re PR target/79354 (-mcpu=power8 -O2 generates power9 instruction on powerpc64le-linux)

	PR target/79354
	* config/rs6000/rs6000.md (movsi_from_sf): Use wb constraint instead of
	wu for stxssp alternative.

	* gcc.target/powerpc/pr79354.c: New test.
	* gcc.c-torture/execute/pr79354.c: New test.

From-SVN: r245157

gcc/ChangeLog

+2017-02-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/79354
+	* config/rs6000/rs6000.md (movsi_from_sf): Use wb constraint instead of
+	wu for stxssp alternative.
+
 2017-02-03  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/79352

gcc/config/rs6000/rs6000.md

@@ -6814,7 +6814,7 @@
 
 	(unspec:SI [(match_operand:SF 1 "input_operand"
 		"r,          m,           Z,           Z,        r,
-		 f,          wu,          wu,          wIwH,     r,
+		 f,          wb,          wu,          wIwH,     r,
 		 wK")]
 		    UNSPEC_SI_FROM_SF))
 

gcc/testsuite/ChangeLog

+2017-02-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/79354
+	* gcc.target/powerpc/pr79354.c: New test.
+	* gcc.c-torture/execute/pr79354.c: New test.
+
 2017-02-03  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/79352

gcc/testsuite/gcc.c-torture/execute/pr79354.c

+/* PR target/79354 */
+
+int b, f, g;
+float e;
+unsigned long d;
+
+__attribute__((noinline, noclone)) void
+foo (int *a)
+{
+  for (g = 0; g < 32; g++)
+    if (f)
+      {
+        e = d;
+        __builtin_memcpy (&b, &e, sizeof (float));
+        b = *a;
+      }
+}
+
+int
+main ()
+{
+  int h = 5;
+  f = 1;
+  asm volatile ("" : : : "memory");
+  foo (&h);
+  asm volatile ("" : : : "memory");
+  foo (&b);
+  asm volatile ("" : : : "memory");
+  return 0;
+}

gcc/testsuite/gcc.target/powerpc/pr79354.c

+/* PR target/79354 */
+/* { dg-do compile } */
+/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } { "-mcpu=power8" } } */
+/* { dg-require-effective-target powerpc_p8vector_ok } */
+/* { dg-options "-mcpu=power8 -O2" } */
+/* { dg-final { scan-assembler-not {\mstxssp\M} } } */
+
+int b, f, g;
+float e;
+unsigned long d;
+
+void
+foo (int *a)
+{
+  for (g = 0; g < 32; g++)
+    if (f)
+      {
+        e = d;
+        __builtin_memcpy (&b, &e, sizeof (float));
+        b = *a;
+      }
+}