Re: [Patch] Bug 88521 - gcc 9.0 from r266355 miscompile x265 for mingw-w64 target

[Uros Bizjak <ubizjak at gmail dot com>]

On Thu, Dec 20, 2018 at 1:09 PM Jakub Jelinek <jakub@redhat.com> wrote:
>
> On Thu, Dec 20, 2018 at 01:42:15PM +0530, Lokesh Janghel wrote:
> > Hi Mateuszb,
> >
> > I tested with your proposition patch and it is working right.
> > I also added the patch with test case.
> > Please let me know your thoughts/suggestions.
>
> ChangeLog entry is missing, please write it (and mention there
> Mateusz's name/mail as he wrote the i386.c part).
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index b3c8676..e54c489 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -9063,6 +9063,13 @@ function_value_ms_64 (machine_mode orig_mode, machine_mode mode,
>               && !COMPLEX_MODE_P (mode))
>             regno = FIRST_SSE_REG;
>           break;
> +       case 8:
> +       case 4:
> +         if (valtype != NULL_TREE && AGGREGATE_TYPE_P (valtype))
> +           break;
> +         if (mode == SFmode || mode == DFmode)
> +           regno = FIRST_SSE_REG;
> +         break;
>         default:
>           break;
>          }
> diff --git a/gcc/testsuite/gcc.target/i386/pr88521.c b/gcc/testsuite/gcc.target/i386/pr88521.c
> new file mode 100644
> index 0000000..f42703a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr88521.c
> @@ -0,0 +1,30 @@
> +/* { dg-do compile { target lp64 } } */
> +/* { dg-options "-O2" } */
> +/* { dg-final { scan-assembler-times "movl\[^\n\r]*, %eax|mov\[ \t]*eax," 1 } } */
>
> You try here to handle both -masm=att and -masm=intel
>
> +/* { dg-final { scan-assembler-times "movss\[^\n\r]*, %xmm" 1 } } */
> +/* { dg-final { scan-assembler-times "movsd\[^\n\r]*, %xmm" 1 } } */
>
> but not here.  For that it would need to be "movss\[^\n\r]*(?:, %xmm|xmm, )"
> and similarly for movsd (please verify with
> make check-gcc RUNTESTFLAGS='--target_board=unix\{-m32/-masm=att,-m32/-masm=intel,-m64/-masm=att,-m64/-masm=intel\} i386.exp=pr88521.c'
>
> I'll defer the final review to Uros.

This patch should be reviewed and evenutually approved by cygwin/mingw
maintainer.

Uros.