1 files changed, 14 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index 52a779520a5..4ed0f2e16c8 100644
--- a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -473,8 +473,10 @@ static void setDeducedOverflowingFlags(Value *V, Instruction::BinaryOps Opcode,
   }
 }
 
+static bool processBinOp(BinaryOperator *BinOp, LazyValueInfo *LVI);
+
 // Rewrite this with.overflow intrinsic as non-overflowing.
-static void processOverflowIntrinsic(WithOverflowInst *WO) {
+static void processOverflowIntrinsic(WithOverflowInst *WO, LazyValueInfo *LVI) {
   IRBuilder<> B(WO);
   Instruction::BinaryOps Opcode = WO->getBinaryOp();
   bool NSW = WO->isSigned();
@@ -492,9 +494,13 @@ static void processOverflowIntrinsic(WithOverflowInst *WO) {
   WO->replaceAllUsesWith(NewI);
   WO->eraseFromParent();
   ++NumOverflows;
+
+  // See if we can infer the other no-wrap too.
+  if (auto *BO = dyn_cast<BinaryOperator>(NewOp))
+    processBinOp(BO, LVI);
 }
 
-static void processSaturatingInst(SaturatingInst *SI) {
+static void processSaturatingInst(SaturatingInst *SI, LazyValueInfo *LVI) {
   Instruction::BinaryOps Opcode = SI->getBinaryOp();
   bool NSW = SI->isSigned();
   bool NUW = !SI->isSigned();
@@ -506,6 +512,10 @@ static void processSaturatingInst(SaturatingInst *SI) {
   SI->replaceAllUsesWith(BinOp);
   SI->eraseFromParent();
   ++NumSaturating;
+
+  // See if we can infer the other no-wrap too.
+  if (auto *BO = dyn_cast<BinaryOperator>(BinOp))
+    processBinOp(BO, LVI);
 }
 
 /// Infer nonnull attributes for the arguments at the specified callsite.
@@ -515,14 +525,14 @@ static bool processCallSite(CallSite CS, LazyValueInfo *LVI) {
 
   if (auto *WO = dyn_cast<WithOverflowInst>(CS.getInstruction())) {
     if (WO->getLHS()->getType()->isIntegerTy() && willNotOverflow(WO, LVI)) {
-      processOverflowIntrinsic(WO);
+      processOverflowIntrinsic(WO, LVI);
       return true;
     }
   }
 
   if (auto *SI = dyn_cast<SaturatingInst>(CS.getInstruction())) {
     if (SI->getType()->isIntegerTy() && willNotOverflow(SI, LVI)) {
-      processSaturatingInst(SI);
+      processSaturatingInst(SI, LVI);
       return true;
     }
   }