X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Ffloor.c;h=cf29b196c331d2f8399287b706daf94a7724bfbc;hb=974b76b72e84d226e4bdfd9ec6f7d955e3d2a199;hp=05a6591a4b40a183307ed04d9f4e04f22a4f64d1;hpb=33d6a0e5ca06c6d0a8b0fddba8c7f41bbd6794ae;p=gnulib.git diff --git a/lib/floor.c b/lib/floor.c index 05a6591a4..cf29b196c 100644 --- a/lib/floor.c +++ b/lib/floor.c @@ -1,5 +1,5 @@ /* Round towards negative infinity. - Copyright (C) 2007 Free Software Foundation, Inc. + Copyright (C) 2007, 2010-2013 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -16,7 +16,9 @@ /* Written by Bruno Haible , 2007. */ -#include +#if ! defined USE_LONG_DOUBLE +# include +#endif /* Specification. */ #include @@ -40,6 +42,12 @@ # define L_(literal) literal##f #endif +/* MSVC with option -fp:strict refuses to compile constant initializers that + contain floating-point operations. Pacify this compiler. */ +#ifdef _MSC_VER +# pragma fenv_access (off) +#endif + /* 2^(MANT_DIG-1). */ static const DOUBLE TWO_MANT_DIG = /* Assume MANT_DIG <= 5 * 31. @@ -65,29 +73,33 @@ FUNC (DOUBLE x) if (z > L_(0.0)) { + /* For 0 < x < 1, return +0.0 even if the current rounding mode is + FE_DOWNWARD. */ + if (z < L_(1.0)) + z = L_(0.0); /* Avoid rounding errors for values near 2^k, where k >= MANT_DIG-1. */ - if (z < TWO_MANT_DIG) - { - /* Round to the next integer (nearest or up or down, doesn't matter). */ - z += TWO_MANT_DIG; - z -= TWO_MANT_DIG; - /* Enforce rounding down. */ - if (z > y) - z -= L_(1.0); - } + else if (z < TWO_MANT_DIG) + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z += TWO_MANT_DIG; + z -= TWO_MANT_DIG; + /* Enforce rounding down. */ + if (z > y) + z -= L_(1.0); + } } else if (z < L_(0.0)) { /* Avoid rounding errors for values near -2^k, where k >= MANT_DIG-1. */ if (z > - TWO_MANT_DIG) - { - /* Round to the next integer (nearest or up or down, doesn't matter). */ - z -= TWO_MANT_DIG; - z += TWO_MANT_DIG; - /* Enforce rounding down. */ - if (z > y) - z -= L_(1.0); - } + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z -= TWO_MANT_DIG; + z += TWO_MANT_DIG; + /* Enforce rounding down. */ + if (z > y) + z -= L_(1.0); + } } return z; }