From 60f435bb0c097ead2d4609aa7e45a203eb24e43c Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Tue, 1 Dec 2015 01:01:36 +0000 Subject: [PATCH] Use hex float constants in sysdeps/ieee754/dbl-64/e_sqrt.c. Various sysdeps/ieee754/dbl-64 functions use double constants defined using a union between a double and two ints, with separate big-endian and little-endian definitions of the constants. With modern C, this is unnecessary complication; hex float constants (or __builtin_inf etc.) suffice to specify the exact value desired, and so can avoid separate versions for each endianness. Having this complication also complicates cleanups such as removing slow paths from these library functions, as they need to make sure to remove both copies of variables that are no longer used after such a cleanup (and in at least one case, proper removal of a slow path will also involve removing slow-path-only values from the middle of an array - an array with both big-endian and little-endian copies - and adjusting other references to that array). So it makes sense to clean up the code to define these constants using hex floats and so eliminate the endianness conditional. This patch does so in the case of sqrt, where the two constants are such that it makes sense just to put them directly in the code using them and eliminate the names for them altogether. Tested for arm (the code generated for sqrt does change, though not in any significant way). * sysdeps/ieee754/dbl-64/e_sqrt.c: Do not include uroot.h. (__ieee754_sqrt): Use hex float constants instead of tm256.x and t512.x. * sysdeps/ieee754/dbl-64/uroot.h: Remove file. --- ChangeLog | 7 ++++++ sysdeps/ieee754/dbl-64/e_sqrt.c | 5 ++-- sysdeps/ieee754/dbl-64/uroot.h | 43 --------------------------------- 3 files changed, 9 insertions(+), 46 deletions(-) delete mode 100644 sysdeps/ieee754/dbl-64/uroot.h diff --git a/ChangeLog b/ChangeLog index 038181cf63..5a44a8a0b7 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2015-12-01 Joseph Myers + + * sysdeps/ieee754/dbl-64/e_sqrt.c: Do not include uroot.h. + (__ieee754_sqrt): Use hex float constants instead of tm256.x and + t512.x. + * sysdeps/ieee754/dbl-64/uroot.h: Remove file. + 2015-11-30 Amit Pawar [BZ #19214] diff --git a/sysdeps/ieee754/dbl-64/e_sqrt.c b/sysdeps/ieee754/dbl-64/e_sqrt.c index fff6d148fe..c1fed7d97e 100644 --- a/sysdeps/ieee754/dbl-64/e_sqrt.c +++ b/sysdeps/ieee754/dbl-64/e_sqrt.c @@ -21,7 +21,7 @@ /* */ /* FUNCTION: usqrt */ /* */ -/* FILES NEEDED: dla.h endian.h mydefs.h uroot.h */ +/* FILES NEEDED: dla.h endian.h mydefs.h */ /* uroot.tbl */ /* */ /* An ultimate sqrt routine. Given an IEEE double machine number x */ @@ -47,7 +47,6 @@ double __ieee754_sqrt (double x) { -#include "uroot.h" static const double rt0 = 9.99999999859990725855365213134618E-01, rt1 = 4.99999999495955425917856814202739E-01, @@ -134,7 +133,7 @@ __ieee754_sqrt (double x) return x; /* sqrt(+0)=+0, sqrt(-0)=-0 */ if (k < 0) return (x - x) / (x - x); /* sqrt(-ve)=sNaN */ - return tm256.x * __ieee754_sqrt (x * t512.x); + return 0x1p-256 * __ieee754_sqrt (x * 0x1p512); } } strong_alias (__ieee754_sqrt, __sqrt_finite) diff --git a/sysdeps/ieee754/dbl-64/uroot.h b/sysdeps/ieee754/dbl-64/uroot.h deleted file mode 100644 index 4bbcc3bac7..0000000000 --- a/sysdeps/ieee754/dbl-64/uroot.h +++ /dev/null @@ -1,43 +0,0 @@ -/* - * IBM Accurate Mathematical Library - * Written by International Business Machines Corp. - * Copyright (C) 2001-2015 Free Software Foundation, Inc. - * - * This program 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. - * - * This program 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 this program; if not, see . - */ - -/******************************************************************/ -/* */ -/* MODULE_NAME:uroot.h */ -/* */ -/* common data and variables prototype and definition */ -/******************************************************************/ - -#ifndef UROOT_H -#define UROOT_H - -#ifdef BIG_ENDI - static const mynumber -/**/ t512 = {{0x5ff00000, 0x00000000 }}, /* 2^512 */ -/**/ tm256 = {{0x2ff00000, 0x00000000 }}; /* 2^-256 */ - -#else -#ifdef LITTLE_ENDI - static const mynumber -/**/ t512 = {{0x00000000, 0x5ff00000 }}, /* 2^512 */ -/**/ tm256 = {{0x00000000, 0x2ff00000 }}; /* 2^-256 */ -#endif -#endif - -#endif