From 900617094505bba1fcf4d29c54901f48a0dacfa5 Mon Sep 17 00:00:00 2001 From: Ted Kremenek Date: Wed, 28 Aug 2013 06:21:46 +0000 Subject: 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 --- lib/Support/APFloat.cpp | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'lib/Support/APFloat.cpp') diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp index 676e2d4ba0..34bc6b6dd6 100644 --- a/lib/Support/APFloat.cpp +++ b/lib/Support/APFloat.cpp @@ -3546,14 +3546,11 @@ void APFloat::toString(SmallVectorImpl &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. -- cgit v1.2.3