[Bug target/20614] PowerPC - inefficient use of condition register
segher at gcc dot gnu.org
gcc-bugzilla@gcc.gnu.org
Thu Mar 30 22:57:00 GMT 2017
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=20614
Segher Boessenkool <segher at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
CC| |segher at gcc dot gnu.org
Resolution|--- |FIXED
--- Comment #7 from Segher Boessenkool <segher at gcc dot gnu.org> ---
At least as far back as 4.9 GCC does no longer generate subfic; is uses
a mix of cntlzw/srwi, addic/subfe, and cmpw insns. Using more than three
CR fields is a bad idea (you then need to save and restore CR, which is
expensive on any CPU).
No doubt we could generate better code for this, but the reported
problem is no longer there, so I'm closing this bug.
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