void
mpdivmodfixfix(Mpint *q, Mpint *r, Mpint *n, Mpint *d)
{
int i, ns, ds;
ns = n->neg;
ds = d->neg;
n->neg = 0;
d->neg = 0;
mpmovefixfix(r, n);
mpmovecfix(q, 0);
// shift denominator until it
// is larger than numerator
for(i=0; i<Mpprec*Mpscale; i++) {
if(mpcmp(d, r) > 0)
break;
mplsh(d);
}
// if it never happens
// denominator is probably zero
if(i >= Mpprec*Mpscale) {
q->ovf = 1;
r->ovf = 1;
n->neg = ns;
d->neg = ds;
yyerror("set ovf in mpdivmodfixfix");
return;
}
// shift denominator back creating
// quotient a bit at a time
// when done the remaining numerator
// will be the remainder
for(; i>0; i--) {
mplsh(q);
mprsh(d);
if(mpcmp(d, r) <= 0) {
mpaddcfix(q, 1);
mpsubfixfix(r, d);
}
}
n->neg = ns;
d->neg = ds;
r->neg = ns;
q->neg = ns^ds;
}
//
// right shift mpint by Mpscale
// ignores sign and overflow
//
static void
mprshw(Mpint *a)
{
long *a1, lo;
int i;
lo = a->a[0];
a1 = &a->a[0];
for(i=1; i<Mpprec; i++) {
a1[0] = a1[1];
a1++;
}
a1[0] = 0;
if(a->neg && lo != 0)
mpaddcfix(a, -1);
}
//
// right shift mpint by one
// ignores sign and overflow
//
static void
mprsh(Mpint *a)
{
long *a1, x, lo;
int i, c;
c = 0;
lo = a->a[0] & 1;
a1 = &a->a[Mpprec];
for(i=0; i<Mpprec; i++) {
x = *--a1;
*a1 = (x + c) >> 1;
c = 0;
if(x & 1)
c = Mpbase;
}
if(a->neg && lo != 0)
mpaddcfix(a, -1);
}
//
// fixed point input
// required syntax is [+-][0[x]]d*
//
void
mpatofix(Mpint *a, char *as)
{
int c, f;
char *s, *s0;
s = as;
f = 0;
mpmovecfix(a, 0);
c = *s++;
switch(c) {
case '-':
f = 1;
case '+':
c = *s++;
if(c != '0')
break;
case '0':
goto oct;
}
while(c) {
if(c >= '0' && c <= '9') {
mpmulcfix(a, 10);
mpaddcfix(a, c-'0');
c = *s++;
continue;
}
goto bad;
}
goto out;
oct:
c = *s++;
if(c == 'x' || c == 'X')
goto hex;
while(c) {
if(c >= '0' && c <= '7') {
mpmulcfix(a, 8);
mpaddcfix(a, c-'0');
c = *s++;
continue;
}
goto bad;
}
goto out;
hex:
s0 = s;
c = *s;
while(c) {
if((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')) {
s++;
c = *s;
continue;
}
goto bad;
}
mphextofix(a, s0, s-s0);
if(a->ovf)
goto bad;
out:
if(f)
mpnegfix(a);
return;
bad:
yyerror("constant too large: %s", as);
mpmovecfix(a, 0);
}
//
// fixed point input
// required syntax is [+-][0[x]]d*
//
void
mpatofix(Mpint *a, char *as)
{
int c, f;
char *s;
s = as;
f = 0;
mpmovecfix(a, 0);
c = *s++;
switch(c) {
case '-':
f = 1;
case '+':
c = *s++;
if(c != '0')
break;
case '0':
goto oct;
}
while(c) {
if(c >= '0' && c <= '9') {
mpmulcfix(a, 10);
mpaddcfix(a, c-'0');
c = *s++;
continue;
}
goto bad;
}
goto out;
oct:
c = *s++;
if(c == 'x' || c == 'X')
goto hex;
while(c) {
if(c >= '0' && c <= '7') {
mpmulcfix(a, 8);
mpaddcfix(a, c-'0');
c = *s++;
continue;
}
goto bad;
}
goto out;
hex:
c = *s++;
while(c) {
if(c >= '0' && c <= '9') {
mpmulcfix(a, 16);
mpaddcfix(a, c-'0');
c = *s++;
continue;
}
if(c >= 'a' && c <= 'f') {
mpmulcfix(a, 16);
mpaddcfix(a, c+10-'a');
c = *s++;
continue;
}
if(c >= 'A' && c <= 'F') {
mpmulcfix(a, 16);
mpaddcfix(a, c+10-'A');
c = *s++;
continue;
}
goto bad;
}
out:
if(f)
mpnegfix(a);
return;
bad:
yyerror("set ovf in mpatov: %s", as);
mpmovecfix(a, 0);
}
