Re: [PATCH] s390: Fix test vector/long-double-to-i64.c

[Stefan Schulze Frielinghaus <stefansf@linux.ibm.com>]

On Mon, Mar 11, 2024 at 11:14:04AM +0100, Andreas Krebbel wrote:
> On 2/29/24 13:15, Stefan Schulze Frielinghaus wrote:
> > Starting with r14-8319-g86de9b66480b71 fwprop improved so that vpdi is
> > no longer required.
> > 
> > gcc/testsuite/ChangeLog:
> > 
> > 	* gcc.target/s390/vector/long-double-to-i64.c: Fix scan
> > 	assembler directive.
> 
> Should we perhaps rather turn the scan-assembler directives into something which checks for the
> absence of vpdi then? In order to get notified once this really useful optimization breaks?

I thought about checking for the most optimal code which would be just
two loads and a convert instruction.  Thus if this fails, then we have a
regression.  Speaking of regressions, the old behaviour was restored by
r14-9412-g3e3e4156a5f93e which means we are back using vpdi.  Thus, I
will leave this patch on hold and have a second look.

Cheers,
Stefan

> 
> Andreas
> 
> > ---
> >  .../gcc.target/s390/vector/long-double-to-i64.c     | 13 +++++++++----
> >  1 file changed, 9 insertions(+), 4 deletions(-)
> > 
> > diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-to-i64.c b/gcc/testsuite/gcc.target/s390/vector/long-double-to-i64.c
> > index 2dbbb5d1c03..ed89878e6ee 100644
> > --- a/gcc/testsuite/gcc.target/s390/vector/long-double-to-i64.c
> > +++ b/gcc/testsuite/gcc.target/s390/vector/long-double-to-i64.c
> > @@ -1,19 +1,24 @@
> >  /* { dg-do compile } */
> >  /* { dg-options "-O3 -march=z14 -mzarch --save-temps" } */
> >  /* { dg-do run { target { s390_z14_hw } } } */
> > +/* { dg-final { check-function-bodies "**" "" "" { target { lp64 } } } } */
> > +
> >  #include <assert.h>
> >  #include <stdint.h>
> >  
> > +/*
> > +** long_double_to_i64:
> > +**	ld	%f0,0\(%r2\)
> > +**	ld	%f2,8\(%r2\)
> > +**	cgxbr	%r2,5,%f0
> > +**	br	%r14
> > +*/
> >  __attribute__ ((noipa)) static int64_t
> >  long_double_to_i64 (long double x)
> >  {
> >    return x;
> >  }
> >  
> > -/* { dg-final { scan-assembler-times {\n\tvpdi\t%v\d+,%v\d+,%v\d+,1\n} 1 } } */
> > -/* { dg-final { scan-assembler-times {\n\tvpdi\t%v\d+,%v\d+,%v\d+,5\n} 1 } } */
> > -/* { dg-final { scan-assembler-times {\n\tcgxbr\t} 1 } } */
> > -
> >  int
> >  main (void)
> >  {
>