Fix APFloat::convert so that it handles narrowing conversions correctly; it
was returning incorrect values in rare cases, and incorrectly marking
exact conversions as inexact in some more common cases. Fixes PR11406, and a
missed optimization in test/CodeGen/X86/fp-stack-O0.ll.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145141 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/ADT/APFloatTest.cpp b/unittests/ADT/APFloatTest.cpp
index b6e02e3..cc207f7 100644
--- a/unittests/ADT/APFloatTest.cpp
+++ b/unittests/ADT/APFloatTest.cpp
@@ -653,4 +653,28 @@
EXPECT_EQ(1.7976931348623158e+308, APFloat::getLargest(APFloat::IEEEdouble).convertToDouble());
}
+TEST(APFloatTest, convert) {
+ bool losesInfo;
+ APFloat test(APFloat::IEEEdouble, "1.0");
+ test.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &losesInfo);
+ EXPECT_EQ(1.0f, test.convertToFloat());
+ EXPECT_FALSE(losesInfo);
+
+ test = APFloat(APFloat::x87DoubleExtended, "0x1p-53");
+ test.add(APFloat(APFloat::x87DoubleExtended, "1.0"), APFloat::rmNearestTiesToEven);
+ test.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &losesInfo);
+ EXPECT_EQ(1.0, test.convertToDouble());
+ EXPECT_TRUE(losesInfo);
+
+ test = APFloat(APFloat::IEEEquad, "0x1p-53");
+ test.add(APFloat(APFloat::IEEEquad, "1.0"), APFloat::rmNearestTiesToEven);
+ test.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &losesInfo);
+ EXPECT_EQ(1.0, test.convertToDouble());
+ EXPECT_TRUE(losesInfo);
+
+ test = APFloat(APFloat::x87DoubleExtended, "0xf.fffffffp+28");
+ test.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &losesInfo);
+ EXPECT_EQ(4294967295.0, test.convertToDouble());
+ EXPECT_FALSE(losesInfo);
+}
}