ack/mach/m68020/ce/mach.c
1988-11-10 13:46:53 +00:00

168 lines
2.7 KiB
C

#include "mach.h"
#include <back.h>
#include <system.h>
arg_error( s, arg)
char *s;
int arg;
{
fprint( STDERR, "arg_error %s %d\n", s, arg);
}
/*
do_open( filename)
char *filename;
{
if ( filename == (char *)0 || !sys_open( filename, OP_WRITE, &codefile))
return( 0);
fprint( codefile, ".sect .text; .sect .rom; .sect .data; .sect .bss\n");
return( 1);
}
*/
con_float(str, argval)
char *str;
int argval;
{
#ifdef NOFLOAT
static int been_here;
if (argval != 4 && argval != 8)
arg_error("fcon", argval);
if (argval == 8)
gen4((FOUR_BYTES) 0);
gen4((FOUR_BYTES) 0);
if ( !been_here++)
{
fprint(STDERR, "Warning : dummy float-constant(s)\n");
}
#else
#define IEEEFLOAT
double f;
double atof();
int i;
int j;
double frexp();
#ifndef OWNFLOAT
int sign = 0;
int fraction[4] ;
#else OWNFLOAT
float fl;
char *p;
#endif OWNFLOAT
if (argval!= 4 && argval!= 8) {
arg_error("fcon", argval);
argval = 8;
}
f = atof(str);
if (f == 0) {
if (argval == 8) gen4((FOUR_BYTES) 0);
gen4((FOUR_BYTES) 0);
return;
}
#ifdef OWNFLOAT
if (argval == 4) {
/* careful: avoid overflow */
double ldexp();
f = frexp(f, &i);
fl = f;
fl = frexp(fl,&j);
if (i+j > 127) {
/* overflow situation */
gen1(f<0?0377:0177);
gen1(0377);
gen1(0377);
gen1(0377);
return;
}
if (i+j < -127) {
/* underflow situation */
gen1(f<0?0200:0);
gen1(0200);
gen1(0);
gen1(0);
return;
}
fl = ldexp(fl, i+j);
p = (char *) &fl;
}
else {
p = (char *) &f;
}
gen1(*p++&0377);
for (i = argval-1; i; i--) {
gen1(*p++&0377);
}
#else OWNFLOAT
f = frexp(f, &i);
if (f < 0) {
f = -f;
sign = 1;
}
while (f < 0.5) {
f += f;
i --;
}
f = 2*f - 1.0; /* hidden bit */
#ifdef IEEEFLOAT
if (argval == 4) {
#endif IEEEFLOAT
i = (i + 128) & 0377;
fraction[0] = (sign << 15) | (i << 7);
for (j = 6; j>= 0; j--) {
f *= 2;
if (f >= 1.0) {
f -= 1.0;
fraction[0] |= (1 << j);
}
}
#ifdef IEEEFLOAT
}
else {
i = (i + 1024) & 03777;
fraction[0] = (sign << 15) | (i << 4);
for (j = 3; j>= 0; j--) {
f *= 2;
if (f >= 1.0) {
fraction[0] |= (1 << j);
f -= 1.0;
}
}
}
#endif IEEEFLOAT
for (i = 1; i < argval / 2; i++) {
fraction[i] = 0;
for (j = 15; j>= 0; j--) {
f *= 2;
if (f >= 1.0) {
fraction[i] |= (1 << j);
f -= 1.0;
}
}
}
if (f >= 0.5) {
for (i = argval/2 - 1; i >= 0; i--) {
for (j = 0; j < 16; j++) {
if (fraction[i] & (1 << j)) {
fraction[i] &= ~(1 << j);
}
else {
fraction[i] |= (1 << j);
break;
}
}
if (j != 16) break;
}
}
for (i = 0; i < argval/2; i++) {
gen1((fraction[i]>>8)&0377);
gen1(fraction[i]&0377);
}
#endif OWNFLOAT
#endif
}