1 /* Internal function for converting integers to ASCII. 2 Copyright (C) 1994,1995,1996,1999,2000,2002 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Torbjorn Granlund <tege@matematik.su.se> 5 and Ulrich Drepper <drepper@gnu.org>. 6 7 The GNU C Library is free software; you can redistribute it and/or 8 modify it under the terms of the GNU Lesser General Public 9 License as published by the Free Software Foundation; either 10 version 2.1 of the License, or (at your option) any later version. 11 12 The GNU C Library is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 Lesser General Public License for more details. 16 17 You should have received a copy of the GNU Lesser General Public 18 License along with the GNU C Library; if not, write to the Free 19 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 20 02111-1307 USA. */ 21 22 #include <gmp-mparam.h> 23 #include <gmp.h> 24 #include <stdlib/gmp-impl.h> 25 #include <stdlib/longlong.h> 26 27 #include "_itowa.h" 28 29 30 /* Canonize environment. For some architectures not all values might 31 be defined in the GMP header files. */ 32 #ifndef UMUL_TIME 33 # define UMUL_TIME 1 34 #endif 35 #ifndef UDIV_TIME 36 # define UDIV_TIME 3 37 #endif 38 39 /* Control memory layout. */ 40 #ifdef PACK 41 # undef PACK 42 # define PACK __attribute__ ((packed)) 43 #else 44 # define PACK 45 #endif 46 47 48 /* Declare local types. */ 49 struct base_table_t 50 { 51 #if (UDIV_TIME > 2 * UMUL_TIME) 52 mp_limb_t base_multiplier; 53 #endif 54 char flag; 55 char post_shift; 56 #if BITS_PER_MP_LIMB == 32 57 struct 58 { 59 char normalization_steps; 60 char ndigits; 61 mp_limb_t base PACK; 62 #if UDIV_TIME > 2 * UMUL_TIME 63 mp_limb_t base_ninv PACK; 64 #endif 65 } big; 66 #endif 67 }; 68 69 /* To reduce the memory needed we include some fields of the tables 70 only conditionally. */ 71 #if UDIV_TIME > 2 * UMUL_TIME 72 # define SEL1(X) X, 73 # define SEL2(X) ,X 74 #else 75 # define SEL1(X) 76 # define SEL2(X) 77 #endif 78 79 /* Factor table for the different bases. */ 80 extern const struct base_table_t _itoa_base_table[] attribute_hidden; 81 82 /* Lower-case digits. */ 83 extern const wchar_t _itowa_lower_digits[] attribute_hidden; 84 /* Upper-case digits. */ 85 extern const wchar_t _itowa_upper_digits[] attribute_hidden; 86 87 88 wchar_t * 89 _itowa (value, buflim, base, upper_case) 90 unsigned long long int value; 91 wchar_t *buflim; 92 unsigned int base; 93 int upper_case; 94 { 95 const wchar_t *digits = (upper_case 96 ? _itowa_upper_digits : _itowa_lower_digits); 97 wchar_t *bp = buflim; 98 const struct base_table_t *brec = &_itoa_base_table[base - 2]; 99 100 switch (base) 101 { 102 #define RUN_2N(BITS) \ 103 do \ 104 { \ 105 /* `unsigned long long int' always has 64 bits. */ \ 106 mp_limb_t work_hi = value >> (64 - BITS_PER_MP_LIMB); \ 107 \ 108 if (BITS_PER_MP_LIMB == 32) \ 109 { \ 110 if (work_hi != 0) \ 111 { \ 112 mp_limb_t work_lo; \ 113 int cnt; \ 114 \ 115 work_lo = value & 0xfffffffful; \ 116 for (cnt = BITS_PER_MP_LIMB / BITS; cnt > 0; --cnt) \ 117 { \ 118 *--bp = digits[work_lo & ((1ul << BITS) - 1)]; \ 119 work_lo >>= BITS; \ 120 } \ 121 if (BITS_PER_MP_LIMB % BITS != 0) \ 122 { \ 123 work_lo \ 124 |= ((work_hi \ 125 & ((1 << (BITS - BITS_PER_MP_LIMB%BITS)) \ 126 - 1)) \ 127 << BITS_PER_MP_LIMB % BITS); \ 128 work_hi >>= BITS - BITS_PER_MP_LIMB % BITS; \ 129 if (work_hi == 0) \ 130 work_hi = work_lo; \ 131 else \ 132 *--bp = digits[work_lo]; \ 133 } \ 134 } \ 135 else \ 136 work_hi = value & 0xfffffffful; \ 137 } \ 138 do \ 139 { \ 140 *--bp = digits[work_hi & ((1 << BITS) - 1)]; \ 141 work_hi >>= BITS; \ 142 } \ 143 while (work_hi != 0); \ 144 } \ 145 while (0) 146 case 8: 147 RUN_2N (3); 148 break; 149 150 case 16: 151 RUN_2N (4); 152 break; 153 154 default: 155 { 156 #if BITS_PER_MP_LIMB == 64 157 mp_limb_t base_multiplier = brec->base_multiplier; 158 if (brec->flag) 159 while (value != 0) 160 { 161 mp_limb_t quo, rem, x, dummy; 162 163 umul_ppmm (x, dummy, value, base_multiplier); 164 quo = (x + ((value - x) >> 1)) >> (brec->post_shift - 1); 165 rem = value - quo * base; 166 *--bp = digits[rem]; 167 value = quo; 168 } 169 else 170 while (value != 0) 171 { 172 mp_limb_t quo, rem, x, dummy; 173 174 umul_ppmm (x, dummy, value, base_multiplier); 175 quo = x >> brec->post_shift; 176 rem = value - quo * base; 177 *--bp = digits[rem]; 178 value = quo; 179 } 180 #endif 181 #if BITS_PER_MP_LIMB == 32 182 mp_limb_t t[3]; 183 int n; 184 185 /* First convert x0 to 1-3 words in base s->big.base. 186 Optimize for frequent cases of 32 bit numbers. */ 187 if ((mp_limb_t) (value >> 32) >= 1) 188 { 189 #if UDIV_TIME > 2 * UMUL_TIME || UDIV_NEEDS_NORMALIZATION 190 int big_normalization_steps = brec->big.normalization_steps; 191 mp_limb_t big_base_norm 192 = brec->big.base << big_normalization_steps; 193 #endif 194 if ((mp_limb_t) (value >> 32) >= brec->big.base) 195 { 196 mp_limb_t x1hi, x1lo, r; 197 /* If you want to optimize this, take advantage of 198 that the quotient in the first udiv_qrnnd will 199 always be very small. It might be faster just to 200 subtract in a tight loop. */ 201 202 #if UDIV_TIME > 2 * UMUL_TIME 203 mp_limb_t x, xh, xl; 204 205 if (big_normalization_steps == 0) 206 xh = 0; 207 else 208 xh = (mp_limb_t) (value >> (64 - big_normalization_steps)); 209 xl = (mp_limb_t) (value >> (32 - big_normalization_steps)); 210 udiv_qrnnd_preinv (x1hi, r, xh, xl, big_base_norm, 211 brec->big.base_ninv); 212 213 xl = ((mp_limb_t) value) << big_normalization_steps; 214 udiv_qrnnd_preinv (x1lo, x, r, xl, big_base_norm, 215 brec->big.base_ninv); 216 t[2] = x >> big_normalization_steps; 217 218 if (big_normalization_steps == 0) 219 xh = x1hi; 220 else 221 xh = ((x1hi << big_normalization_steps) 222 | (x1lo >> (32 - big_normalization_steps))); 223 xl = x1lo << big_normalization_steps; 224 udiv_qrnnd_preinv (t[0], x, xh, xl, big_base_norm, 225 brec->big.base_ninv); 226 t[1] = x >> big_normalization_steps; 227 #elif UDIV_NEEDS_NORMALIZATION 228 mp_limb_t x, xh, xl; 229 230 if (big_normalization_steps == 0) 231 xh = 0; 232 else 233 xh = (mp_limb_t) (value >> 64 - big_normalization_steps); 234 xl = (mp_limb_t) (value >> 32 - big_normalization_steps); 235 udiv_qrnnd (x1hi, r, xh, xl, big_base_norm); 236 237 xl = ((mp_limb_t) value) << big_normalization_steps; 238 udiv_qrnnd (x1lo, x, r, xl, big_base_norm); 239 t[2] = x >> big_normalization_steps; 240 241 if (big_normalization_steps == 0) 242 xh = x1hi; 243 else 244 xh = ((x1hi << big_normalization_steps) 245 | (x1lo >> 32 - big_normalization_steps)); 246 xl = x1lo << big_normalization_steps; 247 udiv_qrnnd (t[0], x, xh, xl, big_base_norm); 248 t[1] = x >> big_normalization_steps; 249 #else 250 udiv_qrnnd (x1hi, r, 0, (mp_limb_t) (value >> 32), 251 brec->big.base); 252 udiv_qrnnd (x1lo, t[2], r, (mp_limb_t) value, brec->big.base); 253 udiv_qrnnd (t[0], t[1], x1hi, x1lo, brec->big.base); 254 #endif 255 n = 3; 256 } 257 else 258 { 259 #if (UDIV_TIME > 2 * UMUL_TIME) 260 mp_limb_t x; 261 262 value <<= brec->big.normalization_steps; 263 udiv_qrnnd_preinv (t[0], x, (mp_limb_t) (value >> 32), 264 (mp_limb_t) value, big_base_norm, 265 brec->big.base_ninv); 266 t[1] = x >> brec->big.normalization_steps; 267 #elif UDIV_NEEDS_NORMALIZATION 268 mp_limb_t x; 269 270 value <<= big_normalization_steps; 271 udiv_qrnnd (t[0], x, (mp_limb_t) (value >> 32), 272 (mp_limb_t) value, big_base_norm); 273 t[1] = x >> big_normalization_steps; 274 #else 275 udiv_qrnnd (t[0], t[1], (mp_limb_t) (value >> 32), 276 (mp_limb_t) value, brec->big.base); 277 #endif 278 n = 2; 279 } 280 } 281 else 282 { 283 t[0] = value; 284 n = 1; 285 } 286 287 /* Convert the 1-3 words in t[], word by word, to ASCII. */ 288 do 289 { 290 mp_limb_t ti = t[--n]; 291 int ndig_for_this_limb = 0; 292 293 #if UDIV_TIME > 2 * UMUL_TIME 294 mp_limb_t base_multiplier = brec->base_multiplier; 295 if (brec->flag) 296 while (ti != 0) 297 { 298 mp_limb_t quo, rem, x, dummy; 299 300 umul_ppmm (x, dummy, ti, base_multiplier); 301 quo = (x + ((ti - x) >> 1)) >> (brec->post_shift - 1); 302 rem = ti - quo * base; 303 *--bp = digits[rem]; 304 ti = quo; 305 ++ndig_for_this_limb; 306 } 307 else 308 while (ti != 0) 309 { 310 mp_limb_t quo, rem, x, dummy; 311 312 umul_ppmm (x, dummy, ti, base_multiplier); 313 quo = x >> brec->post_shift; 314 rem = ti - quo * base; 315 *--bp = digits[rem]; 316 ti = quo; 317 ++ndig_for_this_limb; 318 } 319 #else 320 while (ti != 0) 321 { 322 mp_limb_t quo, rem; 323 324 quo = ti / base; 325 rem = ti % base; 326 *--bp = digits[rem]; 327 ti = quo; 328 ++ndig_for_this_limb; 329 } 330 #endif 331 /* If this wasn't the most significant word, pad with zeros. */ 332 if (n != 0) 333 while (ndig_for_this_limb < brec->big.ndigits) 334 { 335 *--bp = '0'; 336 ++ndig_for_this_limb; 337 } 338 } 339 while (n != 0); 340 #endif 341 } 342 break; 343 } 344 345 return bp; 346 } 347