1 files changed, 15 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 05ab16668743..481438de0e53 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -2343,6 +2343,7 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   std::vector<llvm::Type *> ArgElemTypes;
   std::vector<llvm::Value*> Args;
   llvm::BitVector ResultTypeRequiresCast;
+  llvm::BitVector ResultRegIsFlagReg;
 
   // Keep track of inout constraints.
   std::string InOutConstraints;
@@ -2400,6 +2401,9 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
       ResultRegQualTys.push_back(QTy);
       ResultRegDests.push_back(Dest);
 
+      bool IsFlagReg = llvm::StringRef(OutputConstraint).startswith("{@cc");
+      ResultRegIsFlagReg.push_back(IsFlagReg);
+
       llvm::Type *Ty = ConvertTypeForMem(QTy);
       const bool RequiresCast = Info.allowsRegister() &&
           (getTargetHooks().isScalarizableAsmOperand(*this, Ty) ||
@@ -2717,10 +2721,21 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   // ResultRegDests can be also populated by addReturnRegisterOutputs() above,
   // in which case its size may grow.
   assert(ResultTypeRequiresCast.size() <= ResultRegDests.size());
+  assert(ResultRegIsFlagReg.size() <= ResultRegDests.size());
   for (unsigned i = 0, e = RegResults.size(); i != e; ++i) {
     llvm::Value *Tmp = RegResults[i];
     llvm::Type *TruncTy = ResultTruncRegTypes[i];
 
+    if ((i < ResultRegIsFlagReg.size()) && ResultRegIsFlagReg[i]) {
+      // Target must guarantee the Value `Tmp` here is lowered to a boolean
+      // value.
+      llvm::Constant *Two = llvm::ConstantInt::get(Tmp->getType(), 2);
+      llvm::Value *IsBooleanValue =
+          Builder.CreateCmp(llvm::CmpInst::ICMP_ULT, Tmp, Two);
+      llvm::Function *FnAssume = CGM.getIntrinsic(llvm::Intrinsic::assume);
+      Builder.CreateCall(FnAssume, IsBooleanValue);
+    }
+
     // If the result type of the LLVM IR asm doesn't match the result type of
     // the expression, do the conversion.
     if (ResultRegTypes[i] != ResultTruncRegTypes[i]) {