2009-09-02 Richard Guenther <rguenther@suse.de>

        Revert
        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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@151320 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 82 insertions, 18 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7e369e31b10..a35edee60a1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2009-09-02  Richard Guenther  <rguenther@suse.de>
+
+	Revert
+	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.
+
 2009-08-01  Christian Bruel  <christian.bruel@st.com>
 
 	Revert:
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 7ea899d19ba..b657275720e 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -8990,8 +8990,6 @@ 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);
 
@@ -9014,16 +9012,62 @@ fold_builtin_memory_op (location_t loc, tree dest, tree src,
 	    }
 
 	  /* If *src and *dest can't overlap, optimize into memcpy as well.  */
-	  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))
+	  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))
 	    {
-	      tree fn = implicit_built_in_decls[BUILT_IN_MEMCPY];
+	      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];
 	      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 14f1fb47006..7e83a84b82c 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -168,9 +168,12 @@ ptr_deref_may_alias_decl_p (tree ptr, tree decl)
 {
   struct ptr_info_def *pi;
 
-  gcc_assert (TREE_CODE (decl) == VAR_DECL
-	      || TREE_CODE (decl) == PARM_DECL
-	      || TREE_CODE (decl) == RESULT_DECL);
+  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));
 
   /* Non-aliased variables can not be pointed to.  */
   if (!may_be_aliased (decl))
@@ -194,9 +197,9 @@ ptr_deref_may_alias_decl_p (tree ptr, tree decl)
 	return true;
     }
 
-  /* We can end up with dereferencing non-SSA name pointers.
+  /* We can end up with dereferencing constant pointers.
      Just bail out in this case.  */
-  if (TREE_CODE (ptr) != SSA_NAME)
+  if (TREE_CODE (ptr) == INTEGER_CST)
     return true;
 
   /* If we do not have useful points-to information for this pointer
@@ -217,6 +220,13 @@ 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)
@@ -244,10 +254,10 @@ ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
 	return true;
     }
 
-  /* We can end up with dereferencing non-SSA name pointers.
+  /* We can end up with dereferencing constant pointers.
      Just bail out in this case.  */
-  if (TREE_CODE (ptr1) != SSA_NAME 
-      || TREE_CODE (ptr2) != SSA_NAME)
+  if (TREE_CODE (ptr1) == INTEGER_CST
+      || TREE_CODE (ptr2) == INTEGER_CST)
     return true;
 
   /* We may end up with two empty points-to solutions for two same pointers.
@@ -771,9 +781,7 @@ 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)
-      || TREE_CODE (base1) == CONSTRUCTOR
-      || TREE_CODE (base2) == CONSTRUCTOR)
+      || is_gimple_min_invariant (base2))
     return false;
 
   /* Defer to simple offset based disambiguation if we have