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author | Ted Kremenek <kremenek@apple.com> | 2013-08-28 06:21:46 +0000 |
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committer | Ted Kremenek <kremenek@apple.com> | 2013-08-28 06:21:46 +0000 |
commit | 900617094505bba1fcf4d29c54901f48a0dacfa5 (patch) | |
tree | 1fa5cfc66e7fd32070de6a795ea09e81e1200cd7 | |
parent | 631bce51b962df5f4821dfd4f91599d3f7ba05f9 (diff) | |
download | external_llvm-900617094505bba1fcf4d29c54901f48a0dacfa5.zip external_llvm-900617094505bba1fcf4d29c54901f48a0dacfa5.tar.gz external_llvm-900617094505bba1fcf4d29c54901f48a0dacfa5.tar.bz2 |
Revert r189442 "Change default # of digits for APFloat::toString"
This is breaking numerous Clang tests on the buildbot.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189447 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Support/APFloat.cpp | 13 | ||||
-rw-r--r-- | unittests/ADT/APFloatTest.cpp | 9 |
2 files changed, 9 insertions, 13 deletions
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp index 676e2d4..34bc6b6 100644 --- a/lib/Support/APFloat.cpp +++ b/lib/Support/APFloat.cpp @@ -3546,14 +3546,11 @@ void APFloat::toString(SmallVectorImpl<char> &Str, // Set FormatPrecision if zero. We want to do this before we // truncate trailing zeros, as those are part of the precision. if (!FormatPrecision) { - // We use enough digits so the number can be round-tripped back to an - // APFloat. The formula comes from "How to Print Floating-Point Numbers - // Accurately" by Steele and White. - // FIXME: Using a formula based purely on the precision is conservative; - // we can print fewer digits depending on the actual value being printed. - - // FormatPrecision = 2 + floor(significandBits / lg_2(10)) - FormatPrecision = 2 + semantics->precision * 59 / 196; + // It's an interesting question whether to use the nominal + // precision or the active precision here for denormals. + + // FormatPrecision = ceil(significandBits / lg_2(10)) + FormatPrecision = (semantics->precision * 59 + 195) / 196; } // Ignore trailing binary zeros. diff --git a/unittests/ADT/APFloatTest.cpp b/unittests/ADT/APFloatTest.cpp index e57c8d4..3b69de2 100644 --- a/unittests/ADT/APFloatTest.cpp +++ b/unittests/ADT/APFloatTest.cpp @@ -866,11 +866,10 @@ TEST(APFloatTest, toString) { ASSERT_EQ("0.0101", convertToString(1.01E-2, 5, 2)); ASSERT_EQ("0.0101", convertToString(1.01E-2, 4, 2)); ASSERT_EQ("1.01E-2", convertToString(1.01E-2, 5, 1)); - ASSERT_EQ("0.78539816339744828", convertToString(0.78539816339744830961, 0, 3)); - ASSERT_EQ("4.9406564584124654E-324", convertToString(4.9406564584124654e-324, 0, 3)); - ASSERT_EQ("873.18340000000001", convertToString(873.1834, 0, 1)); - ASSERT_EQ("8.7318340000000001E+2", convertToString(873.1834, 0, 0)); - ASSERT_EQ("1.7976931348623157E+308", convertToString(1.7976931348623157E+308, 0, 0)); + ASSERT_EQ("0.7853981633974483", convertToString(0.78539816339744830961, 0, 3)); + ASSERT_EQ("4.940656458412465E-324", convertToString(4.9406564584124654e-324, 0, 3)); + ASSERT_EQ("873.1834", convertToString(873.1834, 0, 1)); + ASSERT_EQ("8.731834E+2", convertToString(873.1834, 0, 0)); } TEST(APFloatTest, toInteger) { |