From: Haochen Gui <guihaoc@gcc.gnu.org>
Date: Fri, 17 Nov 2023 09:17:59 +0000 (+0800)
Subject: rs6000: Fix regression cases caused 16-byte by pieces move
X-Git-Tag: basepoints/gcc-15~4590
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10615c8a10d6b61e813254924d76be728dbd4688;p=thirdparty%2Fgcc.git

rs6000: Fix regression cases caused 16-byte by pieces move

The previous patch enables 16-byte by pieces move. Originally 16-byte
move is implemented via pattern.  expand_block_move does an optimization
on P8 LE to leverage V2DI reversed load/store for memory to memory move.
Now 16-byte move is implemented via by pieces move and finally split to
two DI load/store.  This patch creates an insn_and_split pattern to
retake the optimization.

gcc/
	PR target/111449
	* config/rs6000/vsx.md (*vsx_le_mem_to_mem_mov_ti): New.

gcc/testsuite/
	PR target/111449
	* gcc.target/powerpc/pr111449-2.c: New.
---

diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
index f3b40229094b..26fa32829af6 100644
--- a/gcc/config/rs6000/vsx.md
+++ b/gcc/config/rs6000/vsx.md
@@ -414,6 +414,27 @@
 
 ;; VSX moves
 
+;; TImode memory to memory move optimization on LE with p8vector
+(define_insn_and_split "*vsx_le_mem_to_mem_mov_ti"
+  [(set (match_operand:TI 0 "indexed_or_indirect_operand" "=Z")
+	(match_operand:TI 1 "indexed_or_indirect_operand" "Z"))]
+  "!BYTES_BIG_ENDIAN
+   && TARGET_VSX
+   && !TARGET_P9_VECTOR
+   && can_create_pseudo_p ()"
+  "#"
+  "&& 1"
+  [(const_int 0)]
+{
+  rtx tmp = gen_reg_rtx (V2DImode);
+  rtx src =  adjust_address (operands[1], V2DImode, 0);
+  emit_insn (gen_vsx_ld_elemrev_v2di (tmp, src));
+  rtx dest = adjust_address (operands[0], V2DImode, 0);
+  emit_insn (gen_vsx_st_elemrev_v2di (dest, tmp));
+  DONE;
+}
+  [(set_attr "length" "16")])
+
 ;; The patterns for LE permuted loads and stores come before the general
 ;; VSX moves so they match first.
 (define_insn_and_split "*vsx_le_perm_load_<mode>"
diff --git a/gcc/testsuite/gcc.target/powerpc/pr111449-2.c b/gcc/testsuite/gcc.target/powerpc/pr111449-2.c
new file mode 100644
index 000000000000..7003bdc02084
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr111449-2.c
@@ -0,0 +1,18 @@
+/* { dg-do compile { target { has_arch_pwr8 } } } */
+/* { dg-require-effective-target powerpc_p8vector_ok } */
+/* { dg-options "-mvsx -O2" } */
+
+/* Ensure 16-byte by pieces move is enabled.  */
+
+void move1 (void *s1, void *s2)
+{
+  __builtin_memcpy (s1, s2, 16);
+}
+
+void move2 (void *s1)
+{
+  __builtin_memcpy (s1, "0123456789012345", 16);
+}
+
+/* { dg-final { scan-assembler-times {\mlxvd2x\M|\mp?lxv\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mstxvd2x\M|\mstxv\M} 2 } } */