[PATCH][committed]middle-end: Fix signbit tests when ran on ISA with support for masks.

[Sandra Loosemore]

On 11/10/21 4:54 AM, Tamar Christina via Gcc-patches wrote:
> Hi All,
> 
> These test don't work on vector ISAs where the truth
> type don't match the vector mode of the operation.
> 
> However I still want the tests to run on these
> architectures but just turn off the ISA modes that
> enable masks.
> 
> This thus turns off SVE is it's on and turns off
> AVX512 if it's on.
> 
> Regtested on aarch64-none-linux-gnu with SVE on,
> and x86_64-pc-linux-gnu with AVX512 on and no
> issues.
> 
> Committed under the obvious rule.
> 
> Thanks,
> Tamar
> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.dg/signbit-2.c: Turn of masks.
> 	* gcc.dg/signbit-5.c: Likewise.

I'm seeing this failure on nios2-elf:

FAIL: gcc.dg/signbit-2.c scan-tree-dump-times optimized "\\s+>\\s+{ 0, 
0, 0, 0 }" 1

I don't understand what it is expecting to happen here.  Should it be 
skipped on this target, or restricted to ARM and x86?  Adding some 
comments to the testcase to explain the significance of that pattern 
might be useful too.

-Sandra