[PATCH] D103820: [X86] Prefer vpmovq2m over vpternlogd + vpcmpgtq

[David Zarzycki via Phabricator via llvm-commits]

davezarzycki added inline comments.


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:22802
+  if (SetCCOpcode == ISD::SETGT && ISD::isBuildVectorAllOnes(Op1.getNode())) {
+    SetCCOpcode = ISD::SETGE;
+    Op1 = DAG.getConstant(0, dl, Op1.getValueType());
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craig.topper wrote:
> I'm a little confused. the vpmovq2m patter is (setgt imm_allzeros, X). Does this SETGE get canonicalized again?
Oh, sorry about that. I originally made a logic error and converted > -1 to < 0 instead of >= 0; but at that time, I did verify that VPMOVQ2M was generated. You are right that the desired instruction is not generated with SETGE now that the logic error is fixed. In any case, I'd like to update the tests ahead of any code change. Is there a preferred file to put the current suboptimal code gen?


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  https://reviews.llvm.org/D103820/new/

https://reviews.llvm.org/D103820