diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp --- a/clang/lib/CodeGen/CGExprConstant.cpp +++ b/clang/lib/CodeGen/CGExprConstant.cpp @@ -1401,6 +1401,64 @@ return nullptr; } + llvm::Constant *VisitBinaryOperator(BinaryOperator *B, QualType T) { + // Can we attempt to handle this opcode? + switch (B->getOpcode()) { + default: + return nullptr; + case BO_And: + case BO_Xor: + case BO_Or: + case BO_EQ: + case BO_NE: + break; + } + + // Constant evaluate LHS + Expr *LHS = B->getLHS(); + llvm::Constant *LHSC = Visit(LHS, T); + + // Only handle integers for now. + if (!LHSC || !isa(LHSC)) + return nullptr; + + // Constant evaluate RHS + Expr *RHS = B->getRHS(); + llvm::Constant *RHSC = Visit(RHS, T); + + // Only handle integers for now. + if (!RHSC || !isa(RHSC)) + return nullptr; + + const llvm::APInt R = cast(RHSC)->getValue(); + const llvm::APInt L = cast(LHSC)->getValue(); + llvm::APInt Ret; + + // Fold + switch (B->getOpcode()) { + default: + // Should have return earlier. + llvm_unreachable("unhandled BinaryOperator kind"); + case BO_And: + Ret = L & R; + break; + case BO_Xor: + Ret = L ^ R; + break; + case BO_Or: + Ret = L | R; + break; + case BO_EQ: + Ret = L == R; + break; + case BO_NE: + Ret = L != R; + break; + } + + return llvm::ConstantInt::get(CGM.getLLVMContext(), Ret); + } + // Utility methods llvm::Type *ConvertType(QualType T) { return CGM.getTypes().ConvertType(T);