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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_lrintl.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
downloadglibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz
2.5-18.1
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_lrintl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_lrintl.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_lrintl.c b/sysdeps/ieee754/ldbl-128ibm/s_lrintl.c
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index 0000000000..e28934842a
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+++ b/sysdeps/ieee754/ldbl-128ibm/s_lrintl.c
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+/* 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>
+
+
+#ifdef __STDC__
+long
+__lrintl (long double x)
+#else
+long
+__lrintl (x)
+ long double x;
+#endif
+{
+ double xh, xl;
+ long res, hi, lo;
+ int save_round;
+
+ 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
+ )
+ {
+ save_round = fegetround ();
+
+#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;
+ switch (save_round)
+ {
+ case FE_TONEAREST:
+ if (fabs (xh) < 0.5
+ || (fabs (xh) == 0.5
+ && ((xh > 0.0 && xl < 0.0)
+ || (xh < 0.0 && xl > 0.0)
+ || (xl == 0.0 && (res & 1) == 0))))
+ return res;
+
+ if (xh < 0.0)
+ res -= 1;
+ else
+ res += 1;
+ break;
+
+ case FE_TOWARDZERO:
+ if (res > 0 && (xh < 0.0 || (xh == 0.0 && xl < 0.0)))
+ res -= 1;
+ else if (res < 0 && (xh > 0.0 || (xh == 0.0 && xl > 0.0)))
+ res += 1;
+ return res;
+ break;
+
+ case FE_UPWARD:
+ if (xh > 0.0 || (xh == 0.0 && xl > 0.0))
+ res += 1;
+ break;
+
+ case FE_DOWNWARD:
+ if (xh < 0.0 || (xh == 0.0 && xl < 0.0))
+ res -= 1;
+ break;
+ }
+
+ 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, __lrintl, lrintl);