Inline asm constraints: allow ICE-like pointers for the "n" constraint (PR40890)
Apparently GCC allows this, and there's code relying on it (see bug).
The idea is to allow expression that would have been allowed if they
were cast to int. So I based the code on how such a cast would be done
(the CK_PointerToIntegral case in IntExprEvaluator::VisitCastExpr()).
Differential Revision: https://reviews.llvm.org/D58821
llvm-svn: 355491
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 5b5113b..b9905a2 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -1838,8 +1838,15 @@
// (immediate or symbolic), try to emit it as such.
if (!Info.allowsRegister() && !Info.allowsMemory()) {
if (Info.requiresImmediateConstant()) {
- llvm::APSInt AsmConst = InputExpr->EvaluateKnownConstInt(getContext());
- return llvm::ConstantInt::get(getLLVMContext(), AsmConst);
+ Expr::EvalResult EVResult;
+ InputExpr->EvaluateAsRValue(EVResult, getContext(), true);
+
+ llvm::APSInt IntResult;
+ if (!EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(),
+ getContext()))
+ llvm_unreachable("Invalid immediate constant!");
+
+ return llvm::ConstantInt::get(getLLVMContext(), IntResult);
}
Expr::EvalResult Result;