[Bug target/101345] New: wrong code at -O1 with vector modulo

zsojka at seznam dot cz gcc-bugzilla@gcc.gnu.org
Tue Jul 6 16:35:39 GMT 2021


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101345

            Bug ID: 101345
           Summary: wrong code at -O1 with vector modulo
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: powerpc64le-unknown-linux-gnu

Created attachment 51110
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51110&action=edit
reduced testcase

Output:
$ powerpc64le-unknown-linux-gnu-gcc -O testcase.c -static
$ qemu-ppc64le -- ./a.out 
qemu: uncaught target signal 6 (Aborted) - core dumped
Aborted

The value is 0x2828282828282828 instead of 0x1414141414141414
Already the computed value of "y" is wrong.

        subfic 10,10,4   # tmp160, tmp159,

looks wrong, if replaced by

        subfic 10,10,2   # tmp160, tmp159,

the code works correctly

$ powerpc64le-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-powerpc64le/bin/powerpc64le-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r12-2049-20210706092228-gb019b28ebd6-checking-yes-rtl-df-extra-powerpc64le/bin/../libexec/gcc/powerpc64le-unknown-linux-gnu/12.0.0/lto-wrapper
Target: powerpc64le-unknown-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl
--with-sysroot=/usr/powerpc64le-unknown-linux-gnu --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=powerpc64le-unknown-linux-gnu
--with-ld=/usr/bin/powerpc64le-unknown-linux-gnu-ld
--with-as=/usr/bin/powerpc64le-unknown-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r12-2049-20210706092228-gb019b28ebd6-checking-yes-rtl-df-extra-powerpc64le
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20210706 (experimental) (GCC)


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