[llvm] 98b114d - [InstCombine] Retain exact instruction name for some cases in SimplifyDemandedUseBits. (#68371)

[via llvm-commits]

Author: Craig Topper
Date: 2023-10-06T09:11:36-07:00
New Revision: 98b114d1c707d5981244d44d747a17413ffab12b

URL: https://github.com/llvm/llvm-project/commit/98b114d1c707d5981244d44d747a17413ffab12b
DIFF: https://github.com/llvm/llvm-project/commit/98b114d1c707d5981244d44d747a17413ffab12b.diff

LOG: [InstCombine] Retain exact instruction name for some cases in SimplifyDemandedUseBits. (#68371)

Retain name for SExt->ZExt and AShr->LShr. Previously SExt->ZExt copied
the name with a numeric suffix. AShr->LShr dropped it.

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index abdaf167d3d9dfb..5b5d2da041f1447 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -461,7 +461,8 @@ Value *InstCombinerImpl::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
     if (InputKnown.isNonNegative() ||
         DemandedMask.getActiveBits() <= SrcBitWidth) {
       // Convert to ZExt cast.
-      CastInst *NewCast = new ZExtInst(I->getOperand(0), VTy, I->getName());
+      CastInst *NewCast = new ZExtInst(I->getOperand(0), VTy);
+      NewCast->takeName(I);
       return InsertNewInstWith(NewCast, I->getIterator());
      }
 
@@ -770,6 +771,7 @@ Value *InstCombinerImpl::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
         BinaryOperator *LShr = BinaryOperator::CreateLShr(I->getOperand(0),
                                                           I->getOperand(1));
         LShr->setIsExact(cast<BinaryOperator>(I)->isExact());
+        LShr->takeName(I);
         return InsertNewInstWith(LShr, I->getIterator());
       } else if (Known.One[BitWidth-ShiftAmt-1]) { // New bits are known one.
         Known.One |= HighBits;