0.9.29 no trunc support in libm
Kevin Day
thekevinday at gmail.com
Sat May 26 00:32:00 UTC 2007
Okay, so not many programs use trunc, but eventually I ran across one that did.
This is when I noticed trunc was not in 0.9.29.
I decided to take one of my 0.9.28 patches that added trunc code,
which is simply just a ripped glibc trunc function code and add it to
my 0.9.29.
However, looking into the uClibc-0.9.29 structured, this caught my
eye. ftrunc() is defined within libm as a wrapper to trunc(). And
trunc is not defined?
Here is my patch that is directly from glibc that adds trunc support,
without changing your ftrunc() implimentation.
--- uClibc-0.9.29/libm/Makefile.in.orig 2007-05-25 19:07:10 -0500
+++ uClibc-0.9.29/libm/Makefile.in 2007-05-25 19:07:20 -0500
@@ -72,7 +72,7 @@
w_cosh.c w_drem.c w_exp.c w_fmod.c w_gamma.c w_gamma_r.c \
w_hypot.c w_j0.c w_j1.c w_jn.c w_lgamma.c w_lgamma_r.c \
w_log.c w_log10.c w_pow.c w_remainder.c w_scalb.c w_sinh.c \
- w_sqrt.c fpmacros.c nan.c carg.c s_llrint.c
+ w_sqrt.c fpmacros.c nan.c carg.c s_llrint.c s_trunc.c
FL_MOBJ := \
acosf.o acoshf.o asinf.o asinhf.o atan2f.o atanf.o atanhf.o cbrtf.o \
ceilf.o copysignf.o cosf.o coshf.o erfcf.o erff.o exp2f.o expf.o \
--- uClibc-0.9.28/libm/s_trunc.c.orig 2006-06-04 11:54:40.000000000 -0500
+++ uClibc-0.9.28/libm/s_trunc.c 2006-06-04 12:00:19.000000000 -0500
@@ -0,0 +1,56 @@
+/* Truncate argument to nearest integral value not larger than the argument.
+ Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper at cygnus.com>, 1997.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <math.h>
+
+#include "math_private.h"
+
+
+double
+trunc (double x)
+{
+ int32_t i0, j0;
+ u_int32_t i1;
+ int sx;
+
+ EXTRACT_WORDS (i0, i1, x);
+ sx = i0 & 0x80000000;
+ j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+ if (j0 < 20)
+ {
+ if (j0 < 0)
+ /* The magnitude of the number is < 1 so the result is +-0. */
+ INSERT_WORDS (x, sx, 0);
+ else
+ INSERT_WORDS (x, sx | (i0 & ~(0x000fffff >> j0)), 0);
+ }
+ else if (j0 > 51)
+ {
+ if (j0 == 0x400)
+ /* x is inf or NaN. */
+ return x + x;
+ }
+ else
+ {
+ INSERT_WORDS (x, i0, i1 & ~(0xffffffffu >> (j0 - 20)));
+ }
+
+ return x;
+}
--
Kevin Day
More information about the uClibc
mailing list