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authorUlrich Drepper <drepper@redhat.com>2006-09-17 07:26:24 +0000
committerUlrich Drepper <drepper@redhat.com>2006-09-17 07:26:24 +0000
commitfb146a76a5bfbd4a7afd65a8c749715336444241 (patch)
treef4e85e84d5442fab7fc5b91873c89369ac3d4c06 /sysdeps/ieee754/ldbl-128ibm/s_lroundl.c
parentbd6d3b7dadf39f8afbbb5736614c378aa970f5c3 (diff)
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* io/Makefile (CFLAGS-fstatat.c): Set.
(CFLAGS-fstatat64.c): Likewise. (CFLAGS-mknodat.c): Likewise. * sysdeps/ieee754/ldbl-128ibm/s_llrintl.c: Comment fixes. * sysdeps/ieee754/ldbl-128ibm/s_llroundl.c: Likewise. * sysdeps/ieee754/ldbl-128ibm/s_lrintl.c: Rewritten. * sysdeps/ieee754/ldbl-128ibm/s_lroundl.c: Rewritten. 2006-09-14 Jakub Jelinek <jakub@redhat.com>
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_lroundl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_lroundl.c139
1 files changed, 136 insertions, 3 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_lroundl.c b/sysdeps/ieee754/ldbl-128ibm/s_lroundl.c
index 7c5de36..a5251ee 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_lroundl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_lroundl.c
@@ -1,9 +1,142 @@
-/* FIXME */
+/* Round to long int 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>
-long int __lroundl (long double d)
+#ifdef __STDC__
+long
+__lroundl (long double x)
+#else
+long
+__lroundl (x)
+ long double x;
+#endif
{
- return llroundl (d);
+ double xh, xl;
+ long res, hi, lo;
+
+ ldbl_unpack (x, &xh, &xl);
+
+ /* Limit the range of values handled by the conversion to long.
+ We do this because we aren't sure whether that conversion properly
+ raises FE_INVALID. */
+ if (
+#if __LONG_MAX__ == 2147483647
+ __builtin_expect
+ ((__builtin_fabs (xh) <= (double) __LONG_MAX__ + 2), 1)
+#else
+ __builtin_expect
+ ((__builtin_fabs (xh) <= -(double) (-__LONG_MAX__ - 1)), 1)
+#endif
+#if !defined (FE_INVALID)
+ || 1
+#endif
+ )
+ {
+#if __LONG_MAX__ == 2147483647
+ long long llhi = (long long) xh;
+ if (llhi != (long) llhi)
+ hi = llhi < 0 ? -__LONG_MAX__ - 1 : __LONG_MAX__;
+ else
+ hi = llhi;
+ xh -= hi;
+#else
+ if (__builtin_expect ((xh == -(double) (-__LONG_MAX__ - 1)), 0))
+ {
+ /* When XH is 9223372036854775808.0, converting to long long will
+ overflow, resulting in an invalid operation. However, XL might
+ be negative and of sufficient magnitude that the overall long
+ double is in fact in range. Avoid raising an exception. In any
+ case we need to convert this value specially, because
+ the converted value is not exactly represented as a double
+ thus subtracting HI from XH suffers rounding error. */
+ hi = __LONG_MAX__;
+ xh = 1.0;
+ }
+ else
+ {
+ hi = (long) xh;
+ xh -= hi;
+ }
+#endif
+ ldbl_canonicalize (&xh, &xl);
+
+ lo = (long) xh;
+
+ /* Peg at max/min values, assuming that the above conversions do so.
+ Strictly speaking, we can return anything for values that overflow,
+ but this is more useful. */
+ res = hi + lo;
+
+ /* This is just sign(hi) == sign(lo) && sign(res) != sign(hi). */
+ if (__builtin_expect (((~(hi ^ lo) & (res ^ hi)) < 0), 0))
+ goto overflow;
+
+ xh -= lo;
+ ldbl_canonicalize (&xh, &xl);
+
+ hi = res;
+ if (xh > 0.5)
+ {
+ res += 1;
+ }
+ else if (xh == 0.5)
+ {
+ if (xl > 0.0 || (xl == 0.0 && res >= 0))
+ res += 1;
+ }
+ else if (-xh > 0.5)
+ {
+ res -= 1;
+ }
+ else if (-xh == 0.5)
+ {
+ if (xl < 0.0 || (xl == 0.0 && res <= 0))
+ res -= 1;
+ }
+
+ if (__builtin_expect (((~(hi ^ (res - hi)) & (res ^ hi)) < 0), 0))
+ goto overflow;
+
+ return res;
+ }
+ else
+ {
+ if (xh > 0.0)
+ hi = __LONG_MAX__;
+ else if (xh < 0.0)
+ hi = -__LONG_MAX__ - 1;
+ else
+ /* Nan */
+ hi = 0;
+ }
+
+overflow:
+#ifdef FE_INVALID
+ feraiseexcept (FE_INVALID);
+#endif
+ return hi;
}
+
long_double_symbol (libm, __lroundl, lroundl);