dmisc.c revision 1.1.1.2
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 #ifndef MULTIPLE_THREADS 35 char *dtoa_result; 36 #endif 37 38 char * 39 #ifdef KR_headers 40 rv_alloc(i) int i; 41 #else 42 rv_alloc(int i) 43 #endif 44 { 45 int j, k, *r; 46 47 j = sizeof(ULong); 48 for(k = 0; 49 sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i; 50 j <<= 1) 51 k++; 52 r = (int*)Balloc(k); 53 *r = k; 54 return 55 #ifndef MULTIPLE_THREADS 56 dtoa_result = 57 #endif 58 (char *)(r+1); 59 } 60 61 char * 62 #ifdef KR_headers 63 nrv_alloc(s, rve, n) char *s, **rve; int n; 64 #else 65 nrv_alloc(char *s, char **rve, int n) 66 #endif 67 { 68 char *rv, *t; 69 70 t = rv = rv_alloc(n); 71 while((*t = *s++) !=0) 72 t++; 73 if (rve) 74 *rve = t; 75 return rv; 76 } 77 78 /* freedtoa(s) must be used to free values s returned by dtoa 79 * when MULTIPLE_THREADS is #defined. It should be used in all cases, 80 * but for consistency with earlier versions of dtoa, it is optional 81 * when MULTIPLE_THREADS is not defined. 82 */ 83 84 void 85 #ifdef KR_headers 86 freedtoa(s) char *s; 87 #else 88 freedtoa(char *s) 89 #endif 90 { 91 Bigint *b = (Bigint *)((int *)s - 1); 92 b->maxwds = 1 << (b->k = *(int*)b); 93 Bfree(b); 94 #ifndef MULTIPLE_THREADS 95 if (s == dtoa_result) 96 dtoa_result = 0; 97 #endif 98 } 99 100 int 101 quorem 102 #ifdef KR_headers 103 (b, S) Bigint *b, *S; 104 #else 105 (Bigint *b, Bigint *S) 106 #endif 107 { 108 int n; 109 ULong *bx, *bxe, q, *sx, *sxe; 110 #ifdef ULLong 111 ULLong borrow, carry, y, ys; 112 #else 113 ULong borrow, carry, y, ys; 114 #ifdef Pack_32 115 ULong si, z, zs; 116 #endif 117 #endif 118 119 n = S->wds; 120 #ifdef DEBUG 121 /*debug*/ if (b->wds > n) 122 /*debug*/ Bug("oversize b in quorem"); 123 #endif 124 if (b->wds < n) 125 return 0; 126 sx = S->x; 127 sxe = sx + --n; 128 bx = b->x; 129 bxe = bx + n; 130 q = *bxe / (*sxe + 1); /* ensure q <= true quotient */ 131 #ifdef DEBUG 132 /*debug*/ if (q > 9) 133 /*debug*/ Bug("oversized quotient in quorem"); 134 #endif 135 if (q) { 136 borrow = 0; 137 carry = 0; 138 do { 139 #ifdef ULLong 140 ys = *sx++ * (ULLong)q + carry; 141 carry = ys >> 32; 142 y = *bx - (ys & 0xffffffffUL) - borrow; 143 borrow = y >> 32 & 1UL; 144 *bx++ = y & 0xffffffffUL; 145 #else 146 #ifdef Pack_32 147 si = *sx++; 148 ys = (si & 0xffff) * q + carry; 149 zs = (si >> 16) * q + (ys >> 16); 150 carry = zs >> 16; 151 y = (*bx & 0xffff) - (ys & 0xffff) - borrow; 152 borrow = (y & 0x10000) >> 16; 153 z = (*bx >> 16) - (zs & 0xffff) - borrow; 154 borrow = (z & 0x10000) >> 16; 155 Storeinc(bx, z, y); 156 #else 157 ys = *sx++ * q + carry; 158 carry = ys >> 16; 159 y = *bx - (ys & 0xffff) - borrow; 160 borrow = (y & 0x10000) >> 16; 161 *bx++ = y & 0xffff; 162 #endif 163 #endif 164 } 165 while(sx <= sxe); 166 if (!*bxe) { 167 bx = b->x; 168 while(--bxe > bx && !*bxe) 169 --n; 170 b->wds = n; 171 } 172 } 173 if (cmp(b, S) >= 0) { 174 q++; 175 borrow = 0; 176 carry = 0; 177 bx = b->x; 178 sx = S->x; 179 do { 180 #ifdef ULLong 181 ys = *sx++ + carry; 182 carry = ys >> 32; 183 y = *bx - (ys & 0xffffffffUL) - borrow; 184 borrow = y >> 32 & 1UL; 185 *bx++ = y & 0xffffffffUL; 186 #else 187 #ifdef Pack_32 188 si = *sx++; 189 ys = (si & 0xffff) + carry; 190 zs = (si >> 16) + (ys >> 16); 191 carry = zs >> 16; 192 y = (*bx & 0xffff) - (ys & 0xffff) - borrow; 193 borrow = (y & 0x10000) >> 16; 194 z = (*bx >> 16) - (zs & 0xffff) - borrow; 195 borrow = (z & 0x10000) >> 16; 196 Storeinc(bx, z, y); 197 #else 198 ys = *sx++ + carry; 199 carry = ys >> 16; 200 y = *bx - (ys & 0xffff) - borrow; 201 borrow = (y & 0x10000) >> 16; 202 *bx++ = y & 0xffff; 203 #endif 204 #endif 205 } 206 while(sx <= sxe); 207 bx = b->x; 208 bxe = bx + n; 209 if (!*bxe) { 210 while(--bxe > bx && !*bxe) 211 --n; 212 b->wds = n; 213 } 214 } 215 return q; 216 } 217
Indexes created Sun Oct 12 09:09:55 GMT 2025