[PATCH] D67875: [X86] X86DAGToDAGISel::matchBEXTRFromAndImm(): if can't use BEXTR, fallback to BZHI (PR43381)

David Zarzycki via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Sat Sep 21 08:32:30 PDT 2019


davezarzycki added a comment.

Neat! If you have the time, the BZHI bits-to-preserve operand only needs MOVB for initialization. That being said, MOVL probably avoids partial register update stalls, so maybe that’s why you’re seeing a performance gain.


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