[PATCH] D80563: [X86][SSE] Convert PTEST to MOVMSK for allsign bits vector results.

[Craig Topper via Phabricator via llvm-commits]

craig.topper accepted this revision.
craig.topper added a comment.
This revision is now accepted and ready to land.

LGTM



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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:40178
+            Res = DAG.getBitcast(MovmskVT, Res);
+            Res = getPMOVMSKB(DL, Res, DAG, Subtarget);
+            Res = DAG.getNode(ISD::AND, DL, MVT::i32, Res,
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RKSimon wrote:
> craig.topper wrote:
> > Do we need getPMOVMSKB here or can we just use plain getNode? The only thing getPMOVMSKB does is handle AVX and BWI splitting right? But if we start from PTEST we should never need to split?
> AVX1 code can technically get here for v16i16/v32i8 cases depending how good a job SimplifyMultipleUseDemandedBits has managed. VPTEST is one of the rare 256-bit integer instructions that is available on AVX1!
Ok thanks for the clarification.


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D80563/new/

https://reviews.llvm.org/D80563