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 ((rv & STRTOG_Retmask) == STRTOG_Zero) { 65 if (fpi->sudden_underflow) { 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 rv1 &= STRTOG_Inexlo | STRTOG_Underflow | STRTOG_Zero; 73 rv1 |= STRTOG_Inexhi | STRTOG_Denormal; 74 goto swapcheck; 75 } 76 if (b1->wds > nw 77 || (nb1 && b1->x[nw1] & 1L << nb1)) { 78 if (++e1 > fpi->emax) 79 rv1 = STRTOG_Infinite | STRTOG_Inexhi; 80 rshift(b1, 1); 81 } 82 else if ((rv & STRTOG_Retmask) == STRTOG_Denormal) { 83 if (b1->x[nw1] & 1L << nb11) { 84 rv1 += STRTOG_Normal - STRTOG_Denormal; 85 rv1 &= ~STRTOG_Underflow; 86 } 87 } 88 } 89 else { 90 swap = STRTOG_Neg; 91 if ((rv & STRTOG_Retmask) == STRTOG_Infinite) { 92 b1 = set_ones(b1, nb); 93 e1 = fpi->emax; 94 rv1 = STRTOG_Normal | STRTOG_Inexlo; 95 goto swapcheck; 96 } 97 decrement(b1); 98 if ((rv & STRTOG_Retmask) == STRTOG_Denormal) { 99 for(i = nw1; !b1->x[i]; --i) 100 if (!i) { 101 rv1 = STRTOG_Zero | STRTOG_Inexlo; 102 break; 103 } 104 goto swapcheck; 105 } 106 if (!(b1->x[nw1] & 1L << nb11)) { 107 if (e1 == fpi->emin) { 108 if (fpi->sudden_underflow) 109 rv1 += STRTOG_Zero - STRTOG_Normal; 110 else 111 rv1 += STRTOG_Denormal - STRTOG_Normal; 112 rv1 |= STRTOG_Underflow; 113 } 114 else { 115 b1 = lshift(b1, 1); 116 b1->x[0] |= 1; 117 --e1; 118 } 119 } 120 } 121 swapcheck: 122 if (swap ^ (rv & STRTOG_Neg)) { 123 rvp[0] = rv1; 124 rvp[1] = rv; 125 B[0] = b1; 126 B[1] = b; 127 exp[1] = exp[0]; 128 exp[0] = e1; 129 } 130 else { 131 rvp[0] = rv; 132 rvp[1] = rv1; 133 B[1] = b1; 134 exp[1] = e1; 135 } 136 return rv; 137 } 138