Re: [PATCH V3] rs6000: Don't ICE when compiling the __builtin_vsx_splat_2di built-in [PR113950]

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi,

on 2024/3/4 02:55, jeevitha wrote:
> Hi All,
> 
> The following patch has been bootstrapped and regtested on powerpc64le-linux.
> 										
> When we expand the __builtin_vsx_splat_2di function, we were allowing immediate
> value for second operand which causes an unrecognizable insn ICE. Even though
> the immediate value was forced into a register, it wasn't correctly assigned
> to the second operand. So corrected the assignment of op1 to operands[1].
> 
> 2024-02-29  Jeevitha Palanisamy  <jeevitha@linux.ibm.com>
> 
> gcc/
> 	PR target/113950
> 	* config/rs6000/vsx.md (vsx_splat_<mode>): Corrected assignment to
> 	operand1.

Nit: s/Corrected/Correct/, maybe add "and simplify else if with else.".

> 
> gcc/testsuite/
> 	PR target/113950
> 	* gcc.target/powerpc/pr113950.c: New testcase.
> 
> diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
> index 6111cc90eb7..f135fa079bd 100644
> --- a/gcc/config/rs6000/vsx.md
> +++ b/gcc/config/rs6000/vsx.md
> @@ -4666,8 +4666,8 @@
>    rtx op1 = operands[1];
>    if (MEM_P (op1))
>      operands[1] = rs6000_force_indexed_or_indirect_mem (op1);
> -  else if (!REG_P (op1))
> -    op1 = force_reg (<VSX_D:VEC_base>mode, op1);
> +  else
> +    operands[1] = force_reg (<VSX_D:VEC_base>mode, op1);
>  })
>  
>  (define_insn "vsx_splat_<mode>_reg"
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr113950.c b/gcc/testsuite/gcc.target/powerpc/pr113950.c
> new file mode 100644
> index 00000000000..64566a580d9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr113950.c
> @@ -0,0 +1,24 @@
> +/* PR target/113950 */
> +/* { dg-require-effective-target powerpc_vsx_ok } */
> +/* { dg-options "-O1 -mvsx" } */

Nit: s/-O1/-O2/, -O2 is preferred when the failure can be reproduced
with -O2 (not just -O1), since optimization may change the level in
which it's placed, -O2 is more general.

As the discussions in the thread of the previous versions, I think
Segher agreed this approach, so OK for trunk with the above nits
tweaked, thanks!

BR,
Kewen

> +
> +/* Verify we do not ICE on the following.  */
> +
> +void abort (void);
> +
> +int main ()
> +{
> +  int i;
> +  vector signed long long vsll_result, vsll_expected_result;
> +  signed long long sll_arg1;
> +
> +  sll_arg1 = 300;
> +  vsll_expected_result = (vector signed long long) {300, 300};
> +  vsll_result = __builtin_vsx_splat_2di (sll_arg1);  
> +
> +  for (i = 0; i < 2; i++)
> +    if (vsll_result[i] != vsll_expected_result[i])
> +      abort();
> +
> +  return 0;
> +}
> 
>