https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110381
--- Comment #15 from Christophe Lyon <clyon at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #14)
> (In reply to Christophe Lyon from comment #12)
> > The new testcase (gcc.dg/vect/pr110381.c) fails:
> > FAIL: gcc.dg/vect/pr110381.c -flto -ffat-lto-objects execution test
> > FAIL: gcc.dg/vect/pr110381.c execution test
> >
> > on arm-linux-gnueabihf configured with --with-float=hard
> > --with-fpu=neon-fp-armv8 --with-mode=thumb --with-arch=armv8-a
>
> Can you check if it works now? I've added a missing check_vect () call in
> case the harness passes in command-line options that your HW doesn't
> support. Otherwise I'd appreciate command-line options to reproduce.
I still fails (check_vect() passes on my config, so there's no change).
Here is what sum_8_foos looks like:
sum_8_foos:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
@ link register save eliminated.
vmov.i64 d0, #0 @ float
add r3, r0, #192
.L10:
vldr.64 d16, [r0, #8]
adds r0, r0, #24
vldr.64 d18, [r0, #-24]
vldr.64 d17, [r0, #-8]
cmp r3, r0
vadd.f64 d16, d16, d18
vadd.f64 d16, d16, d17
vadd.f64 d0, d0, d16
bne .L10
bx lr
so we load:
d16=5
d17=-__DBL_MAX__
d18=__DBL_MAX__
the first addition makes d16=__DBL_MAX__
and the second one makes d16=0
> I cannot get anything to vectorize with a cc1 cross using
>
> > ./cc1 -quiet t.c -O2 -ftree-vectorize -fno-vect-cost-model -fopt-info-vec
> > -I include tri
>
> but I have a cross configured with --with-float=hard --with-cpu=cortex-a9
> --with-fpu=neon-fp16
Not sure what happens. I tried my native compiler with the above flags, I get
the same code.
I tried to build my native compiler with the same flags, same code too.
>
> I hope the FPU is compliant enough to compute __DBL_MAX__ + -__DBL_MAX__ +
> 5. to 5.
