Stefan Krah | 1919b7e | 2012-03-21 18:25:23 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2008-2012 Stefan Krah. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND |
| 16 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 17 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 18 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 19 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 20 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 21 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 22 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 23 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 24 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 25 | * SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | |
| 29 | #ifndef TYPEARITH_H |
| 30 | #define TYPEARITH_H |
| 31 | |
| 32 | |
| 33 | #include "mpdecimal.h" |
| 34 | |
| 35 | |
| 36 | /*****************************************************************************/ |
| 37 | /* Low level native arithmetic on basic types */ |
| 38 | /*****************************************************************************/ |
| 39 | |
| 40 | |
| 41 | /** ------------------------------------------------------------ |
| 42 | ** Double width multiplication and division |
| 43 | ** ------------------------------------------------------------ |
| 44 | */ |
| 45 | |
| 46 | #if defined(CONFIG_64) |
| 47 | #if defined(ANSI) |
| 48 | #if defined(HAVE_UINT128_T) |
| 49 | static inline void |
| 50 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 51 | { |
| 52 | __uint128_t hl; |
| 53 | |
| 54 | hl = (__uint128_t)a * b; |
| 55 | |
| 56 | *hi = hl >> 64; |
| 57 | *lo = (mpd_uint_t)hl; |
| 58 | } |
| 59 | |
| 60 | static inline void |
| 61 | _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t hi, mpd_uint_t lo, |
| 62 | mpd_uint_t d) |
| 63 | { |
| 64 | __uint128_t hl; |
| 65 | |
| 66 | hl = ((__uint128_t)hi<<64) + lo; |
| 67 | *q = (mpd_uint_t)(hl / d); /* quotient is known to fit */ |
| 68 | *r = (mpd_uint_t)(hl - (__uint128_t)(*q) * d); |
| 69 | } |
| 70 | #else |
| 71 | static inline void |
| 72 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 73 | { |
| 74 | uint32_t w[4], carry; |
| 75 | uint32_t ah, al, bh, bl; |
| 76 | uint64_t hl; |
| 77 | |
| 78 | ah = (uint32_t)(a>>32); al = (uint32_t)a; |
| 79 | bh = (uint32_t)(b>>32); bl = (uint32_t)b; |
| 80 | |
| 81 | hl = (uint64_t)al * bl; |
| 82 | w[0] = (uint32_t)hl; |
| 83 | carry = (uint32_t)(hl>>32); |
| 84 | |
| 85 | hl = (uint64_t)ah * bl + carry; |
| 86 | w[1] = (uint32_t)hl; |
| 87 | w[2] = (uint32_t)(hl>>32); |
| 88 | |
| 89 | hl = (uint64_t)al * bh + w[1]; |
| 90 | w[1] = (uint32_t)hl; |
| 91 | carry = (uint32_t)(hl>>32); |
| 92 | |
| 93 | hl = ((uint64_t)ah * bh + w[2]) + carry; |
| 94 | w[2] = (uint32_t)hl; |
| 95 | w[3] = (uint32_t)(hl>>32); |
| 96 | |
| 97 | *hi = ((uint64_t)w[3]<<32) + w[2]; |
| 98 | *lo = ((uint64_t)w[1]<<32) + w[0]; |
| 99 | } |
| 100 | |
| 101 | /* |
| 102 | * By Henry S. Warren: http://www.hackersdelight.org/HDcode/divlu.c.txt |
| 103 | * http://www.hackersdelight.org/permissions.htm: |
| 104 | * "You are free to use, copy, and distribute any of the code on this web |
| 105 | * site, whether modified by you or not. You need not give attribution." |
| 106 | * |
| 107 | * Slightly modified, comments are mine. |
| 108 | */ |
| 109 | static inline int |
| 110 | nlz(uint64_t x) |
| 111 | { |
| 112 | int n; |
| 113 | |
| 114 | if (x == 0) return(64); |
| 115 | |
| 116 | n = 0; |
| 117 | if (x <= 0x00000000FFFFFFFF) {n = n +32; x = x <<32;} |
| 118 | if (x <= 0x0000FFFFFFFFFFFF) {n = n +16; x = x <<16;} |
| 119 | if (x <= 0x00FFFFFFFFFFFFFF) {n = n + 8; x = x << 8;} |
| 120 | if (x <= 0x0FFFFFFFFFFFFFFF) {n = n + 4; x = x << 4;} |
| 121 | if (x <= 0x3FFFFFFFFFFFFFFF) {n = n + 2; x = x << 2;} |
| 122 | if (x <= 0x7FFFFFFFFFFFFFFF) {n = n + 1;} |
| 123 | |
| 124 | return n; |
| 125 | } |
| 126 | |
| 127 | static inline void |
| 128 | _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t u1, mpd_uint_t u0, |
| 129 | mpd_uint_t v) |
| 130 | { |
| 131 | const mpd_uint_t b = 4294967296; |
| 132 | mpd_uint_t un1, un0, |
| 133 | vn1, vn0, |
| 134 | q1, q0, |
| 135 | un32, un21, un10, |
| 136 | rhat, t; |
| 137 | int s; |
| 138 | |
| 139 | assert(u1 < v); |
| 140 | |
| 141 | s = nlz(v); |
| 142 | v = v << s; |
| 143 | vn1 = v >> 32; |
| 144 | vn0 = v & 0xFFFFFFFF; |
| 145 | |
| 146 | t = (s == 0) ? 0 : u0 >> (64 - s); |
| 147 | un32 = (u1 << s) | t; |
| 148 | un10 = u0 << s; |
| 149 | |
| 150 | un1 = un10 >> 32; |
| 151 | un0 = un10 & 0xFFFFFFFF; |
| 152 | |
| 153 | q1 = un32 / vn1; |
| 154 | rhat = un32 - q1*vn1; |
| 155 | again1: |
| 156 | if (q1 >= b || q1*vn0 > b*rhat + un1) { |
| 157 | q1 = q1 - 1; |
| 158 | rhat = rhat + vn1; |
| 159 | if (rhat < b) goto again1; |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * Before again1 we had: |
| 164 | * (1) q1*vn1 + rhat = un32 |
| 165 | * (2) q1*vn1*b + rhat*b + un1 = un32*b + un1 |
| 166 | * |
| 167 | * The statements inside the if-clause do not change the value |
| 168 | * of the left-hand side of (2), and the loop is only exited |
| 169 | * if q1*vn0 <= rhat*b + un1, so: |
| 170 | * |
| 171 | * (3) q1*vn1*b + q1*vn0 <= un32*b + un1 |
| 172 | * (4) q1*v <= un32*b + un1 |
| 173 | * (5) 0 <= un32*b + un1 - q1*v |
| 174 | * |
| 175 | * By (5) we are certain that the possible add-back step from |
| 176 | * Knuth's algorithm D is never required. |
| 177 | * |
| 178 | * Since the final quotient is less than 2**64, the following |
| 179 | * must be true: |
| 180 | * |
| 181 | * (6) un32*b + un1 - q1*v <= UINT64_MAX |
| 182 | * |
| 183 | * This means that in the following line, the high words |
| 184 | * of un32*b and q1*v can be discarded without any effect |
| 185 | * on the result. |
| 186 | */ |
| 187 | un21 = un32*b + un1 - q1*v; |
| 188 | |
| 189 | q0 = un21 / vn1; |
| 190 | rhat = un21 - q0*vn1; |
| 191 | again2: |
| 192 | if (q0 >= b || q0*vn0 > b*rhat + un0) { |
| 193 | q0 = q0 - 1; |
| 194 | rhat = rhat + vn1; |
| 195 | if (rhat < b) goto again2; |
| 196 | } |
| 197 | |
| 198 | *q = q1*b + q0; |
| 199 | *r = (un21*b + un0 - q0*v) >> s; |
| 200 | } |
| 201 | #endif |
| 202 | |
| 203 | /* END ANSI */ |
| 204 | #elif defined(ASM) |
| 205 | static inline void |
| 206 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 207 | { |
| 208 | mpd_uint_t h, l; |
| 209 | |
Stefan Krah | a0346e5 | 2012-09-30 17:31:04 +0200 | [diff] [blame] | 210 | __asm__ ( "mulq %3\n\t" |
| 211 | : "=d" (h), "=a" (l) |
| 212 | : "%a" (a), "rm" (b) |
| 213 | : "cc" |
Stefan Krah | 1919b7e | 2012-03-21 18:25:23 +0100 | [diff] [blame] | 214 | ); |
| 215 | |
| 216 | *hi = h; |
| 217 | *lo = l; |
| 218 | } |
| 219 | |
| 220 | static inline void |
| 221 | _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t hi, mpd_uint_t lo, |
| 222 | mpd_uint_t d) |
| 223 | { |
| 224 | mpd_uint_t qq, rr; |
| 225 | |
Stefan Krah | a0346e5 | 2012-09-30 17:31:04 +0200 | [diff] [blame] | 226 | __asm__ ( "divq %4\n\t" |
| 227 | : "=a" (qq), "=d" (rr) |
| 228 | : "a" (lo), "d" (hi), "rm" (d) |
| 229 | : "cc" |
Stefan Krah | 1919b7e | 2012-03-21 18:25:23 +0100 | [diff] [blame] | 230 | ); |
| 231 | |
| 232 | *q = qq; |
| 233 | *r = rr; |
| 234 | } |
| 235 | /* END GCC ASM */ |
| 236 | #elif defined(MASM) |
| 237 | #include <intrin.h> |
| 238 | #pragma intrinsic(_umul128) |
| 239 | |
| 240 | static inline void |
| 241 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 242 | { |
| 243 | *lo = _umul128(a, b, hi); |
| 244 | } |
| 245 | |
| 246 | void _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t hi, mpd_uint_t lo, |
| 247 | mpd_uint_t d); |
| 248 | |
| 249 | /* END MASM (_MSC_VER) */ |
| 250 | #else |
| 251 | #error "need platform specific 128 bit multiplication and division" |
| 252 | #endif |
| 253 | |
| 254 | #define DIVMOD(q, r, v, d) *q = v / d; *r = v - *q * d |
| 255 | static inline void |
| 256 | _mpd_divmod_pow10(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t v, mpd_uint_t exp) |
| 257 | { |
| 258 | assert(exp <= 19); |
| 259 | |
| 260 | if (exp <= 9) { |
| 261 | if (exp <= 4) { |
| 262 | switch (exp) { |
| 263 | case 0: *q = v; *r = 0; break; |
| 264 | case 1: DIVMOD(q, r, v, 10UL); break; |
| 265 | case 2: DIVMOD(q, r, v, 100UL); break; |
| 266 | case 3: DIVMOD(q, r, v, 1000UL); break; |
| 267 | case 4: DIVMOD(q, r, v, 10000UL); break; |
| 268 | } |
| 269 | } |
| 270 | else { |
| 271 | switch (exp) { |
| 272 | case 5: DIVMOD(q, r, v, 100000UL); break; |
| 273 | case 6: DIVMOD(q, r, v, 1000000UL); break; |
| 274 | case 7: DIVMOD(q, r, v, 10000000UL); break; |
| 275 | case 8: DIVMOD(q, r, v, 100000000UL); break; |
| 276 | case 9: DIVMOD(q, r, v, 1000000000UL); break; |
| 277 | } |
| 278 | } |
| 279 | } |
| 280 | else { |
| 281 | if (exp <= 14) { |
| 282 | switch (exp) { |
| 283 | case 10: DIVMOD(q, r, v, 10000000000ULL); break; |
| 284 | case 11: DIVMOD(q, r, v, 100000000000ULL); break; |
| 285 | case 12: DIVMOD(q, r, v, 1000000000000ULL); break; |
| 286 | case 13: DIVMOD(q, r, v, 10000000000000ULL); break; |
| 287 | case 14: DIVMOD(q, r, v, 100000000000000ULL); break; |
| 288 | } |
| 289 | } |
| 290 | else { |
| 291 | switch (exp) { |
| 292 | case 15: DIVMOD(q, r, v, 1000000000000000ULL); break; |
| 293 | case 16: DIVMOD(q, r, v, 10000000000000000ULL); break; |
| 294 | case 17: DIVMOD(q, r, v, 100000000000000000ULL); break; |
| 295 | case 18: DIVMOD(q, r, v, 1000000000000000000ULL); break; |
| 296 | case 19: DIVMOD(q, r, v, 10000000000000000000ULL); break; /* GCOV_NOT_REACHED */ |
| 297 | } |
| 298 | } |
| 299 | } |
| 300 | } |
| 301 | |
| 302 | /* END CONFIG_64 */ |
| 303 | #elif defined(CONFIG_32) |
| 304 | #if defined(ANSI) |
| 305 | #if !defined(LEGACY_COMPILER) |
| 306 | static inline void |
| 307 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 308 | { |
| 309 | mpd_uuint_t hl; |
| 310 | |
| 311 | hl = (mpd_uuint_t)a * b; |
| 312 | |
| 313 | *hi = hl >> 32; |
| 314 | *lo = (mpd_uint_t)hl; |
| 315 | } |
| 316 | |
| 317 | static inline void |
| 318 | _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t hi, mpd_uint_t lo, |
| 319 | mpd_uint_t d) |
| 320 | { |
| 321 | mpd_uuint_t hl; |
| 322 | |
| 323 | hl = ((mpd_uuint_t)hi<<32) + lo; |
| 324 | *q = (mpd_uint_t)(hl / d); /* quotient is known to fit */ |
| 325 | *r = (mpd_uint_t)(hl - (mpd_uuint_t)(*q) * d); |
| 326 | } |
| 327 | /* END ANSI + uint64_t */ |
| 328 | #else |
| 329 | static inline void |
| 330 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 331 | { |
| 332 | uint16_t w[4], carry; |
| 333 | uint16_t ah, al, bh, bl; |
| 334 | uint32_t hl; |
| 335 | |
| 336 | ah = (uint16_t)(a>>16); al = (uint16_t)a; |
| 337 | bh = (uint16_t)(b>>16); bl = (uint16_t)b; |
| 338 | |
| 339 | hl = (uint32_t)al * bl; |
| 340 | w[0] = (uint16_t)hl; |
| 341 | carry = (uint16_t)(hl>>16); |
| 342 | |
| 343 | hl = (uint32_t)ah * bl + carry; |
| 344 | w[1] = (uint16_t)hl; |
| 345 | w[2] = (uint16_t)(hl>>16); |
| 346 | |
| 347 | hl = (uint32_t)al * bh + w[1]; |
| 348 | w[1] = (uint16_t)hl; |
| 349 | carry = (uint16_t)(hl>>16); |
| 350 | |
| 351 | hl = ((uint32_t)ah * bh + w[2]) + carry; |
| 352 | w[2] = (uint16_t)hl; |
| 353 | w[3] = (uint16_t)(hl>>16); |
| 354 | |
| 355 | *hi = ((uint32_t)w[3]<<16) + w[2]; |
| 356 | *lo = ((uint32_t)w[1]<<16) + w[0]; |
| 357 | } |
| 358 | |
| 359 | /* |
| 360 | * By Henry S. Warren: http://www.hackersdelight.org/HDcode/divlu.c.txt |
| 361 | * http://www.hackersdelight.org/permissions.htm: |
| 362 | * "You are free to use, copy, and distribute any of the code on this web |
| 363 | * site, whether modified by you or not. You need not give attribution." |
| 364 | * |
| 365 | * Slightly modified, comments are mine. |
| 366 | */ |
| 367 | static inline int |
| 368 | nlz(uint32_t x) |
| 369 | { |
| 370 | int n; |
| 371 | |
| 372 | if (x == 0) return(32); |
| 373 | |
| 374 | n = 0; |
| 375 | if (x <= 0x0000FFFF) {n = n +16; x = x <<16;} |
| 376 | if (x <= 0x00FFFFFF) {n = n + 8; x = x << 8;} |
| 377 | if (x <= 0x0FFFFFFF) {n = n + 4; x = x << 4;} |
| 378 | if (x <= 0x3FFFFFFF) {n = n + 2; x = x << 2;} |
| 379 | if (x <= 0x7FFFFFFF) {n = n + 1;} |
| 380 | |
| 381 | return n; |
| 382 | } |
| 383 | |
| 384 | static inline void |
| 385 | _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t u1, mpd_uint_t u0, |
| 386 | mpd_uint_t v) |
| 387 | { |
| 388 | const mpd_uint_t b = 65536; |
| 389 | mpd_uint_t un1, un0, |
| 390 | vn1, vn0, |
| 391 | q1, q0, |
| 392 | un32, un21, un10, |
| 393 | rhat, t; |
| 394 | int s; |
| 395 | |
| 396 | assert(u1 < v); |
| 397 | |
| 398 | s = nlz(v); |
| 399 | v = v << s; |
| 400 | vn1 = v >> 16; |
| 401 | vn0 = v & 0xFFFF; |
| 402 | |
| 403 | t = (s == 0) ? 0 : u0 >> (32 - s); |
| 404 | un32 = (u1 << s) | t; |
| 405 | un10 = u0 << s; |
| 406 | |
| 407 | un1 = un10 >> 16; |
| 408 | un0 = un10 & 0xFFFF; |
| 409 | |
| 410 | q1 = un32 / vn1; |
| 411 | rhat = un32 - q1*vn1; |
| 412 | again1: |
| 413 | if (q1 >= b || q1*vn0 > b*rhat + un1) { |
| 414 | q1 = q1 - 1; |
| 415 | rhat = rhat + vn1; |
| 416 | if (rhat < b) goto again1; |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * Before again1 we had: |
| 421 | * (1) q1*vn1 + rhat = un32 |
| 422 | * (2) q1*vn1*b + rhat*b + un1 = un32*b + un1 |
| 423 | * |
| 424 | * The statements inside the if-clause do not change the value |
| 425 | * of the left-hand side of (2), and the loop is only exited |
| 426 | * if q1*vn0 <= rhat*b + un1, so: |
| 427 | * |
| 428 | * (3) q1*vn1*b + q1*vn0 <= un32*b + un1 |
| 429 | * (4) q1*v <= un32*b + un1 |
| 430 | * (5) 0 <= un32*b + un1 - q1*v |
| 431 | * |
| 432 | * By (5) we are certain that the possible add-back step from |
| 433 | * Knuth's algorithm D is never required. |
| 434 | * |
| 435 | * Since the final quotient is less than 2**32, the following |
| 436 | * must be true: |
| 437 | * |
| 438 | * (6) un32*b + un1 - q1*v <= UINT32_MAX |
| 439 | * |
| 440 | * This means that in the following line, the high words |
| 441 | * of un32*b and q1*v can be discarded without any effect |
| 442 | * on the result. |
| 443 | */ |
| 444 | un21 = un32*b + un1 - q1*v; |
| 445 | |
| 446 | q0 = un21 / vn1; |
| 447 | rhat = un21 - q0*vn1; |
| 448 | again2: |
| 449 | if (q0 >= b || q0*vn0 > b*rhat + un0) { |
| 450 | q0 = q0 - 1; |
| 451 | rhat = rhat + vn1; |
| 452 | if (rhat < b) goto again2; |
| 453 | } |
| 454 | |
| 455 | *q = q1*b + q0; |
| 456 | *r = (un21*b + un0 - q0*v) >> s; |
| 457 | } |
| 458 | #endif /* END ANSI + LEGACY_COMPILER */ |
| 459 | |
| 460 | /* END ANSI */ |
| 461 | #elif defined(ASM) |
| 462 | static inline void |
| 463 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 464 | { |
| 465 | mpd_uint_t h, l; |
| 466 | |
Stefan Krah | a0346e5 | 2012-09-30 17:31:04 +0200 | [diff] [blame] | 467 | __asm__ ( "mull %3\n\t" |
| 468 | : "=d" (h), "=a" (l) |
| 469 | : "%a" (a), "rm" (b) |
| 470 | : "cc" |
Stefan Krah | 1919b7e | 2012-03-21 18:25:23 +0100 | [diff] [blame] | 471 | ); |
| 472 | |
| 473 | *hi = h; |
| 474 | *lo = l; |
| 475 | } |
| 476 | |
| 477 | static inline void |
| 478 | _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t hi, mpd_uint_t lo, |
| 479 | mpd_uint_t d) |
| 480 | { |
| 481 | mpd_uint_t qq, rr; |
| 482 | |
Stefan Krah | a0346e5 | 2012-09-30 17:31:04 +0200 | [diff] [blame] | 483 | __asm__ ( "divl %4\n\t" |
| 484 | : "=a" (qq), "=d" (rr) |
| 485 | : "a" (lo), "d" (hi), "rm" (d) |
| 486 | : "cc" |
Stefan Krah | 1919b7e | 2012-03-21 18:25:23 +0100 | [diff] [blame] | 487 | ); |
| 488 | |
| 489 | *q = qq; |
| 490 | *r = rr; |
| 491 | } |
| 492 | /* END GCC ASM */ |
| 493 | #elif defined(MASM) |
| 494 | static inline void __cdecl |
| 495 | _mpd_mul_words(mpd_uint_t *hi, mpd_uint_t *lo, mpd_uint_t a, mpd_uint_t b) |
| 496 | { |
| 497 | mpd_uint_t h, l; |
| 498 | |
| 499 | __asm { |
| 500 | mov eax, a |
| 501 | mul b |
| 502 | mov h, edx |
| 503 | mov l, eax |
| 504 | } |
| 505 | |
| 506 | *hi = h; |
| 507 | *lo = l; |
| 508 | } |
| 509 | |
| 510 | static inline void __cdecl |
| 511 | _mpd_div_words(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t hi, mpd_uint_t lo, |
| 512 | mpd_uint_t d) |
| 513 | { |
| 514 | mpd_uint_t qq, rr; |
| 515 | |
| 516 | __asm { |
| 517 | mov eax, lo |
| 518 | mov edx, hi |
| 519 | div d |
| 520 | mov qq, eax |
| 521 | mov rr, edx |
| 522 | } |
| 523 | |
| 524 | *q = qq; |
| 525 | *r = rr; |
| 526 | } |
| 527 | /* END MASM (_MSC_VER) */ |
| 528 | #else |
| 529 | #error "need platform specific 64 bit multiplication and division" |
| 530 | #endif |
| 531 | |
| 532 | #define DIVMOD(q, r, v, d) *q = v / d; *r = v - *q * d |
| 533 | static inline void |
| 534 | _mpd_divmod_pow10(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t v, mpd_uint_t exp) |
| 535 | { |
| 536 | assert(exp <= 9); |
| 537 | |
| 538 | if (exp <= 4) { |
| 539 | switch (exp) { |
| 540 | case 0: *q = v; *r = 0; break; |
| 541 | case 1: DIVMOD(q, r, v, 10UL); break; |
| 542 | case 2: DIVMOD(q, r, v, 100UL); break; |
| 543 | case 3: DIVMOD(q, r, v, 1000UL); break; |
| 544 | case 4: DIVMOD(q, r, v, 10000UL); break; |
| 545 | } |
| 546 | } |
| 547 | else { |
| 548 | switch (exp) { |
| 549 | case 5: DIVMOD(q, r, v, 100000UL); break; |
| 550 | case 6: DIVMOD(q, r, v, 1000000UL); break; |
| 551 | case 7: DIVMOD(q, r, v, 10000000UL); break; |
| 552 | case 8: DIVMOD(q, r, v, 100000000UL); break; |
| 553 | case 9: DIVMOD(q, r, v, 1000000000UL); break; /* GCOV_NOT_REACHED */ |
| 554 | } |
| 555 | } |
| 556 | } |
| 557 | /* END CONFIG_32 */ |
| 558 | |
| 559 | /* NO CONFIG */ |
| 560 | #else |
| 561 | #error "define CONFIG_64 or CONFIG_32" |
| 562 | #endif /* CONFIG */ |
| 563 | |
| 564 | |
| 565 | static inline void |
| 566 | _mpd_div_word(mpd_uint_t *q, mpd_uint_t *r, mpd_uint_t v, mpd_uint_t d) |
| 567 | { |
| 568 | *q = v / d; |
| 569 | *r = v - *q * d; |
| 570 | } |
| 571 | |
| 572 | static inline void |
| 573 | _mpd_idiv_word(mpd_ssize_t *q, mpd_ssize_t *r, mpd_ssize_t v, mpd_ssize_t d) |
| 574 | { |
| 575 | *q = v / d; |
| 576 | *r = v - *q * d; |
| 577 | } |
| 578 | |
| 579 | |
| 580 | /** ------------------------------------------------------------ |
| 581 | ** Arithmetic with overflow checking |
| 582 | ** ------------------------------------------------------------ |
| 583 | */ |
| 584 | |
| 585 | /* The following macros do call exit() in case of an overflow. |
| 586 | If the library is used correctly (i.e. with valid context |
| 587 | parameters), such overflows cannot occur. The macros are used |
| 588 | as sanity checks in a couple of strategic places and should |
| 589 | be viewed as a handwritten version of gcc's -ftrapv option. */ |
| 590 | |
| 591 | static inline mpd_size_t |
| 592 | add_size_t(mpd_size_t a, mpd_size_t b) |
| 593 | { |
| 594 | if (a > MPD_SIZE_MAX - b) { |
| 595 | mpd_err_fatal("add_size_t(): overflow: check the context"); /* GCOV_NOT_REACHED */ |
| 596 | } |
| 597 | return a + b; |
| 598 | } |
| 599 | |
| 600 | static inline mpd_size_t |
| 601 | sub_size_t(mpd_size_t a, mpd_size_t b) |
| 602 | { |
| 603 | if (b > a) { |
| 604 | mpd_err_fatal("sub_size_t(): overflow: check the context"); /* GCOV_NOT_REACHED */ |
| 605 | } |
| 606 | return a - b; |
| 607 | } |
| 608 | |
| 609 | #if MPD_SIZE_MAX != MPD_UINT_MAX |
| 610 | #error "adapt mul_size_t() and mulmod_size_t()" |
| 611 | #endif |
| 612 | |
| 613 | static inline mpd_size_t |
| 614 | mul_size_t(mpd_size_t a, mpd_size_t b) |
| 615 | { |
| 616 | mpd_uint_t hi, lo; |
| 617 | |
| 618 | _mpd_mul_words(&hi, &lo, (mpd_uint_t)a, (mpd_uint_t)b); |
| 619 | if (hi) { |
| 620 | mpd_err_fatal("mul_size_t(): overflow: check the context"); /* GCOV_NOT_REACHED */ |
| 621 | } |
| 622 | return lo; |
| 623 | } |
| 624 | |
| 625 | static inline mpd_size_t |
| 626 | add_size_t_overflow(mpd_size_t a, mpd_size_t b, mpd_size_t *overflow) |
| 627 | { |
| 628 | mpd_size_t ret; |
| 629 | |
| 630 | *overflow = 0; |
| 631 | ret = a + b; |
| 632 | if (ret < a) *overflow = 1; |
| 633 | return ret; |
| 634 | } |
| 635 | |
| 636 | static inline mpd_size_t |
| 637 | mul_size_t_overflow(mpd_size_t a, mpd_size_t b, mpd_size_t *overflow) |
| 638 | { |
| 639 | mpd_uint_t lo; |
| 640 | |
| 641 | _mpd_mul_words((mpd_uint_t *)overflow, &lo, (mpd_uint_t)a, |
| 642 | (mpd_uint_t)b); |
| 643 | return lo; |
| 644 | } |
| 645 | |
| 646 | static inline mpd_ssize_t |
| 647 | mod_mpd_ssize_t(mpd_ssize_t a, mpd_ssize_t m) |
| 648 | { |
| 649 | mpd_ssize_t r = a % m; |
| 650 | return (r < 0) ? r + m : r; |
| 651 | } |
| 652 | |
| 653 | static inline mpd_size_t |
| 654 | mulmod_size_t(mpd_size_t a, mpd_size_t b, mpd_size_t m) |
| 655 | { |
| 656 | mpd_uint_t hi, lo; |
| 657 | mpd_uint_t q, r; |
| 658 | |
| 659 | _mpd_mul_words(&hi, &lo, (mpd_uint_t)a, (mpd_uint_t)b); |
| 660 | _mpd_div_words(&q, &r, hi, lo, (mpd_uint_t)m); |
| 661 | |
| 662 | return r; |
| 663 | } |
| 664 | |
| 665 | |
| 666 | #endif /* TYPEARITH_H */ |
| 667 | |
| 668 | |
| 669 | |