diff options
Diffstat (limited to 'contrib/gdtoa/strtoIg.c')
| -rw-r--r-- | contrib/gdtoa/strtoIg.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/contrib/gdtoa/strtoIg.c b/contrib/gdtoa/strtoIg.c new file mode 100644 index 0000000..a766813 --- /dev/null +++ b/contrib/gdtoa/strtoIg.c @@ -0,0 +1,139 @@ +/**************************************************************** + +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 + Bell Laboratories, Room 2C-463 + 600 Mountain Avenue + Murray Hill, NJ 07974-0636 + U.S.A. + dmg@bell-labs.com + */ + +#include "gdtoaimp.h" + + int +#ifdef KR_headers +strtoIg(s00, se, fpi, exp, B, rvp) CONST char *s00; char **se; FPI *fpi; Long *exp; Bigint **B; int *rvp; +#else +strtoIg(CONST char *s00, char **se, FPI *fpi, Long *exp, Bigint **B, int *rvp) +#endif +{ + Bigint *b, *b1; + int i, nb, nw, nw1, rv, rv1, swap; + unsigned int nb1, nb11; + Long e1; + + b = *B; + rv = strtodg(s00, se, fpi, exp, b->x); + if (!(rv & STRTOG_Inexact)) { + B[1] = 0; + return *rvp = rv; + } + e1 = exp[0]; + rv1 = rv ^ STRTOG_Inexact; + b1 = Balloc(b->k); + Bcopy(b1, b); + nb = fpi->nbits; + nb1 = nb & 31; + nb11 = (nb1 - 1) & 31; + nw = b->wds; + nw1 = nw - 1; + if (rv & STRTOG_Inexlo) { + swap = 0; + b1 = increment(b1); + if (fpi->sudden_underflow + && (rv & STRTOG_Retmask) == STRTOG_Zero) { + b1->x[0] = 0; + b1->x[nw1] = 1L << nb11; + rv1 += STRTOG_Normal - STRTOG_Zero; + rv1 &= ~STRTOG_Underflow; + goto swapcheck; + } + if (b1->wds > nw + || nb1 && b1->x[nw1] & 1L << nb1) { + if (++e1 > fpi->emax) + rv1 = STRTOG_Infinite | STRTOG_Inexhi; + rshift(b1, 1); + } + else if ((rv & STRTOG_Retmask) == STRTOG_Denormal) { + if (b1->x[nw1] & 1L << nb11) { + rv1 += STRTOG_Normal - STRTOG_Denormal; + rv1 &= ~STRTOG_Underflow; + } + } + } + else { + swap = STRTOG_Neg; + if ((rv & STRTOG_Retmask) == STRTOG_Infinite) { + b1 = set_ones(b1, nb); + e1 = fpi->emax; + rv1 = STRTOG_Normal | STRTOG_Inexlo; + goto swapcheck; + } + decrement(b1); + if ((rv & STRTOG_Retmask) == STRTOG_Denormal) { + for(i = nw1; !b1->x[i]; --i) + if (!i) { + rv1 = STRTOG_Zero | STRTOG_Inexlo; + break; + } + goto swapcheck; + } + if (!(b1->x[nw1] & 1L << nb11)) { + if (e1 == fpi->emin) { + if (fpi->sudden_underflow) + rv1 += STRTOG_Zero - STRTOG_Normal; + else + rv1 += STRTOG_Denormal - STRTOG_Normal; + rv1 |= STRTOG_Underflow; + } + else { + b1 = lshift(b1, 1); + b1->x[0] |= 1; + --e1; + } + } + } + swapcheck: + if (swap ^ (rv & STRTOG_Neg)) { + rvp[0] = rv1; + rvp[1] = rv; + B[0] = b1; + B[1] = b; + exp[1] = exp[0]; + exp[0] = e1; + } + else { + rvp[0] = rv; + rvp[1] = rv1; + B[1] = b1; + exp[1] = e1; + } + return rv; + } |
