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riscv-gcc-1
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 1081 additions and 1065 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;
...@@ -127,23 +122,7 @@ static GTY (()) struct ssa_operand_memory_d *operand_memory = NULL; ...@@ -127,23 +122,7 @@ 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;
static vuse_optype_p free_vuses = NULL; static vuse_optype_p free_vuses = 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);
} }
...@@ -735,421 +724,842 @@ append_v_must_def (tree var) ...@@ -735,421 +724,842 @@ 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.
static void FOR_CLOBBER is true is this is adding a virtual operand for a call
parse_ssa_operands (tree stmt) clobber. */
{
enum tree_code code;
code = TREE_CODE (stmt);
switch (code)
{
case MODIFY_EXPR:
/* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if
either only part of LHS is modified or if the RHS might throw,
otherwise, use V_MUST_DEF.
??? If it might throw, we should represent somehow that it is killed
on the fallthrough path. */
{
tree lhs = TREE_OPERAND (stmt, 0);
int lhs_flags = opf_is_def;
get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none);
/* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether
or not the entire LHS is modified; that depends on what's
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); static bool
} access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
break; HOST_WIDE_INT size)
{
bool offsetgtz = offset > 0;
unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset;
tree base = ref ? get_base_address (ref) : NULL;
case COND_EXPR: /* If ALIAS is an SFT, it can't be touched if the offset
get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none); and size of the access is not overlapping with the SFT offset and
break; 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
case SWITCH_EXPR: struct gcc_target
get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none); {
break; struct asm_out
{
const char *byte_op;
struct asm_int_op
{
const char *hi;
} aligned_op;
} asm_out;
} targetm;
foo = &targetm.asm_out.aligned_op;
return foo->hi;
case ASM_EXPR: SFT.1, which represents hi, will have SFT_OFFSET=32 because in
get_asm_expr_operands (stmt); terms of SFT_PARENT_VAR, that is where it is.
break; 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;
}
case RETURN_EXPR: /* Without strict aliasing, it is impossible for a component access
get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_none); through a pointer to touch a random variable, unless that
break; variable *is* a structure or a pointer.
case GOTO_EXPR: That is, given p->c, and some random global variable b,
get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_none); there is no legal way that p->c could be an access to b.
break;
Without strict aliasing on, we consider it legal to do something
like:
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; }
(taken from 20000623-1.c)
*/
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
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;
}
/* These nodes contain no variable references. */ /* If the offset of the access is greater than the size of one of
case BIND_EXPR: the possible aliases, it can't be touching that alias, because it
case CASE_LABEL_EXPR: would be past the end of the structure. */
case TRY_CATCH_EXPR: else if (ref
case TRY_FINALLY_EXPR: && flag_strict_aliasing
case EH_FILTER_EXPR: && TREE_CODE (ref) != INDIRECT_REF
case CATCH_EXPR: && !MTAG_P (alias)
case RESX_EXPR: && !POINTER_TYPE_P (TREE_TYPE (alias))
break; && 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;
}
default: return true;
/* 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;
}
} }
/* Create an operands cache for STMT. */
static void /* Add VAR to the virtual operands array. FLAGS is as in
build_ssa_operands (tree 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
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;
/* 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)
parse_ssa_operands (stmt); s_ann->has_volatile_ops = true;
operand_build_sort_virtual (build_vuses);
operand_build_sort_virtual (build_v_may_defs);
operand_build_sort_virtual (build_v_must_defs);
finalize_ssa_stmt_operands (stmt); /* If the variable cannot be modified and this is a V_MAY_DEF change
} it into a VUSE. This happens when read-only variables are marked
call-clobbered and/or aliased to writable variables. So we only
check that this only happens on non-specific stores.
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.
/* Free any operands vectors in OPS. */ This can happen when programs cast away const, leaving us with a
void store to read-only memory. If the statement is actually executed
free_ssa_operands (stmt_operands_p ops) 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. */
ops->def_ops = NULL; if ((flags & opf_non_specific) && unmodifiable_var_p (var))
ops->use_ops = NULL; flags &= ~(opf_is_def | opf_kill_def);
ops->maydef_ops = NULL;
ops->mustdef_ops = NULL; /* The variable is not a GIMPLE register. Add it (or its aliases) to
ops->vuse_ops = NULL; virtual operands, unless the caller has specifically requested
} not to add virtual operands (used when adding operands inside an
ADDR_EXPR expression). */
if (flags & opf_no_vops)
/* 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;
/* The optimizers cannot handle statements that are nothing but a
_DECL. This indicates a bug in the gimplifier. */ aliases = v_ann->may_aliases;
gcc_assert (!SSA_VAR_P (stmt)); 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;
/* The variable is aliased. Add its aliases to the virtual
operands. */
gcc_assert (VEC_length (tree, aliases) != 0);
if (flags & opf_is_def)
{
bool none_added = true;
gcc_assert (ann->modified); 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);
}
timevar_push (TV_TREE_OPS); /* If the variable is also an alias tag, add a virtual
operand for it, otherwise we will miss representing
references to the members of the variable's alias set.
This fixes the bug in gcc.c-torture/execute/20020503-1.c.
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. */
build_ssa_operands (stmt); if (none_added && !updating_used_alone && aliases_computed_p
&& TREE_CODE (var) == TYPE_MEMORY_TAG)
gcc_assert (TMT_USED_ALONE (var));
/* Clear the modified bit for STMT. Subsequent calls to append_v_may_def (var);
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; 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);
}
timevar_pop (TV_TREE_OPS); /* 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. */
void /* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in
copy_virtual_operands (tree dest, tree src) 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. */
static void
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); var = *var_p;
gcc_assert (SSA_VAR_P (var));
/* Copy all the virtual fields. */ is_real_op = is_gimple_reg (var);
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 /* If this is a real operand, the operand is either an SSA name or a
&& VEC_length (tree, build_v_may_defs) == 0 decl. Virtual operands may only be decls. */
&& VEC_length (tree, build_v_must_defs) == 0) gcc_assert (is_real_op || DECL_P (var));
return;
/* Now commit the virtual operands to this stmt. */ sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
finalize_ssa_v_must_defs (dest); v_ann = var_ann (sym);
finalize_ssa_v_may_defs (dest);
finalize_ssa_vuses (dest);
/* Finally, set the field to the same values as then originals. */ /* 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;
if (is_real_op)
t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE);
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.
FULL_REF contains the full pointer dereference expression, if we
have it, or NULL otherwise.
/* Specifically for use in DOM's expression analysis. Given a store, we OFFSET and SIZE are the location of the access inside the
create an artificial stmt which looks like a load from the store, this can dereferenced pointer, if known.
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 RECURSE_ON_BASE should be set to true if we want to continue
create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt) calling get_expr_operands on the base pointer, and false if
{ something else will do it for us. */
stmt_ann_t ann;
tree op;
ssa_op_iter iter;
use_operand_p use_p;
unsigned x;
ann = get_stmt_ann (new_stmt); static void
get_indirect_ref_operands (tree stmt, tree expr, int flags,
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);
/* process the stmt looking for operands. */ /* Stores into INDIRECT_REF operands are never killing definitions. */
start_ssa_stmt_operands (); flags &= ~opf_kill_def;
parse_ssa_operands (new_stmt);
for (x = 0; x < VEC_length (tree, build_vuses); x++) 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
for (x = 0; x < VEC_length (tree, build_v_may_defs); x++)
{
tree t = VEC_index (tree, build_v_may_defs, x);
if (TREE_CODE (t) != SSA_NAME)
{ {
var_ann_t ann = var_ann (t); /* If PTR is not an SSA_NAME or it doesn't have a name
ann->in_v_may_def_list = 0; tag, use its type memory tag. */
} var_ann_t v_ann;
}
/* 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. */ /* If we are emitting debugging dumps, display a warning if
FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES) PTR is an SSA_NAME with no flow-sensitive alias
delink_imm_use (use_p); information. That means that we may need to compute
} aliasing again. */
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);
}
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
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;
} }
} }
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;
}
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); /* MEM_REFs should never be killing. */
class = TREE_CODE_CLASS (code); flags &= ~opf_kill_def;
switch (code) if (TMR_SYMBOL (expr))
{ {
case ADDR_EXPR: stmt_ann_t ann = stmt_ann (stmt);
/* Taking the address of a variable does not represent a add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken);
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 if (!tag)
should be no VUSEs created, since the referenced objects are {
not really accessed. The only operands that we should find /* Something weird, so ensure that we will be careful. */
here are ARRAY_REF indices which will always be real operands stmt_ann (stmt)->has_volatile_ops = true;
(GIMPLE does not allow non-registers as array indices). */
flags |= opf_no_vops;
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
return; return;
}
case SSA_NAME: if (DECL_P (tag))
case STRUCT_FIELD_TAG: {
case TYPE_MEMORY_TAG: get_expr_operands (stmt, &tag, flags);
case NAME_MEMORY_TAG: return;
add_stmt_operand (expr_p, s_ann, flags); }
return;
case VAR_DECL:
case PARM_DECL:
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);
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)
{
bool exact;
if (overlap_subvar (offset, maxsize, sv->var, &exact))
{
int subvar_flags = flags;
if (!exact || size != maxsize)
subvar_flags &= ~opf_kill_def;
add_stmt_operand (&sv->var, s_ann, subvar_flags);
}
}
}
case MISALIGNED_INDIRECT_REF:
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
/* fall through */
case ALIGN_INDIRECT_REF: /* Add clobbering definitions for .GLOBAL_VAR or for each of the call
case INDIRECT_REF: clobbered variables in the function. */
get_indirect_ref_operands (stmt, expr, flags, NULL_TREE,
0, -1, true);
return;
case TARGET_MEM_REF: static void
get_tmr_operands (stmt, expr, flags); add_call_clobber_ops (tree stmt, tree callee)
return; {
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;
case ARRAY_RANGE_REF: /* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases
/* Treat array references as references to the virtual variable for the heuristic used to decide whether to create .GLOBAL_VAR or not. */
representing the array. The virtual variable for an ARRAY_REF if (global_var)
is the VAR_DECL for the array. */ {
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); add_stmt_operand (&global_var, s_ann, opf_is_def);
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; return;
}
case ARRAY_REF: /* Get info for local and module level statics. There is a bit
case COMPONENT_REF: set for each static if the call being processed does not read
case REALPART_EXPR: or write that variable. */
case IMAGPART_EXPR: 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);
}
}
/* A subroutine of get_expr_operands to handle CALL_EXPR. */
static void
get_call_expr_operands (tree stmt, tree expr)
{
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));
}
/* Find uses in the called function. */
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none);
for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op))
get_expr_operands (stmt, &TREE_VALUE (op), opf_none);
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
}
/* Scan operands in the ASM_EXPR stmt referred to in INFO. */
static void
get_asm_expr_operands (tree stmt)
{
stmt_ann_t s_ann = stmt_ann (stmt);
int noutputs = list_length (ASM_OUTPUTS (stmt));
const char **oconstraints
= (const char **) alloca ((noutputs) * sizeof (const char *));
int i;
tree link;
const char *constraint;
bool allows_mem, allows_reg, is_inout;
for (i=0, link = ASM_OUTPUTS (stmt); 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);
/* This should have been split in gimplify_asm_expr. */
gcc_assert (!allows_reg || !is_inout);
/* Memory operands are addressable. Note that STMT needs the
address of this operand. */
if (!allows_reg && allows_mem)
{
tree t = get_base_address (TREE_VALUE (link));
if (t && DECL_P (t) && s_ann)
add_to_addressable_set (t, &s_ann->addresses_taken);
}
get_expr_operands (stmt, &TREE_VALUE (link), opf_is_def);
}
for (link = ASM_INPUTS (stmt); link; 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);
/* Memory operands are addressable. Note that STMT needs the
address of this operand. */
if (!allows_reg && allows_mem)
{
tree t = get_base_address (TREE_VALUE (link));
if (t && DECL_P (t) && s_ann)
add_to_addressable_set (t, &s_ann->addresses_taken);
}
get_expr_operands (stmt, &TREE_VALUE (link), 0);
}
/* Clobber memory for asm ("" : : : "memory"); */
for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
{
unsigned i;
bitmap_iterator bi;
/* Clobber all call-clobbered variables (or .GLOBAL_VAR if we
decided to group them). */
if (global_var)
add_stmt_operand (&global_var, s_ann, opf_is_def);
else
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
{
tree var = referenced_var (i);
add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
}
/* Now clobber all addressables. */
EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i, bi)
{
tree var = referenced_var (i);
/* Subvars are explicitly represented in this list, so
we don't need the original to be added to the clobber
ops, but the original *will* be in this list because
we keep the addressability of the original
variable up-to-date so we don't screw up the rest of
the backend. */
if (var_can_have_subvars (var)
&& get_subvars_for_var (var) != NULL)
continue;
add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
}
break;
}
}
/* Recursively scan the expression pointed to by EXPR_P in statement
referred to by INFO. FLAGS is one of the OPF_* constants modifying
how to interpret the operands found. */
static void
get_expr_operands (tree stmt, tree *expr_p, int flags)
{
enum tree_code code;
enum tree_code_class class;
tree expr = *expr_p;
stmt_ann_t s_ann = stmt_ann (stmt);
if (expr == NULL)
return;
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:
case PARM_DECL:
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);
return;
}
case MISALIGNED_INDIRECT_REF:
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; tree ref;
HOST_WIDE_INT offset, size, maxsize; HOST_WIDE_INT offset, size, maxsize;
bool none = true; bool none = true;
...@@ -1309,625 +1719,352 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) ...@@ -1309,625 +1719,352 @@ get_expr_operands (tree stmt, tree *expr_p, int flags)
case OMP_MASTER: case OMP_MASTER:
case OMP_ORDERED: case OMP_ORDERED:
case OMP_CRITICAL: case OMP_CRITICAL:
/* Expressions that make no memory references. */ /* Expressions that make no memory references. */
return;
default:
if (class == tcc_unary)
goto do_unary;
if (class == tcc_binary || class == tcc_comparison)
goto do_binary;
if (class == tcc_constant || class == tcc_type)
return;
}
/* If we get here, something has gone wrong. */
#ifdef ENABLE_CHECKING
fprintf (stderr, "unhandled expression in get_expr_operands():\n");
debug_tree (expr);
fputs ("\n", stderr);
internal_error ("internal error");
#endif
gcc_unreachable ();
}
/* Scan operands in the ASM_EXPR stmt referred to in INFO. */
static void
get_asm_expr_operands (tree stmt)
{
stmt_ann_t s_ann = stmt_ann (stmt);
int noutputs = list_length (ASM_OUTPUTS (stmt));
const char **oconstraints
= (const char **) alloca ((noutputs) * sizeof (const char *));
int i;
tree link;
const char *constraint;
bool allows_mem, allows_reg, is_inout;
for (i=0, link = ASM_OUTPUTS (stmt); 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);
/* This should have been split in gimplify_asm_expr. */
gcc_assert (!allows_reg || !is_inout);
/* Memory operands are addressable. Note that STMT needs the
address of this operand. */
if (!allows_reg && allows_mem)
{
tree t = get_base_address (TREE_VALUE (link));
if (t && DECL_P (t) && s_ann)
add_to_addressable_set (t, &s_ann->addresses_taken);
}
get_expr_operands (stmt, &TREE_VALUE (link), opf_is_def);
}
for (link = ASM_INPUTS (stmt); link; 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);
/* Memory operands are addressable. Note that STMT needs the
address of this operand. */
if (!allows_reg && allows_mem)
{
tree t = get_base_address (TREE_VALUE (link));
if (t && DECL_P (t) && s_ann)
add_to_addressable_set (t, &s_ann->addresses_taken);
}
get_expr_operands (stmt, &TREE_VALUE (link), 0);
}
/* Clobber memory for asm ("" : : : "memory"); */
for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
{
unsigned i;
bitmap_iterator bi;
/* Clobber all call-clobbered variables (or .GLOBAL_VAR if we
decided to group them). */
if (global_var)
add_stmt_operand (&global_var, s_ann, opf_is_def);
else
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
{
tree var = referenced_var (i);
add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
}
/* Now clobber all addressables. */
EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i, bi)
{
tree var = referenced_var (i);
/* Subvars are explicitly represented in this list, so
we don't need the original to be added to the clobber
ops, but the original *will* be in this list because
we keep the addressability of the original
variable up-to-date so we don't screw up the rest of
the backend. */
if (var_can_have_subvars (var)
&& get_subvars_for_var (var) != NULL)
continue;
add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
}
break;
}
}
/* 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
calling get_expr_operands on the base pointer, and false if
something else will do it for us. */
static void
get_indirect_ref_operands (tree stmt, tree expr, int flags,
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);
/* Stores into INDIRECT_REF operands are never killing definitions. */
flags &= ~opf_kill_def;
if (SSA_VAR_P (ptr))
{
struct ptr_info_def *pi = NULL;
/* 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)
{
/* 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
tag, use its type memory tag. */
var_ann_t v_ann;
/* 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)
{
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)
ptr = SSA_NAME_VAR (ptr);
v_ann = var_ann (ptr);
if (v_ann->type_mem_tag)
add_virtual_operand (v_ann->type_mem_tag, s_ann, flags,
full_ref, offset, size, false);
}
}
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 default:
{ if (class == tcc_unary)
/* Ok, this isn't even is_gimple_min_invariant. Something's broke. */ goto do_unary;
gcc_unreachable (); if (class == tcc_binary || class == tcc_comparison)
goto do_binary;
if (class == tcc_constant || class == tcc_type)
return;
} }
/* If requested, add a USE operand for the base pointer. */ /* If we get here, something has gone wrong. */
if (recurse_on_base) #ifdef ENABLE_CHECKING
get_expr_operands (stmt, pptr, opf_none); fprintf (stderr, "unhandled expression in get_expr_operands():\n");
debug_tree (expr);
fputs ("\n", stderr);
#endif
gcc_unreachable ();
} }
/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ /* Parse STMT looking for operands. OLD_OPS is the original stmt operand
cache for STMT, if it existed before. When finished, the various build_*
operand vectors will have potential operands. in them. */
static void static void
get_tmr_operands (tree stmt, tree expr, int flags) parse_ssa_operands (tree stmt)
{ {
tree tag = TMR_TAG (expr), ref; enum tree_code code;
HOST_WIDE_INT offset, size, maxsize;
subvar_t svars, sv;
stmt_ann_t s_ann = stmt_ann (stmt);
/* First record the real operands. */ code = TREE_CODE (stmt);
get_expr_operands (stmt, &TMR_BASE (expr), opf_none); switch (code)
get_expr_operands (stmt, &TMR_INDEX (expr), opf_none); {
case MODIFY_EXPR:
/* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if
either only part of LHS is modified or if the RHS might throw,
otherwise, use V_MUST_DEF.
/* MEM_REFs should never be killing. */ ??? If it might throw, we should represent somehow that it is killed
flags &= ~opf_kill_def; on the fallthrough path. */
{
tree lhs = TREE_OPERAND (stmt, 0);
int lhs_flags = opf_is_def;
if (TMR_SYMBOL (expr)) get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none);
{
stmt_ann_t ann = stmt_ann (stmt);
add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken);
}
if (!tag) /* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether
{ or not the entire LHS is modified; that depends on what's
/* Something weird, so ensure that we will be careful. */ inside the VIEW_CONVERT_EXPR. */
stmt_ann (stmt)->has_volatile_ops = true; if (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
return; lhs = TREE_OPERAND (lhs, 0);
}
if (DECL_P (tag)) if (TREE_CODE (lhs) != ARRAY_RANGE_REF
{ && TREE_CODE (lhs) != BIT_FIELD_REF)
get_expr_operands (stmt, &tag, flags); lhs_flags |= opf_kill_def;
return;
}
ref = get_ref_base_and_extent (tag, &offset, &size, &maxsize); get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), lhs_flags);
gcc_assert (ref != NULL_TREE); }
svars = get_subvars_for_var (ref); break;
for (sv = svars; sv; sv = sv->next)
{ case COND_EXPR:
bool exact; get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none);
if (overlap_subvar (offset, maxsize, sv->var, &exact)) break;
{
int subvar_flags = flags; case SWITCH_EXPR:
if (!exact || size != maxsize) get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none);
subvar_flags &= ~opf_kill_def; break;
add_stmt_operand (&sv->var, s_ann, subvar_flags);
} 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;
} }
} }
/* A subroutine of get_expr_operands to handle CALL_EXPR. */ /* Create an operands cache for STMT. */
static void static void
get_call_expr_operands (tree stmt, tree expr) build_ssa_operands (tree stmt)
{ {
tree op; stmt_ann_t ann = get_stmt_ann (stmt);
int call_flags = call_expr_flags (expr);
/* Initially assume that the statement has no volatile operands. */
if (ann)
ann->has_volatile_ops = false;
/* If aliases have been computed already, add V_MAY_DEF or V_USE start_ssa_stmt_operands ();
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));
}
/* Find uses in the called function. */ parse_ssa_operands (stmt);
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none); operand_build_sort_virtual (build_vuses);
operand_build_sort_virtual (build_v_may_defs);
operand_build_sort_virtual (build_v_must_defs);
for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op)) finalize_ssa_stmt_operands (stmt);
get_expr_operands (stmt, &TREE_VALUE (op), opf_none); }
get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
/* Free any operands vectors in OPS. */
void
free_ssa_operands (stmt_operands_p ops)
{
ops->def_ops = NULL;
ops->use_ops = NULL;
ops->maydef_ops = NULL;
ops->mustdef_ops = NULL;
ops->vuse_ops = NULL;
} }
/* REF is a tree that contains the entire pointer dereference
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
access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
HOST_WIDE_INT size)
{
bool offsetgtz = offset > 0;
unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset;
tree base = ref ? get_base_address (ref) : NULL;
/* If ALIAS is an SFT, it can't be touched if the offset /* Get the operands of statement STMT. Note that repeated calls to
and size of the access is not overlapping with the SFT offset and get_stmt_operands for the same statement will do nothing until the
size. This is only true if we are accessing through a pointer statement is marked modified by a call to mark_stmt_modified(). */
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 void
{ update_stmt_operands (tree stmt)
struct asm_out {
{ stmt_ann_t ann = get_stmt_ann (stmt);
const char *byte_op;
struct asm_int_op
{
const char *hi;
} aligned_op;
} asm_out;
} targetm;
foo = &targetm.asm_out.aligned_op;
return foo->hi;
SFT.1, which represents hi, will have SFT_OFFSET=32 because in /* If get_stmt_operands is called before SSA is initialized, dont
terms of SFT_PARENT_VAR, that is where it is. do anything. */
However, the access through the foo pointer will be at offset 0. */ if (!ssa_operands_active ())
if (size != -1 return;
&& 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;
}
/* Without strict aliasing, it is impossible for a component access /* The optimizers cannot handle statements that are nothing but a
through a pointer to touch a random variable, unless that _DECL. This indicates a bug in the gimplifier. */
variable *is* a structure or a pointer. gcc_assert (!SSA_VAR_P (stmt));
That is, given p->c, and some random global variable b, gcc_assert (ann->modified);
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
like:
struct foos { int l; }; timevar_push (TV_TREE_OPS);
int foo;
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; }
(taken from 20000623-1.c)
*/
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
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;
}
/* If the offset of the access is greater than the size of one of build_ssa_operands (stmt);
the possible aliases, it can't be touching that alias, because it
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
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; /* 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);
}
/* Add VAR to the virtual operands array. FLAGS is as in
get_expr_operands. FULL_REF is a tree that contains the entire /* Copies virtual operands from SRC to DST. */
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 void
add_virtual_operand (tree var, stmt_ann_t s_ann, int flags, copy_virtual_operands (tree dest, tree src)
tree full_ref, HOST_WIDE_INT offset,
HOST_WIDE_INT size, bool for_clobber)
{ {
VEC(tree,gc) *aliases; tree t;
tree sym; ssa_op_iter iter, old_iter;
var_ann_t v_ann; use_operand_p use_p, u2;
def_operand_p def_p, d2;
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;
/* If the variable cannot be modified and this is a V_MAY_DEF change build_ssa_operands (dest);
it into a VUSE. This happens when read-only variables are marked
call-clobbered and/or aliased to writable variables. So we only
check that this only happens on non-specific stores.
Note that if this is a specific store, i.e. associated with a /* Copy all the virtual fields. */
modify_expr, then we can't suppress the V_MAY_DEF, lest we run FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VUSE)
into validation problems. 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);
This can happen when programs cast away const, leaving us with a if (VEC_length (tree, build_vuses) == 0
store to read-only memory. If the statement is actually executed && VEC_length (tree, build_v_may_defs) == 0
at runtime, then the program is ill formed. If the statement is && VEC_length (tree, build_v_must_defs) == 0)
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
virtual operands, unless the caller has specifically requested
not to add virtual operands (used when adding operands inside an
ADDR_EXPR expression). */
if (flags & opf_no_vops)
return; 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. */
aliases = v_ann->may_aliases; t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE);
if (aliases == NULL) FOR_EACH_SSA_USE_OPERAND (use_p, dest, iter, SSA_OP_VUSE)
{ {
/* The variable is not aliased or it is an alias tag. */ gcc_assert (!op_iter_done (&old_iter));
if (flags & opf_is_def) SET_USE (use_p, t);
{ t = op_iter_next_tree (&old_iter);
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 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)
{ {
unsigned i; gcc_assert (!op_iter_done (&old_iter));
tree al; SET_USE (use_p, USE_FROM_PTR (u2));
SET_DEF (def_p, DEF_FROM_PTR (d2));
/* The variable is aliased. Add its aliases to the virtual op_iter_next_maymustdef (&u2, &d2, &old_iter);
operands. */ }
gcc_assert (VEC_length (tree, aliases) != 0); gcc_assert (op_iter_done (&old_iter));
if (flags & opf_is_def)
{
bool none_added = true;
for (i = 0; VEC_iterate (tree, aliases, i, al); i++) op_iter_init_mustdef (&old_iter, src, &u2, &d2);
{ FOR_EACH_SSA_MUSTDEF_OPERAND (def_p, use_p, dest, iter)
if (!access_can_touch_variable (full_ref, al, offset, size)) {
continue; gcc_assert (!op_iter_done (&old_iter));
SET_USE (use_p, USE_FROM_PTR (u2));
none_added = false; SET_DEF (def_p, DEF_FROM_PTR (d2));
append_v_may_def (al); op_iter_next_maymustdef (&u2, &d2, &old_iter);
} }
gcc_assert (op_iter_done (&old_iter));
/* If the variable is also an alias tag, add a virtual }
operand for it, otherwise we will miss representing
references to the members of the variable's alias set.
This fixes the bug in gcc.c-torture/execute/20020503-1.c.
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 /* Specifically for use in DOM's expression analysis. Given a store, we
&& TREE_CODE (var) == TYPE_MEMORY_TAG) create an artificial stmt which looks like a load from the store, this can
gcc_assert (TMT_USED_ALONE (var)); 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
create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt)
{
stmt_ann_t ann;
tree op;
ssa_op_iter iter;
use_operand_p use_p;
unsigned x;
ann = get_stmt_ann (new_stmt);
/* process the stmt looking for operands. */
start_ssa_stmt_operands ();
parse_ssa_operands (new_stmt);
append_v_may_def (var); for (x = 0; x < VEC_length (tree, build_vuses); x++)
} {
tree t = VEC_index (tree, build_vuses, x);
if (TREE_CODE (t) != SSA_NAME)
{
var_ann_t ann = var_ann (t);
ann->in_vuse_list = 0;
} }
else }
for (x = 0; x < VEC_length (tree, build_v_may_defs); x++)
{
tree t = VEC_index (tree, build_v_may_defs, x);
if (TREE_CODE (t) != SSA_NAME)
{ {
bool none_added = true; var_ann_t ann = var_ann (t);
for (i = 0; VEC_iterate (tree, aliases, i, al); i++) ann->in_v_may_def_list = 0;
{
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);
} }
} }
}
/* 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);
/* Now build the operands for this new stmt. */
finalize_ssa_stmt_operands (new_stmt);
static void /* All uses in this fake stmt must not be in the immediate use lists. */
add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags) FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES)
{ delink_imm_use (use_p);
bool is_real_op; }
tree var, sym;
var_ann_t v_ann;
var = *var_p;
gcc_assert (SSA_VAR_P (var));
is_real_op = is_gimple_reg (var); /* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done
to test the validity of the swap operation. */
/* If this is a real operand, the operand is either an SSA name or a void
decl. Virtual operands may only be decls. */ swap_tree_operands (tree stmt, tree *exp0, tree *exp1)
gcc_assert (is_real_op || DECL_P (var)); {
tree op0, op1;
op0 = *exp0;
op1 = *exp1;
sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); /* If the operand cache is active, attempt to preserve the relative positions
v_ann = var_ann (sym); of these two operands in their respective immediate use lists. */
if (ssa_operands_active () && op0 != op1)
{
use_optype_p use0, use1, ptr;
use0 = use1 = NULL;
/* Mark statements with volatile operands. Optimizers should back /* Find the 2 operands in the cache, if they are there. */
off from statements having volatile operands. */ for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
if (TREE_THIS_VOLATILE (sym) && s_ann) if (USE_OP_PTR (ptr)->use == exp0)
s_ann->has_volatile_ops = true; {
use0 = ptr;
break;
}
if (is_real_op) for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
{ if (USE_OP_PTR (ptr)->use == exp1)
/* The variable is a GIMPLE register. Add it to real operands. */ {
if (flags & opf_is_def) use1 = ptr;
append_def (var_p); break;
else }
append_use (var_p);
/* 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;
}
} }
else
add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false); /* 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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