diff options
author | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
---|---|---|
committer | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
commit | 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch) | |
tree | 4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/sysdeps/ieee754/dbl-64/s_lround.c | |
parent | 199fc19d3aaaf57944ef036e15904febe877fc93 (diff) | |
download | glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.tar.gz glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.tar.xz glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.zip |
Prepare for radical source tree reorganization. zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control).
Diffstat (limited to 'REORG.TODO/sysdeps/ieee754/dbl-64/s_lround.c')
-rw-r--r-- | REORG.TODO/sysdeps/ieee754/dbl-64/s_lround.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/ieee754/dbl-64/s_lround.c b/REORG.TODO/sysdeps/ieee754/dbl-64/s_lround.c new file mode 100644 index 0000000000..df4775e344 --- /dev/null +++ b/REORG.TODO/sysdeps/ieee754/dbl-64/s_lround.c @@ -0,0 +1,113 @@ +/* Round double value to long int. + Copyright (C) 1997-2017 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, see + <http://www.gnu.org/licenses/>. */ + +#include <fenv.h> +#include <limits.h> +#include <math.h> + +#include <math_private.h> +#include <fix-fp-int-convert-overflow.h> + + +long int +__lround (double x) +{ + int32_t j0; + u_int32_t i1, i0; + long int result; + int sign; + + EXTRACT_WORDS (i0, i1, x); + j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; + sign = (i0 & 0x80000000) != 0 ? -1 : 1; + i0 &= 0xfffff; + i0 |= 0x100000; + + if (j0 < 20) + { + if (j0 < 0) + return j0 < -1 ? 0 : sign; + else + { + i0 += 0x80000 >> j0; + + result = i0 >> (20 - j0); + } + } + else if (j0 < (int32_t) (8 * sizeof (long int)) - 1) + { + if (j0 >= 52) + result = ((long int) i0 << (j0 - 20)) | ((long int) i1 << (j0 - 52)); + else + { + u_int32_t j = i1 + (0x80000000 >> (j0 - 20)); + if (j < i1) + ++i0; + + if (j0 == 20) + result = (long int) i0; + else + { + result = ((long int) i0 << (j0 - 20)) | (j >> (52 - j0)); +#ifdef FE_INVALID + if (sizeof (long int) == 4 + && sign == 1 + && result == LONG_MIN) + /* Rounding brought the value out of range. */ + feraiseexcept (FE_INVALID); +#endif + } + } + } + else + { + /* The number is too large. Unless it rounds to LONG_MIN, + FE_INVALID must be raised and the return value is + unspecified. */ +#ifdef FE_INVALID + if (FIX_DBL_LONG_CONVERT_OVERFLOW + && !(sign == -1 + && (sizeof (long int) == 4 + ? x > (double) LONG_MIN - 0.5 + : x >= (double) LONG_MIN))) + { + feraiseexcept (FE_INVALID); + return sign == 1 ? LONG_MAX : LONG_MIN; + } + else if (!FIX_DBL_LONG_CONVERT_OVERFLOW + && sizeof (long int) == 4 + && x <= (double) LONG_MIN - 0.5) + { + /* If truncation produces LONG_MIN, the cast will not raise + the exception, but may raise "inexact". */ + feraiseexcept (FE_INVALID); + return LONG_MIN; + } +#endif + return (long int) x; + } + + return sign * result; +} + +weak_alias (__lround, lround) +#ifdef NO_LONG_DOUBLE +strong_alias (__lround, __lroundl) +weak_alias (__lround, lroundl) +#endif |