Initial commit
This commit is contained in:
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/* @(#)e_rem_pio2.c 1.4 95/01/18 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*
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*/
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/* __ieee754_rem_pio2(x,y)
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*
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* return the remainder of x rem pi/2 in y[0]+y[1]
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* use __kernel_rem_pio2()
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*/
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#include "fdlibm.h"
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/*
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* Table of constants for 2/pi, 396 Hex digits (476 decimal) of 2/pi
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*/
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#ifdef __STDC__
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static const int two_over_pi[] = {
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#else
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static int two_over_pi[] = {
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#endif
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0xA2F983, 0x6E4E44, 0x1529FC, 0x2757D1, 0xF534DD, 0xC0DB62,
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0x95993C, 0x439041, 0xFE5163, 0xABDEBB, 0xC561B7, 0x246E3A,
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0x424DD2, 0xE00649, 0x2EEA09, 0xD1921C, 0xFE1DEB, 0x1CB129,
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0xA73EE8, 0x8235F5, 0x2EBB44, 0x84E99C, 0x7026B4, 0x5F7E41,
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0x3991D6, 0x398353, 0x39F49C, 0x845F8B, 0xBDF928, 0x3B1FF8,
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0x97FFDE, 0x05980F, 0xEF2F11, 0x8B5A0A, 0x6D1F6D, 0x367ECF,
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0x27CB09, 0xB74F46, 0x3F669E, 0x5FEA2D, 0x7527BA, 0xC7EBE5,
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0xF17B3D, 0x0739F7, 0x8A5292, 0xEA6BFB, 0x5FB11F, 0x8D5D08,
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0x560330, 0x46FC7B, 0x6BABF0, 0xCFBC20, 0x9AF436, 0x1DA9E3,
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0x91615E, 0xE61B08, 0x659985, 0x5F14A0, 0x68408D, 0xFFD880,
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0x4D7327, 0x310606, 0x1556CA, 0x73A8C9, 0x60E27B, 0xC08C6B,
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};
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#ifdef __STDC__
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static const int npio2_hw[] = {
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#else
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static int npio2_hw[] = {
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#endif
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0x3FF921FB, 0x400921FB, 0x4012D97C, 0x401921FB, 0x401F6A7A, 0x4022D97C,
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0x4025FDBB, 0x402921FB, 0x402C463A, 0x402F6A7A, 0x4031475C, 0x4032D97C,
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0x40346B9C, 0x4035FDBB, 0x40378FDB, 0x403921FB, 0x403AB41B, 0x403C463A,
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0x403DD85A, 0x403F6A7A, 0x40407E4C, 0x4041475C, 0x4042106C, 0x4042D97C,
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0x4043A28C, 0x40446B9C, 0x404534AC, 0x4045FDBB, 0x4046C6CB, 0x40478FDB,
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0x404858EB, 0x404921FB,
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};
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/*
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* invpio2: 53 bits of 2/pi
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* pio2_1: first 33 bit of pi/2
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* pio2_1t: pi/2 - pio2_1
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* pio2_2: second 33 bit of pi/2
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* pio2_2t: pi/2 - (pio2_1+pio2_2)
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* pio2_3: third 33 bit of pi/2
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* pio2_3t: pi/2 - (pio2_1+pio2_2+pio2_3)
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*/
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#ifdef __STDC__
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static const double
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#else
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static double
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#endif
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zero = 0.00000000000000000000e+00, /* 0x00000000, 0x00000000 */
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half = 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */
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two24 = 1.67772160000000000000e+07, /* 0x41700000, 0x00000000 */
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invpio2 = 6.36619772367581382433e-01, /* 0x3FE45F30, 0x6DC9C883 */
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pio2_1 = 1.57079632673412561417e+00, /* 0x3FF921FB, 0x54400000 */
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pio2_1t = 6.07710050650619224932e-11, /* 0x3DD0B461, 0x1A626331 */
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pio2_2 = 6.07710050630396597660e-11, /* 0x3DD0B461, 0x1A600000 */
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pio2_2t = 2.02226624879595063154e-21, /* 0x3BA3198A, 0x2E037073 */
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pio2_3 = 2.02226624871116645580e-21, /* 0x3BA3198A, 0x2E000000 */
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pio2_3t = 8.47842766036889956997e-32; /* 0x397B839A, 0x252049C1 */
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#ifdef __STDC__
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int __ieee754_rem_pio2(double x, double *y)
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#else
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int __ieee754_rem_pio2(x,y)
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double x,y[];
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#endif
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{
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double z,w,t,r,fn;
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double tx[3];
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int e0,i,j,nx,n,ix,hx;
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hx = __HI(x); /* high word of x */
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ix = hx&0x7fffffff;
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if(ix<=0x3fe921fb) /* |x| ~<= pi/4 , no need for reduction */
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{y[0] = x; y[1] = 0; return 0;}
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if(ix<0x4002d97c) { /* |x| < 3pi/4, special case with n=+-1 */
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if(hx>0) {
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z = x - pio2_1;
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if(ix!=0x3ff921fb) { /* 33+53 bit pi is good enough */
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y[0] = z - pio2_1t;
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y[1] = (z-y[0])-pio2_1t;
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} else { /* near pi/2, use 33+33+53 bit pi */
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z -= pio2_2;
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y[0] = z - pio2_2t;
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y[1] = (z-y[0])-pio2_2t;
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}
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return 1;
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} else { /* negative x */
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z = x + pio2_1;
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if(ix!=0x3ff921fb) { /* 33+53 bit pi is good enough */
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y[0] = z + pio2_1t;
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y[1] = (z-y[0])+pio2_1t;
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} else { /* near pi/2, use 33+33+53 bit pi */
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z += pio2_2;
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y[0] = z + pio2_2t;
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y[1] = (z-y[0])+pio2_2t;
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}
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return -1;
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}
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}
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if(ix<=0x413921fb) { /* |x| ~<= 2^19*(pi/2), medium size */
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t = fabs(x);
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n = (int) (t*invpio2+half);
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fn = (double)n;
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r = t-fn*pio2_1;
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w = fn*pio2_1t; /* 1st round good to 85 bit */
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if(n<32&&ix!=npio2_hw[n-1]) {
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y[0] = r-w; /* quick check no cancellation */
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} else {
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j = ix>>20;
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y[0] = r-w;
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i = j-(((__HI(y[0]))>>20)&0x7ff);
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if(i>16) { /* 2nd iteration needed, good to 118 */
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t = r;
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w = fn*pio2_2;
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r = t-w;
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w = fn*pio2_2t-((t-r)-w);
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y[0] = r-w;
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i = j-(((__HI(y[0]))>>20)&0x7ff);
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if(i>49) { /* 3rd iteration need, 151 bits acc */
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t = r; /* will cover all possible cases */
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w = fn*pio2_3;
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r = t-w;
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w = fn*pio2_3t-((t-r)-w);
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y[0] = r-w;
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}
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}
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}
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y[1] = (r-y[0])-w;
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if(hx<0) {y[0] = -y[0]; y[1] = -y[1]; return -n;}
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else return n;
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}
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/*
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* all other (large) arguments
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*/
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if(ix>=0x7ff00000) { /* x is inf or NaN */
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y[0]=y[1]=x-x; return 0;
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}
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/* set z = scalbn(|x|,ilogb(x)-23) */
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__LO(z) = __LO(x);
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e0 = (ix>>20)-1046; /* e0 = ilogb(z)-23; */
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__HI(z) = ix - (e0<<20);
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for(i=0;i<2;i++) {
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tx[i] = (double)((int)(z));
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z = (z-tx[i])*two24;
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}
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tx[2] = z;
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nx = 3;
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while(tx[nx-1]==zero) nx--; /* skip zero term */
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n = __kernel_rem_pio2(tx,y,e0,nx,2,two_over_pi);
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if(hx<0) {y[0] = -y[0]; y[1] = -y[1]; return -n;}
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return n;
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}
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+216
@@ -0,0 +1,216 @@
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#pragma once
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/* @(#)fdlibm.h 1.5 04/04/22 */
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/*
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* ====================================================
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* Copyright (C) 2004 by Sun Microsystems, Inc. All rights reserved.
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*
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/* Sometimes it's necessary to define __LITTLE_ENDIAN explicitly
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but these catch some common cases. */
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#if defined(__wasm__) || defined(i386) || defined(i486) || \
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defined(intel) || defined(x86) || defined(i86pc) || \
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defined(__alpha) || defined(__osf__)
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#define __LITTLE_ENDIAN
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#endif
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#ifdef __LITTLE_ENDIAN
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#define __HI(x) *(1+(int*)&x)
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#define __LO(x) *(int*)&x
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#define __HIp(x) *(1+(int*)x)
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#define __LOp(x) *(int*)x
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#else
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#define __HI(x) *(int*)&x
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#define __LO(x) *(1+(int*)&x)
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#define __HIp(x) *(int*)x
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#define __LOp(x) *(1+(int*)x)
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#endif
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#ifdef __STDC__
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#define __P(p) p
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#else
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#define __P(p) ()
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#endif
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/*
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* ANSI/POSIX
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*/
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extern int signgam;
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#define MAXFLOAT ((float)3.40282346638528860e+38)
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enum fdversion {fdlibm_ieee = -1, fdlibm_svid, fdlibm_xopen, fdlibm_posix};
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#define _LIB_VERSION_TYPE enum fdversion
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#define _LIB_VERSION _fdlib_version
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/* if global variable _LIB_VERSION is not desirable, one may
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* change the following to be a constant by:
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* #define _LIB_VERSION_TYPE const enum version
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* In that case, after one initializes the value _LIB_VERSION (see
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* s_lib_version.c) during compile time, it cannot be modified
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* in the middle of a program
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*/
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extern _LIB_VERSION_TYPE _LIB_VERSION;
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#define _IEEE_ fdlibm_ieee
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#define _SVID_ fdlibm_svid
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#define _XOPEN_ fdlibm_xopen
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#define _POSIX_ fdlibm_posix
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struct exception {
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int type;
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char *name;
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double arg1;
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double arg2;
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double retval;
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};
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#define HUGE MAXFLOAT
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/*
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* set X_TLOSS = pi*2**52, which is possibly defined in <values.h>
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* (one may replace the following line by "#include <values.h>")
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*/
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#define X_TLOSS 1.41484755040568800000e+16
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#define DOMAIN 1
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#define SING 2
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#define OVERFLOW 3
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#define UNDERFLOW 4
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#define TLOSS 5
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#define PLOSS 6
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/*
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* ANSI/POSIX
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*/
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extern double acos __P((double));
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extern double asin __P((double));
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extern double atan __P((double));
|
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extern double atan2 __P((double, double));
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extern double cos __P((double));
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extern double sin __P((double));
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extern double tan __P((double));
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extern double cosh __P((double));
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extern double sinh __P((double));
|
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extern double tanh __P((double));
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extern double exp __P((double));
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extern double frexp __P((double, int *));
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extern double ldexp __P((double, int));
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extern double log __P((double));
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extern double log10 __P((double));
|
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extern double modf __P((double, double *));
|
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|
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extern double pow __P((double, double));
|
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extern double sqrt __P((double));
|
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|
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extern double ceil __P((double));
|
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extern double fabs __P((double));
|
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extern double floor __P((double));
|
||||
extern double fmod __P((double, double));
|
||||
|
||||
extern double erf __P((double));
|
||||
extern double erfc __P((double));
|
||||
extern double gamma __P((double));
|
||||
extern double hypot __P((double, double));
|
||||
extern int isnan __P((double));
|
||||
extern int finite __P((double));
|
||||
extern double j0 __P((double));
|
||||
extern double j1 __P((double));
|
||||
extern double jn __P((int, double));
|
||||
extern double lgamma __P((double));
|
||||
extern double y0 __P((double));
|
||||
extern double y1 __P((double));
|
||||
extern double yn __P((int, double));
|
||||
|
||||
extern double acosh __P((double));
|
||||
extern double asinh __P((double));
|
||||
extern double atanh __P((double));
|
||||
extern double cbrt __P((double));
|
||||
extern double logb __P((double));
|
||||
extern double nextafter __P((double, double));
|
||||
extern double remainder __P((double, double));
|
||||
#ifdef _SCALB_INT
|
||||
extern double scalb __P((double, int));
|
||||
#else
|
||||
extern double scalb __P((double, double));
|
||||
#endif
|
||||
|
||||
extern int matherr __P((struct exception *));
|
||||
|
||||
/*
|
||||
* IEEE Test Vector
|
||||
*/
|
||||
extern double significand __P((double));
|
||||
|
||||
/*
|
||||
* Functions callable from C, intended to support IEEE arithmetic.
|
||||
*/
|
||||
extern double copysign __P((double, double));
|
||||
extern int ilogb __P((double));
|
||||
extern double rint __P((double));
|
||||
extern double scalbn __P((double, int));
|
||||
|
||||
/*
|
||||
* BSD math library entry points
|
||||
*/
|
||||
extern double expm1 __P((double));
|
||||
extern double log1p __P((double));
|
||||
|
||||
/*
|
||||
* Reentrant version of gamma & lgamma; passes signgam back by reference
|
||||
* as the second argument; user must allocate space for signgam.
|
||||
*/
|
||||
#ifdef _REENTRANT
|
||||
extern double gamma_r __P((double, int *));
|
||||
extern double lgamma_r __P((double, int *));
|
||||
#endif /* _REENTRANT */
|
||||
|
||||
/* ieee style elementary functions */
|
||||
extern double __ieee754_sqrt __P((double));
|
||||
extern double __ieee754_acos __P((double));
|
||||
extern double __ieee754_acosh __P((double));
|
||||
extern double __ieee754_log __P((double));
|
||||
extern double __ieee754_atanh __P((double));
|
||||
extern double __ieee754_asin __P((double));
|
||||
extern double __ieee754_atan2 __P((double,double));
|
||||
extern double __ieee754_exp __P((double));
|
||||
extern double __ieee754_cosh __P((double));
|
||||
extern double __ieee754_fmod __P((double,double));
|
||||
extern double __ieee754_pow __P((double,double));
|
||||
extern double __ieee754_lgamma_r __P((double,int *));
|
||||
extern double __ieee754_gamma_r __P((double,int *));
|
||||
extern double __ieee754_lgamma __P((double));
|
||||
extern double __ieee754_gamma __P((double));
|
||||
extern double __ieee754_log10 __P((double));
|
||||
extern double __ieee754_sinh __P((double));
|
||||
extern double __ieee754_hypot __P((double,double));
|
||||
extern double __ieee754_j0 __P((double));
|
||||
extern double __ieee754_j1 __P((double));
|
||||
extern double __ieee754_y0 __P((double));
|
||||
extern double __ieee754_y1 __P((double));
|
||||
extern double __ieee754_jn __P((int,double));
|
||||
extern double __ieee754_yn __P((int,double));
|
||||
extern double __ieee754_remainder __P((double,double));
|
||||
extern int __ieee754_rem_pio2 __P((double,double*));
|
||||
#ifdef _SCALB_INT
|
||||
extern double __ieee754_scalb __P((double,int));
|
||||
#else
|
||||
extern double __ieee754_scalb __P((double,double));
|
||||
#endif
|
||||
|
||||
/* fdlibm kernel function */
|
||||
extern double __kernel_standard __P((double,double,int));
|
||||
extern double __kernel_sin __P((double,double,int));
|
||||
extern double __kernel_cos __P((double,double));
|
||||
extern double __kernel_tan __P((double,double,int));
|
||||
extern int __kernel_rem_pio2 __P((double*,double*,int,int,int,const int*));
|
||||
@@ -0,0 +1,92 @@
|
||||
|
||||
/* @(#)k_cos.c 1.3 95/01/18 */
|
||||
/*
|
||||
* ====================================================
|
||||
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||||
*
|
||||
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
||||
* Permission to use, copy, modify, and distribute this
|
||||
* software is freely granted, provided that this notice
|
||||
* is preserved.
|
||||
* ====================================================
|
||||
*/
|
||||
|
||||
/*
|
||||
* __kernel_cos( x, y )
|
||||
* kernel cos function on [-pi/4, pi/4], pi/4 ~ 0.785398164
|
||||
* Input x is assumed to be bounded by ~pi/4 in magnitude.
|
||||
* Input y is the tail of x.
|
||||
*
|
||||
* Algorithm
|
||||
* 1. Since cos(-x) = cos(x), we need only to consider positive x.
|
||||
* 2. if x < 2^-27 (hx<0x3e400000 0), return 1 with inexact if x!=0.
|
||||
* 3. cos(x) is approximated by a polynomial of degree 14 on
|
||||
* [0,pi/4]
|
||||
* 4 14
|
||||
* cos(x) ~ 1 - x*x/2 + C1*x + ... + C6*x
|
||||
* where the remez error is
|
||||
*
|
||||
* | 2 4 6 8 10 12 14 | -58
|
||||
* |cos(x)-(1-.5*x +C1*x +C2*x +C3*x +C4*x +C5*x +C6*x )| <= 2
|
||||
* | |
|
||||
*
|
||||
* 4 6 8 10 12 14
|
||||
* 4. let r = C1*x +C2*x +C3*x +C4*x +C5*x +C6*x , then
|
||||
* cos(x) = 1 - x*x/2 + r
|
||||
* since cos(x+y) ~ cos(x) - sin(x)*y
|
||||
* ~ cos(x) - x*y,
|
||||
* a correction term is necessary in cos(x) and hence
|
||||
* cos(x+y) = 1 - (x*x/2 - (r - x*y))
|
||||
* For better accuracy when x > 0.3, let qx = |x|/4 with
|
||||
* the last 32 bits mask off, and if x > 0.78125, let qx = 0.28125.
|
||||
* Then
|
||||
* cos(x+y) = (1-qx) - ((x*x/2-qx) - (r-x*y)).
|
||||
* Note that 1-qx and (x*x/2-qx) is EXACT here, and the
|
||||
* magnitude of the latter is at least a quarter of x*x/2,
|
||||
* thus, reducing the rounding error in the subtraction.
|
||||
*/
|
||||
|
||||
#include "fdlibm.h"
|
||||
|
||||
#ifdef __STDC__
|
||||
static const double
|
||||
#else
|
||||
static double
|
||||
#endif
|
||||
one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
|
||||
C1 = 4.16666666666666019037e-02, /* 0x3FA55555, 0x5555554C */
|
||||
C2 = -1.38888888888741095749e-03, /* 0xBF56C16C, 0x16C15177 */
|
||||
C3 = 2.48015872894767294178e-05, /* 0x3EFA01A0, 0x19CB1590 */
|
||||
C4 = -2.75573143513906633035e-07, /* 0xBE927E4F, 0x809C52AD */
|
||||
C5 = 2.08757232129817482790e-09, /* 0x3E21EE9E, 0xBDB4B1C4 */
|
||||
C6 = -1.13596475577881948265e-11; /* 0xBDA8FAE9, 0xBE8838D4 */
|
||||
|
||||
#ifdef __STDC__
|
||||
double __kernel_cos(double x, double y)
|
||||
#else
|
||||
double __kernel_cos(x, y)
|
||||
double x,y;
|
||||
#endif
|
||||
{
|
||||
double a,hz,z,r,qx;
|
||||
int ix;
|
||||
ix = __HI(x)&0x7fffffff; /* ix = |x|'s high word*/
|
||||
if(ix<0x3e400000) { /* if x < 2**27 */
|
||||
if(((int)x)==0) return one; /* generate inexact */
|
||||
}
|
||||
z = x*x;
|
||||
r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6)))));
|
||||
if(ix < 0x3FD33333) /* if |x| < 0.3 */
|
||||
return one - (0.5*z - (z*r - x*y));
|
||||
else {
|
||||
if(ix > 0x3fe90000) { /* x > 0.78125 */
|
||||
qx = 0.28125;
|
||||
} else {
|
||||
__HI(qx) = ix-0x00200000; /* x/4 */
|
||||
__LO(qx) = 0;
|
||||
}
|
||||
hz = 0.5*z-qx;
|
||||
a = one-qx;
|
||||
return a - (hz - (z*r-x*y));
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,316 @@
|
||||
|
||||
/* @(#)k_rem_pio2.c 1.3 95/01/18 */
|
||||
/*
|
||||
* ====================================================
|
||||
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||||
*
|
||||
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
||||
* Permission to use, copy, modify, and distribute this
|
||||
* software is freely granted, provided that this notice
|
||||
* is preserved.
|
||||
* ====================================================
|
||||
*/
|
||||
|
||||
/*
|
||||
* __kernel_rem_pio2(x,y,e0,nx,prec,ipio2)
|
||||
* double x[],y[]; int e0,nx,prec; int ipio2[];
|
||||
*
|
||||
* __kernel_rem_pio2 return the last three digits of N with
|
||||
* y = x - N*pi/2
|
||||
* so that |y| < pi/2.
|
||||
*
|
||||
* The method is to compute the integer (mod 8) and fraction parts of
|
||||
* (2/pi)*x without doing the full multiplication. In general we
|
||||
* skip the part of the product that are known to be a huge integer (
|
||||
* more accurately, = 0 mod 8 ). Thus the number of operations are
|
||||
* independent of the exponent of the input.
|
||||
*
|
||||
* (2/pi) is represented by an array of 24-bit integers in ipio2[].
|
||||
*
|
||||
* Input parameters:
|
||||
* x[] The input value (must be positive) is broken into nx
|
||||
* pieces of 24-bit integers in double precision format.
|
||||
* x[i] will be the i-th 24 bit of x. The scaled exponent
|
||||
* of x[0] is given in input parameter e0 (i.e., x[0]*2^e0
|
||||
* match x's up to 24 bits.
|
||||
*
|
||||
* Example of breaking a double positive z into x[0]+x[1]+x[2]:
|
||||
* e0 = ilogb(z)-23
|
||||
* z = scalbn(z,-e0)
|
||||
* for i = 0,1,2
|
||||
* x[i] = floor(z)
|
||||
* z = (z-x[i])*2**24
|
||||
*
|
||||
*
|
||||
* y[] ouput result in an array of double precision numbers.
|
||||
* The dimension of y[] is:
|
||||
* 24-bit precision 1
|
||||
* 53-bit precision 2
|
||||
* 64-bit precision 2
|
||||
* 113-bit precision 3
|
||||
* The actual value is the sum of them. Thus for 113-bit
|
||||
* precison, one may have to do something like:
|
||||
*
|
||||
* long double t,w,r_head, r_tail;
|
||||
* t = (long double)y[2] + (long double)y[1];
|
||||
* w = (long double)y[0];
|
||||
* r_head = t+w;
|
||||
* r_tail = w - (r_head - t);
|
||||
*
|
||||
* e0 The exponent of x[0]
|
||||
*
|
||||
* nx dimension of x[]
|
||||
*
|
||||
* prec an integer indicating the precision:
|
||||
* 0 24 bits (single)
|
||||
* 1 53 bits (double)
|
||||
* 2 64 bits (extended)
|
||||
* 3 113 bits (quad)
|
||||
*
|
||||
* ipio2[]
|
||||
* integer array, contains the (24*i)-th to (24*i+23)-th
|
||||
* bit of 2/pi after binary point. The corresponding
|
||||
* floating value is
|
||||
*
|
||||
* ipio2[i] * 2^(-24(i+1)).
|
||||
*
|
||||
* External function:
|
||||
* double scalbn(), floor();
|
||||
*
|
||||
*
|
||||
* Here is the description of some local variables:
|
||||
*
|
||||
* jk jk+1 is the initial number of terms of ipio2[] needed
|
||||
* in the computation. The recommended value is 2,3,4,
|
||||
* 6 for single, double, extended,and quad.
|
||||
*
|
||||
* jz local integer variable indicating the number of
|
||||
* terms of ipio2[] used.
|
||||
*
|
||||
* jx nx - 1
|
||||
*
|
||||
* jv index for pointing to the suitable ipio2[] for the
|
||||
* computation. In general, we want
|
||||
* ( 2^e0*x[0] * ipio2[jv-1]*2^(-24jv) )/8
|
||||
* is an integer. Thus
|
||||
* e0-3-24*jv >= 0 or (e0-3)/24 >= jv
|
||||
* Hence jv = max(0,(e0-3)/24).
|
||||
*
|
||||
* jp jp+1 is the number of terms in PIo2[] needed, jp = jk.
|
||||
*
|
||||
* q[] double array with integral value, representing the
|
||||
* 24-bits chunk of the product of x and 2/pi.
|
||||
*
|
||||
* q0 the corresponding exponent of q[0]. Note that the
|
||||
* exponent for q[i] would be q0-24*i.
|
||||
*
|
||||
* PIo2[] double precision array, obtained by cutting pi/2
|
||||
* into 24 bits chunks.
|
||||
*
|
||||
* f[] ipio2[] in floating point
|
||||
*
|
||||
* iq[] integer array by breaking up q[] in 24-bits chunk.
|
||||
*
|
||||
* fq[] final product of x*(2/pi) in fq[0],..,fq[jk]
|
||||
*
|
||||
* ih integer. If >0 it indicates q[] is >= 0.5, hence
|
||||
* it also indicates the *sign* of the result.
|
||||
*
|
||||
*/
|
||||
|
||||
|
||||
/*
|
||||
* Constants:
|
||||
* The hexadecimal values are the intended ones for the following
|
||||
* constants. The decimal values may be used, provided that the
|
||||
* compiler will convert from decimal to binary accurately enough
|
||||
* to produce the hexadecimal values shown.
|
||||
*/
|
||||
|
||||
#include "fdlibm.h"
|
||||
|
||||
#ifdef __STDC__
|
||||
static const int init_jk[] = {2,3,4,6}; /* initial value for jk */
|
||||
#else
|
||||
static int init_jk[] = {2,3,4,6};
|
||||
#endif
|
||||
|
||||
#ifdef __STDC__
|
||||
static const double PIo2[] = {
|
||||
#else
|
||||
static double PIo2[] = {
|
||||
#endif
|
||||
1.57079625129699707031e+00, /* 0x3FF921FB, 0x40000000 */
|
||||
7.54978941586159635335e-08, /* 0x3E74442D, 0x00000000 */
|
||||
5.39030252995776476554e-15, /* 0x3CF84698, 0x80000000 */
|
||||
3.28200341580791294123e-22, /* 0x3B78CC51, 0x60000000 */
|
||||
1.27065575308067607349e-29, /* 0x39F01B83, 0x80000000 */
|
||||
1.22933308981111328932e-36, /* 0x387A2520, 0x40000000 */
|
||||
2.73370053816464559624e-44, /* 0x36E38222, 0x80000000 */
|
||||
2.16741683877804819444e-51, /* 0x3569F31D, 0x00000000 */
|
||||
};
|
||||
|
||||
#ifdef __STDC__
|
||||
static const double
|
||||
#else
|
||||
static double
|
||||
#endif
|
||||
zero = 0.0,
|
||||
one = 1.0,
|
||||
two24 = 1.67772160000000000000e+07, /* 0x41700000, 0x00000000 */
|
||||
twon24 = 5.96046447753906250000e-08; /* 0x3E700000, 0x00000000 */
|
||||
|
||||
#ifdef __STDC__
|
||||
int __kernel_rem_pio2(double *x, double *y, int e0, int nx, int prec, const int *ipio2)
|
||||
#else
|
||||
int __kernel_rem_pio2(x,y,e0,nx,prec,ipio2)
|
||||
double x[], y[]; int e0,nx,prec; int ipio2[];
|
||||
#endif
|
||||
{
|
||||
int jz,jx,jv,jp,jk,carry,n,iq[20],i,j,k,m,q0,ih;
|
||||
double z,fw,f[20],fq[20],q[20];
|
||||
|
||||
/* initialize jk*/
|
||||
jk = init_jk[prec];
|
||||
jp = jk;
|
||||
|
||||
/* determine jx,jv,q0, note that 3>q0 */
|
||||
jx = nx-1;
|
||||
jv = (e0-3)/24; if(jv<0) jv=0;
|
||||
q0 = e0-24*(jv+1);
|
||||
|
||||
/* set up f[0] to f[jx+jk] where f[jx+jk] = ipio2[jv+jk] */
|
||||
j = jv-jx; m = jx+jk;
|
||||
for(i=0;i<=m;i++,j++) f[i] = (j<0)? zero : (double) ipio2[j];
|
||||
|
||||
/* compute q[0],q[1],...q[jk] */
|
||||
for (i=0;i<=jk;i++) {
|
||||
for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j]; q[i] = fw;
|
||||
}
|
||||
|
||||
jz = jk;
|
||||
recompute:
|
||||
/* distill q[] into iq[] reversingly */
|
||||
for(i=0,j=jz,z=q[jz];j>0;i++,j--) {
|
||||
fw = (double)((int)(twon24* z));
|
||||
iq[i] = (int)(z-two24*fw);
|
||||
z = q[j-1]+fw;
|
||||
}
|
||||
|
||||
/* compute n */
|
||||
z = scalbn(z,q0); /* actual value of z */
|
||||
z -= 8.0*floor(z*0.125); /* trim off integer >= 8 */
|
||||
n = (int) z;
|
||||
z -= (double)n;
|
||||
ih = 0;
|
||||
if(q0>0) { /* need iq[jz-1] to determine n */
|
||||
i = (iq[jz-1]>>(24-q0)); n += i;
|
||||
iq[jz-1] -= i<<(24-q0);
|
||||
ih = iq[jz-1]>>(23-q0);
|
||||
}
|
||||
else if(q0==0) ih = iq[jz-1]>>23;
|
||||
else if(z>=0.5) ih=2;
|
||||
|
||||
if(ih>0) { /* q > 0.5 */
|
||||
n += 1; carry = 0;
|
||||
for(i=0;i<jz ;i++) { /* compute 1-q */
|
||||
j = iq[i];
|
||||
if(carry==0) {
|
||||
if(j!=0) {
|
||||
carry = 1; iq[i] = 0x1000000- j;
|
||||
}
|
||||
} else iq[i] = 0xffffff - j;
|
||||
}
|
||||
if(q0>0) { /* rare case: chance is 1 in 12 */
|
||||
switch(q0) {
|
||||
case 1:
|
||||
iq[jz-1] &= 0x7fffff; break;
|
||||
case 2:
|
||||
iq[jz-1] &= 0x3fffff; break;
|
||||
}
|
||||
}
|
||||
if(ih==2) {
|
||||
z = one - z;
|
||||
if(carry!=0) z -= scalbn(one,q0);
|
||||
}
|
||||
}
|
||||
|
||||
/* check if recomputation is needed */
|
||||
if(z==zero) {
|
||||
j = 0;
|
||||
for (i=jz-1;i>=jk;i--) j |= iq[i];
|
||||
if(j==0) { /* need recomputation */
|
||||
for(k=1;iq[jk-k]==0;k++); /* k = no. of terms needed */
|
||||
|
||||
for(i=jz+1;i<=jz+k;i++) { /* add q[jz+1] to q[jz+k] */
|
||||
f[jx+i] = (double) ipio2[jv+i];
|
||||
for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j];
|
||||
q[i] = fw;
|
||||
}
|
||||
jz += k;
|
||||
goto recompute;
|
||||
}
|
||||
}
|
||||
|
||||
/* chop off zero terms */
|
||||
if(z==0.0) {
|
||||
jz -= 1; q0 -= 24;
|
||||
while(iq[jz]==0) { jz--; q0-=24;}
|
||||
} else { /* break z into 24-bit if necessary */
|
||||
z = scalbn(z,-q0);
|
||||
if(z>=two24) {
|
||||
fw = (double)((int)(twon24*z));
|
||||
iq[jz] = (int)(z-two24*fw);
|
||||
jz += 1; q0 += 24;
|
||||
iq[jz] = (int) fw;
|
||||
} else iq[jz] = (int) z ;
|
||||
}
|
||||
|
||||
/* convert integer "bit" chunk to floating-point value */
|
||||
fw = scalbn(one,q0);
|
||||
for(i=jz;i>=0;i--) {
|
||||
q[i] = fw*(double)iq[i]; fw*=twon24;
|
||||
}
|
||||
|
||||
/* compute PIo2[0,...,jp]*q[jz,...,0] */
|
||||
for(i=jz;i>=0;i--) {
|
||||
for(fw=0.0,k=0;k<=jp&&k<=jz-i;k++) fw += PIo2[k]*q[i+k];
|
||||
fq[jz-i] = fw;
|
||||
}
|
||||
|
||||
/* compress fq[] into y[] */
|
||||
switch(prec) {
|
||||
case 0:
|
||||
fw = 0.0;
|
||||
for (i=jz;i>=0;i--) fw += fq[i];
|
||||
y[0] = (ih==0)? fw: -fw;
|
||||
break;
|
||||
case 1:
|
||||
case 2:
|
||||
fw = 0.0;
|
||||
for (i=jz;i>=0;i--) fw += fq[i];
|
||||
y[0] = (ih==0)? fw: -fw;
|
||||
fw = fq[0]-fw;
|
||||
for (i=1;i<=jz;i++) fw += fq[i];
|
||||
y[1] = (ih==0)? fw: -fw;
|
||||
break;
|
||||
case 3: /* painful */
|
||||
for (i=jz;i>0;i--) {
|
||||
fw = fq[i-1]+fq[i];
|
||||
fq[i] += fq[i-1]-fw;
|
||||
fq[i-1] = fw;
|
||||
}
|
||||
for (i=jz;i>1;i--) {
|
||||
fw = fq[i-1]+fq[i];
|
||||
fq[i] += fq[i-1]-fw;
|
||||
fq[i-1] = fw;
|
||||
}
|
||||
for (fw=0.0,i=jz;i>=2;i--) fw += fq[i];
|
||||
if(ih==0) {
|
||||
y[0] = fq[0]; y[1] = fq[1]; y[2] = fw;
|
||||
} else {
|
||||
y[0] = -fq[0]; y[1] = -fq[1]; y[2] = -fw;
|
||||
}
|
||||
}
|
||||
return n&7;
|
||||
}
|
||||
@@ -0,0 +1,74 @@
|
||||
|
||||
/* @(#)k_sin.c 1.3 95/01/18 */
|
||||
/*
|
||||
* ====================================================
|
||||
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||||
*
|
||||
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
||||
* Permission to use, copy, modify, and distribute this
|
||||
* software is freely granted, provided that this notice
|
||||
* is preserved.
|
||||
* ====================================================
|
||||
*/
|
||||
|
||||
/* __kernel_sin( x, y, iy)
|
||||
* kernel sin function on [-pi/4, pi/4], pi/4 ~ 0.7854
|
||||
* Input x is assumed to be bounded by ~pi/4 in magnitude.
|
||||
* Input y is the tail of x.
|
||||
* Input iy indicates whether y is 0. (if iy=0, y assume to be 0).
|
||||
*
|
||||
* Algorithm
|
||||
* 1. Since sin(-x) = -sin(x), we need only to consider positive x.
|
||||
* 2. if x < 2^-27 (hx<0x3e400000 0), return x with inexact if x!=0.
|
||||
* 3. sin(x) is approximated by a polynomial of degree 13 on
|
||||
* [0,pi/4]
|
||||
* 3 13
|
||||
* sin(x) ~ x + S1*x + ... + S6*x
|
||||
* where
|
||||
*
|
||||
* |sin(x) 2 4 6 8 10 12 | -58
|
||||
* |----- - (1+S1*x +S2*x +S3*x +S4*x +S5*x +S6*x )| <= 2
|
||||
* | x |
|
||||
*
|
||||
* 4. sin(x+y) = sin(x) + sin'(x')*y
|
||||
* ~ sin(x) + (1-x*x/2)*y
|
||||
* For better accuracy, let
|
||||
* 3 2 2 2 2
|
||||
* r = x *(S2+x *(S3+x *(S4+x *(S5+x *S6))))
|
||||
* then 3 2
|
||||
* sin(x) = x + (S1*x + (x *(r-y/2)+y))
|
||||
*/
|
||||
|
||||
#include "fdlibm.h"
|
||||
|
||||
#ifdef __STDC__
|
||||
static const double
|
||||
#else
|
||||
static double
|
||||
#endif
|
||||
half = 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */
|
||||
S1 = -1.66666666666666324348e-01, /* 0xBFC55555, 0x55555549 */
|
||||
S2 = 8.33333333332248946124e-03, /* 0x3F811111, 0x1110F8A6 */
|
||||
S3 = -1.98412698298579493134e-04, /* 0xBF2A01A0, 0x19C161D5 */
|
||||
S4 = 2.75573137070700676789e-06, /* 0x3EC71DE3, 0x57B1FE7D */
|
||||
S5 = -2.50507602534068634195e-08, /* 0xBE5AE5E6, 0x8A2B9CEB */
|
||||
S6 = 1.58969099521155010221e-10; /* 0x3DE5D93A, 0x5ACFD57C */
|
||||
|
||||
#ifdef __STDC__
|
||||
double __kernel_sin(double x, double y, int iy)
|
||||
#else
|
||||
double __kernel_sin(x, y, iy)
|
||||
double x,y; int iy; /* iy=0 if y is zero */
|
||||
#endif
|
||||
{
|
||||
double z,r,v;
|
||||
int ix;
|
||||
ix = __HI(x)&0x7fffffff; /* high word of x */
|
||||
if(ix<0x3e400000) /* |x| < 2**-27 */
|
||||
{if((int)x==0) return x;} /* generate inexact */
|
||||
z = x*x;
|
||||
v = z*x;
|
||||
r = S2+z*(S3+z*(S4+z*(S5+z*S6)));
|
||||
if(iy==0) return x+v*(S1+z*r);
|
||||
else return x-((z*(half*y-v*r)-y)-v*S1);
|
||||
}
|
||||
@@ -0,0 +1,12 @@
|
||||
clang --target=wasm32 -O2 -ffreestanding -fno-builtin -nostdlib -Wl,--no-entry -Wl,--export=sin -Wl,--export=cos -o fdlibm.wasm \
|
||||
s_sin.c s_cos.c k_sin.c k_cos.c e_rem_pio2.c k_rem_pio2.c s_scalbn.c
|
||||
|
||||
define __LITTLE_ENDIAN for wasm
|
||||
must provide implementation for the functions below
|
||||
|
||||
# wasm-ld-21: error: /tmp/e_rem_pio2-14e979.o: undefined symbol: fabs
|
||||
# wasm-ld-21: error: /tmp/k_rem_pio2-6d7f33.o: undefined symbol: floor
|
||||
# wasm-ld-21: error: /tmp/s_scalbn-8b4ff9.o: undefined symbol: copysign
|
||||
# wasm-ld-21: error: /tmp/s_scalbn-8b4ff9.o: undefined symbol: copysign
|
||||
# wasm-ld-21: error: /tmp/s_scalbn-8b4ff9.o: undefined symbol: copysign
|
||||
# clang: error: linker command failed with exit code 1 (use -v to see invocation)
|
||||
@@ -0,0 +1,78 @@
|
||||
|
||||
/* @(#)s_cos.c 1.3 95/01/18 */
|
||||
/*
|
||||
* ====================================================
|
||||
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||||
*
|
||||
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
||||
* Permission to use, copy, modify, and distribute this
|
||||
* software is freely granted, provided that this notice
|
||||
* is preserved.
|
||||
* ====================================================
|
||||
*/
|
||||
|
||||
/* cos(x)
|
||||
* Return cosine function of x.
|
||||
*
|
||||
* kernel function:
|
||||
* __kernel_sin ... sine function on [-pi/4,pi/4]
|
||||
* __kernel_cos ... cosine function on [-pi/4,pi/4]
|
||||
* __ieee754_rem_pio2 ... argument reduction routine
|
||||
*
|
||||
* Method.
|
||||
* Let S,C and T denote the sin, cos and tan respectively on
|
||||
* [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
|
||||
* in [-pi/4 , +pi/4], and let n = k mod 4.
|
||||
* We have
|
||||
*
|
||||
* n sin(x) cos(x) tan(x)
|
||||
* ----------------------------------------------------------
|
||||
* 0 S C T
|
||||
* 1 C -S -1/T
|
||||
* 2 -S -C T
|
||||
* 3 -C S -1/T
|
||||
* ----------------------------------------------------------
|
||||
*
|
||||
* Special cases:
|
||||
* Let trig be any of sin, cos, or tan.
|
||||
* trig(+-INF) is NaN, with signals;
|
||||
* trig(NaN) is that NaN;
|
||||
*
|
||||
* Accuracy:
|
||||
* TRIG(x) returns trig(x) nearly rounded
|
||||
*/
|
||||
|
||||
#include "fdlibm.h"
|
||||
|
||||
#ifdef __STDC__
|
||||
double cos(double x)
|
||||
#else
|
||||
double cos(x)
|
||||
double x;
|
||||
#endif
|
||||
{
|
||||
double y[2],z=0.0;
|
||||
int n, ix;
|
||||
|
||||
/* High word of x. */
|
||||
ix = __HI(x);
|
||||
|
||||
/* |x| ~< pi/4 */
|
||||
ix &= 0x7fffffff;
|
||||
if(ix <= 0x3fe921fb) return __kernel_cos(x,z);
|
||||
|
||||
/* cos(Inf or NaN) is NaN */
|
||||
else if (ix>=0x7ff00000) return x-x;
|
||||
|
||||
/* argument reduction needed */
|
||||
else {
|
||||
n = __ieee754_rem_pio2(x,y);
|
||||
switch(n&3) {
|
||||
case 0: return __kernel_cos(y[0],y[1]);
|
||||
case 1: return -__kernel_sin(y[0],y[1],1);
|
||||
case 2: return -__kernel_cos(y[0],y[1]);
|
||||
default:
|
||||
return __kernel_sin(y[0],y[1],1);
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,72 @@
|
||||
|
||||
/* @(#)s_scalbn.c 1.3 95/01/18 */
|
||||
/*
|
||||
* ====================================================
|
||||
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||||
*
|
||||
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
||||
* Permission to use, copy, modify, and distribute this
|
||||
* software is freely granted, provided that this notice
|
||||
* is preserved.
|
||||
* ====================================================
|
||||
*/
|
||||
|
||||
/*
|
||||
* scalbn (double x, int n)
|
||||
* scalbn(x,n) returns x* 2**n computed by exponent
|
||||
* manipulation rather than by actually performing an
|
||||
* exponentiation or a multiplication.
|
||||
*/
|
||||
|
||||
#include "fdlibm.h"
|
||||
|
||||
#ifdef __STDC__
|
||||
static const double
|
||||
#else
|
||||
static double
|
||||
#endif
|
||||
two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
|
||||
twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
|
||||
huge = 1.0e+300, tiny = 1.0e-300;
|
||||
|
||||
#ifdef __STDC__
|
||||
double scalbn(double x, int n)
|
||||
#else
|
||||
double scalbn(x, n)
|
||||
double x;
|
||||
int n;
|
||||
#endif
|
||||
{
|
||||
int k, hx, lx;
|
||||
hx = __HI(x);
|
||||
lx = __LO(x);
|
||||
k = (hx & 0x7ff00000) >> 20; /* extract exponent */
|
||||
if (k == 0) { /* 0 or subnormal x */
|
||||
if ((lx | (hx & 0x7fffffff)) == 0)
|
||||
return x; /* +-0 */
|
||||
x *= two54;
|
||||
hx = __HI(x);
|
||||
k = ((hx & 0x7ff00000) >> 20) - 54;
|
||||
if (n < -50000)
|
||||
return tiny * x; /*underflow*/
|
||||
}
|
||||
if (k == 0x7ff)
|
||||
return x + x; /* NaN or Inf */
|
||||
k = k + n;
|
||||
if (k > 0x7fe)
|
||||
return huge * copysign(huge, x); /* overflow */
|
||||
if (k > 0) /* normal result */
|
||||
{
|
||||
__HI(x) = (hx & 0x800fffff) | (k << 20);
|
||||
return x;
|
||||
}
|
||||
if (k <= -54) {
|
||||
if (n > 50000) /* in case integer overflow in n+k */
|
||||
return huge * copysign(huge, x); /*overflow*/
|
||||
else
|
||||
return tiny * copysign(tiny, x); /*underflow*/
|
||||
}
|
||||
k += 54; /* subnormal result */
|
||||
__HI(x) = (hx & 0x800fffff) | (k << 20);
|
||||
return x * twom54;
|
||||
}
|
||||
@@ -0,0 +1,78 @@
|
||||
|
||||
/* @(#)s_sin.c 1.3 95/01/18 */
|
||||
/*
|
||||
* ====================================================
|
||||
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||||
*
|
||||
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
||||
* Permission to use, copy, modify, and distribute this
|
||||
* software is freely granted, provided that this notice
|
||||
* is preserved.
|
||||
* ====================================================
|
||||
*/
|
||||
|
||||
/* sin(x)
|
||||
* Return sine function of x.
|
||||
*
|
||||
* kernel function:
|
||||
* __kernel_sin ... sine function on [-pi/4,pi/4]
|
||||
* __kernel_cos ... cose function on [-pi/4,pi/4]
|
||||
* __ieee754_rem_pio2 ... argument reduction routine
|
||||
*
|
||||
* Method.
|
||||
* Let S,C and T denote the sin, cos and tan respectively on
|
||||
* [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
|
||||
* in [-pi/4 , +pi/4], and let n = k mod 4.
|
||||
* We have
|
||||
*
|
||||
* n sin(x) cos(x) tan(x)
|
||||
* ----------------------------------------------------------
|
||||
* 0 S C T
|
||||
* 1 C -S -1/T
|
||||
* 2 -S -C T
|
||||
* 3 -C S -1/T
|
||||
* ----------------------------------------------------------
|
||||
*
|
||||
* Special cases:
|
||||
* Let trig be any of sin, cos, or tan.
|
||||
* trig(+-INF) is NaN, with signals;
|
||||
* trig(NaN) is that NaN;
|
||||
*
|
||||
* Accuracy:
|
||||
* TRIG(x) returns trig(x) nearly rounded
|
||||
*/
|
||||
|
||||
#include "fdlibm.h"
|
||||
|
||||
#ifdef __STDC__
|
||||
double sin(double x)
|
||||
#else
|
||||
double sin(x)
|
||||
double x;
|
||||
#endif
|
||||
{
|
||||
double y[2],z=0.0;
|
||||
int n, ix;
|
||||
|
||||
/* High word of x. */
|
||||
ix = __HI(x);
|
||||
|
||||
/* |x| ~< pi/4 */
|
||||
ix &= 0x7fffffff;
|
||||
if(ix <= 0x3fe921fb) return __kernel_sin(x,z,0);
|
||||
|
||||
/* sin(Inf or NaN) is NaN */
|
||||
else if (ix>=0x7ff00000) return x-x;
|
||||
|
||||
/* argument reduction needed */
|
||||
else {
|
||||
n = __ieee754_rem_pio2(x,y);
|
||||
switch(n&3) {
|
||||
case 0: return __kernel_sin(y[0],y[1],1);
|
||||
case 1: return __kernel_cos(y[0],y[1]);
|
||||
case 2: return -__kernel_sin(y[0],y[1],1);
|
||||
default:
|
||||
return -__kernel_cos(y[0],y[1]);
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user