Re: [PATCH 3/3] Testcases for move sub blocks on param and ret

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

Hi!

Some comments on the testcases:

On Tue, Nov 29, 2022 at 09:45:07PM +0800, Jiufu Guo wrote:
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr65421-1.c
> @@ -0,0 +1,25 @@
> +/* PR target/65421 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +/* { dg-require-effective-target powerpc_elfv2 } */
> +
> +typedef struct SA
> +{
> +  double a[3];
> +  long l;
> +} A;
> +
> +/* 2 vec load, 2 vec store.  */
> +A ret_arg_pt (A *a){return *a;}
> +
> +/* 4 std */
> +A ret_arg (A a) {return a;}
> +
> +/* 4 std */
> +void st_arg (A a, A *p) {*p = a;}
> +
> +/* { dg-final { scan-assembler-times {\mlxvd2x\M|\mlxv\M|\mlvx\M} 2 } } */
> +/* { dg-final { scan-assembler-times {\mstxvd2x\M|\mstxv\M|\mstvx\M} 2 } } */
> +/* { dg-final { scan-assembler-times {\mstd\M} 8 } } */

You need at least ISA 2.06 (power7) to have {l,st}xvd2x, and elfv2 does
not guarantee that.  Have you tested on something old as well (say 970)
to see if the lvx/stvx is generated as expected?  For that you need to
have AltiVec enabled as well, so dg-require that?

> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr65421.c
> @@ -0,0 +1,22 @@
> +/* PR target/65421 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +/* { dg-require-effective-target powerpc_elfv2 } */
> +
> +typedef struct SA
> +{
> +  double a[3];
> +} A;
> +
> +/* 3 lfd */
> +A ret_arg_pt (A *a){return *a;}
> +
> +/* blr */
> +A ret_arg (A a) {return a;}
> +
> +/* 3 stfd */
> +void st_arg (A a, A *p) {*p = a;}
> +
> +/* { dg-final { scan-assembler-times {\mlfd\M} 3 } } */
> +/* { dg-final { scan-assembler-times {\mstfd\M} 3 } } */
> +/* { dg-final { scan-assembler-times {(?n)^\s+[a-z]} 9 } } */

Comment that last one?  Just something as simple as "count insns" is
enough :-)


Segher