diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 980ae1ec3d32..c118ecf43b5e 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -871,7 +871,8 @@ lltok::Kind LLLexer::Lex0x() {
     // HexFPConstant - Floating point constant represented in IEEE format as a
     // hexadecimal number for when exponential notation is not precise enough.
     // Half, Float, and double only.
-    APFloatVal = APFloat(BitsToDouble(HexIntToVal(TokStart + 2, CurPtr)));
+    APFloatVal = APFloat(APFloat::IEEEdouble,
+                         APInt(64, HexIntToVal(TokStart + 2, CurPtr)));
     return lltok::APFloat;
   }