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-rw-r--r--libm/s_trunc.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/libm/s_trunc.c b/libm/s_trunc.c
new file mode 100644
index 000000000..8a4f5ae05
--- /dev/null
+++ b/libm/s_trunc.c
@@ -0,0 +1,58 @@
+/* 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@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"
+
+
+libm_hidden_proto(trunc)
+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;
+}
+libm_hidden_def(trunc)