[Bug target/93709] [10 regression] fortran.dg/minlocval_4.f90 fails on power 9 after r10-4161

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93709

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Jiu Fu Guo
<guojiufu@gcc.gnu.org>:

https://gcc.gnu.org/g:d01cb80e0fbe23510a861faab9909b76837faf98

commit r9-8401-gd01cb80e0fbe23510a861faab9909b76837faf98
Author: Jiufu Guo <guojiufu@linux.ibm.com>
Date:   Tue Mar 10 13:51:57 2020 +0800

    rs6000: Check -+0 and NaN for smax/smin generation

    PR93709 mentioned regressions on maxlocval_4.f90 and minlocval_f.f90 which
    relates to max of '-inf' and 'nan'. This regression occur on P9 because
    P9 new instruction 'xsmaxcdp' is generated.
    And for C code `a < b ? b : a` is also generated as `xsmaxcdp` under -O2
    for P9. While this instruction behavior more like C/C++ semantic (a>b?a:b).
    In GCC9, the issue also occur as the new test case shows.

    This generates prevents 'xsmaxcdp' to be generated for those cases.
    'xsmincdp' also is handled in patch.

    gcc/
    2020-03-19  Jiufu Guo  <guojiufu@linux.ibm.com>

            PR target/93709
            * gcc/config/rs6000/rs6000.c (rs6000_emit_p9_fp_minmax): Check
            NAN and SIGNED_ZEROR for smax/smin.

    gcc/testsuite
    2020-03-19  Jiufu Guo  <guojiufu@linux.ibm.com>

            PR target/93709
            * gcc.target/powerpc/p9-minmax-3.c: New test.