1 /**************************************************************** 2 3 The author of this software is David M. Gay. 4 5 Copyright (C) 1998 by Lucent Technologies 6 All Rights Reserved 7 8 Permission to use, copy, modify, and distribute this software and 9 its documentation for any purpose and without fee is hereby 10 granted, provided that the above copyright notice appear in all 11 copies and that both that the copyright notice and this 12 permission notice and warranty disclaimer appear in supporting 13 documentation, and that the name of Lucent or any of its entities 14 not be used in advertising or publicity pertaining to 15 distribution of the software without specific, written prior 16 permission. 17 18 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 19 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 20 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 21 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 22 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 23 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 24 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 25 THIS SOFTWARE. 26 27 ****************************************************************/ 28 29 /* Please send bug reports to David M. Gay (dmg at acm dot org, 30 * with " at " changed at "@" and " dot " changed to "."). */ 31 32 #include "gdtoaimp.h" 33 34 int 35 #ifdef KR_headers 36 strtoIg(s00, se, fpi, exp, B, rvp) CONST char *s00; char **se; FPI *fpi; Long *exp; Bigint **B; int *rvp; 37 #else 38 strtoIg(CONST char *s00, char **se, FPI *fpi, Long *exp, Bigint **B, int *rvp) 39 #endif 40 { 41 Bigint *b, *b1; 42 int i, nb, nw, nw1, rv, rv1, swap; 43 unsigned int nb1, nb11; 44 Long e1; 45 46 b = *B; 47 rv = strtodg(s00, se, fpi, exp, b->x); 48 if (!(rv & STRTOG_Inexact)) { 49 B[1] = 0; 50 return *rvp = rv; 51 } 52 e1 = exp[0]; 53 rv1 = rv ^ STRTOG_Inexact; 54 b1 = Balloc(b->k); 55 Bcopy(b1, b); 56 nb = fpi->nbits; 57 nb1 = nb & 31; 58 nb11 = (nb1 - 1) & 31; 59 nw = b->wds; 60 nw1 = nw - 1; 61 if (rv & STRTOG_Inexlo) { 62 swap = 0; 63 b1 = increment(b1); 64 if (fpi->sudden_underflow 65 && (rv & STRTOG_Retmask) == STRTOG_Zero) { 66 b1->x[0] = 0; 67 b1->x[nw1] = 1L << nb11; 68 rv1 += STRTOG_Normal - STRTOG_Zero; 69 rv1 &= ~STRTOG_Underflow; 70 goto swapcheck; 71 } 72 if (b1->wds > nw 73 || nb1 && b1->x[nw1] & 1L << nb1) { 74 if (++e1 > fpi->emax) 75 rv1 = STRTOG_Infinite | STRTOG_Inexhi; 76 rshift(b1, 1); 77 } 78 else if ((rv & STRTOG_Retmask) == STRTOG_Denormal) { 79 if (b1->x[nw1] & 1L << nb11) { 80 rv1 += STRTOG_Normal - STRTOG_Denormal; 81 rv1 &= ~STRTOG_Underflow; 82 } 83 } 84 } 85 else { 86 swap = STRTOG_Neg; 87 if ((rv & STRTOG_Retmask) == STRTOG_Infinite) { 88 b1 = set_ones(b1, nb); 89 e1 = fpi->emax; 90 rv1 = STRTOG_Normal | STRTOG_Inexlo; 91 goto swapcheck; 92 } 93 decrement(b1); 94 if ((rv & STRTOG_Retmask) == STRTOG_Denormal) { 95 for(i = nw1; !b1->x[i]; --i) 96 if (!i) { 97 rv1 = STRTOG_Zero | STRTOG_Inexlo; 98 break; 99 } 100 goto swapcheck; 101 } 102 if (!(b1->x[nw1] & 1L << nb11)) { 103 if (e1 == fpi->emin) { 104 if (fpi->sudden_underflow) 105 rv1 += STRTOG_Zero - STRTOG_Normal; 106 else 107 rv1 += STRTOG_Denormal - STRTOG_Normal; 108 rv1 |= STRTOG_Underflow; 109 } 110 else { 111 b1 = lshift(b1, 1); 112 b1->x[0] |= 1; 113 --e1; 114 } 115 } 116 } 117 swapcheck: 118 if (swap ^ (rv & STRTOG_Neg)) { 119 rvp[0] = rv1; 120 rvp[1] = rv; 121 B[0] = b1; 122 B[1] = b; 123 exp[1] = exp[0]; 124 exp[0] = e1; 125 } 126 else { 127 rvp[0] = rv; 128 rvp[1] = rv1; 129 B[1] = b1; 130 exp[1] = e1; 131 } 132 return rv; 133 } 134