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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.18.0/] [newlib/] [libc/] [stdlib/] [gdtoa-gethex.c] - Rev 297
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/**************************************************************** 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 <_ansi.h> #include <reent.h> #include <string.h> #include "mprec.h" #include "gdtoa.h" #include "gd_qnan.h" #include "locale.h" unsigned char hexdig[256]; static void _DEFUN (htinit, (h, s, inc), unsigned char *h _AND unsigned char *s _AND int inc) { int i, j; for(i = 0; (j = s[i]) !=0; i++) h[j] = i + inc; } void _DEFUN_VOID (hexdig_init) { #define USC (unsigned char *) htinit(hexdig, USC "0123456789", 0x10); htinit(hexdig, USC "abcdef", 0x10 + 10); htinit(hexdig, USC "ABCDEF", 0x10 + 10); } static void _DEFUN(rshift, (b, k), _Bigint *b _AND int k) { __ULong *x, *x1, *xe, y; int n; x = x1 = b->_x; n = k >> kshift; if (n < b->_wds) { xe = x + b->_wds; x += n; if (k &= kmask) { n = ULbits - k; y = *x++ >> k; while(x < xe) { *x1++ = (y | (*x << n)) & ALL_ON; y = *x++ >> k; } if ((*x1 = y) !=0) x1++; } else while(x < xe) *x1++ = *x++; } if ((b->_wds = x1 - b->_x) == 0) b->_x[0] = 0; } static _Bigint * _DEFUN (increment, (ptr, b), struct _reent *ptr _AND _Bigint *b) { __ULong *x, *xe; _Bigint *b1; #ifdef Pack_16 __ULong carry = 1, y; #endif x = b->_x; xe = x + b->_wds; #ifdef Pack_32 do { if (*x < (__ULong)0xffffffffL) { ++*x; return b; } *x++ = 0; } while(x < xe); #else do { y = *x + carry; carry = y >> 16; *x++ = y & 0xffff; if (!carry) return b; } while(x < xe); if (carry) #endif { if (b->_wds >= b->_maxwds) { b1 = Balloc(ptr, b->_k+1); Bcopy(b1, b); Bfree(ptr, b); b = b1; } b->_x[b->_wds++] = 1; } return b; } int _DEFUN(gethex, (ptr, sp, fpi, exp, bp, sign), struct _reent *ptr _AND _CONST char **sp _AND FPI *fpi _AND Long *exp _AND _Bigint **bp _AND 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; unsigned char *decimalpoint = (unsigned char *) _localeconv_r (ptr)->decimal_point; size_t decp_len = strlen ((const char *) decimalpoint); unsigned char decp_end = decimalpoint[decp_len - 1]; if (!hexdig['0']) hexdig_init(); 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 (strncmp ((const char *) s, (const char *) decimalpoint, decp_len) != 0) goto pcheck; decpt = (s += decp_len); if (!hexdig[*s]) goto pcheck; while(*s == '0') s++; if (hexdig[*s]) zret = 0; havedig = 1; s0 = s; } while(hexdig[*s]) s++; if (strncmp ((const char *) s, (const char *) decimalpoint, decp_len) == 0 && !decpt) { decpt = (s += decp_len); 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; /* no break */ 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 = (char*)s; if (zret) return havedig ? STRTOG_Zero : STRTOG_NoNumber; n = s1 - s0 - 1; for(k = 0; n > 7; n >>= 1) k++; b = Balloc(ptr, k); x = b->_x; n = 0; L = 0; while(s1 > s0) { if (*--s1 == decp_end && s1 - decp_len + 1 >= s0 && strncmp ((const char *) s1 - decp_len + 1, (const char *) decimalpoint, decp_len) == 0) { s1 -= decp_len - 1; /* Note the --s1 above! */ continue; } if (n == 32) { *x++ = L; L = 0; n = 0; } L |= (hexdig[*s1] & 0x0f) << n; n += 4; } *x++ = L; b->_wds = n = 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[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(ptr, b, n); e -= n; x = b->_x; } if (e > fpi->emax) { ovfl: Bfree(ptr, 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: *exp = fpi->emin; x[0] = b->_wds = 1; *bp = b; return STRTOG_Denormal | STRTOG_Inexhi | STRTOG_Underflow; } } Bfree(ptr, 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[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(ptr, b); 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))) { rshift(b,1); if (++e > fpi->emax) goto ovfl; } irv |= STRTOG_Inexhi; } else irv |= STRTOG_Inexlo; } *bp = b; *exp = e; return irv; }
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