ValueTracking: Handle extractelement and extractvalue in computeKnownFPClass

1 files changed, 23 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 48a9dc1..545ff49 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4524,6 +4524,29 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
 
     break;
   }
+  case Instruction::ExtractElement: {
+    // Look through extract element. If the index is non-constant or
+    // out-of-range demand all elements, otherwise just the extracted element.
+    const Value *Vec = Op->getOperand(0);
+    const Value *Idx = Op->getOperand(1);
+    auto *CIdx = dyn_cast<ConstantInt>(Idx);
+
+    if (auto *VecTy = dyn_cast<FixedVectorType>(Vec->getType())) {
+      unsigned NumElts = VecTy->getNumElements();
+      APInt DemandedVecElts = APInt::getAllOnes(NumElts);
+      if (CIdx && CIdx->getValue().ult(NumElts))
+        DemandedVecElts = APInt::getOneBitSet(NumElts, CIdx->getZExtValue());
+      return computeKnownFPClass(Vec, DemandedVecElts, InterestedClasses, Known,
+                                 Depth + 1, Q, TLI);
+    }
+
+    break;
+  }
+  case Instruction::ExtractValue: {
+    computeKnownFPClass(Op->getOperand(0), DemandedElts, InterestedClasses,
+                        Known, Depth + 1, Q, TLI);
+    break;
+  }
   default:
     break;
   }