[llvm-branch-commits] [SPARC] Use lzcnt to implement CTLZ when we have VIS3 (PR #135715)

[via llvm-branch-commits]

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@@ -1815,7 +1817,8 @@ SparcTargetLowering::SparcTargetLowering(const TargetMachine &TM,
   setOperationAction(ISD::FREM , MVT::f32, Expand);
   setOperationAction(ISD::FMA  , MVT::f32, Expand);
   setOperationAction(ISD::CTTZ , MVT::i32, Expand);
-  setOperationAction(ISD::CTLZ , MVT::i32, Expand);
+  setOperationAction(ISD::CTLZ, MVT::i32,
+                     Subtarget->isVIS3() ? Promote : LibCall);
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koachan wrote:

Looking at GCC output, it seem to produce `clzdi2` on 32-bit target too, so I think it's safe to use it.
https://godbolt.org/z/xfnob5P1a

https://github.com/llvm/llvm-project/pull/135715