On Thu, Jul 18, 2024 at 10:31 PM Stefan Schulze Frielinghaus <stefa...@gcc.gnu.org> wrote: > > Previously we optimized expressions of the form a < 0 ? -1 : 0 to > (signed)a >> 31 during vcond expanding. Since r15-1741-g2ccdd0f22312a1 > this is done in match.pd. The implementation in the back end as well as > in match.pd are basically the same but still distinct. For the tests in > vcond-shift.c the back end emitted > > (xx - (xx >> 31)) >> 1 > > whereas now via match.pd > > ((int) ((unsigned int) xx >> 31) + xx) >> 1 > > which is basically the same. We just have to adapt the scan-assembler > directives w.r.t. signed/unsigned shifts which is done by this patch.
Note I filed https://gcc.gnu.org/PR115999 because I noticed those 2 form produce slightly different code generation for scalars (I assume it will produce similar issues for vectors too). Thanks, Andrew Pinski > > gcc/testsuite/ChangeLog: > > * gcc.target/s390/vector/vcond-shift.c: Adapt to new match.pd > rule and change scan-assembler-times for shifts. > --- > Regtested on s390. Ok for mainline? > > gcc/testsuite/gcc.target/s390/vector/vcond-shift.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/gcc/testsuite/gcc.target/s390/vector/vcond-shift.c > b/gcc/testsuite/gcc.target/s390/vector/vcond-shift.c > index a6b4e97aa50..b942f44039d 100644 > --- a/gcc/testsuite/gcc.target/s390/vector/vcond-shift.c > +++ b/gcc/testsuite/gcc.target/s390/vector/vcond-shift.c > @@ -3,13 +3,13 @@ > /* { dg-do compile { target { s390*-*-* } } } */ > /* { dg-options "-O3 -march=z13 -mzarch" } */ > > -/* { dg-final { scan-assembler-times "vesraf\t%v.?,%v.?,31" 6 } } */ > -/* { dg-final { scan-assembler-times "vesrah\t%v.?,%v.?,15" 6 } } */ > -/* { dg-final { scan-assembler-times "vesrab\t%v.?,%v.?,7" 6 } } */ > +/* { dg-final { scan-assembler-times "vesraf\t%v.?,%v.?,31" 4 } } */ > +/* { dg-final { scan-assembler-times "vesrah\t%v.?,%v.?,15" 4 } } */ > +/* { dg-final { scan-assembler-times "vesrab\t%v.?,%v.?,7" 4 } } */ > /* { dg-final { scan-assembler-not "vzero\t*" } } */ > -/* { dg-final { scan-assembler-times "vesrlf\t%v.?,%v.?,31" 4 } } */ > -/* { dg-final { scan-assembler-times "vesrlh\t%v.?,%v.?,15" 4 } } */ > -/* { dg-final { scan-assembler-times "vesrlb\t%v.?,%v.?,7" 4 } } */ > +/* { dg-final { scan-assembler-times "vesrlf\t%v.?,%v.?,31" 6 } } */ > +/* { dg-final { scan-assembler-times "vesrlh\t%v.?,%v.?,15" 6 } } */ > +/* { dg-final { scan-assembler-times "vesrlb\t%v.?,%v.?,7" 6 } } */ > > /* Make it expand to two vector operations. */ > #define ITER(X) (2 * (16 / sizeof (X[1]))) > -- > 2.45.2 >
