Re: [PATCH v2, rs6000] Change insn condition from TARGET_64BIT to TARGET_POWERPC64 for VSX scalar extract/insert instructions

[Segher Boessenkool <segher@kernel.crashing.org>]

Hi!

On Fri, Sep 02, 2022 at 04:31:38PM +0800, HAO CHEN GUI wrote:
>   This patch is for internal issue1136.

This isn't useful to most people.  Either just don't mention it here,
or make a public PR for it if that is useful?

> It changes insn condition from
> TARGET_64BIT to TARGET_POWERPC64 for VSX scalar extract/insert instructions.
> These instructions all use DI registers and can be invoked with -mpowerpc64
> in a 32-bit environment.

> gcc/
> 	* config/rs6000/vsx.md (xsxexpdp): Change insn condition from
> 	TARGET_64BIT to TARGET_POWERPC64.
> 	(xsxsigdp): Likewise.
> 	(xsiexpdp): Likewise.
> 	(xsiexpdpf): Likewise.
> 
> gcc/testsuite/
> 	* gcc.target/powerpc/bfp/scalar-extract-exp-0.c: Change effective
> 	target from lp64 to has_arch_ppc64 and add -mpowerpc64 for 32-bit
> 	environment.
> 	* gcc.target/powerpc/bfp/scalar-extract-exp-6.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-extract-exp-7.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-extract-sig-0.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-extract-sig-6.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-extract-sig-7.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-insert-exp-0.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-insert-exp-12.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-insert-exp-13.c: Likewise.
> 	* gcc.target/powerpc/bfp/scalar-insert-exp-3.c: Likewise.

> -  const signed long __builtin_vsx_scalar_extract_exp (double);
> +  const unsigned long long __builtin_vsx_scalar_extract_exp (double);
>      VSEEDP xsxexpdp {}
> 
> -  const signed long __builtin_vsx_scalar_extract_sig (double);
> +  const unsigned long long __builtin_vsx_scalar_extract_sig (double);
>      VSESDP xsxsigdp {}

This also brings these legacy builtins in line with the vec_ versions,
which are the preferred builtins (they are defined in the PVIPR).

> --- a/gcc/config/rs6000/vsx.md
> +++ b/gcc/config/rs6000/vsx.md
> @@ -5098,7 +5098,7 @@ (define_insn "xsxexpdp"
>    [(set (match_operand:DI 0 "register_operand" "=r")
>  	(unspec:DI [(match_operand:DF 1 "vsx_register_operand" "wa")]
>  	 UNSPEC_VSX_SXEXPDP))]
> -  "TARGET_P9_VECTOR && TARGET_64BIT"
> +  "TARGET_P9_VECTOR && TARGET_POWERPC64"
>    "xsxexpdp %0,%x1"
>    [(set_attr "type" "integer")])

This doesn't need POWERPC64 even -- instead, it could use :GPR instead
of :DI, the output is always tiny.

> --- a/gcc/testsuite/gcc.target/powerpc/bfp/scalar-extract-exp-0.c
> +++ b/gcc/testsuite/gcc.target/powerpc/bfp/scalar-extract-exp-0.c
> @@ -1,7 +1,8 @@
> -/* { dg-do compile { target { powerpc*-*-* } } } */
> -/* { dg-require-effective-target lp64 } */
> -/* { dg-require-effective-target powerpc_p9vector_ok } */
> +/* { dg-do compile { target { powerpc*-*-linux* } } } */

Why?

>  /* { dg-options "-mdejagnu-cpu=power9" } */
> +/* { dg-additional-options "-mpowerpc64" } */
> +/* { dg-require-effective-target has_arch_ppc64 } */

This is guaranteed already by that -mpowerpc64.

It probably is best if you do not add -mpowerpc64 at all.  That solves
both problems, is simpler, and gives better coverage as well :-)

So just use has_arch_ppc64 instead of lp64.  That makes it run on a
strict superset of cases :-)

> --- a/gcc/testsuite/gcc.target/powerpc/bfp/scalar-extract-exp-6.c
> +++ b/gcc/testsuite/gcc.target/powerpc/bfp/scalar-extract-exp-6.c
> @@ -1,7 +1,7 @@
> -/* { dg-do run { target { powerpc*-*-* } } } */
> -/* { dg-require-effective-target lp64 } */
> -/* { dg-require-effective-target p9vector_hw } */
> +/* { dg-do run { target { powerpc*-*-linux* } } } */
>  /* { dg-options "-mdejagnu-cpu=power9" } */
> +/* { dg-require-effective-target has_arch_ppc64 } */
> +/* { dg-require-effective-target p9vector_hw } */

Nothing in gcc.target/powerpc has to check for powerpc*-*-* at all.  If
you want to test for linux (you shouldn't here afaics?), that is just
*-*-linux* .


Segher