/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
╚──────────────────────────────────────────────────────────────────────────────╝
│ │
│ The author of this software is David M. Gay. │
│ Please send bug reports to David M. Gay <dmg@acm.org> │
│ or Justine Tunney <jtunney@gmail.com> │
│ │
│ Copyright (C) 1998, 1999 by Lucent Technologies │
│ All Rights Reserved │
│ │
│ Permission to use, copy, modify, and distribute this software and │
│ its documentation for any purpose and without fee is hereby │
│ granted, provided that the above copyright notice appear in all │
│ copies and that both that the copyright notice and this │
│ permission notice and warranty disclaimer appear in supporting │
│ documentation, and that the name of Lucent or any of its entities │
│ not be used in advertising or publicity pertaining to │
│ distribution of the software without specific, written prior │
│ permission. │
│ │
│ LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, │
│ INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. │
│ IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY │
│ SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES │
│ WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER │
│ IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, │
│ ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF │
│ THIS SOFTWARE. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/errno.h"
#include "third_party/gdtoa/gdtoa.internal.h"
int
__gdtoa_gethex(const char **sp, const FPI *fpi,
Long *exp, Bigint **bp, int sign, ThInfo **PTI)
{
Bigint *b;
const unsigned char *decpt, *s0, *s, *s1;
int big, esign, havedig, irv, j, k, n, n0, nbits, up, zret;
ULong L, lostbits, *x;
Long e, e1;
/**** if (!__gdtoa_hexdig['0']) __gdtoa_hexdig_init(); ****/
*bp = 0;
havedig = 0;
s0 = *(const unsigned char **)sp + 2;
while(s0[havedig] == '0')
havedig++;
s0 += havedig;
s = s0;
decpt = 0;
zret = 0;
e = 0;
if (__gdtoa_hexdig[*s])
havedig++;
else {
zret = 1;
if (*s != '.')
goto pcheck;
decpt = ++s;
if (!__gdtoa_hexdig[*s])
goto pcheck;
while(*s == '0')
s++;
if (__gdtoa_hexdig[*s])
zret = 0;
havedig = 1;
s0 = s;
}
while(__gdtoa_hexdig[*s])
s++;
if (*s == '.' && !decpt) {
decpt = ++s;
while(__gdtoa_hexdig[*s])
s++;
}/*}*/
if (decpt)
e = -(((Long)(s-decpt)) << 2);
pcheck:
s1 = s;
big = esign = 0;
switch(*s) {
case 'p':
case 'P':
switch(*++s) {
case '-':
esign = 1;
/* no break */
case '+':
s++;
}
if ((n = __gdtoa_hexdig[*s]) == 0 || n > 0x19) {
s = s1;
break;
}
e1 = n - 0x10;
while((n = __gdtoa_hexdig[*++s]) !=0 && n <= 0x19) {
if (e1 & 0xf8000000)
big = 1;
e1 = 10*e1 + n - 0x10;
}
if (esign)
e1 = -e1;
e += e1;
}
*sp = (char*)s;
if (!havedig)
*sp = (char*)s0 - 1;
if (zret)
return STRTOG_Zero;
if (big) {
if (esign) {
switch(fpi->rounding) {
case FPI_Round_up:
if (sign)
break;
goto ret_tiny;
case FPI_Round_down:
if (!sign)
break;
goto ret_tiny;
}
goto retz;
ret_tiny:
b = __gdtoa_Balloc(0, PTI);
b->wds = 1;
b->x[0] = 1;
goto dret;
}
switch(fpi->rounding) {
case FPI_Round_near:
goto ovfl1;
case FPI_Round_up:
if (!sign)
goto ovfl1;
goto ret_big;
case FPI_Round_down:
if (sign)
goto ovfl1;
}
ret_big:
nbits = fpi->nbits;
n0 = n = nbits >> kshift;
if (nbits & kmask)
++n;
for(j = n, k = 0; j >>= 1; ++k);
*bp = b = __gdtoa_Balloc(k, PTI);
b->wds = n;
for(j = 0; j < n0; ++j)
b->x[j] = ALL_ON;
if (n > n0)
b->x[j] = ALL_ON >> (ULbits - (nbits & kmask));
*exp = fpi->emax;
return STRTOG_Normal | STRTOG_Inexlo;
}
n = s1 - s0 - 1;
for(k = 0; n > (1 << (kshift-2)) - 1; n >>= 1)
k++;
b = __gdtoa_Balloc(k, PTI);
x = b->x;
n = 0;
L = 0;
while(s1 > s0) {
if (*--s1 == '.')
continue;
if (n == ULbits) {
*x++ = L;
L = 0;
n = 0;
}
L |= (__gdtoa_hexdig[*s1] & 0x0f) << n;
n += 4;
}
*x++ = L;
b->wds = n = x - b->x;
n = ULbits*n - hi0bits(L);
nbits = fpi->nbits;
lostbits = 0;
x = b->x;
if (n > nbits) {
n -= nbits;
if (__gdtoa_any_on(b,n)) {
lostbits = 1;
k = n - 1;
if (x[k>>kshift] & 1 << (k & kmask)) {
lostbits = 2;
if (k > 0 && __gdtoa_any_on(b,k))
lostbits = 3;
}
}
__gdtoa_rshift(b, n);
e += n;
}
else if (n < nbits) {
n = nbits - n;
b = __gdtoa_lshift(b, n, PTI);
e -= n;
x = b->x;
}
if (e > fpi->emax) {
ovfl:
__gdtoa_Bfree(b, PTI);
ovfl1:
errno = ERANGE;
switch (fpi->rounding) {
case FPI_Round_zero:
goto ret_big;
case FPI_Round_down:
if (!sign)
goto ret_big;
break;
case FPI_Round_up:
if (sign)
goto ret_big;
}
return STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;
}
irv = STRTOG_Normal;
if (e < fpi->emin) {
irv = STRTOG_Denormal;
n = fpi->emin - e;
if (n >= nbits) {
switch (fpi->rounding) {
case FPI_Round_near:
if (n == nbits && (n < 2 || lostbits || __gdtoa_any_on(b,n-1)))
goto one_bit;
break;
case FPI_Round_up:
if (!sign)
goto one_bit;
break;
case FPI_Round_down:
if (sign) {
one_bit:
x[0] = b->wds = 1;
dret:
*bp = b;
*exp = fpi->emin;
errno = ERANGE;
return STRTOG_Denormal | STRTOG_Inexhi
| STRTOG_Underflow;
}
}
__gdtoa_Bfree(b, PTI);
retz:
errno = ERANGE;
return STRTOG_Zero | STRTOG_Inexlo | STRTOG_Underflow;
}
k = n - 1;
if (lostbits)
lostbits = 1;
else if (k > 0)
lostbits = __gdtoa_any_on(b,k);
if (x[k>>kshift] & 1 << (k & kmask))
lostbits |= 2;
nbits -= n;
__gdtoa_rshift(b,n);
e = fpi->emin;
}
if (lostbits) {
up = 0;
switch(fpi->rounding) {
case FPI_Round_zero:
break;
case FPI_Round_near:
if (lostbits & 2
&& (lostbits | x[0]) & 1)
up = 1;
break;
case FPI_Round_up:
up = 1 - sign;
break;
case FPI_Round_down:
up = sign;
}
if (up) {
k = b->wds;
b = __gdtoa_increment(b, PTI);
x = b->x;
if (irv == STRTOG_Denormal) {
if (nbits == fpi->nbits - 1
&& x[nbits >> kshift] & 1 << (nbits & kmask))
irv = STRTOG_Normal;
}
else if (b->wds > k
|| ((n = nbits & kmask) !=0
&& hi0bits(x[k-1]) < 32-n)) {
__gdtoa_rshift(b,1);
if (++e > fpi->emax)
goto ovfl;
}
irv |= STRTOG_Inexhi;
}
else
irv |= STRTOG_Inexlo;
}
*bp = b;
*exp = e;
return irv;
}