//
// floating point input
// required syntax is [+-]d*[.]d*[e[+-]d*] or [+-]0xH*[e[+-]d*]
//
void
mpatoflt(Mpflt *a, char *as)
{
Mpflt b;
int dp, c, f, ef, ex, eb, base;
char *s, *start;
while(*as == ' ' || *as == '\t')
as++;
/* determine base */
s = as;
base = -1;
while(base == -1) {
switch(*s++) {
case '-':
case '+':
break;
case '0':
if(*s == 'x')
base = 16;
else
base = 10;
break;
default:
base = 10;
}
}
s = as;
dp = 0; /* digits after decimal point */
f = 0; /* sign */
ex = 0; /* exponent */
eb = 0; /* binary point */
mpmovecflt(a, 0.0);
if(base == 16) {
start = nil;
for(;;) {
c = *s;
if(c == '-') {
f = 1;
s++;
}
else if(c == '+') {
s++;
}
else if(c == '0' && s[1] == 'x') {
s += 2;
start = s;
}
else if((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')) {
s++;
}
else {
break;
}
}
if(start == nil)
goto bad;
mphextofix(&a->val, start, s-start);
if(a->val.ovf)
goto bad;
a->exp = 0;
mpnorm(a);
}
for(;;) {
switch(c = *s++) {
default:
goto bad;
case '-':
f = 1;
case ' ':
case '\t':
case '+':
continue;
case '.':
if(base == 16)
goto bad;
dp = 1;
continue;
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '0':
mpmulcflt(a, 10);
mpaddcflt(a, c-'0');
if(dp)
dp++;
continue;
case 'P':
case 'p':
eb = 1;
case 'E':
case 'e':
ex = 0;
ef = 0;
for(;;) {
c = *s++;
if(c == '+' || c == ' ' || c == '\t')
continue;
if(c == '-') {
ef = 1;
continue;
}
if(c >= '0' && c <= '9') {
ex = ex*10 + (c-'0');
if(ex > 1e8) {
yyerror("constant exponent out of range: %s", as);
errorexit();
}
continue;
}
break;
}
if(ef)
ex = -ex;
case 0:
break;
}
break;
}
if(eb) {
if(dp)
goto bad;
mpsetexp(a, a->exp+ex);
goto out;
}
if(dp)
dp--;
if(mpcmpfltc(a, 0.0) != 0) {
if(ex >= dp) {
mppow10flt(&b, ex-dp);
mpmulfltflt(a, &b);
} else {
// 4 approximates least_upper_bound(log2(10)).
if(dp-ex >= (1<<(8*sizeof(dp)-3)) || (short)(4*(dp-ex)) != 4*(dp-ex)) {
mpmovecflt(a, 0.0);
}
else {
mppow10flt(&b, dp-ex);
mpdivfltflt(a, &b);
}
}
}
out:
if(f)
mpnegflt(a);
return;
bad:
yyerror("constant too large: %s", as);
mpmovecflt(a, 0.0);
}
//
// floating point input
// required syntax is [+-]d*[.]d*[e[+-]d*]
//
void
mpatoflt(Mpflt *a, char *as)
{
Mpflt b;
int dp, c, f, ef, ex, eb, zer;
char *s;
s = as;
dp = 0; /* digits after decimal point */
f = 0; /* sign */
ex = 0; /* exponent */
eb = 0; /* binary point */
zer = 1; /* zero */
mpmovecflt(a, 0.0);
for(;;) {
switch(c = *s++) {
default:
goto bad;
case '-':
f = 1;
case ' ':
case '\t':
case '+':
continue;
case '.':
dp = 1;
continue;
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
zer = 0;
case '0':
mpmulcflt(a, 10);
mpaddcflt(a, c-'0');
if(dp)
dp++;
continue;
case 'P':
case 'p':
eb = 1;
case 'E':
case 'e':
ex = 0;
ef = 0;
for(;;) {
c = *s++;
if(c == '+' || c == ' ' || c == '\t')
continue;
if(c == '-') {
ef = 1;
continue;
}
if(c >= '0' && c <= '9') {
ex = ex*10 + (c-'0');
continue;
}
break;
}
if(ef)
ex = -ex;
case 0:
break;
}
break;
}
if(eb) {
if(dp)
goto bad;
a->exp += ex;
goto out;
}
if(dp)
dp--;
if(mpcmpfltc(a, 0.0) != 0) {
if(ex >= dp) {
mppow10flt(&b, ex-dp);
mpmulfltflt(a, &b);
} else {
mppow10flt(&b, dp-ex);
mpdivfltflt(a, &b);
}
}
out:
if(f)
mpnegflt(a);
return;
bad:
yyerror("set ovf in mpatof");
mpmovecflt(a, 0.0);
}
