[committed] testsuite: Limit bb-slp-pr95839-v8.c to 64-bit vector targets

["Maciej W. Rozycki" <macro@embecosm.com>]

Only run bb-slp-pr95839-v8.c with targets that support vectors of 64 
bits, removing regressions with 32-bit x86 targets:

FAIL: gcc.dg/vect/bb-slp-pr95839-v8.c scan-tree-dump slp2 "optimized: basic block"
FAIL: gcc.dg/vect/bb-slp-pr95839-v8.c -flto -ffat-lto-objects  scan-tree-dump slp2 "optimized: basic block"

	gcc/testsuite/
	* gcc.dg/vect/bb-slp-pr95839-v8.c: Limit to `vect64' targets.
---
On Fri, 21 Jul 2023, Jiang, Haochen wrote:

> > > > I think the issue is we disable V2SF on ia32 because of the conflict
> > > > with MMX which we don't want to use.
> > >
> > >  I'm not sure if I have a way to test with such a target.  Would you
> > > expect:
> > >
> > > /* { dg-require-effective-target vect64 } */
> > >
> > > to cover it?  If so, then I'll put it back as in the original version
> > > and post for Haochen to verify.
> 
> I suppose just commit to trunk and it should be ok since it is only -m32 
> issue.

 Thanks for mentioning `-m32', I was able to use it to verify this change 
and confirm that the qualifier does indeed work for this configuration.  
Committed as posted then and apologies for messing this up.

  Maciej
---
 gcc/testsuite/gcc.dg/vect/bb-slp-pr95839-v8.c |    1 +
 1 file changed, 1 insertion(+)

gcc-test-bb-slp-pr95839-v8-fix.diff
Index: gcc/gcc/testsuite/gcc.dg/vect/bb-slp-pr95839-v8.c
===================================================================
--- gcc.orig/gcc/testsuite/gcc.dg/vect/bb-slp-pr95839-v8.c
+++ gcc/gcc/testsuite/gcc.dg/vect/bb-slp-pr95839-v8.c
@@ -1,5 +1,6 @@
 /* { dg-do compile } */
 /* { dg-require-effective-target vect_float } */
+/* { dg-require-effective-target vect64 } */
 /* { dg-additional-options "-w -Wno-psabi" } */
 
 typedef float __attribute__((vector_size(8))) v2f32;