Fix another roundToIntegral bug where very large values could become infinity. Problem and solution identified by Steve Canon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161969 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index b42a168..ed261a4 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -1770,6 +1770,12 @@
opStatus fs;
assertArithmeticOK(*semantics);
+ // If the exponent is large enough, we know that this value is already
+ // integral, and the arithmetic below would potentially cause it to saturate
+ // to +/-Inf. Bail out early instead.
+ if (exponent+1 >= (int)semanticsPrecision(*semantics))
+ return opOK;
+
// The algorithm here is quite simple: we add 2^(p-1), where p is the
// precision of our format, and then subtract it back off again. The choice
// of rounding modes for the addition/subtraction determines the rounding mode