[llvm] ced41a1 - [InstCombine] Remove redundant urem demanded bits case

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2024-06-18T14:16:03+02:00
New Revision: ced41a125c7efdb11087570850bac27a94891030

URL: https://github.com/llvm/llvm-project/commit/ced41a125c7efdb11087570850bac27a94891030
DIFF: https://github.com/llvm/llvm-project/commit/ced41a125c7efdb11087570850bac27a94891030.diff

LOG: [InstCombine] Remove redundant urem demanded bits case

This does the recursive simplification with all bits demanded,
which is not useful. Fall through to the fallback case instead.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index b3eebee0d0d8c..1b00ceec3bcce 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -893,15 +893,6 @@ Value *InstCombinerImpl::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
     computeKnownBits(I, Known, Depth, CxtI);
     break;
   }
-  case Instruction::URem: {
-    APInt AllOnes = APInt::getAllOnes(BitWidth);
-    if (SimplifyDemandedBits(I, 0, AllOnes, LHSKnown, Depth + 1) ||
-        SimplifyDemandedBits(I, 1, AllOnes, RHSKnown, Depth + 1))
-      return I;
-
-    Known = KnownBits::urem(LHSKnown, RHSKnown);
-    break;
-  }
   case Instruction::Call: {
     bool KnownBitsComputed = false;
     if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {