https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99582
Alexander Monakov <amonakov at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |amonakov at gcc dot gnu.org
--- Comment #3 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
RCL and RCR are supported via microcode sequencer on Intel and involve many (9)
uops on modern AMD, so they are quite slow in comparison to simple
shifts/rotates. Would library developers still want to use them despite the
poor performance? Equivalent code with "classic" shifts should be more
efficient.
https://uops.info/html-instr/RCL_R64_CL.html
