builtins.c (fold_builtin_memory_op): Use the alias oracle to query if the memory regions for memmove overlap.

2009-08-31  Richard Guenther  <rguenther@suse.de>

	* builtins.c (fold_builtin_memory_op): Use the alias oracle
	to query if the memory regions for memmove overlap.
	* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Relax the
	asserts on pointers, instead deal with odd trees.
	(ptr_derefs_may_alias_p): Likewise.
	(refs_may_alias_p_1): Constructor bases also never alias.

From-SVN: r151241

3 files changed, 27 insertions, 70 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index edb982c..9282355 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2009-08-31  Richard Guenther  <rguenther@suse.de>
+
+	* builtins.c (fold_builtin_memory_op): Use the alias oracle
+	to query if the memory regions for memmove overlap.
+	* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Relax the
+	asserts on pointers, instead deal with odd trees.
+	(ptr_derefs_may_alias_p): Likewise.
+	(refs_may_alias_p_1): Constructor bases also never alias.
+
 2009-08-31  Gerald Pfeifer  <gerald@pfeifer.com>
 
 	* doc/install.texi (Final install): Adjust reference on where to
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 1a9e966..ed97d48 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -8990,6 +8990,8 @@ fold_builtin_memory_op (location_t loc, tree dest, tree src,
 
       if (endp == 3)
 	{
+	  ao_ref srcref, destref;
+
 	  src_align = get_pointer_alignment (src, BIGGEST_ALIGNMENT);
 	  dest_align = get_pointer_alignment (dest, BIGGEST_ALIGNMENT);
 
@@ -9012,62 +9014,16 @@ fold_builtin_memory_op (location_t loc, tree dest, tree src,
 	    }
 
 	  /* If *src and *dest can't overlap, optimize into memcpy as well.  */
-	  srcvar = build_fold_indirect_ref_loc (loc, src);
-	  destvar = build_fold_indirect_ref_loc (loc, dest);
-	  if (srcvar
-	      && !TREE_THIS_VOLATILE (srcvar)
-	      && destvar
-	      && !TREE_THIS_VOLATILE (destvar))
+	  ao_ref_init_from_ptr_and_size (&srcref, src, len);
+	  ao_ref_init_from_ptr_and_size (&destref, dest, len);
+	  if (!refs_may_alias_p_1 (&srcref, &destref, false))
 	    {
-	      tree src_base, dest_base, fn;
-	      HOST_WIDE_INT src_offset = 0, dest_offset = 0;
-	      HOST_WIDE_INT size = -1;
-	      HOST_WIDE_INT maxsize = -1;
-
-	      src_base = srcvar;
-	      if (handled_component_p (src_base))
-		src_base = get_ref_base_and_extent (src_base, &src_offset,
-						    &size, &maxsize);
-	      dest_base = destvar;
-	      if (handled_component_p (dest_base))
-		dest_base = get_ref_base_and_extent (dest_base, &dest_offset,
-						     &size, &maxsize);
-	      if (host_integerp (len, 1))
-		{
-		  maxsize = tree_low_cst (len, 1);
-		  if (maxsize
-		      > INTTYPE_MAXIMUM (HOST_WIDE_INT) / BITS_PER_UNIT)
-		    maxsize = -1;
-		  else
-		    maxsize *= BITS_PER_UNIT;
-		}
-	      else
-		maxsize = -1;
-	      if (SSA_VAR_P (src_base)
-		  && SSA_VAR_P (dest_base))
-		{
-		  if (operand_equal_p (src_base, dest_base, 0)
-		      && ranges_overlap_p (src_offset, maxsize,
-					   dest_offset, maxsize))
-		    return NULL_TREE;
-		}
-	      else if (TREE_CODE (src_base) == INDIRECT_REF
-		       && TREE_CODE (dest_base) == INDIRECT_REF)
-		{
-		  if (! operand_equal_p (TREE_OPERAND (src_base, 0),
-					 TREE_OPERAND (dest_base, 0), 0)
-		      || ranges_overlap_p (src_offset, maxsize,
-					   dest_offset, maxsize))
-		    return NULL_TREE;
-		}
-	      else
-		return NULL_TREE;
-
-	      fn = implicit_built_in_decls[BUILT_IN_MEMCPY];
+	      tree fn = implicit_built_in_decls[BUILT_IN_MEMCPY];
 	      if (!fn)
 		return NULL_TREE;
 	      return build_call_expr_loc (loc, fn, 3, dest, src, len);
 	    }
+
 	  return NULL_TREE;
 	}
 
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 7e83a84..14f1fb4 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -168,12 +168,9 @@ ptr_deref_may_alias_decl_p (tree ptr, tree decl)
 {
   struct ptr_info_def *pi;
 
-  gcc_assert ((TREE_CODE (ptr) == SSA_NAME
-	       || TREE_CODE (ptr) == ADDR_EXPR
-	       || TREE_CODE (ptr) == INTEGER_CST)
-	      && (TREE_CODE (decl) == VAR_DECL
-		  || TREE_CODE (decl) == PARM_DECL
-		  || TREE_CODE (decl) == RESULT_DECL));
+  gcc_assert (TREE_CODE (decl) == VAR_DECL
+	      || TREE_CODE (decl) == PARM_DECL
+	      || TREE_CODE (decl) == RESULT_DECL);
 
   /* Non-aliased variables can not be pointed to.  */
   if (!may_be_aliased (decl))
@@ -197,9 +194,9 @@ ptr_deref_may_alias_decl_p (tree ptr, tree decl)
 	return true;
     }
 
-  /* We can end up with dereferencing constant pointers.
+  /* We can end up with dereferencing non-SSA name pointers.
      Just bail out in this case.  */
-  if (TREE_CODE (ptr) == INTEGER_CST)
+  if (TREE_CODE (ptr) != SSA_NAME)
     return true;
 
   /* If we do not have useful points-to information for this pointer
@@ -220,13 +217,6 @@ ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
 {
   struct ptr_info_def *pi1, *pi2;
 
-  gcc_assert ((TREE_CODE (ptr1) == SSA_NAME
-	       || TREE_CODE (ptr1) == ADDR_EXPR
-	       || TREE_CODE (ptr1) == INTEGER_CST)
-	      && (TREE_CODE (ptr2) == SSA_NAME
-		  || TREE_CODE (ptr2) == ADDR_EXPR
-		  || TREE_CODE (ptr2) == INTEGER_CST));
-
   /* ADDR_EXPR pointers either just offset another pointer or directly
      specify the pointed-to set.  */
   if (TREE_CODE (ptr1) == ADDR_EXPR)
@@ -254,10 +244,10 @@ ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
 	return true;
     }
 
-  /* We can end up with dereferencing constant pointers.
+  /* We can end up with dereferencing non-SSA name pointers.
      Just bail out in this case.  */
-  if (TREE_CODE (ptr1) == INTEGER_CST
-      || TREE_CODE (ptr2) == INTEGER_CST)
+  if (TREE_CODE (ptr1) != SSA_NAME 
+      || TREE_CODE (ptr2) != SSA_NAME)
     return true;
 
   /* We may end up with two empty points-to solutions for two same pointers.
@@ -781,7 +771,9 @@ refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
   if (TREE_CODE (base1) == SSA_NAME
       || TREE_CODE (base2) == SSA_NAME
       || is_gimple_min_invariant (base1)
-      || is_gimple_min_invariant (base2))
+      || is_gimple_min_invariant (base2)
+      || TREE_CODE (base1) == CONSTRUCTOR
+      || TREE_CODE (base2) == CONSTRUCTOR)
     return false;
 
   /* Defer to simple offset based disambiguation if we have