diff options
| -rw-r--r-- | lib/Support/APFloat.cpp | 6 | ||||
| -rw-r--r-- | unittests/ADT/APFloatTest.cpp | 26 |
2 files changed, 32 insertions, 0 deletions
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp index 686f91b087..5b68fbb270 100644 --- a/lib/Support/APFloat.cpp +++ b/lib/Support/APFloat.cpp @@ -1913,6 +1913,12 @@ APFloat::convert(const fltSemantics &toSemantics, *losesInfo = (fs != opOK); } else if (category == fcNaN) { *losesInfo = lostFraction != lfExactlyZero || X86SpecialNan; + + // For x87 extended precision, we want to make a NaN, not a special NaN if + // the input wasn't special either. + if (!X86SpecialNan && semantics == &APFloat::x87DoubleExtended) + APInt::tcSetBit(significandParts(), semantics->precision - 1); + // gcc forces the Quiet bit on, which means (float)(double)(float_sNan) // does not give you back the same bits. This is dubious, and we // don't currently do it. You're really supposed to get diff --git a/unittests/ADT/APFloatTest.cpp b/unittests/ADT/APFloatTest.cpp index 7345e124cd..278983565c 100644 --- a/unittests/ADT/APFloatTest.cpp +++ b/unittests/ADT/APFloatTest.cpp @@ -794,6 +794,32 @@ TEST(APFloatTest, convert) { test.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &losesInfo); EXPECT_EQ(4294967295.0, test.convertToDouble()); EXPECT_FALSE(losesInfo); + + test = APFloat::getSNaN(APFloat::IEEEsingle); + APFloat X87SNaN = APFloat::getSNaN(APFloat::x87DoubleExtended); + test.convert(APFloat::x87DoubleExtended, APFloat::rmNearestTiesToEven, + &losesInfo); + EXPECT_TRUE(test.bitwiseIsEqual(X87SNaN)); + EXPECT_FALSE(losesInfo); + + test = APFloat::getQNaN(APFloat::IEEEsingle); + APFloat X87QNaN = APFloat::getQNaN(APFloat::x87DoubleExtended); + test.convert(APFloat::x87DoubleExtended, APFloat::rmNearestTiesToEven, + &losesInfo); + EXPECT_TRUE(test.bitwiseIsEqual(X87QNaN)); + EXPECT_FALSE(losesInfo); + + test = APFloat::getSNaN(APFloat::x87DoubleExtended); + test.convert(APFloat::x87DoubleExtended, APFloat::rmNearestTiesToEven, + &losesInfo); + EXPECT_TRUE(test.bitwiseIsEqual(X87SNaN)); + EXPECT_FALSE(losesInfo); + + test = APFloat::getQNaN(APFloat::x87DoubleExtended); + test.convert(APFloat::x87DoubleExtended, APFloat::rmNearestTiesToEven, + &losesInfo); + EXPECT_TRUE(test.bitwiseIsEqual(X87QNaN)); + EXPECT_FALSE(losesInfo); } TEST(APFloatTest, PPCDoubleDouble) { |