operands. */ case ALIGN_INDIRECT_REF:
get_expr_operands (stmt, &TMR_BASE (expr), opf_none); case INDIRECT_REF:
get_expr_operands (stmt, &TMR_INDEX (expr), opf_none); get_indirect_ref_operands (stmt, expr, flags, NULL_TREE,
0, -1, true);
return;
/* MEM_REFs should never be killing. */ case TARGET_MEM_REF:
flags &= ~opf_kill_def; get_tmr_operands (stmt, expr, flags);
return;
if (TMR_SYMBOL (expr)) case ARRAY_RANGE_REF:
{ /* Treat array references as references to the virtual variable
stmt_ann_t ann = stmt_ann (stmt); representing the array. The virtual variable for an ARRAY_REF
add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken); is the VAR_DECL for the array. */
} get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_none);
return;
if (!tag) case ARRAY_REF:
case COMPONENT_REF:
case REALPART_EXPR:
case IMAGPART_EXPR:
{ {
/* Something weird, so ensure that we will be careful. */ tree ref;
stmt_ann (stmt)->has_volatile_ops = true; HOST_WIDE_INT offset, size, maxsize;
return; bool none = true;
}
if (DECL_P (tag)) /* This component reference becomes an access to all of the
subvariables it can touch, if we can determine that, but
*NOT* the real one. If we can't determine which fields we
could touch, the recursion will eventually get to a
variable and add *all* of its subvars, or whatever is the
minimum correct subset. */
ref = get_ref_base_and_extent (expr, &offset, &size, &maxsize);
if (SSA_VAR_P (ref) && get_subvars_for_var (ref))
{ {
get_expr_operands (stmt, &tag, flags); subvar_t sv;
return; subvar_t svars = get_subvars_for_var (ref);
}
ref = get_ref_base_and_extent (tag, &offset, &size, &maxsize);
gcc_assert (ref != NULL_TREE);
svars = get_subvars_for_var (ref);
for (sv = svars; sv; sv = sv->next) for (sv = svars; sv; sv = sv->next)
{ {
bool exact; bool exact;
if (overlap_subvar (offset, maxsize, sv->var, &exact)) if (overlap_subvar (offset, maxsize, sv->var, &exact))
{ {
int subvar_flags = flags; int subvar_flags = flags;
none = false;
if (!exact || size != maxsize) if (!exact || size != maxsize)
subvar_flags &= ~opf_kill_def; subvar_flags &= ~opf_kill_def;
add_stmt_operand (&sv->var, s_ann, subvar_flags); add_stmt_operand (&sv->var, s_ann, subvar_flags);
} }
} }
}
if (!none)
flags |= opf_no_vops;
}
else if (TREE_CODE (ref) == INDIRECT_REF)
{
get_indirect_ref_operands (stmt, ref, flags, expr,
offset, maxsize, false);
flags |= opf_no_vops;
}
/* A subroutine of get_expr_operands to handle CALL_EXPR. */ /* Even if we found subvars above we need to ensure to see
immediate uses for d in s.a[d]. In case of s.a having
static void a subvar we'd miss it otherwise. */
get_call_expr_operands (tree stmt, tree expr) get_expr_operands (stmt, &TREE_OPERAND (expr, 0),
{ flags & ~opf_kill_def);
tree op;
int call_flags = call_expr_flags (expr);
/* If aliases have been computed already, add V_MAY_DEF or V_USE
operands for all the symbols that have been found to be
call-clobbered.
Note that if aliases have not been computed, the global effects if (code == COMPONENT_REF)
of calls will not be included in the SSA web. This is fine
because no optimizer should run before aliases have been
computed. By not bothering with virtual operands for CALL_EXPRs
we avoid adding superfluous virtual operands, which can be a
significant compile time sink (See PR 15855). */
if (aliases_computed_p
&& !bitmap_empty_p (call_clobbered_vars)
&& !(call_flags & ECF_NOVOPS))
{ {
/* A 'pure' or a 'const' function never call-clobbers anything. if (s_ann && TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1)))
A 'noreturn' function might, but since we don't return anyway s_ann->has_volatile_ops = true;
there is no point in recording that. */ get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
if (TREE_SIDE_EFFECTS (expr) }
&& !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN))) else if (code == ARRAY_REF)
add_call_clobber_ops (stmt, get_callee_fndecl (expr)); {
else if (!(call_flags & ECF_CONST)) get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
add_call_read_ops (stmt, get_callee_fndecl (expr)); get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_none);
} }
/* Find uses in the called function. */ return;
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none); }
for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op)) case WITH_SIZE_EXPR:
get_expr_operands (stmt, &TREE_VALUE (op), opf_none); /* WITH_SIZE_EXPR is a pass-through reference to its first argument,
and an rvalue reference to its second argument. */
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
return;
case CALL_EXPR:
get_call_expr_operands (stmt, expr);
return;
case COND_EXPR:
case VEC_COND_EXPR:
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
return;
} case MODIFY_EXPR:
{
int subflags;
tree op;
/* REF is a tree that contains the entire pointer dereference get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none);
expression, if available, or NULL otherwise. ALIAS is the variable
we are asking if REF can access. OFFSET and SIZE come from the
memory access expression that generated this virtual operand.
FOR_CLOBBER is true is this is adding a virtual operand for a call
clobber. */
static bool op = TREE_OPERAND (expr, 0);
access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset, if (TREE_CODE (op) == WITH_SIZE_EXPR)
HOST_WIDE_INT size) op = TREE_OPERAND (expr, 0);
{ if (TREE_CODE (op) == ARRAY_RANGE_REF
bool offsetgtz = offset > 0; || TREE_CODE (op) == REALPART_EXPR
unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset; || TREE_CODE (op) == IMAGPART_EXPR)
tree base = ref ? get_base_address (ref) : NULL; subflags = opf_is_def;
else
subflags = opf_is_def | opf_kill_def;
/* If ALIAS is an SFT, it can't be touched if the offset get_expr_operands (stmt, &TREE_OPERAND (expr, 0), subflags);
and size of the access is not overlapping with the SFT offset and return;
size. This is only true if we are accessing through a pointer }
to a type that is the same as SFT_PARENT_VAR. Otherwise, we may
be accessing through a pointer to some substruct of the
structure, and if we try to prune there, we will have the wrong
offset, and get the wrong answer.
i.e., we can't prune without more work if we have something like
struct gcc_target case CONSTRUCTOR:
{ {
struct asm_out /* General aggregate CONSTRUCTORs have been decomposed, but they
are still in use as the COMPLEX_EXPR equivalent for vectors. */
constructor_elt *ce;
unsigned HOST_WIDE_INT idx;
for (idx = 0;
VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (expr), idx, ce);
idx++)
get_expr_operands (stmt, &ce->value, opf_none);
return;
}
case TRUTH_NOT_EXPR:
case BIT_FIELD_REF:
case VIEW_CONVERT_EXPR:
do_unary:
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
return;
case TRUTH_AND_EXPR:
case TRUTH_OR_EXPR:
case TRUTH_XOR_EXPR:
case COMPOUND_EXPR:
case OBJ_TYPE_REF:
case ASSERT_EXPR:
do_binary:
{ {
const char *byte_op; get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
struct asm_int_op get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
return;
}
case DOT_PROD_EXPR:
case REALIGN_LOAD_EXPR:
{ {
const char *hi; get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
} aligned_op; get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
} asm_out; get_expr_operands (stmt, &TREE_OPERAND (expr, 2), flags);
} targetm; return;
}
foo = &targetm.asm_out.aligned_op; case BLOCK:
return foo->hi; case FUNCTION_DECL:
case EXC_PTR_EXPR:
case FILTER_EXPR:
case LABEL_DECL:
case CONST_DECL:
case OMP_PARALLEL:
case OMP_SECTIONS:
case OMP_FOR:
case OMP_RETURN_EXPR:
case OMP_SINGLE:
case OMP_MASTER:
case OMP_ORDERED:
case OMP_CRITICAL:
/* Expressions that make no memory references. */
return;
SFT.1, which represents hi, will have SFT_OFFSET=32 because in default:
terms of SFT_PARENT_VAR, that is where it is. if (class == tcc_unary)
However, the access through the foo pointer will be at offset 0. */ goto do_unary;
if (size != -1 if (class == tcc_binary || class == tcc_comparison)
&& TREE_CODE (alias) == STRUCT_FIELD_TAG goto do_binary;
&& base if (class == tcc_constant || class == tcc_type)
&& TREE_TYPE (base) == TREE_TYPE (SFT_PARENT_VAR (alias)) return;
&& !overlap_subvar (offset, size, alias, NULL))
{
#ifdef ACCESS_DEBUGGING
fprintf (stderr, "Access to ");
print_generic_expr (stderr, ref, 0);
fprintf (stderr, " may not touch ");
print_generic_expr (stderr, alias, 0);
fprintf (stderr, " in function %s\n", get_name (current_function_decl));
#endif
return false;
} }
/* Without strict aliasing, it is impossible for a component access /* If we get here, something has gone wrong. */
through a pointer to touch a random variable, unless that #ifdef ENABLE_CHECKING
variable *is* a structure or a pointer. fprintf (stderr, "unhandled expression in get_expr_operands():\n");
debug_tree (expr);
fputs ("\n", stderr);
#endif
gcc_unreachable ();
}
That is, given p->c, and some random global variable b,
there is no legal way that p->c could be an access to b.
Without strict aliasing on, we consider it legal to do something /* Parse STMT looking for operands. OLD_OPS is the original stmt operand
like: cache for STMT, if it existed before. When finished, the various build_*
operand vectors will have potential operands. in them. */
struct foos { int l; }; static void
int foo; parse_ssa_operands (tree stmt)
static struct foos *getfoo(void); {
int main (void) enum tree_code code;
{
struct foos *f = getfoo();
f->l = 1;
foo = 2;
if (f->l == 1)
abort();
exit(0);
}
static struct foos *getfoo(void)
{ return (struct foos *)&foo; }
(taken from 20000623-1.c) code = TREE_CODE (stmt);
*/ switch (code)
else if (ref
&& flag_strict_aliasing
&& TREE_CODE (ref) != INDIRECT_REF
&& !MTAG_P (alias)
&& !AGGREGATE_TYPE_P (TREE_TYPE (alias))
&& TREE_CODE (TREE_TYPE (alias)) != COMPLEX_TYPE
&& !POINTER_TYPE_P (TREE_TYPE (alias)))
{ {
#ifdef ACCESS_DEBUGGING case MODIFY_EXPR:
fprintf (stderr, "Access to "); /* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if
print_generic_expr (stderr, ref, 0); either only part of LHS is modified or if the RHS might throw,
fprintf (stderr, " may not touch "); otherwise, use V_MUST_DEF.
print_generic_expr (stderr, alias, 0);
fprintf (stderr, " in function %s\n", get_name (current_function_decl));
#endif
return false;
}
/* If the offset of the access is greater than the size of one of ??? If it might throw, we should represent somehow that it is killed
the possible aliases, it can't be touching that alias, because it on the fallthrough path. */
would be past the end of the structure. */
else if (ref
&& flag_strict_aliasing
&& TREE_CODE (ref) != INDIRECT_REF
&& !MTAG_P (alias)
&& !POINTER_TYPE_P (TREE_TYPE (alias))
&& offsetgtz
&& DECL_SIZE (alias)
&& TREE_CODE (DECL_SIZE (alias)) == INTEGER_CST
&& uoffset > TREE_INT_CST_LOW (DECL_SIZE (alias)))
{ {
#ifdef ACCESS_DEBUGGING tree lhs = TREE_OPERAND (stmt, 0);
fprintf (stderr, "Access to "); int lhs_flags = opf_is_def;
print_generic_expr (stderr, ref, 0);
fprintf (stderr, " may not touch "); get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none);
print_generic_expr (stderr, alias, 0);
fprintf (stderr, " in function %s\n", get_name (current_function_decl)); /* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether
#endif or not the entire LHS is modified; that depends on what's
return false; inside the VIEW_CONVERT_EXPR. */
if (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
lhs = TREE_OPERAND (lhs, 0);
if (TREE_CODE (lhs) != ARRAY_RANGE_REF
&& TREE_CODE (lhs) != BIT_FIELD_REF)
lhs_flags |= opf_kill_def;
get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), lhs_flags);
} }
break;
return true; case COND_EXPR:
get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none);
break;
case SWITCH_EXPR:
get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none);
break;
case ASM_EXPR:
get_asm_expr_operands (stmt);
break;
case RETURN_EXPR:
get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_none);
break;
case GOTO_EXPR:
get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_none);
break;
case LABEL_EXPR:
get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_none);
break;
/* These nodes contain no variable references. */
case BIND_EXPR:
case CASE_LABEL_EXPR:
case TRY_CATCH_EXPR:
case TRY_FINALLY_EXPR:
case EH_FILTER_EXPR:
case CATCH_EXPR:
case RESX_EXPR:
break;
default:
/* Notice that if get_expr_operands tries to use &STMT as the operand
pointer (which may only happen for USE operands), we will fail in
append_use. This default will handle statements like empty
statements, or CALL_EXPRs that may appear on the RHS of a statement
or as statements themselves. */
get_expr_operands (stmt, &stmt, opf_none);
break;
}
} }
/* Add VAR to the virtual operands array. FLAGS is as in /* Create an operands cache for STMT. */
get_expr_operands. FULL_REF is a tree that contains the entire
pointer dereference expression, if available, or NULL otherwise.
OFFSET and SIZE come from the memory access expression that
generated this virtual operand. FOR_CLOBBER is true is this is
adding a virtual operand for a call clobber. */
static void static void
add_virtual_operand (tree var, stmt_ann_t s_ann, int flags, build_ssa_operands (tree stmt)
tree full_ref, HOST_WIDE_INT offset,
HOST_WIDE_INT size, bool for_clobber)
{ {
VEC(tree,gc) *aliases; stmt_ann_t ann = get_stmt_ann (stmt);
tree sym;
var_ann_t v_ann;
sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); /* Initially assume that the statement has no volatile operands. */
v_ann = var_ann (sym); if (ann)
ann->has_volatile_ops = false;
/* Mark statements with volatile operands. Optimizers should back start_ssa_stmt_operands ();
off from statements having volatile operands. */
if (TREE_THIS_VOLATILE (sym) && s_ann)
s_ann->has_volatile_ops = true;
/* If the variable cannot be modified and this is a V_MAY_DEF change parse_ssa_operands (stmt);
it into a VUSE. This happens when read-only variables are marked operand_build_sort_virtual (build_vuses);
call-clobbered and/or aliased to writable variables. So we only operand_build_sort_virtual (build_v_may_defs);
check that this only happens on non-specific stores. operand_build_sort_virtual (build_v_must_defs);
Note that if this is a specific store, i.e. associated with a finalize_ssa_stmt_operands (stmt);
modify_expr, then we can't suppress the V_MAY_DEF, lest we run }
into validation problems.
This can happen when programs cast away const, leaving us with a
store to read-only memory. If the statement is actually executed
at runtime, then the program is ill formed. If the statement is
not executed then all is well. At the very least, we cannot ICE. */
if ((flags & opf_non_specific) && unmodifiable_var_p (var))
flags &= ~(opf_is_def | opf_kill_def);
/* The variable is not a GIMPLE register. Add it (or its aliases) to /* Free any operands vectors in OPS. */
virtual operands, unless the caller has specifically requested void
not to add virtual operands (used when adding operands inside an free_ssa_operands (stmt_operands_p ops)
ADDR_EXPR expression). */ {
if (flags & opf_no_vops) ops->def_ops = NULL;
ops->use_ops = NULL;
ops->maydef_ops = NULL;
ops->mustdef_ops = NULL;
ops->vuse_ops = NULL;
}
/* Get the operands of statement STMT. Note that repeated calls to
get_stmt_operands for the same statement will do nothing until the
statement is marked modified by a call to mark_stmt_modified(). */
void
update_stmt_operands (tree stmt)
{
stmt_ann_t ann = get_stmt_ann (stmt);
/* If get_stmt_operands is called before SSA is initialized, dont
do anything. */
if (!ssa_operands_active ())
return; return;
aliases = v_ann->may_aliases; /* The optimizers cannot handle statements that are nothing but a
if (aliases == NULL) _DECL. This indicates a bug in the gimplifier. */
{ gcc_assert (!SSA_VAR_P (stmt));
/* The variable is not aliased or it is an alias tag. */
if (flags & opf_is_def) gcc_assert (ann->modified);
{
if (flags & opf_kill_def) timevar_push (TV_TREE_OPS);
build_ssa_operands (stmt);
/* Clear the modified bit for STMT. Subsequent calls to
get_stmt_operands for this statement will do nothing until the
statement is marked modified by a call to mark_stmt_modified(). */
ann->modified = 0;
timevar_pop (TV_TREE_OPS);
}
/* Copies virtual operands from SRC to DST. */
void
copy_virtual_operands (tree dest, tree src)
{
tree t;
ssa_op_iter iter, old_iter;
use_operand_p use_p, u2;
def_operand_p def_p, d2;
build_ssa_operands (dest);
/* Copy all the virtual fields. */
FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VUSE)
append_vuse (t);
FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMAYDEF)
append_v_may_def (t);
FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMUSTDEF)
append_v_must_def (t);
if (VEC_length (tree, build_vuses) == 0
&& VEC_length (tree, build_v_may_defs) == 0
&& VEC_length (tree, build_v_must_defs) == 0)
return;
/* Now commit the virtual operands to this stmt. */
finalize_ssa_v_must_defs (dest);
finalize_ssa_v_may_defs (dest);
finalize_ssa_vuses (dest);
/* Finally, set the field to the same values as then originals. */
t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE);
FOR_EACH_SSA_USE_OPERAND (use_p, dest, iter, SSA_OP_VUSE)
{ {
/* V_MUST_DEF for non-aliased, non-GIMPLE register gcc_assert (!op_iter_done (&old_iter));
variable definitions. */ SET_USE (use_p, t);
gcc_assert (!MTAG_P (var) t = op_iter_next_tree (&old_iter);
|| TREE_CODE (var) == STRUCT_FIELD_TAG);
append_v_must_def (var);
} }
else gcc_assert (op_iter_done (&old_iter));
op_iter_init_maydef (&old_iter, src, &u2, &d2);
FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, dest, iter)
{ {
/* Add a V_MAY_DEF for call-clobbered variables and gcc_assert (!op_iter_done (&old_iter));
memory tags. */ SET_USE (use_p, USE_FROM_PTR (u2));
append_v_may_def (var); SET_DEF (def_p, DEF_FROM_PTR (d2));
} op_iter_next_maymustdef (&u2, &d2, &old_iter);
}
else
append_vuse (var);
} }
else gcc_assert (op_iter_done (&old_iter));
{
unsigned i;
tree al;
/* The variable is aliased. Add its aliases to the virtual
operands. */
gcc_assert (VEC_length (tree, aliases) != 0);
if (flags & opf_is_def) op_iter_init_mustdef (&old_iter, src, &u2, &d2);
FOR_EACH_SSA_MUSTDEF_OPERAND (def_p, use_p, dest, iter)
{ {
gcc_assert (!op_iter_done (&old_iter));
SET_USE (use_p, USE_FROM_PTR (u2));
SET_DEF (def_p, DEF_FROM_PTR (d2));
op_iter_next_maymustdef (&u2, &d2, &old_iter);
}
gcc_assert (op_iter_done (&old_iter));
bool none_added = true; }
for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
{
if (!access_can_touch_variable (full_ref, al, offset, size))
continue;
none_added = false;
append_v_may_def (al);
}
/* If the variable is also an alias tag, add a virtual /* Specifically for use in DOM's expression analysis. Given a store, we
operand for it, otherwise we will miss representing create an artificial stmt which looks like a load from the store, this can
references to the members of the variable's alias set. be used to eliminate redundant loads. OLD_OPS are the operands from the
This fixes the bug in gcc.c-torture/execute/20020503-1.c. store stmt, and NEW_STMT is the new load which represents a load of the
values stored. */
It is also necessary to add bare defs on clobbers for void
TMT's, so that bare TMT uses caused by pruning all the create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt)
aliases will link up properly with calls. In order to {
keep the number of these bare defs we add down to the stmt_ann_t ann;
minimum necessary, we keep track of which TMT's were used tree op;
alone in statement defs or vuses. */ ssa_op_iter iter;
use_operand_p use_p;
unsigned x;
if (v_ann->is_aliased ann = get_stmt_ann (new_stmt);
|| none_added
|| (TREE_CODE (var) == TYPE_MEMORY_TAG && for_clobber
&& TMT_USED_ALONE (var)))
{
/* Every bare tmt def we add should have TMT_USED_ALONE
set on it, or else we will get the wrong answer on
clobbers. */
if (none_added && !updating_used_alone && aliases_computed_p /* process the stmt looking for operands. */
&& TREE_CODE (var) == TYPE_MEMORY_TAG) start_ssa_stmt_operands ();
gcc_assert (TMT_USED_ALONE (var)); parse_ssa_operands (new_stmt);
append_v_may_def (var); for (x = 0; x < VEC_length (tree, build_vuses); x++)
}
}
else
{ {
bool none_added = true; tree t = VEC_index (tree, build_vuses, x);
for (i = 0; VEC_iterate (tree, aliases, i, al); i++) if (TREE_CODE (t) != SSA_NAME)
{ {
if (!access_can_touch_variable (full_ref, al, offset, size)) var_ann_t ann = var_ann (t);
continue; ann->in_vuse_list = 0;
none_added = false; }
append_vuse (al);
} }
/* Similarly, append a virtual uses for VAR itself, when for (x = 0; x < VEC_length (tree, build_v_may_defs); x++)
it is an alias tag. */ {
if (v_ann->is_aliased || none_added) tree t = VEC_index (tree, build_v_may_defs, x);
append_vuse (var); if (TREE_CODE (t) != SSA_NAME)
{
var_ann_t ann = var_ann (t);
ann->in_v_may_def_list = 0;
} }
} }
}
/* Remove any virtual operands that were found. */
VEC_truncate (tree, build_v_may_defs, 0);
VEC_truncate (tree, build_v_must_defs, 0);
VEC_truncate (tree, build_vuses, 0);
/* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in /* For each VDEF on the original statement, we want to create a
get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to VUSE of the V_MAY_DEF result or V_MUST_DEF op on the new
the statement's real operands, otherwise it is added to virtual statement. */
operands. */ FOR_EACH_SSA_TREE_OPERAND (op, old_stmt, iter,
(SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF))
append_vuse (op);
static void /* Now build the operands for this new stmt. */
add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags) finalize_ssa_stmt_operands (new_stmt);
{
bool is_real_op;
tree var, sym;
var_ann_t v_ann;
var = *var_p; /* All uses in this fake stmt must not be in the immediate use lists. */
gcc_assert (SSA_VAR_P (var)); FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES)
delink_imm_use (use_p);
}
is_real_op = is_gimple_reg (var);
/* If this is a real operand, the operand is either an SSA name or a /* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done
decl. Virtual operands may only be decls. */ to test the validity of the swap operation. */
gcc_assert (is_real_op || DECL_P (var));
sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); void
v_ann = var_ann (sym); swap_tree_operands (tree stmt, tree *exp0, tree *exp1)
{
tree op0, op1;
op0 = *exp0;
op1 = *exp1;
/* Mark statements with volatile operands. Optimizers should back /* If the operand cache is active, attempt to preserve the relative positions
off from statements having volatile operands. */ of these two operands in their respective immediate use lists. */
if (TREE_THIS_VOLATILE (sym) && s_ann) if (ssa_operands_active () && op0 != op1)
s_ann->has_volatile_ops = true; {
use_optype_p use0, use1, ptr;
use0 = use1 = NULL;
if (is_real_op) /* Find the 2 operands in the cache, if they are there. */
for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
if (USE_OP_PTR (ptr)->use == exp0)
{ {
/* The variable is a GIMPLE register. Add it to real operands. */ use0 = ptr;
if (flags & opf_is_def) break;
append_def (var_p);
else
append_use (var_p);
} }
else
add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false); for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
if (USE_OP_PTR (ptr)->use == exp1)
{
use1 = ptr;
break;
}
/* If both uses don't have operand entries, there isn't much we can do
at this point. Presumably we dont need to worry about it. */
if (use0 && use1)
{
tree *tmp = USE_OP_PTR (use1)->use;
USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use;
USE_OP_PTR (use0)->use = tmp;
}
}
/* Now swap the data. */
*exp0 = op1;
*exp1 = op0;
} }
...@@ -1976,144 +2113,6 @@ add_to_addressable_set (tree ref, bitmap *addresses_taken) ...@@ -1976,144 +2113,6 @@ add_to_addressable_set (tree ref, bitmap *addresses_taken)
} }
/* Add clobbering definitions for .GLOBAL_VAR or for each of the call
clobbered variables in the function. */
static void
add_call_clobber_ops (tree stmt, tree callee)
{
unsigned u;
bitmap_iterator bi;
stmt_ann_t s_ann = stmt_ann (stmt);
bitmap not_read_b, not_written_b;
/* Functions that are not const, pure or never return may clobber
call-clobbered variables. */
if (s_ann)
s_ann->makes_clobbering_call = true;
/* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases
for the heuristic used to decide whether to create .GLOBAL_VAR or not. */
if (global_var)
{
add_stmt_operand (&global_var, s_ann, opf_is_def);
return;
}
/* Get info for local and module level statics. There is a bit
set for each static if the call being processed does not read
or write that variable. */
not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
not_written_b = callee ? ipa_reference_get_not_written_global (callee) : NULL;
/* Add a V_MAY_DEF operand for every call clobbered variable. */
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
{
tree var = referenced_var_lookup (u);
unsigned int escape_mask = var_ann (var)->escape_mask;
tree real_var = var;
bool not_read;
bool not_written;
/* Not read and not written are computed on regular vars, not
subvars, so look at the parent var if this is an SFT. */
if (TREE_CODE (var) == STRUCT_FIELD_TAG)
real_var = SFT_PARENT_VAR (var);
not_read = not_read_b ? bitmap_bit_p (not_read_b,
DECL_UID (real_var)) : false;
not_written = not_written_b ? bitmap_bit_p (not_written_b,
DECL_UID (real_var)) : false;
gcc_assert (!unmodifiable_var_p (var));
clobber_stats.clobbered_vars++;
/* See if this variable is really clobbered by this function. */
/* Trivial case: Things escaping only to pure/const are not
clobbered by non-pure-const, and only read by pure/const. */
if ((escape_mask & ~(ESCAPE_TO_PURE_CONST)) == 0)
{
tree call = get_call_expr_in (stmt);
if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
{
add_stmt_operand (&var, s_ann, opf_none);
clobber_stats.unescapable_clobbers_avoided++;
continue;
}
else
{
clobber_stats.unescapable_clobbers_avoided++;
continue;
}
}
if (not_written)
{
clobber_stats.static_write_clobbers_avoided++;
if (!not_read)
add_stmt_operand (&var, s_ann, opf_none);
else
clobber_stats.static_read_clobbers_avoided++;
}
else
add_virtual_operand (var, s_ann, opf_is_def,
NULL, 0, -1, true);
}
}
/* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the
function. */
static void
add_call_read_ops (tree stmt, tree callee)
{
unsigned u;
bitmap_iterator bi;
stmt_ann_t s_ann = stmt_ann (stmt);
bitmap not_read_b;
/* if the function is not pure, it may reference memory. Add
a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var
for the heuristic used to decide whether to create .GLOBAL_VAR. */
if (global_var)
{
add_stmt_operand (&global_var, s_ann, opf_none);
return;
}
not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
/* Add a VUSE for each call-clobbered variable. */
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
{
tree var = referenced_var (u);
tree real_var = var;
bool not_read;
clobber_stats.readonly_clobbers++;
/* Not read and not written are computed on regular vars, not
subvars, so look at the parent var if this is an SFT. */
if (TREE_CODE (var) == STRUCT_FIELD_TAG)
real_var = SFT_PARENT_VAR (var);
not_read = not_read_b ? bitmap_bit_p (not_read_b,
DECL_UID (real_var)) : false;
if (not_read)
{
clobber_stats.static_readonly_clobbers_avoided++;
continue;
}
add_stmt_operand (&var, s_ann, opf_none | opf_non_specific);
}
}
/* Scan the immediate_use list for VAR making sure its linked properly. /* Scan the immediate_use list for VAR making sure its linked properly.
return RTUE iof there is a problem. */ return RTUE iof there is a problem. */
......
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