/* $NetBSD: gethex.c,v 1.3.14.1 2008/04/08 21:10:55 jdc Exp $ */ /**************************************************************** The author of this software is David M. Gay. Copyright (C) 1998 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. ****************************************************************/ /* Please send bug reports to David M. Gay (dmg at acm dot org, * with " at " changed at "@" and " dot " changed to "."). */ #include #include "gdtoaimp.h" #ifdef USE_LOCALE #include "locale.h" #endif int gethex( CONST char **sp, CONST FPI *fpi, Long *expt, Bigint **bp, int sign) { Bigint *b; CONST unsigned char *decpt, *s0, *s, *s1; int esign, havedig, irv, k, n, nbits, up, zret; ULong L, lostbits, *x; Long e, e1; #ifdef USE_LOCALE unsigned char decimalpoint = *localeconv()->decimal_point; #else #define decimalpoint '.' #endif if (!hexdig['0']) hexdig_init_D2A(); havedig = 0; s0 = *(CONST unsigned char **)sp + 2; while(s0[havedig] == '0') havedig++; s0 += havedig; s = s0; decpt = 0; zret = 0; e = 0; if (!hexdig[*s]) { zret = 1; if (*s != decimalpoint) goto pcheck; decpt = ++s; if (!hexdig[*s]) goto pcheck; while(*s == '0') s++; if (hexdig[*s]) zret = 0; havedig = 1; s0 = s; } while(hexdig[*s]) s++; if (*s == decimalpoint && !decpt) { decpt = ++s; while(hexdig[*s]) s++; } if (decpt) e = -(((Long)(s-decpt)) << 2); pcheck: s1 = s; switch(*s) { case 'p': case 'P': esign = 0; switch(*++s) { case '-': esign = 1; /* FALLTHROUGH */ case '+': s++; } if ((n = hexdig[*s]) == 0 || n > 0x19) { s = s1; break; } e1 = n - 0x10; while((n = hexdig[*++s]) !=0 && n <= 0x19) e1 = 10*e1 + n - 0x10; if (esign) e1 = -e1; e += e1; } *sp = __UNCONST(s); if (zret) return havedig ? STRTOG_Zero : STRTOG_NoNumber; n = (int)(s1 - s0 - 1); for(k = 0; n > 7; n = (unsigned int)n >> 1) k++; b = Balloc(k); if (b == NULL) return STRTOG_NoMemory; x = b->x; n = 0; L = 0; while(s1 > s0) { if (*--s1 == decimalpoint) continue; if (n == 32) { *x++ = L; L = 0; n = 0; } L |= (hexdig[*s1] & 0x0f) << n; n += 4; } *x++ = L; b->wds = n = (int)(x - b->x); n = 32*n - hi0bits(L); nbits = fpi->nbits; lostbits = 0; x = b->x; if (n > nbits) { n -= nbits; if (any_on(b,n)) { lostbits = 1; k = n - 1; if (x[(unsigned int)k>>kshift] & 1 << (k & kmask)) { lostbits = 2; if (k > 1 && any_on(b,k-1)) lostbits = 3; } } rshift(b, n); e += n; } else if (n < nbits) { n = nbits - n; b = lshift(b, n); if (b == NULL) return STRTOG_NoMemory; e -= n; x = b->x; } if (e > fpi->emax) { ovfl: Bfree(b); *bp = 0; 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 || 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: *expt = fpi->emin; x[0] = b->wds = 1; *bp = b; return STRTOG_Denormal | STRTOG_Inexhi | STRTOG_Underflow; } } Bfree(b); *bp = 0; return STRTOG_Zero | STRTOG_Inexlo | STRTOG_Underflow; } k = n - 1; if (lostbits) lostbits = 1; else if (k > 0) lostbits = any_on(b,k); if (x[(unsigned int)k>>kshift] & 1 << (k & kmask)) lostbits |= 2; nbits -= n; 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 & 1) | (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 = increment(b); x = b->x; if (irv == STRTOG_Denormal) { if (nbits == fpi->nbits - 1 && x[(unsigned int)nbits >> kshift] & 1 << (nbits & kmask)) irv = STRTOG_Normal; } else if (b->wds > k || ((n = nbits & kmask) !=0 && hi0bits(x[k-1]) < 32-n)) { rshift(b,1); if (++e > fpi->emax) goto ovfl; } irv |= STRTOG_Inexhi; } else irv |= STRTOG_Inexlo; } *bp = b; *expt = e; return irv; }