APFloat::roundToIntegral: Special values don't keep the exponent value up to date, don't rely on it.
Add a couple of unit tests for special floats. Fixes 13929, found by MemorySanitizer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164698 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index f143e6d..d07a3c9 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -1775,7 +1775,7 @@
// 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))
+ if (category == fcNormal && exponent+1 >= (int)semanticsPrecision(*semantics))
return opOK;
// The algorithm here is quite simple: we add 2^(p-1), where p is the
diff --git a/unittests/ADT/APFloatTest.cpp b/unittests/ADT/APFloatTest.cpp
index 00b62fe..c8d7177 100644
--- a/unittests/ADT/APFloatTest.cpp
+++ b/unittests/ADT/APFloatTest.cpp
@@ -689,6 +689,23 @@
P = R;
P.roundToIntegral(APFloat::rmNearestTiesToEven);
EXPECT_EQ(R.convertToDouble(), P.convertToDouble());
+
+ P = APFloat::getZero(APFloat::IEEEdouble);
+ P.roundToIntegral(APFloat::rmTowardZero);
+ EXPECT_EQ(0.0, P.convertToDouble());
+ P = APFloat::getZero(APFloat::IEEEdouble, true);
+ P.roundToIntegral(APFloat::rmTowardZero);
+ EXPECT_EQ(-0.0, P.convertToDouble());
+ P = APFloat::getNaN(APFloat::IEEEdouble);
+ P.roundToIntegral(APFloat::rmTowardZero);
+ EXPECT_TRUE(IsNAN(P.convertToDouble()));
+ P = APFloat::getInf(APFloat::IEEEdouble);
+ P.roundToIntegral(APFloat::rmTowardZero);
+ EXPECT_TRUE(IsInf(P.convertToDouble()) && P.convertToDouble() > 0.0);
+ P = APFloat::getInf(APFloat::IEEEdouble, true);
+ P.roundToIntegral(APFloat::rmTowardZero);
+ EXPECT_TRUE(IsInf(P.convertToDouble()) && P.convertToDouble() < 0.0);
+
}
TEST(APFloatTest, getLargest) {