Re: [PATCH 2/7] PowerPC tests: Add PLI/PADDI tests.

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

Hi!

On Mon, Jun 29, 2020 at 02:23:22PM -0400, Michael Meissner wrote:
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/prefix-di-constant.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target powerpc_prefixed_addr } */
> +/* { dg-require-effective-target lp64 } */

Please always say (_in the test_) why something is required, if it isn't
obvious.

> +/* { dg-options "-O2 -mdejagnu-cpu=power10" } */
> +
> +/* Test that PLI (PADDI) is generated to load a large constant.  */
> +unsigned long long
> +large (void)
> +{
> +  return 0x12345678ULL;
> +}
> +
> +/* { dg-final { scan-assembler {\mpli\M} } } */

I have no idea why 64-bit mode (or 64-bit addressing) is needed here.
*Is* it needed?

> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/prefix-ds-dq.c
> @@ -0,0 +1,161 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target powerpc_prefixed_addr } */
> +/* { dg-require-effective-target lp64 } */
> +/* { dg-options "-O2 -mdejagnu-cpu=power10" } */

> +  unsigned int si;			/* offset 49 bytes.  */

> +int
> +load_si (struct packed_struct *p)
> +{
> +  return p->si;				/* PLWA 3,49(3).  */
> +}

Here it is because this would be just lwz on 32-bit.

But that is the only difference, so you could just make that single test
conditional, not the whole file.

> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/prefix-no-update.c
> @@ -0,0 +1,51 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target powerpc_prefixed_addr } */
> +/* { dg-require-effective-target lp64 } */
> +/* { dg-options "-O2 -mdejagnu-cpu=power10" } */

For this testcase, I have no idea at all why you want lp64?

Thanks,


Segher