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authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /sysdeps/ieee754/ldbl-128ibm/s_ceill.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
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2.5-18.1
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diff --git a/sysdeps/ieee754/ldbl-128ibm/s_ceill.c b/sysdeps/ieee754/ldbl-128ibm/s_ceill.c
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+/* Ceil (round to +inf) long double floating-point values.
+ IBM extended format long double version.
+ Copyright (C) 2006 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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 <fenv_libc.h>
+#include <math_ldbl_opt.h>
+#include <float.h>
+#include <ieee754.h>
+
+
+#ifdef __STDC__
+long double
+__ceill (long double x)
+#else
+long double
+__ceill (x)
+ long double x;
+#endif
+{
+ double xh, xl, hi, lo;
+
+ ldbl_unpack (x, &xh, &xl);
+
+ /* Return Inf, Nan, +/-0 unchanged. */
+ if (__builtin_expect (xh != 0.0
+ && __builtin_isless (__builtin_fabs (xh),
+ __builtin_inf ()), 1))
+ {
+ double orig_xh;
+ int save_round = fegetround ();
+
+ /* Long double arithmetic, including the canonicalisation below,
+ only works in round-to-nearest mode. */
+ fesetround (FE_TONEAREST);
+
+ /* Convert the high double to integer. */
+ orig_xh = xh;
+ hi = ldbl_nearbyint (xh);
+
+ /* Subtract integral high part from the value. */
+ xh -= hi;
+ ldbl_canonicalize (&xh, &xl);
+
+ /* Now convert the low double, adjusted for any remainder from the
+ high double. */
+ lo = ldbl_nearbyint (xh);
+
+ /* Adjust the result when the remainder is non-zero. nearbyint
+ rounds values to the nearest integer, and values halfway
+ between integers to the nearest even integer. ceill must
+ round towards +Inf. */
+ xh -= lo;
+ ldbl_canonicalize (&xh, &xl);
+
+ if (xh > 0.0 || (xh == 0.0 && xl > 0.0))
+ lo += 1.0;
+
+ /* Ensure the final value is canonical. In certain cases,
+ rounding causes hi,lo calculated so far to be non-canonical. */
+ xh = hi;
+ xl = lo;
+ ldbl_canonicalize (&xh, &xl);
+
+ /* Ensure we return -0 rather than +0 when appropriate. */
+ if (orig_xh < 0.0)
+ xh = -__builtin_fabs (xh);
+
+ fesetround (save_round);
+ }
+
+ return ldbl_pack (xh, xl);
+}
+
+long_double_symbol (libm, __ceill, ceill);