re PR tree-optimization/66142 (Loop is not vectorized because not sufficient support for GOMP_SIMD_LANE)

2015-05-26  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66142
	* tree-ssa-sccvn.c (vn_reference_lookup_3): Manually compare
	MEM_REFs for the same base address.

	* gcc.dg/tree-ssa/ssa-fre-44.c: New testcase.

From-SVN: r223697

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2015-05-26  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/66142
+	* tree-ssa-sccvn.c (vn_reference_lookup_3): Manually compare
+	MEM_REFs for the same base address.
+
 2015-05-26  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
 
 	PR ipa/66181

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2015-05-26  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/66142
+	* gcc.dg/tree-ssa/ssa-fre-44.c: New testcase.
+
 2015-05-26  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/66082

gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-44.c

@@ -0,0 +1,62 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-fre1" } */
+
+struct A { float x, y; };
+struct B { struct A u; };
+void bar (struct A *);
+
+float
+f1 (struct B *x, int y)
+{
+  struct A p;
+  p.x = 1.0f;
+  p.y = 2.0f;
+  struct A *q = &x[y].u;
+  *q = p;
+  float f = x[y].u.x + x[y].u.y;
+  bar (&p);
+  return f;
+}
+
+float
+f2 (struct B *x, int y)
+{
+  struct A p;
+  p.x = 1.0f;
+  p.y = 2.0f;
+  x[y].u = p;
+  float f = x[y].u.x + x[y].u.y;
+  bar (&p);
+  return f;
+}
+
+float
+f3 (struct B *x, int y)
+{
+  struct A p;
+  p.x = 1.0f;
+  p.y = 2.0f;
+  struct A *q = &x[y].u;
+  __builtin_memcpy (&q->x, &p.x, sizeof (float));
+  __builtin_memcpy (&q->y, &p.y, sizeof (float));
+  *q = p;
+  float f = x[y].u.x + x[y].u.y;
+  bar (&p);
+  return f;
+}
+
+float
+f4 (struct B *x, int y)
+{
+  struct A p;
+  p.x = 1.0f;
+  p.y = 2.0f;
+  __builtin_memcpy (&x[y].u.x, &p.x, sizeof (float));
+  __builtin_memcpy (&x[y].u.y, &p.y, sizeof (float));
+  float f = x[y].u.x + x[y].u.y;
+  bar (&p);
+  return f;
+}
+
+/* { dg-final { scan-tree-dump-times "return 3.0" 4 "fre1" } } */
+/* { dg-final { cleanup-tree-dump "fre1" } } */

gcc/tree-ssa-sccvn.c

@@ -1894,7 +1894,12 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
       size2 = lhs_ref.size;
       maxsize2 = lhs_ref.max_size;
       if (maxsize2 == -1
-	  || (base != base2 && !operand_equal_p (base, base2, 0))
+	  || (base != base2
+	      && (TREE_CODE (base) != MEM_REF
+		  || TREE_CODE (base2) != MEM_REF
+		  || TREE_OPERAND (base, 0) != TREE_OPERAND (base2, 0)
+		  || !tree_int_cst_equal (TREE_OPERAND (base, 1),
+					  TREE_OPERAND (base2, 1))))
 	  || offset2 > offset
 	  || offset2 + size2 < offset + maxsize)
 	return (void *)-1;