[PATCH] D22038: [X86] Transform zext+seteq+cmp into shr+lzcnt on btver2 architecture.

Sanjay Patel via llvm-commits llvm-commits at lists.llvm.org
Fri Jul 8 07:43:50 PDT 2016


spatel added a comment.

In http://reviews.llvm.org/D22038#477768, @pgousseau wrote:

> Makes sense yes thanks. This should be done in 3 patches I think.
>  The first patch will be NFC, adding the "isCTLZFast" TLI hook, enabling it for PPC and moving the PPC specific code to DAGCombiner.
>  The second patch will enable "isCTLZFast" for X86.
>  The third patch will add the transformation for the OR case.
>  I think this is what you and Simon are suggesting?


That sounds like a good plan to me.


http://reviews.llvm.org/D22038





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