Move handling of __builtin_nan("") out of CGBuiltin.cpp into ExprConstant.cpp
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57157 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index c20cf4c..2b92cc7 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -556,6 +556,20 @@
case Builtin::BI__builtin_infl:
Result = llvm::APFloat::getInf(Sem);
return true;
+
+ case Builtin::BI__builtin_nan:
+ case Builtin::BI__builtin_nanf:
+ case Builtin::BI__builtin_nanl:
+ // If this is __builtin_nan("") turn this into a simple nan, otherwise we
+ // can't constant fold it.
+ if (const StringLiteral *S =
+ dyn_cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts())) {
+ if (!S->isWide() && S->getByteLength() == 0) { // empty string.
+ Result = llvm::APFloat::getNaN(Sem);
+ return true;
+ }
+ }
+ return false;
}
}