X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FAPFloat.cpp;h=7989e30afae62d4cdbf4b4f552b648387f78448e;hb=e63aae5b7563634c8eb9656c82f75c487a08e042;hp=f9fe09541dbe22c73eeafaab9441052863740f9f;hpb=0b6cb7104b15504cd41f48cc2babcbcee70775f3;p=oota-llvm.git

diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index f9fe09541db..7989e30afae 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -1372,7 +1372,9 @@ APFloat::addOrSubtractSpecials(const APFloat &rhs, bool subtract)
   case PackCategoriesIntoKey(fcZero, fcNaN):
   case PackCategoriesIntoKey(fcNormal, fcNaN):
   case PackCategoriesIntoKey(fcInfinity, fcNaN):
-    sign = false;
+    // We need to be sure to flip the sign here for subtraction because we
+    // don't have a separate negate operation so -NaN becomes 0 - NaN here.
+    sign = rhs.sign ^ subtract;
     category = fcNaN;
     copySignificand(rhs);
     return opOK;