dmisc.c revision 1.3
1 /* $NetBSD: dmisc.c,v 1.3 2007/02/03 16:44:02 christos Exp $ */ 2 3 /**************************************************************** 4 5 The author of this software is David M. Gay. 6 7 Copyright (C) 1998 by Lucent Technologies 8 All Rights Reserved 9 10 Permission to use, copy, modify, and distribute this software and 11 its documentation for any purpose and without fee is hereby 12 granted, provided that the above copyright notice appear in all 13 copies and that both that the copyright notice and this 14 permission notice and warranty disclaimer appear in supporting 15 documentation, and that the name of Lucent or any of its entities 16 not be used in advertising or publicity pertaining to 17 distribution of the software without specific, written prior 18 permission. 19 20 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 22 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 23 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 24 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 25 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 26 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 27 THIS SOFTWARE. 28 29 ****************************************************************/ 30 31 /* Please send bug reports to David M. Gay (dmg at acm dot org, 32 * with " at " changed at "@" and " dot " changed to "."). */ 33 34 #include "gdtoaimp.h" 35 36 #ifndef MULTIPLE_THREADS 37 char *dtoa_result; 38 #endif 39 40 char * 41 #ifdef KR_headers 42 rv_alloc(i) size_t i; 43 #else 44 rv_alloc(size_t i) 45 #endif 46 { 47 size_t j; 48 int k, *r; 49 50 j = sizeof(ULong); 51 for(k = 0; 52 sizeof(Bigint) - sizeof(ULong) - sizeof(int) + j <= i; 53 j <<= 1) 54 k++; 55 r = (int*)(void*)Balloc(k); 56 *r = k; 57 return 58 #ifndef MULTIPLE_THREADS 59 dtoa_result = 60 #endif 61 (char *)(void *)(r+1); 62 } 63 64 char * 65 #ifdef KR_headers 66 nrv_alloc(s, rve, n) CONST char *s; char **rve; size_t n; 67 #else 68 nrv_alloc(CONST char *s, char **rve, size_t n) 69 #endif 70 { 71 char *rv, *t; 72 73 t = rv = rv_alloc(n); 74 while((*t = *s++) !=0) 75 t++; 76 if (rve) 77 *rve = t; 78 return rv; 79 } 80 81 /* freedtoa(s) must be used to free values s returned by dtoa 82 * when MULTIPLE_THREADS is #defined. It should be used in all cases, 83 * but for consistency with earlier versions of dtoa, it is optional 84 * when MULTIPLE_THREADS is not defined. 85 */ 86 87 void 88 #ifdef KR_headers 89 freedtoa(s) char *s; 90 #else 91 freedtoa(char *s) 92 #endif 93 { 94 Bigint *b = (Bigint *)(void *)((int *)(void *)s - 1); 95 b->maxwds = 1 << (b->k = *(int*)(void*)b); 96 Bfree(b); 97 #ifndef MULTIPLE_THREADS 98 if (s == dtoa_result) 99 dtoa_result = 0; 100 #endif 101 } 102 103 int 104 quorem 105 #ifdef KR_headers 106 (b, S) Bigint *b, *S; 107 #else 108 (Bigint *b, Bigint *S) 109 #endif 110 { 111 int n; 112 ULong *bx, *bxe, q, *sx, *sxe; 113 #ifdef ULLong 114 ULLong borrow, carry, y, ys; 115 #else 116 ULong borrow, carry, y, ys; 117 #ifdef Pack_32 118 ULong si, z, zs; 119 #endif 120 #endif 121 122 n = S->wds; 123 #ifdef DEBUG 124 /*debug*/ if (b->wds > n) 125 /*debug*/ Bug("oversize b in quorem"); 126 #endif 127 if (b->wds < n) 128 return 0; 129 sx = S->x; 130 sxe = sx + --n; 131 bx = b->x; 132 bxe = bx + n; 133 q = *bxe / (*sxe + 1); /* ensure q <= true quotient */ 134 #ifdef DEBUG 135 /*debug*/ if (q > 9) 136 /*debug*/ Bug("oversized quotient in quorem"); 137 #endif 138 if (q) { 139 borrow = 0; 140 carry = 0; 141 do { 142 #ifdef ULLong 143 ys = *sx++ * (ULLong)q + carry; 144 carry = ys >> 32; 145 /* LINTED conversion */ 146 y = *bx - (ys & 0xffffffffUL) - borrow; 147 borrow = y >> 32 & 1UL; 148 /* LINTED conversion */ 149 *bx++ = y & 0xffffffffUL; 150 #else 151 #ifdef Pack_32 152 si = *sx++; 153 ys = (si & 0xffff) * q + carry; 154 zs = (si >> 16) * q + (ys >> 16); 155 carry = zs >> 16; 156 y = (*bx & 0xffff) - (ys & 0xffff) - borrow; 157 borrow = (y & 0x10000) >> 16; 158 z = (*bx >> 16) - (zs & 0xffff) - borrow; 159 borrow = (z & 0x10000) >> 16; 160 Storeinc(bx, z, y); 161 #else 162 ys = *sx++ * q + carry; 163 carry = ys >> 16; 164 y = *bx - (ys & 0xffff) - borrow; 165 borrow = (y & 0x10000) >> 16; 166 *bx++ = y & 0xffff; 167 #endif 168 #endif 169 } 170 while(sx <= sxe); 171 if (!*bxe) { 172 bx = b->x; 173 while(--bxe > bx && !*bxe) 174 --n; 175 b->wds = n; 176 } 177 } 178 if (cmp(b, S) >= 0) { 179 q++; 180 borrow = 0; 181 carry = 0; 182 bx = b->x; 183 sx = S->x; 184 do { 185 #ifdef ULLong 186 ys = *sx++ + carry; 187 carry = ys >> 32; 188 /* LINTED conversion */ 189 y = *bx - (ys & 0xffffffffUL) - borrow; 190 borrow = y >> 32 & 1UL; 191 /* LINTED conversion */ 192 *bx++ = y & 0xffffffffUL; 193 #else 194 #ifdef Pack_32 195 si = *sx++; 196 ys = (si & 0xffff) + carry; 197 zs = (si >> 16) + (ys >> 16); 198 carry = zs >> 16; 199 y = (*bx & 0xffff) - (ys & 0xffff) - borrow; 200 borrow = (y & 0x10000) >> 16; 201 z = (*bx >> 16) - (zs & 0xffff) - borrow; 202 borrow = (z & 0x10000) >> 16; 203 Storeinc(bx, z, y); 204 #else 205 ys = *sx++ + carry; 206 carry = ys >> 16; 207 y = *bx - (ys & 0xffff) - borrow; 208 borrow = (y & 0x10000) >> 16; 209 *bx++ = y & 0xffff; 210 #endif 211 #endif 212 } 213 while(sx <= sxe); 214 bx = b->x; 215 bxe = bx + n; 216 if (!*bxe) { 217 while(--bxe > bx && !*bxe) 218 --n; 219 b->wds = n; 220 } 221 } 222 return q; 223 } 224
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