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
This commit is contained in:
Ted Kremenek 2013-08-28 06:21:46 +00:00
parent 631bce51b9
commit 9006170945
2 changed files with 8 additions and 12 deletions

View File

@ -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.
// It's an interesting question whether to use the nominal
// precision or the active precision here for denormals.
// FormatPrecision = 2 + floor(significandBits / lg_2(10))
FormatPrecision = 2 + semantics->precision * 59 / 196;
// FormatPrecision = ceil(significandBits / lg_2(10))
FormatPrecision = (semantics->precision * 59 + 195) / 196;
}
// Ignore trailing binary zeros.

View File

@ -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) {