On Wed, Mar 26, 2025 at 9:23 AM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> In r15-4289 H.J. fixed up the pr55583.c testcase to use unsigned long long
> or long long instead of unsigned long or long. That change looks correct to
> me because the
> void test64r () { b = ((u64)b >> n) | (a << (64 - n)); }
> etc. functions otherwise aren't really 64-bit rotates, but something that
> triggers UB all the time (at least one of the shifts is out of bounds).
> I assume that change fixed the FAILs on -mx32, but it caused
> FAIL: gcc.target/i386/pr55583.c scan-assembler-times (?n)shldl?[\\\\t
> ]*\\\\\$2 1
> FAIL: gcc.target/i386/pr55583.c scan-assembler-times (?n)shrdl?[\\\\t
> ]*\\\\\$2 2
> regression on i686-linux (but just for -m32 without defaulting to SSE2 or
> what). The difference is that for say -m32 -march=x86-64 the stv pass
> handles some of the rotates in SSE and so we get different sh[rl]dl
> instruction counts from the case when SSE isn't enabled and stv pass isn't
> done.
>
> The following patch fixes that by disabling SSE for ia32 and always testing
> for the same number of instructions.
Yes, in the testsuite we (mostly) assume that ia32 lacks MMX and SSE by default.
> Bootstrapped/regtested on x86_64-linux and i686-linux and tested with all of
> make check-gcc
> RUNTESTFLAGS='--target_board=unix\{-m32/-march=x86-64,-m32/-march=i686,-mx32,-m64\}
> i386.exp=pr55583.c'
> ok for trunk?
>
> 2025-03-26 Jakub Jelinek <ja...@redhat.com>
>
> PR target/55583
> PR target/119465
> * gcc.target/i386/pr55583.c: Add -mno-sse -mno-mmx to
> dg-additional-options. Expect 4 shrdl and 2 shldl instructions on
> ia32.
OK.
Thanks,
Uros.
> --- gcc/testsuite/gcc.target/i386/pr55583.c.jj 2024-10-12 13:47:21.966350407
> +0200
> +++ gcc/testsuite/gcc.target/i386/pr55583.c 2025-03-25 16:36:46.320986804
> +0100
> @@ -1,9 +1,8 @@
> /* { dg-do compile } */
> /* { dg-options "-O2 -Wno-shift-count-overflow" } */
> -/* { dg-final { scan-assembler-times {(?n)shrd[ql]?[\t ]*\$2} 4 { target { !
> ia32 } } } } */
> -/* { dg-final { scan-assembler-times {(?n)shrdl?[\t ]*\$2} 2 { target ia32 }
> } } */
> -/* { dg-final { scan-assembler-times {(?n)shldl?[\t ]*\$2} 1 { target ia32 }
> } } */
> -/* { dg-final { scan-assembler-times {(?n)shld[ql]?[\t ]*\$2} 2 { target { !
> ia32 } } } } */
> +/* { dg-additional-options "-mno-sse -mno-mmx" { target ia32 } } */
> +/* { dg-final { scan-assembler-times {(?n)shrd[ql]?[\t ]*\$2} 4 } } */
> +/* { dg-final { scan-assembler-times {(?n)shld[ql]?[\t ]*\$2} 2 } } */
>
> typedef unsigned long long u64;
> typedef unsigned int u32;
>
> Jakub
>
