[PATCH] rs6000: Support vector float/double for vec_sldw

[Segher Boessenkool]

Hi!

On Fri, Jan 21, 2022 at 11:31:34AM -0600, Bill Schmidt wrote:
> It was recently discovered that Clang supports a couple of variants of vec_sldw that
> GCC does not.  After some discussion, we decided that these variants are reasonable,
> and GCC will also support them.  This patch adds that support.

As we discussed, this is reasonable only because we already allow
non-integer inputs (and outputs) for all(?) other permute class
instructions.

> I updated an existing test and discovered it wasn't actually checking for generation
> of the xxsldwi instruction, so I added that check as well.

It can always generate vsldoi instead, which is a strict superset (if
all registers used are VRs).  They will not likely be here, because
these are such simple functions, but that is a bit fragile.

> 	* gcc.target/powerpc/builtins-4.c: Add two test variants.  Adjust
> 	assembler counts.

Is there any justification for the new counts?

... Ah, it didn't count the sld's at all before.  Okay.

> @@ -161,6 +175,6 @@ test_sll_vuill_vuill_vuc (vector unsigned long long int x,
>  /* { dg-final { scan-assembler-times "xvnabssp"  1 } } */
>  /* { dg-final { scan-assembler-times "xvnabsdp"  1 } } */
>  /* { dg-final { scan-assembler-times "vslo"      4 } } */
> -/* { dg-final { scan-assembler-times "xxlor"     30 } } */
> +/* { dg-final { scan-assembler-times "xxlor"     32 } } */

This will need modification for the phase of the moon.  It also does not
even test only xxlor insn (also xxlorc insns, for example).

> +/* { dg-final { scan-assembler-times "xxsldwi"   10 } } */

Okay if you make this
  \mxxsldwi\M
or even
  \m(?:xxsldwi|vsldoi)\M

Thanks!


Segher