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[Bug target/62011] False Data Dependency in popcnt instruction


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62011

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

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                 CC|                            |amonakov at gcc dot gnu.org

--- Comment #2 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
I think adjusting for scheduling won't help much: rather than making the
compiler aware of increased latency, you'd need that either the register
allocator avoids using a recently written hard register for popcnt (I'm not
aware of such capability), or as a stopgap measure the compiler can issue a
dependency-breaking instruction (xor %reg %reg) just before popcnt.


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