re PR tree-optimization/66142 (Loop is not vectorized because not sufficient…

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

2015-05-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66142
	* tree-ssa-sccvn.c (vn_reference_lookup_3): Handle non-GIMPLE
	values better in memcpy destination handling.  Handle non-aliasing
	we discover here.

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

From-SVN: r223816

gcc/ChangeLog

+2015-05-28  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/66142
+	* tree-ssa-sccvn.c (vn_reference_lookup_3): Handle non-GIMPLE
+	values better in memcpy destination handling.  Handle non-aliasing
+	we discover here.
+
 2015-05-28  Lawrence Velázquez  <vq@larryv.me>
 
 	PR target/63810

gcc/testsuite/ChangeLog

+2015-05-28  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/66142
+	* gcc.dg/tree-ssa/ssa-fre-44.c: Fixup.
+
 2015-05-28  Lawrence Velázquez  <vq@larryv.me>
 
 	PR target/63810

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

@@ -39,7 +39,6 @@ f3 (struct B *x, int y)
   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;

gcc/tree-ssa-sccvn.c

@@ -2028,7 +2028,16 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
       lhs = gimple_call_arg (def_stmt, 0);
       lhs_offset = 0;
       if (TREE_CODE (lhs) == SSA_NAME)
-	lhs = SSA_VAL (lhs);
+	{
+	  lhs = SSA_VAL (lhs);
+	  if (TREE_CODE (lhs) == SSA_NAME)
+	    {
+	      gimple def_stmt = SSA_NAME_DEF_STMT (lhs);
+	      if (gimple_assign_single_p (def_stmt)
+		  && gimple_assign_rhs_code (def_stmt) == ADDR_EXPR)
+		lhs = gimple_assign_rhs1 (def_stmt);
+	    }
+	}
       if (TREE_CODE (lhs) == ADDR_EXPR)
 	{
 	  tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (lhs, 0),
@@ -2039,6 +2048,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
 	      && tree_fits_uhwi_p (TREE_OPERAND (tem, 1)))
 	    {
 	      lhs = TREE_OPERAND (tem, 0);
+	      if (TREE_CODE (lhs) == SSA_NAME)
+		lhs = SSA_VAL (lhs);
 	      lhs_offset += tree_to_uhwi (TREE_OPERAND (tem, 1));
 	    }
 	  else if (DECL_P (tem))
@@ -2089,10 +2100,15 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
 		  || TREE_OPERAND (lhs, 0) != base)))
 	return (void *)-1;
 
-      /* And the access has to be contained within the memcpy destination.  */
       at = offset / BITS_PER_UNIT;
       if (TREE_CODE (base) == MEM_REF)
 	at += tree_to_uhwi (TREE_OPERAND (base, 1));
+      /* If the access is completely outside of the memcpy destination
+	 area there is no aliasing.  */
+      if (lhs_offset >= at + maxsize / BITS_PER_UNIT
+	  || lhs_offset + copy_size <= at)
+	return NULL;
+      /* And the access has to be contained within the memcpy destination.  */
       if (lhs_offset > at
 	  || lhs_offset + copy_size < at + maxsize / BITS_PER_UNIT)
 	return (void *)-1;