re PR target/72863 (Powerpc64le: redundant swaps when using vec_vsx_ld/st)

[gcc]

2016-08-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR target/72863
	* vsx.md (vsx_load_<mode>): For P8LE, emit swaps at expand time.
	(vsx_store_<mode>): Likewise.

[gcc/testsuite]

2016-08-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR target/72863
	* gcc.target/powerpc/pr72863.c: New test.

From-SVN: r239394

gcc/ChangeLog

+2016-08-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
+
+	PR target/72863
+	* vsx.md (vsx_load_<mode>): For P8LE, emit swaps at expand time.
+	(vsx_store_<mode>): Likewise.
+
 2015-08-11  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* config/i386/i386.c (timode_scalar_to_vector_candidate_p): Allow

gcc/config/rs6000/vsx.md

@@ -934,13 +934,27 @@
   [(set (match_operand:VSX_M 0 "vsx_register_operand" "")
 	(match_operand:VSX_M 1 "memory_operand" ""))]
   "VECTOR_MEM_VSX_P (<MODE>mode)"
-  "")
+{
+  /* Expand to swaps if needed, prior to swap optimization.  */
+  if (!BYTES_BIG_ENDIAN && !TARGET_P9_VECTOR)
+    {
+      rs6000_emit_le_vsx_move (operands[0], operands[1], <MODE>mode);
+      DONE;
+    }
+})
 
 (define_expand "vsx_store_<mode>"
   [(set (match_operand:VSX_M 0 "memory_operand" "")
 	(match_operand:VSX_M 1 "vsx_register_operand" ""))]
   "VECTOR_MEM_VSX_P (<MODE>mode)"
-  "")
+{
+  /* Expand to swaps if needed, prior to swap optimization.  */
+  if (!BYTES_BIG_ENDIAN && !TARGET_P9_VECTOR)
+    {
+      rs6000_emit_le_vsx_move (operands[0], operands[1], <MODE>mode);
+      DONE;
+    }
+})
 
 ;; Explicit load/store expanders for the builtin functions for lxvd2x, etc.,
 ;; when you really want their element-reversing behavior.

gcc/testsuite/ChangeLog

+2016-08-11  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
+
+	PR target/72863
+	* gcc.target/powerpc/pr72863.c: New test.
+
 2016-08-11  Uros Bizjak  <ubizjak@gmail.com>
 
 	* g++.dg/cpp1z/constexpr-lambda6.C: Remove dg-do run.

gcc/testsuite/gcc.target/powerpc/pr72863.c

+/* { dg-do compile { target { powerpc64le-*-* } } } */
+/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } { "-mcpu=power8" } } */
+/* { dg-options "-mcpu=power8 -O3" } */
+/* { dg-final { scan-assembler "lxvd2x" } } */
+/* { dg-final { scan-assembler "stxvd2x" } } */
+/* { dg-final { scan-assembler-not "xxpermdi" } } */
+
+#include <altivec.h>
+
+extern unsigned char *src, *dst;
+
+void b(void)
+{
+  int i;
+
+  unsigned char *s8 = src;
+  unsigned char *d8 = dst;
+
+  for (i = 0; i < 100; i++) {
+    vector unsigned char vs = vec_vsx_ld(0, s8);
+    vector unsigned char vd = vec_vsx_ld(0, d8);
+    vector unsigned char vr = vec_xor(vs, vd);
+    vec_vsx_st(vr, 0, d8);
+    s8 += 16;
+    d8 += 16;
+  }
+}