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-rw-r--r--sysdeps/libm-ieee754/s_trunc.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_trunc.c b/sysdeps/libm-ieee754/s_trunc.c
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+++ b/sysdeps/libm-ieee754/s_trunc.c
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+/* Truncate argument to nearest integral value not larger than the argument.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. 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;
+}
+weak_alias (__trunc, trunc)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__trunc, __truncl)
+weak_alias (__trunc, truncl)
+#endif