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author | Ulrich Drepper <drepper@redhat.com> | 2001-03-12 00:04:52 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2001-03-12 00:04:52 +0000 |
commit | e4d8276142b9c07b23043ef44b0fe8fa7bcc3121 (patch) | |
tree | f153a80b6ce0fdd3261ff18a16fd80bd965231c3 /sysdeps/ieee754/dbl-64/mpsqrt.c | |
parent | d3c8723f6415af59a6ec14fcb918ad0e4d1fb588 (diff) | |
download | glibc-e4d8276142b9c07b23043ef44b0fe8fa7bcc3121.tar.gz glibc-e4d8276142b9c07b23043ef44b0fe8fa7bcc3121.tar.xz glibc-e4d8276142b9c07b23043ef44b0fe8fa7bcc3121.zip |
Update.
2001-03-11 Ulrich Drepper <drepper@redhat.com> Last-bit accurate math library implementation by IBM Haifa. Contributed by Abraham Ziv <ziv@il.ibm.com>, Moshe Olshansky <olshansk@il.ibm.com>, Ealan Henis <ealan@il.ibm.com>, and Anna Reitman <reitman@il.ibm.com>. * math/Makefile (dbl-only-routines): New variable. (libm-routines): Add $(dbl-only-routines). * sysdeps/ieee754/dbl-64/e_acos.c: Empty, definition is in e_asin.c. * sysdeps/ieee754/dbl-64/e_asin.c: Replaced with accurate asin implementation. * sysdeps/ieee754/dbl-64/e_atan2.c: Replaced with accurate atan2 implementation. * sysdeps/ieee754/dbl-64/e_exp.c: Replaced with accurate exp implementation. * sysdeps/ieee754/dbl-64/e_lgamma_r.c: Don't use __kernel_sin and __kernel_cos. * sysdeps/ieee754/dbl-64/e_log.c: Replaced with accurate log implementation. * sysdeps/ieee754/dbl-64/e_remainder.c: Replaced with accurate remainder implementation. * sysdeps/ieee754/dbl-64/e_pow.c: Replaced with accurate pow implementation. * sysdeps/ieee754/dbl-64/e_sqrt.c: Replaced with accurate sqrt implementation. * sysdeps/ieee754/dbl-64/k_cos.c: Empty, definition is in s_sin.c. * sysdeps/ieee754/dbl-64/k_sin.c: Empty, definition is in s_sin.c. * sysdeps/ieee754/dbl-64/s_atan.c: Replaced with accurate atan implementation. * sysdeps/ieee754/dbl-64/s_cos.c: Empty, definition is in s_sin.c. * sysdeps/ieee754/dbl-64/s_sin.c: Replaced with accurate sin/cos implementation. * sysdeps/ieee754/dbl-64/s_sincos.c: Rewritten to not use __kernel_sin and __kernel_cos. * sysdeps/ieee754/dbl-64/s_tan.c: Replaced with accurate tan implementation. * sysdeps/ieee754/dbl-64/Dist: Add new non-code files. * sysdeps/ieee754/dbl-64/MathLib.h: New file. * sysdeps/ieee754/dbl-64/asincos.tbl: New file. * sysdeps/ieee754/dbl-64/atnat.h: New file. * sysdeps/ieee754/dbl-64/atnat2.h: New file. * sysdeps/ieee754/dbl-64/branred.c: New file. * sysdeps/ieee754/dbl-64/branred.h: New file. * sysdeps/ieee754/dbl-64/dla.h: New file. * sysdeps/ieee754/dbl-64/doasin.c: New file. * sysdeps/ieee754/dbl-64/doasin.h: New file. * sysdeps/ieee754/dbl-64/dosincos.c: New file. * sysdeps/ieee754/dbl-64/dosincos.h: New file. * sysdeps/ieee754/dbl-64/endian.h: New file. * sysdeps/ieee754/dbl-64/halfulp.c: New file. * sysdeps/ieee754/dbl-64/mpa.c: New file. * sysdeps/ieee754/dbl-64/mpa.h: New file. * sysdeps/ieee754/dbl-64/mpa2.h: New file. * sysdeps/ieee754/dbl-64/mpatan.c: New file. * sysdeps/ieee754/dbl-64/mpatan.h: New file. * sysdeps/ieee754/dbl-64/mpatan2.c: New file. * sysdeps/ieee754/dbl-64/mpexp.c: New file. * sysdeps/ieee754/dbl-64/mpexp.h: New file. * sysdeps/ieee754/dbl-64/mplog.c: New file. * sysdeps/ieee754/dbl-64/mplog.h: New file. * sysdeps/ieee754/dbl-64/mpsqrt.c: New file. * sysdeps/ieee754/dbl-64/mpsqrt.h: New file. * sysdeps/ieee754/dbl-64/mptan.c: New file. * sysdeps/ieee754/dbl-64/mydefs.h: New file. * sysdeps/ieee754/dbl-64/powtwo.tbl: New file. * sysdeps/ieee754/dbl-64/root.tbl: New file. * sysdeps/ieee754/dbl-64/sincos.tbl: New file. * sysdeps/ieee754/dbl-64/sincos32.c: New file. * sysdeps/ieee754/dbl-64/sincos32.h: New file. * sysdeps/ieee754/dbl-64/slowexp.c: New file. * sysdeps/ieee754/dbl-64/slowpow.c: New file. * sysdeps/ieee754/dbl-64/uasncs.h: New file. * sysdeps/ieee754/dbl-64/uatan.tbl: New file. * sysdeps/ieee754/dbl-64/uexp.h: New file. * sysdeps/ieee754/dbl-64/uexp.tbl: New file. * sysdeps/ieee754/dbl-64/ulog.h: New file. * sysdeps/ieee754/dbl-64/ulog.tbl: New file. * sysdeps/ieee754/dbl-64/upow.h: New file. * sysdeps/ieee754/dbl-64/upow.tbl: New file. * sysdeps/ieee754/dbl-64/urem.h: New file. * sysdeps/ieee754/dbl-64/uroot.h: New file. * sysdeps/ieee754/dbl-64/usncs.h: New file. * sysdeps/ieee754/dbl-64/utan.h: New file. * sysdeps/ieee754/dbl-64/utan.tbl: New file. * sysdeps/i386/fpu/branred.c: New file. * sysdeps/i386/fpu/doasin.c: New file. * sysdeps/i386/fpu/dosincos.c: New file. * sysdeps/i386/fpu/halfulp.c: New file. * sysdeps/i386/fpu/mpa.c: New file. * sysdeps/i386/fpu/mpatan.c: New file. * sysdeps/i386/fpu/mpatan2.c: New file. * sysdeps/i386/fpu/mpexp.c: New file. * sysdeps/i386/fpu/mplog.c: New file. * sysdeps/i386/fpu/mpsqrt.c: New file. * sysdeps/i386/fpu/mptan.c: New file. * sysdeps/i386/fpu/sincos32.c: New file. * sysdeps/i386/fpu/slowexp.c: New file. * sysdeps/i386/fpu/slowpow.c: New file. * sysdeps/ia64/fpu/branred.c: New file. * sysdeps/ia64/fpu/doasin.c: New file. * sysdeps/ia64/fpu/dosincos.c: New file. * sysdeps/ia64/fpu/halfulp.c: New file. * sysdeps/ia64/fpu/mpa.c: New file. * sysdeps/ia64/fpu/mpatan.c: New file. * sysdeps/ia64/fpu/mpatan2.c: New file. * sysdeps/ia64/fpu/mpexp.c: New file. * sysdeps/ia64/fpu/mplog.c: New file. * sysdeps/ia64/fpu/mpsqrt.c: New file. * sysdeps/ia64/fpu/mptan.c: New file. * sysdeps/ia64/fpu/sincos32.c: New file. * sysdeps/ia64/fpu/slowexp.c: New file. * sysdeps/ia64/fpu/slowpow.c: New file. * sysdeps/m68k/fpu/branred.c: New file. * sysdeps/m68k/fpu/doasin.c: New file. * sysdeps/m68k/fpu/dosincos.c: New file. * sysdeps/m68k/fpu/halfulp.c: New file. * sysdeps/m68k/fpu/mpa.c: New file. * sysdeps/m68k/fpu/mpatan.c: New file. * sysdeps/m68k/fpu/mpatan2.c: New file. * sysdeps/m68k/fpu/mpexp.c: New file. * sysdeps/m68k/fpu/mplog.c: New file. * sysdeps/m68k/fpu/mpsqrt.c: New file. * sysdeps/m68k/fpu/mptan.c: New file. * sysdeps/m68k/fpu/sincos32.c: New file. * sysdeps/m68k/fpu/slowexp.c: New file. * sysdeps/m68k/fpu/slowpow.c: New file. * iconvdata/gconv-modules: Add a number of alias, mostly for IBM codepages.
Diffstat (limited to 'sysdeps/ieee754/dbl-64/mpsqrt.c')
-rw-r--r-- | sysdeps/ieee754/dbl-64/mpsqrt.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/sysdeps/ieee754/dbl-64/mpsqrt.c b/sysdeps/ieee754/dbl-64/mpsqrt.c new file mode 100644 index 0000000000..6f73fae137 --- /dev/null +++ b/sysdeps/ieee754/dbl-64/mpsqrt.c @@ -0,0 +1,102 @@ + +/* + * IBM Accurate Mathematical Library + * Copyright (c) International Business Machines Corp., 2001 + * + * 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 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 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, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ +/****************************************************************************/ +/* MODULE_NAME:mpsqrt.c */ +/* */ +/* FUNCTION:mpsqrt */ +/* fastiroot */ +/* */ +/* FILES NEEDED:endian.h mpa.h mpsqrt.h */ +/* mpa.c */ +/* Multi-Precision square root function subroutine for precision p >= 4. */ +/* The relative error is bounded by 3.501*r**(1-p), where r=2**24. */ +/* */ +/****************************************************************************/ +#include "endian.h" +#include "mpa.h" + +/****************************************************************************/ +/* Multi-Precision square root function subroutine for precision p >= 4. */ +/* The relative error is bounded by 3.501*r**(1-p), where r=2**24. */ +/* Routine receives two pointers to Multi Precision numbers: */ +/* x (left argument) and y (next argument). Routine also receives precision */ +/* p as integer. Routine computes sqrt(*x) and stores result in *y */ +/****************************************************************************/ + +double fastiroot(double); + +void mpsqrt(mp_no *x, mp_no *y, int p) { +#include "mpsqrt.h" + + int i,m,ex,ey; + double dx,dy; + mp_no + mphalf = {0, 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0, + 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0, + 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,}, + mp3halfs = {0, 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0, + 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0, + 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,}; + mp_no mpxn,mpz,mpu,mpt1,mpt2; + + /* Prepare multi-precision 1/2 and 3/2 */ + mphalf.e =0; mphalf.d[0] =ONE; mphalf.d[1] =HALFRAD; + mp3halfs.e=1; mp3halfs.d[0]=ONE; mp3halfs.d[1]=ONE; mp3halfs.d[2]=HALFRAD; + + ex=EX; ey=EX/2; cpy(x,&mpxn,p); mpxn.e -= (ey+ey); + mp_dbl(&mpxn,&dx,p); dy=fastiroot(dx); dbl_mp(dy,&mpu,p); + mul(&mpxn,&mphalf,&mpz,p); + + m=mp[p]; + for (i=0; i<m; i++) { + mul(&mpu,&mpu,&mpt1,p); + mul(&mpt1,&mpz,&mpt2,p); + sub(&mp3halfs,&mpt2,&mpt1,p); + mul(&mpu,&mpt1,&mpt2,p); + cpy(&mpt2,&mpu,p); + } + mul(&mpxn,&mpu,y,p); EY += ey; + + return; +} + +/***********************************************************/ +/* Compute a double precision approximation for 1/sqrt(x) */ +/* with the relative error bounded by 2**-51. */ +/***********************************************************/ +double fastiroot(double x) { + union {long i[2]; double d;} p,q; + double y,z, t; + long n; + static const double c0 = 0.99674, c1 = -0.53380, c2 = 0.45472, c3 = -0.21553; + + p.d = x; + p.i[HIGH_HALF] = (p.i[HIGH_HALF] & 0x3FFFFFFF ) | 0x3FE00000 ; + q.d = x; + y = p.d; + z = y -1.0; + n = (q.i[HIGH_HALF] - p.i[HIGH_HALF])>>1; + z = ((c3*z + c2)*z + c1)*z + c0; /* 2**-7 */ + z = z*(1.5 - 0.5*y*z*z); /* 2**-14 */ + p.d = z*(1.5 - 0.5*y*z*z); /* 2**-28 */ + p.i[HIGH_HALF] -= n; + t = x*p.d; + return p.d*(1.5 - 0.5*p.d*t); +} |