From: Adhemerval Zanella Date: Thu, 28 Mar 2019 19:14:04 +0000 (+0000) Subject: math: Use wordsize-64 version for s_logb X-Git-Tag: upstream/2.30~42 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=105f2ed368ed61785a0a63ddb47fc62b89b58e0d;p=external%2Fglibc.git math: Use wordsize-64 version for s_logb - The resulting binary difference on 32 bits architecture is minimum. On i686-linux-gnu (with architecture optimization routine removed) there is no different using logb benchtests - It helps wordsize-64 architectures that use ldbl-opt. - It add some code simplification with reduction of duplicated implementations. Checked on powerpc-linux-gnu (built without --with-cpu, with --with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch), powerpc64-linux-gnu (built without --with-cp and with --with-cpu=power5+ and --disable-multi-arch). * sysdeps/ieee754/dbl-64/wordsize-64/s_logb.c: Move to ... * sysdeps/ieee754/dbl-64/s_logb.c: ... here. Add work around for powerpc32 integer 0 converting to -0. Reviewed-by: Gabriel F. T. Gomes --- diff --git a/ChangeLog b/ChangeLog index 828f832..c36f8fd 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2019-07-08 Adhemerval Zanella + * sysdeps/ieee754/dbl-64/wordsize-64/s_logb.c: Move to ... + * sysdeps/ieee754/dbl-64/s_logb.c: ... here. Add work around for + powerpc32 integer 0 converting to -0. + * benchtests/Makefile (bench-math): Add logb. * benchtests/logb-inputs: New file. * benchtests/logbf-inputs: New file. diff --git a/sysdeps/ieee754/dbl-64/s_logb.c b/sysdeps/ieee754/dbl-64/s_logb.c index a6de1f6..e336251 100644 --- a/sysdeps/ieee754/dbl-64/s_logb.c +++ b/sysdeps/ieee754/dbl-64/s_logb.c @@ -1,22 +1,24 @@ -/* @(#)s_logb.c 5.1 93/09/24 */ -/* - * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. - * - * Developed at SunPro, a Sun Microsystems, Inc. business. - * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice - * is preserved. - * ==================================================== - */ +/* Compute radix independent exponent. + Copyright (C) 2011-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2011. -/* - * double logb(x) - * IEEE 754 logb. Included to pass IEEE test suite. Not recommend. - * Use ilogb instead. - */ + 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 + . */ #include + #include #include #include @@ -24,28 +26,23 @@ double __logb (double x) { - int32_t lx, ix, rix; + int64_t ix, ex; - EXTRACT_WORDS (ix, lx, x); - ix &= 0x7fffffff; /* high |x| */ - if ((ix | lx) == 0) + EXTRACT_WORDS64 (ix, x); + ix &= UINT64_C(0x7fffffffffffffff); + if (ix == 0) return -1.0 / fabs (x); - if (ix >= 0x7ff00000) + ex = ix >> 52; + if (ex == 0x7ff) return x * x; - if (__glibc_unlikely ((rix = ix >> 20) == 0)) + if (__glibc_unlikely (ex == 0)) { - /* POSIX specifies that denormal number is treated as - though it were normalized. */ - int ma; - if (ix == 0) - ma = __builtin_clz (lx) + 32; - else - ma = __builtin_clz (ix); - rix -= ma - 12; + int m = __builtin_clzll (ix); + ex -= m - 12; } - if (FIX_INT_FP_CONVERT_ZERO && rix == 1023) + if (FIX_INT_FP_CONVERT_ZERO && ex == 1023) return 0.0; - return (double) (rix - 1023); + return (double) (ex - 1023); } #ifndef __logb libm_alias_double (__logb, logb) diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_logb.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_logb.c deleted file mode 100644 index d9b40af..0000000 --- a/sysdeps/ieee754/dbl-64/wordsize-64/s_logb.c +++ /dev/null @@ -1,47 +0,0 @@ -/* Compute radix independent exponent. - Copyright (C) 2011-2019 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper , 2011. - - 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 - . */ - -#include - -#include -#include - - -double -__logb (double x) -{ - int64_t ix, ex; - - EXTRACT_WORDS64 (ix, x); - ix &= UINT64_C(0x7fffffffffffffff); - if (ix == 0) - return -1.0 / fabs (x); - ex = ix >> 52; - if (ex == 0x7ff) - return x * x; - if (__glibc_unlikely (ex == 0)) - { - int m = __builtin_clzll (ix); - ex -= m - 12; - } - return (double) (ex - 1023); -} -#ifndef __logb -libm_alias_double (__logb, logb) -#endif