[Bug rtl-optimization/128545] clmul (n, -1) RTL could be improved to Clang

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128545

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Yeah, I'm aware of that.
__builtin_clmulg (x, typeof(x)-1) can be implemented as
typeof (x) r = x;
for (int i = 1; i < __builtin_popcountg (typeof(x)-1); i <<= 1)
  r ^= r << i;
return r;