[Bug target/115362] fixed_size_simd dot product recognition and sign of determinant not working for stdx::reduce

[jondaniel879 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115362

--- Comment #22 from Jon Daniel <jondaniel879 at gmail dot com> ---
The generated assembler output snippet:

g++:
        vdpps   $113, 72(%rsp), 24(%rsp), %xmm3
        vdpps   $113, 72(%rsp), 24(%rsp), %xmm2
        vsubss  %xmm2, %xmm3, %xmm0

Notice the second dot product result as the first source operand


clang++:
        vdpps   $113, %xmm2, %xmm1, %xmm4
        vdpps   $113, %xmm0, %xmm1, %xmm1
        vsubss %xmm4, %xmm0, %xmm0

Notice the first dot product result as the first source operand