re PR tree-optimization/50698 (pretending to create versioning for alias when not required)

2011-10-13  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/50698
	* tree-data-ref.c (split_constant_offset_1): Also process
	offsets of &MEM.

	* g++.dg/vect/pr50698.cc: New testcase.

From-SVN: r179895

gcc/ChangeLog

+2011-10-13  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/50698
+	* tree-data-ref.c (split_constant_offset_1): Also process
+	offsets of &MEM.
+
 2011-10-12  David S. Miller  <davem@davemloft.net>
 
 	* config/sparc/sparc.h: Do not force TARGET_VIS3 and TARGET_FMAF

gcc/testsuite/ChangeLog

+2011-10-13  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/50698
+	* g++.dg/vect/pr50698.cc: New testcase.
+
 2011-10-12  Janis Johnson  <janisjo@codesourcery.com>
 
 	* gcc.target/powerpc/warn-1.c: Skip if not powerpc_vsx_ok.

gcc/testsuite/g++.dg/vect/pr50698.cc

+// { dg-do compile }
+// { dg-require-effective-target vect_float }
+
+float mem[4096];
+const int N=1024;
+
+struct XYZ {
+    float * mem;
+    int n;
+    float * x() { return mem;}
+    float * y() { return x()+n;}
+    float * z() { return y()+n;}
+};
+
+inline
+void sum(float * x, float * y, float * z, int n) {
+    for (int i=0;i!=n; ++i)
+      x[i]=y[i]+z[i];
+}
+
+void sumS() {
+    XYZ xyz; xyz.mem=mem; xyz.n=N;
+    sum(xyz.x(),xyz.y(),xyz.z(),xyz.n);
+}
+
+// { dg-final { scan-tree-dump-not "run-time aliasing" "vect" } }
+// { dg-final { cleanup-tree-dump "vect" } }

gcc/tree-data-ref.c

@@ -589,9 +589,6 @@ split_constant_offset_1 (tree type, tree op0, enum tree_code code, tree op1,
 	int punsignedp, pvolatilep;
 
 	op0 = TREE_OPERAND (op0, 0);
-	if (!handled_component_p (op0))
-	  return false;
-
 	base = get_inner_reference (op0, &pbitsize, &pbitpos, &poffset,
 				    &pmode, &punsignedp, &pvolatilep, false);