2 files changed, 25 insertions, 16 deletions
diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index f1993d2264..9aaa82d626 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -610,23 +610,14 @@ bool NumericLiteralParser::GetIntegerValue(llvm::APInt &Val) {
   return OverflowOccurred;
 }
 
-llvm::APFloat NumericLiteralParser::
-GetFloatValue(const llvm::fltSemantics &Format, bool* isExact) {
+llvm::APFloat::opStatus
+NumericLiteralParser::GetFloatValue(llvm::APFloat &Result) {
   using llvm::APFloat;
   using llvm::StringRef;
 
   unsigned n = std::min(SuffixBegin - ThisTokBegin, ThisTokEnd - ThisTokBegin);
-
-  APFloat V (Format, APFloat::fcZero, false);
-  APFloat::opStatus status;
-
-  status = V.convertFromString(StringRef(ThisTokBegin, n),
-                               APFloat::rmNearestTiesToEven);
-
-  if (isExact)
-    *isExact = status == APFloat::opOK;
-
-  return V;
+  return Result.convertFromString(StringRef(ThisTokBegin, n),
+                                  APFloat::rmNearestTiesToEven);
 }
 
 
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 24bc29560d..0951677db2 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1585,9 +1585,27 @@ Action::OwningExprResult Sema::ActOnNumericConstant(const Token &Tok) {
 
     const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty);
 
-    // isExact will be set by GetFloatValue().
-    bool isExact = false;
-    llvm::APFloat Val = Literal.GetFloatValue(Format, &isExact);
+    using llvm::APFloat;
+    APFloat Val(Format);
+
+    APFloat::opStatus result = Literal.GetFloatValue(Val);
+    if (result & (APFloat::opOverflow | APFloat::opUnderflow)) {
+      unsigned diagnostic;
+      llvm::SmallVector<char, 20> buffer;
+      if (result & APFloat::opOverflow) {
+        diagnostic = diag::err_float_overflow;
+        APFloat::getLargest(Format).toString(buffer);
+      } else {
+        diagnostic = diag::err_float_underflow;
+        APFloat::getSmallest(Format).toString(buffer);
+      }
+
+      Diag(Tok.getLocation(), diagnostic)
+        << Ty
+        << llvm::StringRef(buffer.data(), buffer.size());
+    }
+
+    bool isExact = (result == APFloat::opOK);
     Res = new (Context) FloatingLiteral(Val, isExact, Ty, Tok.getLocation());
 
   } else if (!Literal.isIntegerLiteral()) {