mirror of git://gcc.gnu.org/git/gcc.git
re PR tree-optimization/36345 (TBAA-pruning of points-to sets ineffective)
2008-06-12 Richard Guenther <rguenther@suse.de> PR tree-optimization/36345 * tree-flow.h (struct ptr_info_def): Align escape_mask, add memory_tag_needed flag. (may_alias_p): Declare. * tree-ssa-alias.c (may_alias_p): Export. (set_initial_properties): Use memory_tag_needed flag. (update_reference_counts): Likewise. (reset_alias_info): Reset memory_tag_needed flag. (create_name_tags): Check memory_tag_needed flag. (dump_points_to_info_for): Dump it. * tree-ssa-structalias.c (struct variable_info): Remove directly_dereferenced flag. (new_var_info): Do not initialize it. (process_constraint_1): Do not set it. (update_alias_info): Set is_dereferenced flag. (set_uids_in_ptset): Use may_alias_p. (set_used_smts): Check memory_tag_needed flag. (find_what_p_points_to): Likewise. Pass is_dereferenced flag. * tree-ssa-alias.c (verify_flow_sensitive_alias_info): Check memory_tag_needed flag. * tree-ssa-alias-warnings.c (dsa_named_for): Try to recover from broken design. * gcc.c-torture/execute/20020619-1.c: Remove broken part of the testcase. From-SVN: r136695
This commit is contained in:
Richard Guenther
Richard Biener
parent
3fd29fa912
commit
b377855627
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@ -1,3 +1,28 @@
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2008-06-12 Richard Guenther <rguenther@suse.de>
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PR tree-optimization/36345
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* tree-flow.h (struct ptr_info_def): Align escape_mask,
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add memory_tag_needed flag.
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(may_alias_p): Declare.
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* tree-ssa-alias.c (may_alias_p): Export.
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(set_initial_properties): Use memory_tag_needed flag.
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(update_reference_counts): Likewise.
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(reset_alias_info): Reset memory_tag_needed flag.
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(create_name_tags): Check memory_tag_needed flag.
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(dump_points_to_info_for): Dump it.
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* tree-ssa-structalias.c (struct variable_info): Remove
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directly_dereferenced flag.
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(new_var_info): Do not initialize it.
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(process_constraint_1): Do not set it.
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(update_alias_info): Set is_dereferenced flag.
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(set_uids_in_ptset): Use may_alias_p.
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(set_used_smts): Check memory_tag_needed flag.
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(find_what_p_points_to): Likewise. Pass is_dereferenced flag.
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* tree-ssa-alias.c (verify_flow_sensitive_alias_info): Check
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memory_tag_needed flag.
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* tree-ssa-alias-warnings.c (dsa_named_for): Try to recover
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from broken design.
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2008-06-12 Kai Tietz <kai.tietz@onevision.com>
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* config/i386/i386.c (ix86_compute_frame_layout): Disable red zone for
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@ -1,3 +1,9 @@
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2008-06-12 Richard Guenther <rguenther@suse.de>
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PR tree-optimization/36345
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* gcc.c-torture/execute/20020619-1.c: Remove broken part of
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the testcase.
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2008-06-11 Edmar Wienskoski <edmar@freescale.com>
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PR target/36425
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@ -14,19 +14,11 @@ static int ref(void)
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return u.i;
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}
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#define MAX(a,b) (a < b ? b : a)
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static int test(void)
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{
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char c[MAX(5, sizeof(int))] __attribute__((aligned)) = { 1, 2, 3, 4 };
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return *(int *)c;
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}
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int main()
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{
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int a = test();
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int b = ref();
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if (a != b)
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if (b != 0x01020304
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&& b != 0x04030201)
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abort ();
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return 0;
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}
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@ -227,6 +227,9 @@ typedef struct
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/* Aliasing information for SSA_NAMEs representing pointer variables. */
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struct ptr_info_def GTY(())
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{
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/* Mask of reasons this pointer's value escapes the function. */
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ENUM_BITFIELD (escape_type) escape_mask : 9;
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/* Nonzero if points-to analysis couldn't determine where this pointer
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is pointing to. */
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unsigned int pt_anything : 1;
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@ -234,7 +237,11 @@ struct ptr_info_def GTY(())
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/* Nonzero if the value of this pointer escapes the current function. */
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unsigned int value_escapes_p : 1;
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/* Nonzero if this pointer is dereferenced. */
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/* Nonzero if a memory tag is needed for this pointer. This is
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true if this pointer is eventually dereferenced. */
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unsigned int memory_tag_needed : 1;
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/* Nonzero if this pointer is really dereferenced. */
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unsigned int is_dereferenced : 1;
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/* Nonzero if this pointer points to a global variable. */
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@ -243,9 +250,6 @@ struct ptr_info_def GTY(())
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/* Nonzero if this pointer points to NULL. */
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unsigned int pt_null : 1;
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/* Mask of reasons this pointer's value escapes the function */
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ENUM_BITFIELD (escape_type) escape_mask : 9;
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/* Set of variables that this pointer may point to. */
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bitmap pt_vars;
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@ -852,6 +856,7 @@ extern void debug_points_to_info (void);
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extern void dump_points_to_info_for (FILE *, tree);
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extern void debug_points_to_info_for (tree);
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extern bool may_be_aliased (tree);
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extern bool may_alias_p (tree, alias_set_type, tree, alias_set_type, bool);
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extern struct ptr_info_def *get_ptr_info (tree);
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extern bool may_point_to_global_var (tree);
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extern void new_type_alias (tree, tree, tree);
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@ -914,6 +914,7 @@ dsa_named_for (tree ptr)
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{
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unsigned ix;
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bitmap_iterator bi;
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bool any = false;
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EXECUTE_IF_SET_IN_BITMAP (pi->pt_vars, 0, ix, bi)
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{
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@ -922,7 +923,16 @@ dsa_named_for (tree ptr)
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if (nonstandard_alias_p (ptr, alias, false))
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strict_aliasing_warn (SSA_NAME_DEF_STMT (ptr),
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ptr, true, alias, false, true);
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else
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any = true;
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}
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/* If there was no object in the points-to set that the pointer
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may alias, unconditionally warn. */
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if (!any)
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warning (OPT_Wstrict_aliasing,
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"dereferencing type-punned pointer %D will "
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"break strict-aliasing rules", SSA_NAME_VAR (ptr));
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}
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}
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}
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@ -197,7 +197,6 @@ static bitmap_obstack alias_bitmap_obstack;
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/* Local functions. */
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static void compute_flow_insensitive_aliasing (struct alias_info *);
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static void dump_alias_stats (FILE *);
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static bool may_alias_p (tree, alias_set_type, tree, alias_set_type, bool);
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static tree create_memory_tag (tree type, bool is_type_tag);
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static tree get_smt_for (tree, struct alias_info *);
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static tree get_nmt_for (tree);
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@ -588,14 +587,14 @@ set_initial_properties (struct alias_info *ai)
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So removing this code and fixing all the bugs would be nice.
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It is the cause of a bunch of clobbering. */
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if ((pi->pt_global_mem || pi->pt_anything)
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&& pi->is_dereferenced && pi->name_mem_tag)
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&& pi->memory_tag_needed && pi->name_mem_tag)
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{
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mark_call_clobbered (pi->name_mem_tag, ESCAPE_IS_GLOBAL);
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MTAG_GLOBAL (pi->name_mem_tag) = true;
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}
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if ((pi->pt_global_mem || pi->pt_anything)
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&& pi->is_dereferenced
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&& pi->memory_tag_needed
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&& tag)
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{
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mark_call_clobbered (tag, ESCAPE_IS_GLOBAL);
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@ -1278,7 +1277,7 @@ update_reference_counts (struct mem_ref_stats_d *mem_ref_stats)
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if (ptr
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&& POINTER_TYPE_P (TREE_TYPE (ptr))
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&& (pi = SSA_NAME_PTR_INFO (ptr)) != NULL
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&& pi->is_dereferenced)
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&& pi->memory_tag_needed)
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{
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unsigned j;
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bitmap_iterator bj;
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@ -2027,6 +2026,7 @@ reset_alias_info (void)
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pi->pt_anything = 0;
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pi->pt_null = 0;
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pi->value_escapes_p = 0;
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pi->memory_tag_needed = 0;
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pi->is_dereferenced = 0;
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if (pi->pt_vars)
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bitmap_clear (pi->pt_vars);
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@ -2170,7 +2170,7 @@ create_name_tags (void)
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pi = SSA_NAME_PTR_INFO (ptr);
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if (pi->pt_anything || !pi->is_dereferenced)
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if (pi->pt_anything || !pi->memory_tag_needed)
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{
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/* No name tags for pointers that have not been
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dereferenced or point to an arbitrary location. */
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@ -2649,7 +2649,7 @@ maybe_create_global_var (void)
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VAR_ALIAS_SET is the alias set for VAR. */
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static bool
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bool
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may_alias_p (tree ptr, alias_set_type mem_alias_set,
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tree var, alias_set_type var_alias_set,
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bool alias_set_only)
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@ -3231,6 +3231,8 @@ dump_points_to_info_for (FILE *file, tree ptr)
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if (pi->is_dereferenced)
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fprintf (file, ", is dereferenced");
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else if (pi->memory_tag_needed)
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fprintf (file, ", is dereferenced in call");
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if (pi->value_escapes_p)
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fprintf (file, ", its value escapes");
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@ -227,11 +227,6 @@ struct variable_info
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/* A link to the variable for the next field in this structure. */
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struct variable_info *next;
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/* True if the variable is directly the target of a dereference.
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This is used to track which variables are *actually* dereferenced
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so we can prune their points to listed. */
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unsigned int directly_dereferenced:1;
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/* True if this is a variable created by the constraint analysis, such as
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heap variables and constraints we had to break up. */
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unsigned int is_artificial_var:1;
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@ -364,7 +359,6 @@ new_var_info (tree t, unsigned int id, const char *name)
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ret->id = id;
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ret->name = name;
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ret->decl = t;
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ret->directly_dereferenced = false;
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ret->is_artificial_var = false;
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ret->is_heap_var = false;
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ret->is_special_var = false;
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@ -2520,14 +2514,6 @@ process_constraint_1 (constraint_t t, bool from_call)
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gcc_assert (rhs.var < VEC_length (varinfo_t, varmap));
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gcc_assert (lhs.var < VEC_length (varinfo_t, varmap));
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if (!from_call)
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{
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if (lhs.type == DEREF)
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get_varinfo (lhs.var)->directly_dereferenced = true;
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if (rhs.type == DEREF)
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get_varinfo (rhs.var)->directly_dereferenced = true;
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}
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if (!use_field_sensitive)
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{
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t->rhs.offset = 0;
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@ -3369,6 +3355,12 @@ update_alias_info (tree stmt, struct alias_info *ai)
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is an escape point, whether OP escapes. */
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count_uses_and_derefs (op, stmt, &num_uses, &num_loads, &num_stores);
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/* For directly dereferenced pointers we can apply
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TBAA-pruning to their points-to set. We may not count the
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implicit dereferences &PTR->FLD here. */
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if (num_loads + num_stores > 0)
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pi->is_dereferenced = 1;
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/* Handle a corner case involving address expressions of the
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form '&PTR->FLD'. The problem with these expressions is that
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they do not represent a dereference of PTR. However, if some
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@ -3409,7 +3401,10 @@ update_alias_info (tree stmt, struct alias_info *ai)
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dereferenced pointers that point to a set of
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variables will be assigned a name tag to alias
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all the variables OP points to. */
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pi->is_dereferenced = 1;
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pi->memory_tag_needed = 1;
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/* ??? For always executed direct dereferences we can
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apply TBAA-pruning to their escape set. */
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/* If this is a store operation, mark OP as being
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dereferenced to store, otherwise mark it as being
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@ -3443,7 +3438,7 @@ update_alias_info (tree stmt, struct alias_info *ai)
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|| stmt_escape_type == ESCAPE_STORED_IN_GLOBAL)
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{
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pointer_set_insert (ai->dereferenced_ptrs_store, var);
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pi->is_dereferenced = 1;
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pi->memory_tag_needed = 1;
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}
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}
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}
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@ -4653,10 +4648,11 @@ set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
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bitmap_set_bit (into, DECL_UID (vi->decl));
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else
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{
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alias_set_type var_alias_set, ptr_alias_set;
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alias_set_type var_alias_set, mem_alias_set;
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var_alias_set = get_alias_set (vi->decl);
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ptr_alias_set = get_alias_set (TREE_TYPE (TREE_TYPE (ptr)));
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if (alias_sets_conflict_p (ptr_alias_set, var_alias_set))
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mem_alias_set = get_alias_set (TREE_TYPE (TREE_TYPE (ptr)));
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if (may_alias_p (SSA_NAME_VAR (ptr), mem_alias_set,
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vi->decl, var_alias_set, true))
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bitmap_set_bit (into, DECL_UID (vi->decl));
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}
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}
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@ -4703,7 +4699,7 @@ set_used_smts (void)
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/* Skip the special variables and those that can't be aliased. */
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if (vi->is_special_var
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|| !SSA_VAR_P (var)
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|| (pi && !pi->is_dereferenced)
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|| (pi && !pi->memory_tag_needed)
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|| (TREE_CODE (var) == VAR_DECL && !may_be_aliased (var))
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|| !POINTER_TYPE_P (TREE_TYPE (var)))
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continue;
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@ -4771,7 +4767,7 @@ find_what_p_points_to (tree p)
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bitmap finished_solution;
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bitmap result;
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if (!pi->is_dereferenced)
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if (!pi->memory_tag_needed)
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return false;
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/* This variable may have been collapsed, let's get the real
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@ -4815,7 +4811,7 @@ find_what_p_points_to (tree p)
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stats.points_to_sets_created++;
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set_uids_in_ptset (p, finished_solution, vi->solution,
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vi->directly_dereferenced,
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pi->is_dereferenced,
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vi->no_tbaa_pruning);
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result = shared_bitmap_lookup (finished_solution);
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@ -559,7 +559,7 @@ verify_flow_sensitive_alias_info (void)
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continue;
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ann = var_ann (var);
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if (pi->is_dereferenced && !pi->name_mem_tag && !ann->symbol_mem_tag)
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if (pi->memory_tag_needed && !pi->name_mem_tag && !ann->symbol_mem_tag)
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{
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error ("dereferenced pointers should have a name or a symbol tag");
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goto err;
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