hans created this revision.
hans added reviewers: thakis, echristo.
hans added a subscriber: cfe-commits.
The tzcnt intrinsics are used non non-BMI targets by code (e.g. ffmpeg) that
uses it as a potentially faster BSF.
The TZCNT instruction is special in that it's encoded in a
echristo accepted this revision.
echristo added a comment.
This revision is now accepted and ready to land.
Sounds good to me. Weird, but fine :)
-eric
http://reviews.llvm.org/D14748
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craig.topper added a subscriber: craig.topper.
craig.topper added a comment.
The summary of why this is ok is slightly misleading. The backend won't try to
encode the TZCNT instruction when the BMI feature is not enabled. Notice this
just maps the to the generic non-x86 specific __builtin_ctz.
