/* $OpenXM: OpenXM_contrib2/asir2000/engine/real.c,v 1.2 2000/02/04 09:27:31 noro Exp $ */
#include "ca.h"
#include "base.h"
#include <math.h>
#if defined(THINK_C)
double RatnToReal(a)
Q a;
{
double nm,dn,t;
int enm,edn;
char buf[BUFSIZ];
nm = NatToReal(NM(a),&enm);
if ( INT(a) )
if ( enm >= 1 )
error("RatnToReal : Overflow");
else
return SGN(a)>0 ? nm : -nm;
else {
dn = NatToReal(DN(a),&edn);
sprintf(buf,"1.0E%d",enm-edn);
sscanf(buf,"%lf",&t);
if ( SGN(a) < 0 )
t = -t;
return nm/dn*t;
}
}
double NatToReal(a,expo)
N a;
int *expo;
{
int *p;
int l,all,i,j,s,tb,top,tail;
unsigned int t,m[2];
p = BD(a); l = PL(a) - 1;
for ( top = 0, t = p[l]; t; t >>= 1, top++ );
all = top + BSH*l; tail = (53-top)%BSH; i = l-(53-top)/BSH-1;
m[1] = i < 0 ? 0 : p[i]>>(BSH-tail);
for ( j = 1, i++, tb = tail; i <= l; i++ ) {
s = 32-tb; t = i < 0 ? 0 : p[i];
if ( BSH > s ) {
m[j] |= ((t&((1<<s)-1))<<tb);
if ( !j )
break;
else {
j--; m[j] = t>>s; tb = BSH-s;
}
} else {
m[j] |= (t<<tb); tb += BSH;
}
}
s = (all-1)+1023;
m[0] = (m[0]&((1<<20)-1))|(MIN(2046,s)<<20); *expo = MAX(s-2046,0);
#ifdef vax
t = m[0]; m[0] = m[1]; m[1] = t; itod(m);
#endif
#if defined(MIPSEL)
t = m[0]; m[0] = m[1]; m[1] = t;
#endif
return (double)(*((short double *)m));
}
#else
double RatnToReal(a)
Q a;
{
double nm,dn,t,man;
int enm,edn,e;
unsigned int *p,s;
nm = NatToReal(NM(a),&enm);
if ( INT(a) )
if ( enm >= 1 )
error("RatnToReal : Overflow");
else
return SGN(a)>0 ? nm : -nm;
else {
dn = NatToReal(DN(a),&edn);
man = nm/dn;
if ( SGN(a) < 0 )
man = -man;
if ( ((e = enm - edn) >= 1024) || (e <= -1023) )
error("RatnToReal : Overflow"); /* XXX */
else if ( !e )
return man;
else
return man*pow(2,e);
}
}
double NatToReal(a,expo)
N a;
int *expo;
{
unsigned int *p;
int l,all,i,j,s,tb,top,tail;
unsigned int t,m[2];
p = BD(a); l = PL(a) - 1;
for ( top = 0, t = p[l]; t; t >>= 1, top++ );
all = top + BSH*l; tail = (53-top)%BSH; i = l-(53-top)/BSH-1;
m[1] = i < 0 ? 0 : p[i]>>(BSH-tail);
for ( j = 1, i++, tb = tail; i <= l; i++ ) {
s = 32-tb; t = i < 0 ? 0 : p[i];
if ( BSH > s ) {
m[j] |= ((t&((1<<s)-1))<<tb);
if ( !j )
break;
else {
j--; m[j] = t>>s; tb = BSH-s;
}
} else {
m[j] |= (t<<tb); tb += BSH;
}
}
s = (all-1)+1023;
m[0] = (m[0]&((1<<20)-1))|(MIN(2046,s)<<20); *expo = MAX(s-2046,0);
#ifdef vax
t = m[0]; m[0] = m[1]; m[1] = t; itod(m);
#endif
#if defined(__i386__) || defined(MIPSEL) || defined(VISUAL) || defined(__alpha) || defined(__FreeBSD__) || defined(__NetBSD__)
t = m[0]; m[0] = m[1]; m[1] = t;
#endif
return *((double *)m);
}
#endif
void addreal(a,b,c)
Num a,b;
Real *c;
{
double t;
t = ToReal(a)+ToReal(b); MKReal(t,*c);
}
void subreal(a,b,c)
Num a,b;
Real *c;
{
double t;
t = ToReal(a)-ToReal(b); MKReal(t,*c);
}
void mulreal(a,b,c)
Num a,b;
Real *c;
{
double t;
if ( !a || !b )
*c = 0;
else {
t = ToReal(a)*ToReal(b);
if ( !t )
error("mulreal : Underflow"); /* XXX */
else
MKReal(t,*c);
}
}
void divreal(a,b,c)
Num a,b;
Real *c;
{
double t;
if ( !a )
*c = 0;
else {
t = ToReal(a)/ToReal(b);
if ( !t )
error("divreal : Underflow"); /* XXX */
else
MKReal(t,*c);
}
}
void chsgnreal(a,c)
Num a,*c;
{
double t;
Real s;
if ( !a )
*c = 0;
else if ( NID(a) == N_Q )
chsgnq((Q)a,(Q *)c);
else {
t = -ToReal(a); MKReal(t,s); *c = (Num)s;
}
}
void pwrreal(a,b,c)
Num a,b;
Real *c;
{
double t;
double pwrreal0();
if ( !b )
MKReal(1.0,*c);
else if ( !a )
*c = 0;
else if ( !RATN(b) || !INT(b) || (PL(NM((Q)b)) > 1) ) {
t = (double)pow((double)ToReal(a),(double)ToReal(b));
if ( !t )
error("pwrreal : Underflow"); /* XXX */
else
MKReal(t,*c);
} else {
t = pwrreal0(BDY((Real)a),BD(NM((Q)b))[0]);
t = SGN((Q)b)>0?t:1/t;
if ( !t )
error("pwrreal : Underflow"); /* XXX */
else
MKReal(t,*c);
}
}
double pwrreal0(n,e)
double n;
int e;
{
double t;
if ( e == 1 )
return n;
else {
t = pwrreal0(n,e / 2);
return e%2 ? t*t*n : t*t;
}
}
int cmpreal(a,b)
Real a,b;
{
double t;
t = ToReal(a)-ToReal(b);
return t>0.0 ? 1 : t<0.0?-1 : 0;
}