From 58589c237ba7b181ce2ba35497e9f1f122afc68e Mon Sep 17 00:00:00 2001
From: rtoy <rtoy>
Date: Wed, 19 Jul 2006 02:45:53 +0000
Subject: [PATCH] Initial import.

---
 lisp/e_rem_pio2.c | 175 +++++++++++++++++++++++++
 lisp/fdlibm.h     | 216 +++++++++++++++++++++++++++++++
 lisp/k_rem_pio2.c | 316 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 707 insertions(+)
 create mode 100644 lisp/e_rem_pio2.c
 create mode 100644 lisp/fdlibm.h
 create mode 100644 lisp/k_rem_pio2.c

diff --git a/lisp/e_rem_pio2.c b/lisp/e_rem_pio2.c
new file mode 100644
index 000000000..7242bb232
--- /dev/null
+++ b/lisp/e_rem_pio2.c
@@ -0,0 +1,175 @@
+
+/* @(#)e_rem_pio2.c 1.4 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.
+ * ====================================================
+ *
+ */
+
+/* __ieee754_rem_pio2(x,y)
+ * 
+ * return the remainder of x rem pi/2 in y[0]+y[1] 
+ * use __kernel_rem_pio2()
+ */
+
+#include "fdlibm.h"
+
+/*
+ * Table of constants for 2/pi, 396 Hex digits (476 decimal) of 2/pi 
+ */
+#ifdef __STDC__
+static const int two_over_pi[] = {
+#else
+static int two_over_pi[] = {
+#endif
+0xA2F983, 0x6E4E44, 0x1529FC, 0x2757D1, 0xF534DD, 0xC0DB62, 
+0x95993C, 0x439041, 0xFE5163, 0xABDEBB, 0xC561B7, 0x246E3A, 
+0x424DD2, 0xE00649, 0x2EEA09, 0xD1921C, 0xFE1DEB, 0x1CB129, 
+0xA73EE8, 0x8235F5, 0x2EBB44, 0x84E99C, 0x7026B4, 0x5F7E41, 
+0x3991D6, 0x398353, 0x39F49C, 0x845F8B, 0xBDF928, 0x3B1FF8, 
+0x97FFDE, 0x05980F, 0xEF2F11, 0x8B5A0A, 0x6D1F6D, 0x367ECF, 
+0x27CB09, 0xB74F46, 0x3F669E, 0x5FEA2D, 0x7527BA, 0xC7EBE5, 
+0xF17B3D, 0x0739F7, 0x8A5292, 0xEA6BFB, 0x5FB11F, 0x8D5D08, 
+0x560330, 0x46FC7B, 0x6BABF0, 0xCFBC20, 0x9AF436, 0x1DA9E3, 
+0x91615E, 0xE61B08, 0x659985, 0x5F14A0, 0x68408D, 0xFFD880, 
+0x4D7327, 0x310606, 0x1556CA, 0x73A8C9, 0x60E27B, 0xC08C6B, 
+};
+
+#ifdef __STDC__
+static const int npio2_hw[] = {
+#else
+static int npio2_hw[] = {
+#endif
+0x3FF921FB, 0x400921FB, 0x4012D97C, 0x401921FB, 0x401F6A7A, 0x4022D97C,
+0x4025FDBB, 0x402921FB, 0x402C463A, 0x402F6A7A, 0x4031475C, 0x4032D97C,
+0x40346B9C, 0x4035FDBB, 0x40378FDB, 0x403921FB, 0x403AB41B, 0x403C463A,
+0x403DD85A, 0x403F6A7A, 0x40407E4C, 0x4041475C, 0x4042106C, 0x4042D97C,
+0x4043A28C, 0x40446B9C, 0x404534AC, 0x4045FDBB, 0x4046C6CB, 0x40478FDB,
+0x404858EB, 0x404921FB,
+};
+
+/*
+ * invpio2:  53 bits of 2/pi
+ * pio2_1:   first  33 bit of pi/2
+ * pio2_1t:  pi/2 - pio2_1
+ * pio2_2:   second 33 bit of pi/2
+ * pio2_2t:  pi/2 - (pio2_1+pio2_2)
+ * pio2_3:   third  33 bit of pi/2
+ * pio2_3t:  pi/2 - (pio2_1+pio2_2+pio2_3)
+ */
+
+#ifdef __STDC__
+static const double 
+#else
+static double 
+#endif
+zero =  0.00000000000000000000e+00, /* 0x00000000, 0x00000000 */
+half =  5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */
+two24 =  1.67772160000000000000e+07, /* 0x41700000, 0x00000000 */
+invpio2 =  6.36619772367581382433e-01, /* 0x3FE45F30, 0x6DC9C883 */
+pio2_1  =  1.57079632673412561417e+00, /* 0x3FF921FB, 0x54400000 */
+pio2_1t =  6.07710050650619224932e-11, /* 0x3DD0B461, 0x1A626331 */
+pio2_2  =  6.07710050630396597660e-11, /* 0x3DD0B461, 0x1A600000 */
+pio2_2t =  2.02226624879595063154e-21, /* 0x3BA3198A, 0x2E037073 */
+pio2_3  =  2.02226624871116645580e-21, /* 0x3BA3198A, 0x2E000000 */
+pio2_3t =  8.47842766036889956997e-32; /* 0x397B839A, 0x252049C1 */
+
+#ifdef __STDC__
+	int __ieee754_rem_pio2(double x, double *y)
+#else
+	int __ieee754_rem_pio2(x,y)
+	double x,y[];
+#endif
+{
+	double z,w,t,r,fn;
+	double tx[3];
+	int e0,i,j,nx,n,ix,hx;
+
+	hx = __HI(x);		/* high word of x */
+	ix = hx&0x7fffffff;
+	if(ix<=0x3fe921fb)   /* |x| ~<= pi/4 , no need for reduction */
+	    {y[0] = x; y[1] = 0; return 0;}
+	if(ix<0x4002d97c) {  /* |x| < 3pi/4, special case with n=+-1 */
+	    if(hx>0) { 
+		z = x - pio2_1;
+		if(ix!=0x3ff921fb) { 	/* 33+53 bit pi is good enough */
+		    y[0] = z - pio2_1t;
+		    y[1] = (z-y[0])-pio2_1t;
+		} else {		/* near pi/2, use 33+33+53 bit pi */
+		    z -= pio2_2;
+		    y[0] = z - pio2_2t;
+		    y[1] = (z-y[0])-pio2_2t;
+		}
+		return 1;
+	    } else {	/* negative x */
+		z = x + pio2_1;
+		if(ix!=0x3ff921fb) { 	/* 33+53 bit pi is good enough */
+		    y[0] = z + pio2_1t;
+		    y[1] = (z-y[0])+pio2_1t;
+		} else {		/* near pi/2, use 33+33+53 bit pi */
+		    z += pio2_2;
+		    y[0] = z + pio2_2t;
+		    y[1] = (z-y[0])+pio2_2t;
+		}
+		return -1;
+	    }
+	}
+	if(ix<=0x413921fb) { /* |x| ~<= 2^19*(pi/2), medium size */
+	    t  = fabs(x);
+	    n  = (int) (t*invpio2+half);
+	    fn = (double)n;
+	    r  = t-fn*pio2_1;
+	    w  = fn*pio2_1t;	/* 1st round good to 85 bit */
+	    if(n<32&&ix!=npio2_hw[n-1]) {	
+		y[0] = r-w;	/* quick check no cancellation */
+	    } else {
+	        j  = ix>>20;
+	        y[0] = r-w; 
+	        i = j-(((__HI(y[0]))>>20)&0x7ff);
+	        if(i>16) {  /* 2nd iteration needed, good to 118 */
+		    t  = r;
+		    w  = fn*pio2_2;	
+		    r  = t-w;
+		    w  = fn*pio2_2t-((t-r)-w);	
+		    y[0] = r-w;
+		    i = j-(((__HI(y[0]))>>20)&0x7ff);
+		    if(i>49)  {	/* 3rd iteration need, 151 bits acc */
+		    	t  = r;	/* will cover all possible cases */
+		    	w  = fn*pio2_3;	
+		    	r  = t-w;
+		    	w  = fn*pio2_3t-((t-r)-w);	
+		    	y[0] = r-w;
+		    }
+		}
+	    }
+	    y[1] = (r-y[0])-w;
+	    if(hx<0) 	{y[0] = -y[0]; y[1] = -y[1]; return -n;}
+	    else	 return n;
+	}
+    /* 
+     * all other (large) arguments
+     */
+	if(ix>=0x7ff00000) {		/* x is inf or NaN */
+	    y[0]=y[1]=x-x; return 0;
+	}
+    /* set z = scalbn(|x|,ilogb(x)-23) */
+	__LO(z) = __LO(x);
+	e0 	= (ix>>20)-1046;	/* e0 = ilogb(z)-23; */
+	__HI(z) = ix - (e0<<20);
+	for(i=0;i<2;i++) {
+		tx[i] = (double)((int)(z));
+		z     = (z-tx[i])*two24;
+	}
+	tx[2] = z;
+	nx = 3;
+	while(tx[nx-1]==zero) nx--;	/* skip zero term */
+	n  =  __kernel_rem_pio2(tx,y,e0,nx,2,two_over_pi);
+	if(hx<0) {y[0] = -y[0]; y[1] = -y[1]; return -n;}
+	return n;
+}
diff --git a/lisp/fdlibm.h b/lisp/fdlibm.h
new file mode 100644
index 000000000..02ca7fb2d
--- /dev/null
+++ b/lisp/fdlibm.h
@@ -0,0 +1,216 @@
+
+/* @(#)fdlibm.h 1.5 04/04/22 */
+/*
+ * ====================================================
+ * Copyright (C) 2004 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice 
+ * is preserved.
+ * ====================================================
+ */
+
+/* Sometimes it's necessary to define __LITTLE_ENDIAN explicitly
+   but these catch some common cases. */
+
+#if defined(i386) || defined(i486) || \
+	defined(intel) || defined(x86) || defined(i86pc) || \
+	defined(__alpha) || defined(__osf__)
+#define __LITTLE_ENDIAN
+#endif
+
+#ifdef __LITTLE_ENDIAN
+#define __HI(x) *(1+(int*)&x)
+#define __LO(x) *(int*)&x
+#define __HIp(x) *(1+(int*)x)
+#define __LOp(x) *(int*)x
+#else
+#define __HI(x) *(int*)&x
+#define __LO(x) *(1+(int*)&x)
+#define __HIp(x) *(int*)x
+#define __LOp(x) *(1+(int*)x)
+#endif
+
+#ifdef __STDC__
+#define	__P(p)	p
+#else
+#define	__P(p)	()
+#endif
+
+/*
+ * ANSI/POSIX
+ */
+
+extern int signgam;
+
+#define	MAXFLOAT	((float)3.40282346638528860e+38)
+
+enum fdversion {fdlibm_ieee = -1, fdlibm_svid, fdlibm_xopen, fdlibm_posix};
+
+#define _LIB_VERSION_TYPE enum fdversion
+#define _LIB_VERSION _fdlib_version  
+
+/* if global variable _LIB_VERSION is not desirable, one may 
+ * change the following to be a constant by: 
+ *	#define _LIB_VERSION_TYPE const enum version
+ * In that case, after one initializes the value _LIB_VERSION (see
+ * s_lib_version.c) during compile time, it cannot be modified
+ * in the middle of a program
+ */ 
+extern  _LIB_VERSION_TYPE  _LIB_VERSION;
+
+#define _IEEE_  fdlibm_ieee
+#define _SVID_  fdlibm_svid
+#define _XOPEN_ fdlibm_xopen
+#define _POSIX_ fdlibm_posix
+
+struct exception {
+	int type;
+	char *name;
+	double arg1;
+	double arg2;
+	double retval;
+};
+
+#define	HUGE		MAXFLOAT
+
+/* 
+ * set X_TLOSS = pi*2**52, which is possibly defined in <values.h>
+ * (one may replace the following line by "#include <values.h>")
+ */
+
+#define X_TLOSS		1.41484755040568800000e+16 
+
+#define	DOMAIN		1
+#define	SING		2
+#define	OVERFLOW	3
+#define	UNDERFLOW	4
+#define	TLOSS		5
+#define	PLOSS		6
+
+/*
+ * ANSI/POSIX
+ */
+extern double acos __P((double));
+extern double asin __P((double));
+extern double atan __P((double));
+extern double atan2 __P((double, double));
+extern double cos __P((double));
+extern double sin __P((double));
+extern double tan __P((double));
+
+extern double cosh __P((double));
+extern double sinh __P((double));
+extern double tanh __P((double));
+
+extern double exp __P((double));
+extern double frexp __P((double, int *));
+extern double ldexp __P((double, int));
+extern double log __P((double));
+extern double log10 __P((double));
+extern double modf __P((double, double *));
+
+extern double pow __P((double, double));
+extern double sqrt __P((double));
+
+extern double ceil __P((double));
+extern double fabs __P((double));
+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*));
diff --git a/lisp/k_rem_pio2.c b/lisp/k_rem_pio2.c
new file mode 100644
index 000000000..ec473ac0d
--- /dev/null
+++ b/lisp/k_rem_pio2.c
@@ -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;
+}
-- 
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