Enable 16-byte by pieces move [PR111449]

Hi,
  The patch 2 enables 16-byte by pieces move on rs6000. This patch fixes
the regression cases caused by previous patch. For sra-17/18, the long
array with 4 elements can be loaded by one 16-byte by pieces move on 32-bit
platform. So the array is not be constructed in LC0 and SRA optimization
is unable to be taken. "no-vsx" option is added for 32-bit platform, as
it sets the MOVE_MAX_PIECES to 4-byte on 32-bit platform and the array
can't be loaded by one by pieces move.

  Another regression is on P8 LE. The 16-byte memory to memory is
implemented by two TImode load/store. The TImode load/store is finally
split to two DImode load/store on P8 LE as it doesn't have unaligned
vector load/store instructions. Actually, 16-byte memory to memory move
can be implement by two V2DI reversed load/store on P8 LE. The patch
creates a insn_and_split pattern for this optimization.

  Bootstrapped and tested on x86 and powerpc64-linux BE and LE with no
regressions. Is this OK for trunk?

Thanks
Gui Haochen

ChangeLog
rs6000: Enable 16-byte by pieces move

This patch enables 16-byte by pieces move.  The 16-byte move is generated
with TImode and finally implemented by vector instructions.  There are
several regression cases after the enablement.  16-byte TImode memory to
memory move is originally implemented by two pairs of DImode load/store on
P8 LE as there is no unalignment vsx load/store on it.  The patch fixes
the problem by creating an insn_and_split pattern and converts it to one
pair of reversed load/store.  Two SRA cases lost the SRA optimization as
the array can be loaded by one 16-byte move so that not be initialized in
LC0 on 32-bit platform.  So fixes them by adding no-vsx option.

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

gcc/testsuite/
	PR target/111449
	* gcc.dg/tree-ssa/sra-17.c: Add no-vsx option for powerpc ilp32.
	* gcc.dg/tree-ssa/sra-18.c: Likewise.
	* gcc.target/powerpc/pr111449-1.c: New.

patch.diff

gcc/config/rs6000/vsx.md

@@ -407,6 +407,27 @@
 
 ;; 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
+   && !MEM_VOLATILE_P (operands[0])
+   && !MEM_VOLATILE_P (operands[1])
+   && !reload_completed"
+  "#"
+  "&& 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>"

gcc/testsuite/gcc.dg/tree-ssa/sra-17.c

@@ -1,6 +1,7 @@
 /* { dg-do run { target { aarch64*-*-* alpha*-*-* arm*-*-* hppa*-*-* powerpc*-*-* s390*-*-* } } } */
 /* { dg-options "-O2 -fdump-tree-esra --param sra-max-scalarization-size-Ospeed=32" } */
 /* { dg-additional-options "-mcpu=ev4" { target alpha*-*-* } } */
+/* { dg-additional-options "-mno-vsx" { target powerpc*-*-* && ilp32 } } */
 
 extern void abort (void);
 

gcc/testsuite/gcc.dg/tree-ssa/sra-18.c

@@ -1,6 +1,7 @@
 /* { dg-do run { target { aarch64*-*-* alpha*-*-* arm*-*-* hppa*-*-* powerpc*-*-* s390*-*-* } } } */
 /* { dg-options "-O2 -fdump-tree-esra --param sra-max-scalarization-size-Ospeed=32" } */
 /* { dg-additional-options "-mcpu=ev4" { target alpha*-*-* } } */
+/* { dg-additional-options "-mno-vsx" { target powerpc*-*-* && ilp32 } } */
 
 extern void abort (void);
 struct foo { long x; };

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 } } */