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File pr27799.diff of Package gcc43 (Revision c045de365e279f27a96a2167170aa5d2)

Currently displaying revision c045de365e279f27a96a2167170aa5d2 , Show latest

2008-04-17  Richard Guenther  <rguenther@suse.de>

* alias.c (alias_set_subset_of): Correctly handle asking
	if zero is a subset of an alias set with zero child.
	* tree-ssa-alias.c (have_common_aliases_p): Simplify logic.
	(compute_flow_insensitive_aliasing): Correctly walk all
	pointers.  Do not unnecessarily union sets.

Index: gcc/alias.c
===================================================================
*** gcc/alias.c	(revision 134383)
--- gcc/alias.c	(working copy)
*************** alias_set_subset_of (alias_set_type set1
*** 305,312 ****
    /* Otherwise, check if set1 is a subset of set2.  */
    ase = get_alias_set_entry (set2);
    if (ase != 0
!       && (splay_tree_lookup (ase->children,
! 			     (splay_tree_key) set1)))
      return true;
    return false;
  }
--- 305,313 ----
    /* Otherwise, check if set1 is a subset of set2.  */
    ase = get_alias_set_entry (set2);
    if (ase != 0
!       && ((ase->has_zero_child && set1 == 0)
! 	  || splay_tree_lookup (ase->children,
! 			        (splay_tree_key) set1)))
      return true;
    return false;
  }
Index: gcc/tree-ssa-alias.c
===================================================================
*** gcc/tree-ssa-alias.c	(revision 134383)
--- gcc/tree-ssa-alias.c	(working copy)
*************** have_common_aliases_p (bitmap tag1aliase
*** 2390,2398 ****
    /* This is the old behavior of have_common_aliases_p, which is to
       return false if both sets are empty, or one set is and the other
       isn't.  */
!      if ((tag1aliases == NULL && tag2aliases != NULL)
!       || (tag2aliases == NULL && tag1aliases != NULL)
!       || (tag1aliases == NULL && tag2aliases == NULL))
      return false;
  
    return bitmap_intersect_p (tag1aliases, tag2aliases);
--- 2390,2396 ----
    /* This is the old behavior of have_common_aliases_p, which is to
       return false if both sets are empty, or one set is and the other
       isn't.  */
!   if (tag1aliases == NULL || tag2aliases == NULL)
      return false;
  
    return bitmap_intersect_p (tag1aliases, tag2aliases);
*************** compute_flow_insensitive_aliasing (struc
*** 2490,2501 ****
        if (PTR_IS_REF_ALL (p_map1->var))
  	continue;
  
!       for (j = i + 1; j < ai->num_pointers; j++)
  	{
  	  struct alias_map_d *p_map2 = ai->pointers[j];
  	  tree tag2 = symbol_mem_tag (p_map2->var);
  	  bitmap may_aliases2 = may_aliases (tag2);
  
  	  if (PTR_IS_REF_ALL (p_map2->var))
  	    continue;
  
--- 2488,2503 ----
        if (PTR_IS_REF_ALL (p_map1->var))
  	continue;
  
!       for (j = 0; j < ai->num_pointers; j++)
  	{
  	  struct alias_map_d *p_map2 = ai->pointers[j];
  	  tree tag2 = symbol_mem_tag (p_map2->var);
  	  bitmap may_aliases2 = may_aliases (tag2);
  
+ 	  /* By convention tags don't alias themselves.  */
+ 	  if (tag1 == tag2)
+ 	    continue;
+ 
  	  if (PTR_IS_REF_ALL (p_map2->var))
  	    continue;
  
*************** compute_flow_insensitive_aliasing (struc
*** 2508,2525 ****
  	  if (have_common_aliases_p (may_aliases1, may_aliases2))
  	    continue;
  
! 	  if (may_aliases2 && !bitmap_empty_p (may_aliases2))
! 	    {
! 	      union_alias_set_into (tag1, may_aliases2);
! 	    }
! 	  else
! 	    {
! 	      /* Since TAG2 does not have any aliases of its own, add
! 		 TAG2 itself to the alias set of TAG1.  */
! 	      add_may_alias (tag1, tag2);
! 	    }
  	}
- 
      }
    timevar_pop (TV_FLOW_INSENSITIVE);
  }
--- 2510,2517 ----
  	  if (have_common_aliases_p (may_aliases1, may_aliases2))
  	    continue;
  
! 	  add_may_alias (tag1, tag2);
  	}
      }
    timevar_pop (TV_FLOW_INSENSITIVE);
  }

2008-04-23  Richard Guenther  <rguenther@suse.de>

PR tree-optimization/27799
	PR tree-optimization/32921
	PR tree-optimization/32624
	* tree-ssa-structalias.c (merge_smts_into): Only merge the
	SMTs aliases and the tag itself into the solution.
	* tree-ssa-alias.c (compute_flow_sensitive_aliasing): Do not
	merge the points-to solution back into the SMT aliases.
	(may_alias_p): Use alias_set_subset_of instead of
	aliases_conflict_p.  A pointer which points to
	memory with alias set zero may access any variable.

* gcc.dg/tree-ssa/pr27799.c: New testcase.
	* gcc.dg/tree-ssa/20030807-7.c: Remove xfail, scan vrp dump.

Index: gcc/tree-ssa-structalias.c
===================================================================
*** gcc/tree-ssa-structalias.c.orig	2008-04-18 12:54:26.000000000 +0200
--- gcc/tree-ssa-structalias.c	2008-04-18 12:54:31.000000000 +0200
*************** set_used_smts (void)
*** 4862,4869 ****
  static void
  merge_smts_into (tree p, bitmap solution)
  {
-   unsigned int i;
-   bitmap_iterator bi;
    tree smt;
    bitmap aliases;
    tree var = p;
--- 4862,4867 ----
*************** merge_smts_into (tree p, bitmap solution
*** 4874,4893 ****
    smt = var_ann (var)->symbol_mem_tag;
    if (smt)
      {
!       alias_set_type smtset = get_alias_set (TREE_TYPE (smt));
! 
!       /* Need to set the SMT subsets first before this
! 	 will work properly.  */
        bitmap_set_bit (solution, DECL_UID (smt));
-       EXECUTE_IF_SET_IN_BITMAP (used_smts, 0, i, bi)
- 	{
- 	  tree newsmt = referenced_var (i);
- 	  tree newsmttype = TREE_TYPE (newsmt);
- 
- 	  if (alias_set_subset_of (get_alias_set (newsmttype),
- 				   smtset))
- 	    bitmap_set_bit (solution, i);
- 	}
  
        aliases = MTAG_ALIASES (smt);
        if (aliases)
--- 4872,4879 ----
    smt = var_ann (var)->symbol_mem_tag;
    if (smt)
      {
!       /* The smt itself isn't included in its aliases.  */
        bitmap_set_bit (solution, DECL_UID (smt));
  
        aliases = MTAG_ALIASES (smt);
        if (aliases)
Index: gcc/tree-ssa-alias.c
===================================================================
*** gcc/tree-ssa-alias.c.orig	2008-04-18 12:54:26.000000000 +0200
--- gcc/tree-ssa-alias.c	2008-04-21 11:12:13.000000000 +0200
*************** compute_flow_sensitive_aliasing (struct 
*** 2354,2360 ****
    for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++)
      {
        struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
-       tree tag = symbol_mem_tag (SSA_NAME_VAR (ptr));
  
        /* Set up aliasing information for PTR's name memory tag (if it has
  	 one).  Note that only pointers that have been dereferenced will
--- 2354,2359 ----
*************** compute_flow_sensitive_aliasing (struct 
*** 2362,2379 ****
        if (pi->name_mem_tag && pi->pt_vars)
  	{
  	  if (!bitmap_empty_p (pi->pt_vars))
! 	    {
! 	      union_alias_set_into (pi->name_mem_tag, pi->pt_vars);
! 	      union_alias_set_into (tag, pi->pt_vars);
! 	      bitmap_clear_bit (MTAG_ALIASES (tag), DECL_UID (tag));
! 	    
! 	      /* It may be the case that this the tag uid was the only
! 		 bit we had set in the aliases list, and in this case,
! 		 we don't want to keep an empty bitmap, as this
! 		 asserts in tree-ssa-operands.c .  */
! 	      if (bitmap_empty_p (MTAG_ALIASES (tag)))
! 		BITMAP_FREE (MTAG_ALIASES (tag));
! 	    }
  	}
      }
    timevar_pop (TV_FLOW_SENSITIVE);
--- 2361,2367 ----
        if (pi->name_mem_tag && pi->pt_vars)
  	{
  	  if (!bitmap_empty_p (pi->pt_vars))
! 	    union_alias_set_into (pi->name_mem_tag, pi->pt_vars);
  	}
      }
    timevar_pop (TV_FLOW_SENSITIVE);
*************** may_alias_p (tree ptr, alias_set_type me
*** 2860,2867 ****
      {
        alias_stats.tbaa_queries++;
  
        /* If the alias sets don't conflict then MEM cannot alias VAR.  */
!       if (!alias_sets_conflict_p (mem_alias_set, var_alias_set))
  	{
  	  alias_stats.alias_noalias++;
  	  alias_stats.tbaa_resolved++;
--- 2848,2866 ----
      {
        alias_stats.tbaa_queries++;
  
+       /* If the pointed to memory has alias set zero or the pointer
+ 	 is ref-all, the MEM can alias VAR.  */
+       if (mem_alias_set == 0
+ 	  || PTR_IS_REF_ALL (ptr))
+ 	{
+ 	  alias_stats.alias_mayalias++;
+ 	  alias_stats.tbaa_resolved++;
+ 	  return true;
+ 	}
+ 
        /* If the alias sets don't conflict then MEM cannot alias VAR.  */
!       if (mem_alias_set != var_alias_set
! 	  && !alias_set_subset_of (mem_alias_set, var_alias_set))
  	{
  	  alias_stats.alias_noalias++;
  	  alias_stats.tbaa_resolved++;
Index: gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c
===================================================================
*** gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c.orig	2008-04-18 12:59:20.000000000 +0200
--- gcc/testsuite/gcc.dg/tree-ssa/20030807-7.c	2008-04-18 12:59:27.000000000 +0200
***************
*** 1,5 ****
  /* { dg-do compile } */
! /* { dg-options "-O2 -fdump-tree-dom3" } */
    
  extern void abort (void);
  
--- 1,5 ----
  /* { dg-do compile } */
! /* { dg-options "-O2 -fdump-tree-vrp1" } */
    
  extern void abort (void);
  
*************** simplify_condition (cond_p)
*** 32,38 ****
    c_simplify_stmt (&decl);
  }
  
! /* There should be exactly one IF conditional.  TBAA is not able to 
!    determine that 'decl' and 'cond' can't alias.  */
! /* { dg-final { scan-tree-dump-times "if " 1 "dom3" { xfail *-*-* } } } */
! /* { dg-final { cleanup-tree-dump "dom3" } } */
--- 32,37 ----
    c_simplify_stmt (&decl);
  }
  
! /* There should be exactly one IF conditional.  */
! /* { dg-final { scan-tree-dump-times "if " 1 "vrp1" } } */
! /* { dg-final { cleanup-tree-dump "vrp1" } } */
Index: gcc/testsuite/gcc.dg/tree-ssa/pr27799.c
===================================================================
*** /dev/null	1970-01-01 00:00:00.000000000 +0000
--- gcc/testsuite/gcc.dg/tree-ssa/pr27799.c	2008-04-18 12:56:00.000000000 +0200
***************
*** 0 ****
--- 1,26 ----
+ /* { dg-do link } */
+ /* { dg-options "-O2" } */
+ 
+ struct X { double m; int x; };
+ struct Y { int y; short d; };
+ struct YY { int y; short d; char c; };
+ 
+ extern void link_error (void);
+ 
+ int foo(struct X *x,  struct Y *y)
+ {
+   x->x =  0;
+   y->y =  1;
+   if (x->x != 0)
+     link_error ();
+ }
+ 
+ int foo_no(struct X *x,  struct YY *y)
+ {
+   x->x =  0;
+   y->y =  1;
+   if (x->x != 0)
+     link_error ();
+ }
+ 
+ int main() {}

Fix wrong alias info with missing SFT aliases for SMTs.  bnc#419260

Index: gcc/tree-ssa-alias.c
===================================================================
--- gcc/tree-ssa-alias.c.orig	2008-08-21 18:39:07.000000000 +0200
+++ gcc/tree-ssa-alias.c	2008-08-21 18:37:07.000000000 +0200
@@ -2511,6 +2511,7 @@
 	  struct alias_map_d *v_map;
 	  var_ann_t v_ann;
 	  bool tag_stored_p, var_stored_p;
+	  tree alias_var;
 	  
 	  v_map = ai->addressable_vars[j];
 	  var = v_map->var;
@@ -2526,8 +2527,12 @@
 	                 || is_call_clobbered (var);
 	  if (!tag_stored_p && !var_stored_p)
 	    continue;
-	     
-	  if (may_alias_p (p_map->var, p_map->set, var, v_map->set, false))
+
+	  /* For the may_alias_p query we have to use the parent variable.  */
+	  alias_var = (TREE_CODE (var) == STRUCT_FIELD_TAG
+		       ? SFT_PARENT_VAR (var) : var);
+	  if (may_alias_p (p_map->var, p_map->set,
+			   alias_var, get_alias_set (alias_var), false))
 	    {
 	      /* We should never have a var with subvars here, because
 	         they shouldn't get into the set of addressable vars */
Index: gcc/testsuite/gcc.c-torture/execute/nov419260.c
===================================================================
*** gcc/testsuite/gcc.c-torture/execute/nov419260.c	(revision 0)
--- gcc/testsuite/gcc.c-torture/execute/nov419260.c	(revision 0)
***************
*** 0 ****
--- 1,27 ----
+ struct seq_elem {
+     struct seq_elem *next;
+     struct seq_elem *prev;
+ };
+ 
+ static struct seq_elem b;
+ void
+ __attribute__((noinline))
+ init (struct seq_elem *a)
+ {
+   b.prev = a;
+   b.next = 0;
+   a->prev = 0;
+   a->next = &b;
+ }
+ 
+ extern void abort (void);
+ int main(void)
+ {
+   struct seq_elem a;
+   init (&a);
+   struct seq_elem *ttt = a.next;
+   ttt->prev->next = ttt->next;
+   if (ttt == a.next)
+     abort ();
+   return 0;
+ }

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