Ping [PATCHv2, rs6000] Merge two vector shift when their sources are the same

[HAO CHEN GUI <guihaoc@linux.ibm.com>]

Hi
  Gently ping this.
https://gcc.gnu.org/pipermail/gcc-patches/2023-February/612944.html

Thanks
Gui Haochen

在 2023/2/28 10:31, HAO CHEN GUI 写道:
> Hi,
>   This patch merges two "vsldoi" insns when their sources are the
> same. Particularly, it is simplified to be one move if the total
> shift is multiples of 16 bytes.
> 
>   Bootstrapped and tested on powerpc64-linux BE and LE with no
> regressions.
> 
> Thanks
> Gui Haochen
> 
> 
> ChangeLog
> 2023-02-28  Haochen Gui <guihaoc@linux.ibm.com>
> 
> gcc/
> 	* config/rs6000/altivec.md (*altivec_vsldoi_dup_<mode>): New
> 	insn_and_split to merge two vsldoi when the sources are the same.
> 
> gcc/testsuite/
> 	* gcc.target/powerpc/vsldoi_merge.c: New.
> 
> 
> 
> patch.diff
> diff --git a/gcc/config/rs6000/altivec.md b/gcc/config/rs6000/altivec.md
> index 84660073f32..fae8ec2b2e8 100644
> --- a/gcc/config/rs6000/altivec.md
> +++ b/gcc/config/rs6000/altivec.md
> @@ -2529,6 +2529,35 @@ (define_insn "altivec_vsldoi_<mode>"
>    "vsldoi %0,%1,%2,%3"
>    [(set_attr "type" "vecperm")])
> 
> +(define_insn_and_split "*altivec_vsldoi_dup_<mode>"
> +  [(set (match_operand:VM 0 "register_operand" "=v")
> +	(unspec:VM [(unspec:VM [(match_operand:VM 1 "register_operand" "v")
> +				(match_dup 1)
> +				(match_operand:QI 2 "immediate_operand" "i")]
> +			       UNSPEC_VSLDOI)
> +		    (unspec:VM [(match_dup 1)
> +				(match_dup 1)
> +				(match_dup 2)]
> +			       UNSPEC_VSLDOI)
> +		    (match_operand:QI 3 "immediate_operand" "i")]
> +		   UNSPEC_VSLDOI))]
> +  "TARGET_ALTIVEC"
> +  "#"
> +  "&& 1"
> +  [(const_int 0)]
> +{
> +  unsigned int shift1 = UINTVAL (operands[2]);
> +  unsigned int shift2 = UINTVAL (operands[3]);
> +
> +  unsigned int shift = (shift1 + shift2) % 16;
> +  if (shift)
> +    emit_insn (gen_altivec_vsldoi_<mode> (operands[0], operands[1],
> +					  operands[1], GEN_INT (shift)));
> +  else
> +    emit_move_insn (operands[0], operands[1]);
> +  DONE;
> +})
> +
>  (define_insn "altivec_vupkhs<VU_char>"
>    [(set (match_operand:VP 0 "register_operand" "=v")
>  	(unspec:VP [(match_operand:<VP_small> 1 "register_operand" "v")]
> diff --git a/gcc/testsuite/gcc.target/powerpc/vsldoi_merge.c b/gcc/testsuite/gcc.target/powerpc/vsldoi_merge.c
> new file mode 100644
> index 00000000000..eebd7b4d382
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/vsldoi_merge.c
> @@ -0,0 +1,59 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target powerpc_vsx_ok } */
> +/* { dg-options "-O2 -mvsx -save-temps" } */
> +
> +#include "altivec.h"
> +
> +#ifdef DEBUG
> +#include <stdio.h>
> +#endif
> +
> +void abort (void);
> +
> +__attribute__ ((noipa)) vector signed int
> +test1 (vector signed int a)
> +{
> +  a = vec_sld (a, a, 2);
> +  a = vec_sld (a, a, 6);
> +  return a;
> +}
> +
> +__attribute__ ((noipa)) vector signed int
> +test2 (vector signed int a)
> +{
> +  a = vec_sld (a, a, 14);
> +  a = vec_sld (a, a, 2);
> +  return a;
> +}
> +
> +int main (void)
> +{
> +  vector signed int a = {1,2,3,4};
> +  vector signed int result_a;
> +  int i;
> +
> +  result_a = test1 (a);
> +  vector signed int expect_a = {3,4,1,2};
> +
> +  for (i = 0; i< 4; i++)
> +    if (result_a[i] != expect_a[i])
> +#ifdef DEBUG
> +      printf("ERROR: test1 result[%d] = %d, not expected[%d] = %d\n",
> +              i, result_a[i], i, expect_a[i]);
> +#else
> +      abort ();
> +#endif
> +
> +  result_a = test2 (a);
> +
> +  for (i = 0; i< 4; i++)
> +    if (result_a[i] != a[i])
> +#ifdef DEBUG
> +      printf("ERROR: test2 result[%d] = %d, not expected[%d] = %d\n",
> +              i, result_a[i], i, a[i]);
> +#else
> +      abort ();
> +#endif
> +}
> +
> +/* { dg-final { scan-assembler-times {\mvsldoi\M} 1 } } */