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author"Steven J. Hill" <sjhill@realitydiluted.com>2006-12-16 04:24:51 +0000
committer"Steven J. Hill" <sjhill@realitydiluted.com>2006-12-16 04:24:51 +0000
commitcd77d284cfdfcea1ef4410543f2a388cffa06da2 (patch)
treec9e1f2f7c0194f998c6d508f22c3b03ce4684fbb
parenta733fde6f617996d51a85bdba6bc0fd7dc05474a (diff)
downloaduClibc-alpine-cd77d284cfdfcea1ef4410543f2a388cffa06da2.tar.bz2
uClibc-alpine-cd77d284cfdfcea1ef4410543f2a388cffa06da2.tar.xz
Copy from trunk.
-rw-r--r--libm/s_lrint.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/libm/s_lrint.c b/libm/s_lrint.c
new file mode 100644
index 000000000..61c521240
--- /dev/null
+++ b/libm/s_lrint.c
@@ -0,0 +1,94 @@
+/* Round argument to nearest integral value according to current rounding
+ direction.
+ Copyright (C) 1997, 2004 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 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"
+
+static const double two52[2] =
+{
+ 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
+ -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
+};
+
+
+libm_hidden_proto(lrint)
+long int
+lrint (double x)
+{
+ int32_t j0;
+ u_int32_t i0,i1;
+ volatile double w;
+ double t;
+ long int result;
+ int sx;
+
+ EXTRACT_WORDS (i0, i1, x);
+ j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+ sx = i0 >> 31;
+ i0 &= 0xfffff;
+ i0 |= 0x100000;
+
+ if (j0 < 20)
+ {
+ if (j0 < -1)
+ return 0;
+ else
+ {
+ w = two52[sx] + x;
+ t = w - two52[sx];
+ EXTRACT_WORDS (i0, i1, t);
+ j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+ i0 &= 0xfffff;
+ i0 |= 0x100000;
+
+ result = i0 >> (20 - j0);
+ }
+ }
+ else if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
+ {
+ if (j0 >= 52)
+ result = ((long int) i0 << (j0 - 20)) | (i1 << (j0 - 52));
+ else
+ {
+ w = two52[sx] + x;
+ t = w - two52[sx];
+ EXTRACT_WORDS (i0, i1, t);
+ j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
+ i0 &= 0xfffff;
+ i0 |= 0x100000;
+
+ if (j0 == 20)
+ result = (long int) i0;
+ else
+ result = ((long int) i0 << (j0 - 20)) | (i1 >> (52 - j0));
+ }
+ }
+ else
+ {
+ /* The number is too large. It is left implementation defined
+ what happens. */
+ return (long int) x;
+ }
+
+ return sx ? -result : result;
+}
+libm_hidden_def(lrint)