re PR c++/85077 (V[248][SD]F abs not optimized to)

	PR c++/85077
	* cp-gimplify.c (cp_fold) <case CONSTRUCTOR>: For ctors with vector
	type call fold to generate VECTOR_CSTs when possible.

	* g++.dg/ext/vector35.C: New test.

From-SVN: r258903

gcc/cp/ChangeLog

 2018-03-27  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/85077
+	* cp-gimplify.c (cp_fold) <case CONSTRUCTOR>: For ctors with vector
+	type call fold to generate VECTOR_CSTs when possible.
+
 	PR c++/85076
 	* tree.c (cp_build_reference_type): If to_type is error_mark_node,
 	return it right away.

gcc/cp/cp-gimplify.c

@@ -2504,6 +2504,8 @@ cp_fold (tree x)
 	    CONSTRUCTOR_PLACEHOLDER_BOUNDARY (x)
 	      = CONSTRUCTOR_PLACEHOLDER_BOUNDARY (org_x);
 	  }
+	if (VECTOR_TYPE_P (TREE_TYPE (x)))
+	  x = fold (x);
 	break;
       }
     case TREE_VEC:

gcc/testsuite/ChangeLog

 2018-03-27  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/85077
+	* g++.dg/ext/vector35.C: New test.
+
 	PR c++/85061
 	* g++.dg/ext/builtin-offsetof3.C: New test.
 

gcc/testsuite/g++.dg/ext/vector35.C

+// PR c++/85077
+// { dg-do compile }
+// { dg-options "-Ofast -fdump-tree-forwprop1" }
+
+typedef float V __attribute__((vector_size (4 * sizeof (float))));
+typedef double W __attribute__((vector_size (2 * sizeof (double))));
+
+void
+foo (V *y)
+{
+  V x = *y;
+  *y = x < 0 ? -x : x;
+}
+
+void
+bar (W *y)
+{
+  W x = *y;
+  *y = x < 0 ? -x : x;
+}
+
+// { dg-final { scan-tree-dump-times "ABS_EXPR <" 2 "forwprop1" } }