https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111280
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Note, in PR111309 we briefly discussed adding
__builtin_{clz,ctz,popcount,ffs,clrsb} builtin type-generic variants which
would be well defined for clz/ctz cases.
I think the best representation of that would be to lower those builtins (dunno
what suffix to use for them yet) to .CLZ/.CTZ ifns with 2 arguments where the
second argument would be the value to be returned if the first argument is
zero.
Then at expansion time we could compare that value against
C?Z_VALUE_DEFINED_AT_ZERO, if it is the same, don't do anything special,
otherwise add a test against 0.
