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Diffstat (limited to 'winsup/mingw/mingwex/math/cephes_emath.c')
| -rw-r--r-- | winsup/mingw/mingwex/math/cephes_emath.c | 1318 |
1 files changed, 0 insertions, 1318 deletions
diff --git a/winsup/mingw/mingwex/math/cephes_emath.c b/winsup/mingw/mingwex/math/cephes_emath.c deleted file mode 100644 index ab798a2d2..000000000 --- a/winsup/mingw/mingwex/math/cephes_emath.c +++ /dev/null @@ -1,1318 +0,0 @@ -/* This file is extracted from S L Moshier's ioldoubl.c, - * modified for use in MinGW - * - * Extended precision arithmetic functions for long double I/O. - * This program has been placed in the public domain. - */ - - - -/* - * Revision history: - * - * 5 Jan 84 PDP-11 assembly language version - * 6 Dec 86 C language version - * 30 Aug 88 100 digit version, improved rounding - * 15 May 92 80-bit long double support - * - * Author: S. L. Moshier. - * - * 6 Oct 02 Modified for MinGW by inlining utility routines, - * removing global variables and splitting out strtold - * from _IO_ldtoa and _IO_ldtostr. - * - * Danny Smith <dannysmith@users.sourceforge.net> - * - */ - - -#include "cephes_emath.h" - -/* - * The constants are for 64 bit precision. - */ - - -/* Move in external format number, - * converting it to internal format. - */ -void __emovi(const short unsigned int * __restrict__ a, - short unsigned int * __restrict__ b) -{ -register const unsigned short *p; -register unsigned short *q; -int i; - -q = b; -p = a + (NE-1); /* point to last word of external number */ -/* get the sign bit */ -if( *p & 0x8000 ) - *q++ = 0xffff; -else - *q++ = 0; -/* get the exponent */ -*q = *p--; -*q++ &= 0x7fff; /* delete the sign bit */ -#ifdef INFINITY -if( (*(q-1) & 0x7fff) == 0x7fff ) - { -#ifdef NANS - if( __eisnan(a) ) - { - *q++ = 0; - for( i=3; i<NI; i++ ) - *q++ = *p--; - return; - } -#endif - for( i=2; i<NI; i++ ) - *q++ = 0; - return; - } -#endif -/* clear high guard word */ -*q++ = 0; -/* move in the significand */ -for( i=0; i<NE-1; i++ ) - *q++ = *p--; -/* clear low guard word */ -*q = 0; -} - - -/* -; Add significands -; x + y replaces y -*/ - -void __eaddm(const short unsigned int * __restrict__ x, - short unsigned int * __restrict__ y) -{ -register unsigned long a; -int i; -unsigned int carry; - -x += NI-1; -y += NI-1; -carry = 0; -for( i=M; i<NI; i++ ) - { - a = (unsigned long )(*x) + (unsigned long )(*y) + carry; - if( a & 0x10000 ) - carry = 1; - else - carry = 0; - *y = (unsigned short )a; - --x; - --y; - } -} - -/* -; Subtract significands -; y - x replaces y -*/ - -void __esubm(const short unsigned int * __restrict__ x, - short unsigned int * __restrict__ y) -{ -unsigned long a; -int i; -unsigned int carry; - -x += NI-1; -y += NI-1; -carry = 0; -for( i=M; i<NI; i++ ) - { - a = (unsigned long )(*y) - (unsigned long )(*x) - carry; - if( a & 0x10000 ) - carry = 1; - else - carry = 0; - *y = (unsigned short )a; - --x; - --y; - } -} - - -/* Multiply significand of e-type number b -by 16-bit quantity a, e-type result to c. */ - -static void __m16m(short unsigned int a, - short unsigned int * __restrict__ b, - short unsigned int * __restrict__ c) -{ -register unsigned short *pp; -register unsigned long carry; -unsigned short *ps; -unsigned short p[NI]; -unsigned long aa, m; -int i; - -aa = a; -pp = &p[NI-2]; -*pp++ = 0; -*pp = 0; -ps = &b[NI-1]; - -for( i=M+1; i<NI; i++ ) - { - if( *ps == 0 ) - { - --ps; - --pp; - *(pp-1) = 0; - } - else - { - m = (unsigned long) aa * *ps--; - carry = (m & 0xffff) + *pp; - *pp-- = (unsigned short )carry; - carry = (carry >> 16) + (m >> 16) + *pp; - *pp = (unsigned short )carry; - *(pp-1) = carry >> 16; - } - } -for( i=M; i<NI; i++ ) - c[i] = p[i]; -} - - -/* Divide significands. Neither the numerator nor the denominator -is permitted to have its high guard word nonzero. */ - - -int __edivm(short unsigned int * __restrict__ den, - short unsigned int * __restrict__ num) -{ -int i; -register unsigned short *p; -unsigned long tnum; -unsigned short j, tdenm, tquot; -unsigned short tprod[NI+1]; -unsigned short equot[NI]; - -p = &equot[0]; -*p++ = num[0]; -*p++ = num[1]; - -for( i=M; i<NI; i++ ) - { - *p++ = 0; - } -__eshdn1( num ); -tdenm = den[M+1]; -for( i=M; i<NI; i++ ) - { - /* Find trial quotient digit (the radix is 65536). */ - tnum = (((unsigned long) num[M]) << 16) + num[M+1]; - - /* Do not execute the divide instruction if it will overflow. */ - if( (tdenm * 0xffffUL) < tnum ) - tquot = 0xffff; - else - tquot = tnum / tdenm; - - /* Prove that the divide worked. */ -/* - tcheck = (unsigned long )tquot * tdenm; - if( tnum - tcheck > tdenm ) - tquot = 0xffff; -*/ - /* Multiply denominator by trial quotient digit. */ - __m16m( tquot, den, tprod ); - /* The quotient digit may have been overestimated. */ - if( __ecmpm( tprod, num ) > 0 ) - { - tquot -= 1; - __esubm( den, tprod ); - if( __ecmpm( tprod, num ) > 0 ) - { - tquot -= 1; - __esubm( den, tprod ); - } - } - __esubm( tprod, num ); - equot[i] = tquot; - __eshup6(num); - } -/* test for nonzero remainder after roundoff bit */ -p = &num[M]; -j = 0; -for( i=M; i<NI; i++ ) - { - j |= *p++; - } -if( j ) - j = 1; - -for( i=0; i<NI; i++ ) - num[i] = equot[i]; - -return( (int )j ); -} - - - -/* Multiply significands */ -int __emulm(const short unsigned int * __restrict__ a, - short unsigned int * __restrict__ b) -{ -const unsigned short *p; -unsigned short *q; -unsigned short pprod[NI]; -unsigned short equot[NI]; -unsigned short j; -int i; - -equot[0] = b[0]; -equot[1] = b[1]; -for( i=M; i<NI; i++ ) - equot[i] = 0; - -j = 0; -p = &a[NI-1]; -q = &equot[NI-1]; -for( i=M+1; i<NI; i++ ) - { - if( *p == 0 ) - { - --p; - } - else - { - __m16m( *p--, b, pprod ); - __eaddm(pprod, equot); - } - j |= *q; - __eshdn6(equot); - } - -for( i=0; i<NI; i++ ) - b[i] = equot[i]; - -/* return flag for lost nonzero bits */ -return( (int)j ); -} - - - -/* - * Normalize and round off. - * - * The internal format number to be rounded is "s". - * Input "lost" indicates whether the number is exact. - * This is the so-called sticky bit. - * - * Input "subflg" indicates whether the number was obtained - * by a subtraction operation. In that case if lost is nonzero - * then the number is slightly smaller than indicated. - * - * Input "exp" is the biased exponent, which may be negative. - * the exponent field of "s" is ignored but is replaced by - * "exp" as adjusted by normalization and rounding. - * - * Input "rcntrl" is the rounding control. - * - * Input "rnprc" is precison control (64 or NBITS). - */ - -void __emdnorm(short unsigned int *s, int lost, int subflg, long int exp, int rcntrl, int rndprc) -{ -int i, j; -unsigned short r; -int rw = NI-1; /* low guard word */ -int re = NI-2; -const unsigned short rmsk = 0xffff; -const unsigned short rmbit = 0x8000; -#if NE == 6 -unsigned short rbit[NI] = {0,0,0,0,0,0,0,1,0}; -#else -unsigned short rbit[NI] = {0,0,0,0,0,0,0,0,0,0,0,1,0}; -#endif - -/* Normalize */ -j = __enormlz( s ); - -/* a blank significand could mean either zero or infinity. */ -#ifndef INFINITY -if( j > NBITS ) - { - __ecleazs( s ); - return; - } -#endif -exp -= j; -#ifndef INFINITY -if( exp >= 32767L ) - goto overf; -#else -if( (j > NBITS) && (exp < 32767L) ) - { - __ecleazs( s ); - return; - } -#endif -if( exp < 0L ) - { - if( exp > (long )(-NBITS-1) ) - { - j = (int )exp; - i = __eshift( s, j ); - if( i ) - lost = 1; - } - else - { - __ecleazs( s ); - return; - } - } -/* Round off, unless told not to by rcntrl. */ -if( rcntrl == 0 ) - goto mdfin; -if (rndprc == 64) - { - rw = 7; - re = 6; - rbit[NI-2] = 0; - rbit[6] = 1; - } - -/* Shift down 1 temporarily if the data structure has an implied - * most significant bit and the number is denormal. - * For rndprc = 64 or NBITS, there is no implied bit. - * But Intel long double denormals lose one bit of significance even so. - */ -#if IBMPC -if( (exp <= 0) && (rndprc != NBITS) ) -#else -if( (exp <= 0) && (rndprc != 64) && (rndprc != NBITS) ) -#endif - { - lost |= s[NI-1] & 1; - __eshdn1(s); - } -/* Clear out all bits below the rounding bit, - * remembering in r if any were nonzero. - */ -r = s[rw] & rmsk; -if( rndprc < NBITS ) - { - i = rw + 1; - while( i < NI ) - { - if( s[i] ) - r |= 1; - s[i] = 0; - ++i; - } - } -s[rw] &= ~rmsk; -if( (r & rmbit) != 0 ) - { - if( r == rmbit ) - { - if( lost == 0 ) - { /* round to even */ - if( (s[re] & 1) == 0 ) - goto mddone; - } - else - { - if( subflg != 0 ) - goto mddone; - } - } - __eaddm( rbit, s ); - } -mddone: -#if IBMPC -if( (exp <= 0) && (rndprc != NBITS) ) -#else -if( (exp <= 0) && (rndprc != 64) && (rndprc != NBITS) ) -#endif - { - __eshup1(s); - } -if( s[2] != 0 ) - { /* overflow on roundoff */ - __eshdn1(s); - exp += 1; - } -mdfin: -s[NI-1] = 0; -if( exp >= 32767L ) - { -#ifndef INFINITY -overf: -#endif -#ifdef INFINITY - s[1] = 32767; - for( i=2; i<NI-1; i++ ) - s[i] = 0; -#else - s[1] = 32766; - s[2] = 0; - for( i=M+1; i<NI-1; i++ ) - s[i] = 0xffff; - s[NI-1] = 0; - if( (rndprc < 64) || (rndprc == 113) ) - s[rw] &= ~rmsk; -#endif - return; - } -if( exp < 0 ) - s[1] = 0; -else - s[1] = (unsigned short )exp; -} - - -/* -; Multiply. -; -; unsigned short a[NE], b[NE], c[NE]; -; emul( a, b, c ); c = b * a -*/ -void __emul(const short unsigned int *a, - const short unsigned int *b, - short unsigned int *c) -{ -unsigned short ai[NI], bi[NI]; -int i, j; -long lt, lta, ltb; - -#ifdef NANS -/* NaN times anything is the same NaN. */ -if( __eisnan(a) ) - { - __emov(a,c); - return; - } -if( __eisnan(b) ) - { - __emov(b,c); - return; - } -/* Zero times infinity is a NaN. */ -if( (__eisinf(a) && __eiiszero(b)) - || (__eisinf(b) && __eiiszero(a)) ) - { - mtherr( "emul", DOMAIN ); - __enan_NBITS( c ); - return; - } -#endif -/* Infinity times anything else is infinity. */ -#ifdef INFINITY -if( __eisinf(a) || __eisinf(b) ) - { - if( __eisneg(a) ^ __eisneg(b) ) - *(c+(NE-1)) = 0x8000; - else - *(c+(NE-1)) = 0; - __einfin(c); - return; - } -#endif -__emovi( a, ai ); -__emovi( b, bi ); -lta = ai[E]; -ltb = bi[E]; -if( ai[E] == 0 ) - { - for( i=1; i<NI-1; i++ ) - { - if( ai[i] != 0 ) - { - lta -= __enormlz( ai ); - goto mnzer1; - } - } - __eclear(c); - return; - } -mnzer1: - -if( bi[E] == 0 ) - { - for( i=1; i<NI-1; i++ ) - { - if( bi[i] != 0 ) - { - ltb -= __enormlz( bi ); - goto mnzer2; - } - } - __eclear(c); - return; - } -mnzer2: - -/* Multiply significands */ -j = __emulm( ai, bi ); -/* calculate exponent */ -lt = lta + ltb - (EXONE - 1); -__emdnorm( bi, j, 0, lt, 64, NBITS ); -/* calculate sign of product */ -if( ai[0] == bi[0] ) - bi[0] = 0; -else - bi[0] = 0xffff; -__emovo( bi, c ); -} - - -/* move out internal format to ieee long double */ -void __toe64(short unsigned int *a, short unsigned int *b) -{ -register unsigned short *p, *q; -unsigned short i; - -#ifdef NANS -if( __eiisnan(a) ) - { - __enan_64( b ); - return; - } -#endif -#ifdef IBMPC -/* Shift Intel denormal significand down 1. */ -if( a[E] == 0 ) - __eshdn1(a); -#endif -p = a; -#ifdef MIEEE -q = b; -#else -q = b + 4; /* point to output exponent */ -#if 1 -/* NOTE: if data type is 96 bits wide, clear the last word here. */ -*(q+1)= 0; -#endif -#endif - -/* combine sign and exponent */ -i = *p++; -#ifdef MIEEE -if( i ) - *q++ = *p++ | 0x8000; -else - *q++ = *p++; -*q++ = 0; -#else -if( i ) - *q-- = *p++ | 0x8000; -else - *q-- = *p++; -#endif -/* skip over guard word */ -++p; -/* move the significand */ -#ifdef MIEEE -for( i=0; i<4; i++ ) - *q++ = *p++; -#else -#ifdef INFINITY -if (__eiisinf (a)) - { - /* Intel long double infinity. */ - *q-- = 0x8000; - *q-- = 0; - *q-- = 0; - *q = 0; - return; - } -#endif -for( i=0; i<4; i++ ) - *q-- = *p++; -#endif -} - - -/* Compare two e type numbers. - * - * unsigned short a[NE], b[NE]; - * ecmp( a, b ); - * - * returns +1 if a > b - * 0 if a == b - * -1 if a < b - * -2 if either a or b is a NaN. - */ -int __ecmp(const short unsigned int * __restrict__ a, - const short unsigned int * __restrict__ b) -{ -unsigned short ai[NI], bi[NI]; -register unsigned short *p, *q; -register int i; -int msign; - -#ifdef NANS -if (__eisnan (a) || __eisnan (b)) - return( -2 ); -#endif -__emovi( a, ai ); -p = ai; -__emovi( b, bi ); -q = bi; - -if( *p != *q ) - { /* the signs are different */ -/* -0 equals + 0 */ - for( i=1; i<NI-1; i++ ) - { - if( ai[i] != 0 ) - goto nzro; - if( bi[i] != 0 ) - goto nzro; - } - return(0); -nzro: - if( *p == 0 ) - return( 1 ); - else - return( -1 ); - } -/* both are the same sign */ -if( *p == 0 ) - msign = 1; -else - msign = -1; -i = NI-1; -do - { - if( *p++ != *q++ ) - { - goto diff; - } - } -while( --i > 0 ); - -return(0); /* equality */ - - - -diff: - -if( *(--p) > *(--q) ) - return( msign ); /* p is bigger */ -else - return( -msign ); /* p is littler */ -} - -/* -; Shift significand -; -; Shifts significand area up or down by the number of bits -; given by the variable sc. -*/ -int __eshift(short unsigned int *x, int sc) -{ -unsigned short lost; -unsigned short *p; - -if( sc == 0 ) - return( 0 ); - -lost = 0; -p = x + NI-1; - -if( sc < 0 ) - { - sc = -sc; - while( sc >= 16 ) - { - lost |= *p; /* remember lost bits */ - __eshdn6(x); - sc -= 16; - } - - while( sc >= 8 ) - { - lost |= *p & 0xff; - __eshdn8(x); - sc -= 8; - } - - while( sc > 0 ) - { - lost |= *p & 1; - __eshdn1(x); - sc -= 1; - } - } -else - { - while( sc >= 16 ) - { - __eshup6(x); - sc -= 16; - } - - while( sc >= 8 ) - { - __eshup8(x); - sc -= 8; - } - - while( sc > 0 ) - { - __eshup1(x); - sc -= 1; - } - } -if( lost ) - lost = 1; -return( (int )lost ); -} - - - -/* -; normalize -; -; Shift normalizes the significand area pointed to by argument -; shift count (up = positive) is returned. -*/ -int __enormlz(short unsigned int *x) -{ -register unsigned short *p; -int sc; - -sc = 0; -p = &x[M]; -if( *p != 0 ) - goto normdn; -++p; -if( *p & 0x8000 ) - return( 0 ); /* already normalized */ -while( *p == 0 ) - { - __eshup6(x); - sc += 16; -/* With guard word, there are NBITS+16 bits available. - * return true if all are zero. - */ - if( sc > NBITS ) - return( sc ); - } -/* see if high byte is zero */ -while( (*p & 0xff00) == 0 ) - { - __eshup8(x); - sc += 8; - } -/* now shift 1 bit at a time */ -while( (*p & 0x8000) == 0) - { - __eshup1(x); - sc += 1; - if( sc > (NBITS+16) ) - { - mtherr( "enormlz", UNDERFLOW ); - return( sc ); - } - } -return( sc ); - -/* Normalize by shifting down out of the high guard word - of the significand */ -normdn: - -if( *p & 0xff00 ) - { - __eshdn8(x); - sc -= 8; - } -while( *p != 0 ) - { - __eshdn1(x); - sc -= 1; - - if( sc < -NBITS ) - { - mtherr( "enormlz", OVERFLOW ); - return( sc ); - } - } -return( sc ); -} - - -/* Move internal format number out, - * converting it to external format. - */ -void __emovo(const short unsigned int * __restrict__ a, - short unsigned int * __restrict__ b) -{ -register const unsigned short *p; -register unsigned short *q; -unsigned short i; - -p = a; -q = b + (NE-1); /* point to output exponent */ -/* combine sign and exponent */ -i = *p++; -if( i ) - *q-- = *p++ | 0x8000; -else - *q-- = *p++; -#ifdef INFINITY -if( *(p-1) == 0x7fff ) - { -#ifdef NANS - if( __eiisnan(a) ) - { - __enan_NBITS( b ); - return; - } -#endif - __einfin(b); - return; - } -#endif -/* skip over guard word */ -++p; -/* move the significand */ -for( i=0; i<NE-1; i++ ) - *q-- = *p++; -} - - -#if USE_LDTOA - - -void __eiremain(short unsigned int *den, short unsigned int *num, - short unsigned int *equot ) -{ -long ld, ln; -unsigned short j; - -ld = den[E]; -ld -= __enormlz( den ); -ln = num[E]; -ln -= __enormlz( num ); -__ecleaz( equot ); -while( ln >= ld ) - { - if( __ecmpm(den,num) <= 0 ) - { - __esubm(den, num); - j = 1; - } - else - { - j = 0; - } - __eshup1(equot); - equot[NI-1] |= j; - __eshup1(num); - ln -= 1; - } -__emdnorm( num, 0, 0, ln, 0, NBITS ); -} - - -void __eadd1(const short unsigned int * __restrict__ a, - const short unsigned int * __restrict__ b, - short unsigned int * __restrict__ c, - int subflg) -{ -unsigned short ai[NI], bi[NI], ci[NI]; -int i, lost, j, k; -long lt, lta, ltb; - -#ifdef INFINITY -if( __eisinf(a) ) - { - __emov(a,c); - if( subflg ) - __eneg(c); - return; - } -if( __eisinf(b) ) - { - __emov(b,c); - return; - } -#endif -__emovi( a, ai ); -__emovi( b, bi ); -if( sub ) - ai[0] = ~ai[0]; - -/* compare exponents */ -lta = ai[E]; -ltb = bi[E]; -lt = lta - ltb; -if( lt > 0L ) - { /* put the larger number in bi */ - __emovz( bi, ci ); - __emovz( ai, bi ); - __emovz( ci, ai ); - ltb = bi[E]; - lt = -lt; - } -lost = 0; -if( lt != 0L ) - { - if( lt < (long )(-NBITS-1) ) - goto done; /* answer same as larger addend */ - k = (int )lt; - lost = __eshift( ai, k ); /* shift the smaller number down */ - } -else - { -/* exponents were the same, so must compare significands */ - i = __ecmpm( ai, bi ); - if( i == 0 ) - { /* the numbers are identical in magnitude */ - /* if different signs, result is zero */ - if( ai[0] != bi[0] ) - { - __eclear(c); - return; - } - /* if same sign, result is double */ - /* double denomalized tiny number */ - if( (bi[E] == 0) && ((bi[3] & 0x8000) == 0) ) - { - __eshup1( bi ); - goto done; - } - /* add 1 to exponent unless both are zero! */ - for( j=1; j<NI-1; j++ ) - { - if( bi[j] != 0 ) - { -/* This could overflow, but let emovo take care of that. */ - ltb += 1; - break; - } - } - bi[E] = (unsigned short )ltb; - goto done; - } - if( i > 0 ) - { /* put the larger number in bi */ - __emovz( bi, ci ); - __emovz( ai, bi ); - __emovz( ci, ai ); - } - } -if( ai[0] == bi[0] ) - { - __eaddm( ai, bi ); - subflg = 0; - } -else - { - __esubm( ai, bi ); - subflg = 1; - } -__emdnorm( bi, lost, subflg, ltb, 64, NBITS); - -done: -__emovo( bi, c ); -} - - -/* y = largest integer not greater than x - * (truncated toward minus infinity) - * - * unsigned short x[NE], y[NE] - * - * efloor( x, y ); - */ - - -void __efloor(short unsigned int *x, short unsigned int *y) -{ -register unsigned short *p; -int e, expon, i; -unsigned short f[NE]; -const unsigned short bmask[] = { -0xffff, -0xfffe, -0xfffc, -0xfff8, -0xfff0, -0xffe0, -0xffc0, -0xff80, -0xff00, -0xfe00, -0xfc00, -0xf800, -0xf000, -0xe000, -0xc000, -0x8000, -0x0000, -}; - -__emov( x, f ); /* leave in external format */ -expon = (int )f[NE-1]; -e = (expon & 0x7fff) - (EXONE - 1); -if( e <= 0 ) - { - __eclear(y); - goto isitneg; - } -/* number of bits to clear out */ -e = NBITS - e; -__emov( f, y ); -if( e <= 0 ) - return; - -p = &y[0]; -while( e >= 16 ) - { - *p++ = 0; - e -= 16; - } -/* clear the remaining bits */ -*p &= bmask[e]; -/* truncate negatives toward minus infinity */ -isitneg: - -if( (unsigned short )expon & (unsigned short )0x8000 ) - { - for( i=0; i<NE-1; i++ ) - { - if( f[i] != y[i] ) - { - __esub( __eone, y, y ); - break; - } - } - } -} - -/* -; Subtract external format numbers. -; -; unsigned short a[NE], b[NE], c[NE]; -; esub( a, b, c ); c = b - a -*/ - - -void __esub(const short unsigned int * a, - const short unsigned int * b, - short unsigned int * c) -{ - -#ifdef NANS -if( __eisnan(a) ) - { - __emov (a, c); - return; - } -if( __eisnan(b) ) - { - __emov(b,c); - return; - } -/* Infinity minus infinity is a NaN. - * Test for subtracting infinities of the same sign. - */ -if( __eisinf(a) && __eisinf(b) && ((__eisneg (a) ^ __eisneg (b)) == 0)) - { - mtherr( "esub", DOMAIN ); - __enan_NBITS( c ); - return; - } -#endif -__eadd1( a, b, c, 1 ); -} - - - -/* -; Divide. -; -; unsigned short a[NI], b[NI], c[NI]; -; ediv( a, b, c ); c = b / a -*/ - -void __ediv(const short unsigned int *a, - const short unsigned int *b, - short unsigned int *c) -{ -unsigned short ai[NI], bi[NI]; -int i; -long lt, lta, ltb; - -#ifdef NANS -/* Return any NaN input. */ -if( __eisnan(a) ) - { - __emov(a,c); - return; - } -if( __eisnan(b) ) - { - __emov(b,c); - return; - } -/* Zero over zero, or infinity over infinity, is a NaN. */ -if( (__eiszero(a) && __eiszero(b)) - || (__eisinf (a) && __eisinf (b)) ) - { - mtherr( "ediv", DOMAIN ); - __enan_NBITS( c ); - return; - } -#endif -/* Infinity over anything else is infinity. */ -#ifdef INFINITY -if( __eisinf(b) ) - { - if( __eisneg(a) ^ __eisneg(b) ) - *(c+(NE-1)) = 0x8000; - else - *(c+(NE-1)) = 0; - __einfin(c); - return; - } -if( __eisinf(a) ) - { - __eclear(c); - return; - } -#endif -__emovi( a, ai ); -__emovi( b, bi ); -lta = ai[E]; -ltb = bi[E]; -if( bi[E] == 0 ) - { /* See if numerator is zero. */ - for( i=1; i<NI-1; i++ ) - { - if( bi[i] != 0 ) - { - ltb -= __enormlz( bi ); - goto dnzro1; - } - } - __eclear(c); - return; - } -dnzro1: - -if( ai[E] == 0 ) - { /* possible divide by zero */ - for( i=1; i<NI-1; i++ ) - { - if( ai[i] != 0 ) - { - lta -= __enormlz( ai ); - goto dnzro2; - } - } - if( ai[0] == bi[0] ) - *(c+(NE-1)) = 0; - else - *(c+(NE-1)) = 0x8000; - __einfin(c); - mtherr( "ediv", SING ); - return; - } -dnzro2: - -i = __edivm( ai, bi ); -/* calculate exponent */ -lt = ltb - lta + EXONE; -__emdnorm( bi, i, 0, lt, 64, NBITS ); -/* set the sign */ -if( ai[0] == bi[0] ) - bi[0] = 0; -else - bi[0] = 0Xffff; -__emovo( bi, c ); -} - -void __e64toe(short unsigned int *pe, short unsigned int *y) -{ -unsigned short yy[NI]; -unsigned short *p, *q, *e; -int i; - -e = pe; -p = yy; -for( i=0; i<NE-5; i++ ) - *p++ = 0; -#ifdef IBMPC -for( i=0; i<5; i++ ) - *p++ = *e++; -#endif -#ifdef DEC -for( i=0; i<5; i++ ) - *p++ = *e++; -#endif -#ifdef MIEEE -p = &yy[0] + (NE-1); -*p-- = *e++; -++e; -for( i=0; i<4; i++ ) - *p-- = *e++; -#endif - -#ifdef IBMPC -/* For Intel long double, shift denormal significand up 1 - -- but only if the top significand bit is zero. */ -if((yy[NE-1] & 0x7fff) == 0 && (yy[NE-2] & 0x8000) == 0) - { - unsigned short temp[NI+1]; - __emovi(yy, temp); - __eshup1(temp); - __emovo(temp,y); - return; - } -#endif -#ifdef INFINITY -/* Point to the exponent field. */ -p = &yy[NE-1]; -if( *p == 0x7fff ) - { -#ifdef NANS -#ifdef IBMPC - for( i=0; i<4; i++ ) - { - if((i != 3 && pe[i] != 0) - /* Check for Intel long double infinity pattern. */ - || (i == 3 && pe[i] != 0x8000)) - { - __enan_NBITS( y ); - return; - } - } -#else - for( i=1; i<=4; i++ ) - { - if( pe[i] != 0 ) - { - __enan_NBITS( y ); - return; - } - } -#endif -#endif /* NANS */ - __eclear( y ); - __einfin( y ); - if( *p & 0x8000 ) - __eneg(y); - return; - } -#endif -p = yy; -q = y; -for( i=0; i<NE; i++ ) - *q++ = *p++; -} - -#endif /* USE_LDTOA */ |