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[PATCH] Fix PR71062
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 12 May 2016 13:10:11 +0200 (CEST)
- Subject: [PATCH] Fix PR71062
- Authentication-results: sourceware.org; auth=none
It was noted that we now simplify pointer equality tests against
restrict qualified pointers which we can't do according to
reading of the fine-prints in the C standard done by Joseph.
Fixed as follows.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2016-05-12 Richard Biener <rguenther@suse.de>
PR tree-optimization/71062
* tree-ssa-alias.h (struct pt_solution): Add vars_contains_restrict
field.
* tree-ssa-structalias.c (set_uids_in_ptset): Set vars_contains_restrict
if the var is a restrict tag.
* tree-ssa-alias.c (ptrs_compare_unequal): If vars_contains_restrict
do not disambiguate pointers against it.
(dump_points_to_solution): Re-structure and adjust for new
vars_contains_restrict flag.
* gimple-pretty-print.c (pp_points_to_solution): Likewise.
* gcc.dg/torture/pr71062.c: New testcase.
Index: gcc/tree-ssa-alias.h
===================================================================
*** gcc/tree-ssa-alias.h (revision 236159)
--- gcc/tree-ssa-alias.h (working copy)
*************** struct GTY(()) pt_solution
*** 47,53 ****
includes memory at address NULL. */
unsigned int null : 1;
-
/* Nonzero if the vars bitmap includes a variable included in 'nonlocal'. */
unsigned int vars_contains_nonlocal : 1;
/* Nonzero if the vars bitmap includes a variable included in 'escaped'. */
--- 47,52 ----
*************** struct GTY(()) pt_solution
*** 55,60 ****
--- 54,62 ----
/* Nonzero if the vars bitmap includes a anonymous heap variable that
escaped the function and thus became global. */
unsigned int vars_contains_escaped_heap : 1;
+ /* Nonzero if the vars bitmap includes a anonymous variable used to
+ represent storage pointed to by a restrict qualified pointer. */
+ unsigned int vars_contains_restrict : 1;
/* Set of variables that this pointer may point to. */
bitmap vars;
Index: gcc/tree-ssa-alias.c
===================================================================
*** gcc/tree-ssa-alias.c (revision 236159)
--- gcc/tree-ssa-alias.c (working copy)
*************** ptrs_compare_unequal (tree ptr1, tree pt
*** 363,376 ****
else if (obj1 && TREE_CODE (ptr2) == SSA_NAME)
{
struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr2);
! if (!pi)
return false;
return !pt_solution_includes (&pi->pt, obj1);
}
else if (TREE_CODE (ptr1) == SSA_NAME && obj2)
{
struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr1);
! if (!pi)
return false;
return !pt_solution_includes (&pi->pt, obj2);
}
--- 363,379 ----
else if (obj1 && TREE_CODE (ptr2) == SSA_NAME)
{
struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr2);
! /* We may not use restrict to optimize pointer comparisons.
! See PR71062. So we have to assume that restrict-pointed-to
! may be in fact obj1. */
! if (!pi || pi->pt.vars_contains_restrict)
return false;
return !pt_solution_includes (&pi->pt, obj1);
}
else if (TREE_CODE (ptr1) == SSA_NAME && obj2)
{
struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr1);
! if (!pi || pi->pt.vars_contains_restrict)
return false;
return !pt_solution_includes (&pi->pt, obj2);
}
*************** dump_points_to_solution (FILE *file, str
*** 521,537 ****
fprintf (file, ", points-to vars: ");
dump_decl_set (file, pt->vars);
if (pt->vars_contains_nonlocal
! && pt->vars_contains_escaped_heap)
! fprintf (file, " (nonlocal, escaped heap)");
! else if (pt->vars_contains_nonlocal
! && pt->vars_contains_escaped)
! fprintf (file, " (nonlocal, escaped)");
! else if (pt->vars_contains_nonlocal)
! fprintf (file, " (nonlocal)");
! else if (pt->vars_contains_escaped_heap)
! fprintf (file, " (escaped heap)");
! else if (pt->vars_contains_escaped)
! fprintf (file, " (escaped)");
}
}
--- 524,554 ----
fprintf (file, ", points-to vars: ");
dump_decl_set (file, pt->vars);
if (pt->vars_contains_nonlocal
! || pt->vars_contains_escaped
! || pt->vars_contains_escaped_heap
! || pt->vars_contains_restrict)
! {
! const char *comma = "";
! fprintf (file, " (");
! if (pt->vars_contains_nonlocal)
! {
! fprintf (file, "nonlocal");
! comma = ", ";
! }
! if (pt->vars_contains_escaped)
! {
! fprintf (file, "%sescaped", comma);
! comma = ", ";
! }
! if (pt->vars_contains_escaped_heap)
! {
! fprintf (file, "%sescaped heap", comma);
! comma = ", ";
! }
! if (pt->vars_contains_restrict)
! fprintf (file, "%srestrict", comma);
! fprintf (file, ")");
! }
}
}
Index: gcc/testsuite/gcc.dg/torture/pr71062.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr71062.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr71062.c (working copy)
***************
*** 0 ****
--- 1,20 ----
+ /* { dg-do run } */
+
+ extern void abort (void);
+
+ char bar;
+
+ int __attribute__((noinline,noclone))
+ foo (char *__restrict p)
+ {
+ if (p == &bar)
+ return 1;
+ return 0;
+ }
+
+ int main()
+ {
+ if (foo (&bar) != 1)
+ abort ();
+ return 0;
+ }
Index: gcc/gimple-pretty-print.c
===================================================================
*** gcc/gimple-pretty-print.c (revision 236159)
--- gcc/gimple-pretty-print.c (working copy)
*************** pp_points_to_solution (pretty_printer *b
*** 632,648 ****
}
pp_right_brace (buffer);
if (pt->vars_contains_nonlocal
! && pt->vars_contains_escaped_heap)
! pp_string (buffer, " (nonlocal, escaped heap)");
! else if (pt->vars_contains_nonlocal
! && pt->vars_contains_escaped)
! pp_string (buffer, " (nonlocal, escaped)");
! else if (pt->vars_contains_nonlocal)
! pp_string (buffer, " (nonlocal)");
! else if (pt->vars_contains_escaped_heap)
! pp_string (buffer, " (escaped heap)");
! else if (pt->vars_contains_escaped)
! pp_string (buffer, " (escaped)");
}
}
--- 633,669 ----
}
pp_right_brace (buffer);
if (pt->vars_contains_nonlocal
! || pt->vars_contains_escaped
! || pt->vars_contains_escaped_heap
! || pt->vars_contains_restrict)
! {
! const char *comma = "";
! pp_string (buffer, " (");
! if (pt->vars_contains_nonlocal)
! {
! pp_string (buffer, "nonlocal");
! comma = ", ";
! }
! if (pt->vars_contains_escaped)
! {
! pp_string (buffer, comma);
! pp_string (buffer, "escaped");
! comma = ", ";
! }
! if (pt->vars_contains_escaped_heap)
! {
! pp_string (buffer, comma);
! pp_string (buffer, "escaped heap");
! comma = ", ";
! }
! if (pt->vars_contains_restrict)
! {
! pp_string (buffer, comma);
! pp_string (buffer, "restrict");
! }
! pp_string (buffer, ")");
! }
!
}
}
Index: gcc/tree-ssa-structalias.c
===================================================================
*** gcc/tree-ssa-structalias.c (revision 236167)
--- gcc/tree-ssa-structalias.c (working copy)
*************** set_uids_in_ptset (bitmap into, bitmap f
*** 6254,6259 ****
--- 6254,6262 ----
pt->vars_contains_escaped_heap = vi->is_heap_var;
}
+ if (vi->is_restrict_var)
+ pt->vars_contains_restrict = true;
+
if (TREE_CODE (vi->decl) == VAR_DECL
|| TREE_CODE (vi->decl) == PARM_DECL
|| TREE_CODE (vi->decl) == RESULT_DECL)
*************** make_pass_build_ealias (gcc::context *ct
*** 7505,7511 ****
/* IPA PTA solutions for ESCAPED. */
struct pt_solution ipa_escaped_pt
! = { true, false, false, false, false, false, false, false, NULL };
/* Associate node with varinfo DATA. Worker for
cgraph_for_symbol_thunks_and_aliases. */
--- 7508,7514 ----
/* IPA PTA solutions for ESCAPED. */
struct pt_solution ipa_escaped_pt
! = { true, false, false, false, false, false, false, false, false, NULL };
/* Associate node with varinfo DATA. Worker for
cgraph_for_symbol_thunks_and_aliases. */