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-rw-r--r--sysdeps/libm-ieee754/s_lrintf.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_lrintf.c b/sysdeps/libm-ieee754/s_lrintf.c
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+++ b/sysdeps/libm-ieee754/s_lrintf.c
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+/* Round argument to nearest integral value according to current rounding
+ direction.
+ 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"
+
+static const double two23[2] =
+{
+ 8.3886080000e+06, /* 0x4B000000 */
+ -8.3886080000e+06, /* 0xCB000000 */
+};
+
+
+long int
+__lrintf (float x)
+{
+ int32_t j0;
+ u_int32_t i, i0;
+ volatile float w;
+ float t;
+ long int result;
+ int sx;
+
+ GET_FLOAT_WORD (i, x);
+
+ sx = i0 >> 31;
+ j0 = ((i0 >> 23) & 0xff) - 0x7f;
+ i0 = i & 0x7fffff;
+ i0 |= 0x800000;
+
+ if (j0 < (int32_t) (sizeof (long int) * 8))
+ {
+ if (j0 < -1)
+ return 0;
+ else if (j0 >= 23)
+ result = (long int) i0 << (j0 - 23);
+ else
+ {
+ w = two23[sx] + x;
+ t = w - two23[sx];
+ GET_FLOAT_WORD (i, t);
+ i0 = i & 0x7fffff;
+ i0 |= 0x800000;
+ j0 = ((i0 >> 23) & 0xff) - 0x7f;
+
+ result = i0 >> (23 - j0);
+ }
+ }
+ else
+ {
+ /* The number is too large. It is left implementation defined
+ what happens. */
+ return (long int) x;
+ }
+
+ return sx ? -result : result;
+}
+
+weak_alias (__lrintf, lrintf)