APInt.cpp revision e0cdd3349df98cb886d9b24351f9116a9a11c5f8
1//===-- APInt.cpp - Implement APInt class ---------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by Sheng Zhou and is distributed under the 6// University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements a class to represent arbitrary precision integral 11// constant values. 12// 13//===----------------------------------------------------------------------===// 14 15#include "llvm/ADT/APInt.h" 16#include "llvm/DerivedTypes.h" 17#include "llvm/Support/MathExtras.h" 18#include <cstring> 19#include <cstdlib> 20#ifndef NDEBUG 21#include <iostream> 22#include <iomanip> 23#endif 24 25using namespace llvm; 26 27// A utility function for allocating memory, checking for allocation failures, 28// and ensuring the contents is zeroed. 29inline static uint64_t* getClearedMemory(uint32_t numWords) { 30 uint64_t * result = new uint64_t[numWords]; 31 assert(result && "APInt memory allocation fails!"); 32 memset(result, 0, numWords * sizeof(uint64_t)); 33 return result; 34} 35 36// A utility function for allocating memory and checking for allocation failure. 37inline static uint64_t* getMemory(uint32_t numWords) { 38 uint64_t * result = new uint64_t[numWords]; 39 assert(result && "APInt memory allocation fails!"); 40 return result; 41} 42 43APInt::APInt(uint32_t numBits, uint64_t val) 44 : BitWidth(numBits), VAL(0) { 45 assert(BitWidth >= IntegerType::MIN_INT_BITS && "bitwidth too small"); 46 assert(BitWidth <= IntegerType::MAX_INT_BITS && "bitwidth too large"); 47 if (isSingleWord()) 48 VAL = val & (~uint64_t(0ULL) >> (APINT_BITS_PER_WORD - BitWidth)); 49 else { 50 pVal = getClearedMemory(getNumWords()); 51 pVal[0] = val; 52 } 53} 54 55APInt::APInt(uint32_t numBits, uint32_t numWords, uint64_t bigVal[]) 56 : BitWidth(numBits), VAL(0) { 57 assert(BitWidth >= IntegerType::MIN_INT_BITS && "bitwidth too small"); 58 assert(BitWidth <= IntegerType::MAX_INT_BITS && "bitwidth too large"); 59 assert(bigVal && "Null pointer detected!"); 60 if (isSingleWord()) 61 VAL = bigVal[0] & (~uint64_t(0ULL) >> (APINT_BITS_PER_WORD - BitWidth)); 62 else { 63 pVal = getMemory(getNumWords()); 64 // Calculate the actual length of bigVal[]. 65 uint32_t maxN = std::max<uint32_t>(numWords, getNumWords()); 66 uint32_t minN = std::min<uint32_t>(numWords, getNumWords()); 67 memcpy(pVal, bigVal, (minN - 1) * APINT_WORD_SIZE); 68 pVal[minN-1] = bigVal[minN-1] & 69 (~uint64_t(0ULL) >> 70 (APINT_BITS_PER_WORD - BitWidth % APINT_BITS_PER_WORD)); 71 if (maxN == getNumWords()) 72 memset(pVal+numWords, 0, (getNumWords() - numWords) * APINT_WORD_SIZE); 73 } 74} 75 76/// @brief Create a new APInt by translating the char array represented 77/// integer value. 78APInt::APInt(uint32_t numbits, const char StrStart[], uint32_t slen, 79 uint8_t radix) 80 : BitWidth(numbits), VAL(0) { 81 fromString(numbits, StrStart, slen, radix); 82} 83 84/// @brief Create a new APInt by translating the string represented 85/// integer value. 86APInt::APInt(uint32_t numbits, const std::string& Val, uint8_t radix) 87 : BitWidth(numbits), VAL(0) { 88 assert(!Val.empty() && "String empty?"); 89 fromString(numbits, Val.c_str(), Val.size(), radix); 90} 91 92/// @brief Copy constructor 93APInt::APInt(const APInt& that) 94 : BitWidth(that.BitWidth), VAL(0) { 95 if (isSingleWord()) 96 VAL = that.VAL; 97 else { 98 pVal = getMemory(getNumWords()); 99 memcpy(pVal, that.pVal, getNumWords() * APINT_WORD_SIZE); 100 } 101} 102 103APInt::~APInt() { 104 if (!isSingleWord() && pVal) 105 delete[] pVal; 106} 107 108/// @brief Copy assignment operator. Create a new object from the given 109/// APInt one by initialization. 110APInt& APInt::operator=(const APInt& RHS) { 111 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 112 if (isSingleWord()) 113 VAL = RHS.VAL; 114 else 115 memcpy(pVal, RHS.pVal, getNumWords() * APINT_WORD_SIZE); 116 return *this; 117} 118 119/// @brief Assignment operator. Assigns a common case integer value to 120/// the APInt. 121APInt& APInt::operator=(uint64_t RHS) { 122 if (isSingleWord()) 123 VAL = RHS; 124 else { 125 pVal[0] = RHS; 126 memset(pVal+1, 0, (getNumWords() - 1) * APINT_WORD_SIZE); 127 } 128 return *this; 129} 130 131/// add_1 - This function adds a single "digit" integer, y, to the multiple 132/// "digit" integer array, x[]. x[] is modified to reflect the addition and 133/// 1 is returned if there is a carry out, otherwise 0 is returned. 134/// @returns the carry of the addition. 135static uint64_t add_1(uint64_t dest[], 136 uint64_t x[], uint32_t len, 137 uint64_t y) { 138 for (uint32_t i = 0; i < len; ++i) { 139 dest[i] = y + x[i]; 140 if (dest[i] < y) 141 y = 1; 142 else { 143 y = 0; 144 break; 145 } 146 } 147 return y; 148} 149 150/// @brief Prefix increment operator. Increments the APInt by one. 151APInt& APInt::operator++() { 152 if (isSingleWord()) 153 ++VAL; 154 else 155 add_1(pVal, pVal, getNumWords(), 1); 156 clearUnusedBits(); 157 return *this; 158} 159 160/// sub_1 - This function subtracts a single "digit" (64-bit word), y, from 161/// the multi-digit integer array, x[], propagating the borrowed 1 value until 162/// no further borrowing is neeeded or it runs out of "digits" in x. The result 163/// is 1 if "borrowing" exhausted the digits in x, or 0 if x was not exhausted. 164/// In other words, if y > x then this function returns 1, otherwise 0. 165static uint64_t sub_1(uint64_t x[], uint32_t len, 166 uint64_t y) { 167 for (uint32_t i = 0; i < len; ++i) { 168 uint64_t X = x[i]; 169 x[i] -= y; 170 if (y > X) 171 y = 1; // We have to "borrow 1" from next "digit" 172 else { 173 y = 0; // No need to borrow 174 break; // Remaining digits are unchanged so exit early 175 } 176 } 177 return y; 178} 179 180/// @brief Prefix decrement operator. Decrements the APInt by one. 181APInt& APInt::operator--() { 182 if (isSingleWord()) 183 --VAL; 184 else 185 sub_1(pVal, getNumWords(), 1); 186 clearUnusedBits(); 187 return *this; 188} 189 190/// add - This function adds the integer array x[] by integer array 191/// y[] and returns the carry. 192static uint64_t add(uint64_t dest[], uint64_t x[], uint64_t y[], uint32_t len) { 193 uint64_t carry = 0; 194 for (uint32_t i = 0; i< len; ++i) { 195 dest[i] = x[i] + y[i] + carry; 196 uint64_t limit = std::min(x[i],y[i]); 197 carry = dest[i] < limit || (carry && dest[i] == limit); 198 } 199 return carry; 200} 201 202/// @brief Addition assignment operator. Adds this APInt by the given APInt& 203/// RHS and assigns the result to this APInt. 204APInt& APInt::operator+=(const APInt& RHS) { 205 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 206 if (isSingleWord()) 207 VAL += RHS.VAL; 208 else { 209 add(pVal, pVal, RHS.pVal, getNumWords()); 210 } 211 clearUnusedBits(); 212 return *this; 213} 214 215/// sub - This function subtracts the integer array x[] by 216/// integer array y[], and returns the borrow-out carry. 217static uint64_t sub(uint64_t *dest, const uint64_t *x, const uint64_t *y, 218 uint32_t len) { 219 bool borrow = false; 220 for (uint32_t i = 0; i < len; ++i) { 221 uint64_t x_tmp = borrow ? x[i] - 1 : x[i]; 222 borrow = y[i] > x_tmp || (borrow && x[i] == 0); 223 dest[i] = x_tmp - y[i]; 224 } 225 return borrow; 226} 227 228/// @brief Subtraction assignment operator. Subtracts this APInt by the given 229/// APInt &RHS and assigns the result to this APInt. 230APInt& APInt::operator-=(const APInt& RHS) { 231 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 232 if (isSingleWord()) 233 VAL -= RHS.VAL; 234 else 235 sub(pVal, pVal, RHS.pVal, getNumWords()); 236 clearUnusedBits(); 237 return *this; 238} 239 240/// mul_1 - This function performs the multiplication operation on a 241/// large integer (represented as an integer array) and a uint64_t integer. 242/// @returns the carry of the multiplication. 243static uint64_t mul_1(uint64_t dest[], 244 uint64_t x[], uint32_t len, 245 uint64_t y) { 246 // Split y into high 32-bit part and low 32-bit part. 247 uint64_t ly = y & 0xffffffffULL, hy = y >> 32; 248 uint64_t carry = 0, lx, hx; 249 for (uint32_t i = 0; i < len; ++i) { 250 lx = x[i] & 0xffffffffULL; 251 hx = x[i] >> 32; 252 // hasCarry - A flag to indicate if has carry. 253 // hasCarry == 0, no carry 254 // hasCarry == 1, has carry 255 // hasCarry == 2, no carry and the calculation result == 0. 256 uint8_t hasCarry = 0; 257 dest[i] = carry + lx * ly; 258 // Determine if the add above introduces carry. 259 hasCarry = (dest[i] < carry) ? 1 : 0; 260 carry = hx * ly + (dest[i] >> 32) + (hasCarry ? (1ULL << 32) : 0); 261 // The upper limit of carry can be (2^32 - 1)(2^32 - 1) + 262 // (2^32 - 1) + 2^32 = 2^64. 263 hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0); 264 265 carry += (lx * hy) & 0xffffffffULL; 266 dest[i] = (carry << 32) | (dest[i] & 0xffffffffULL); 267 carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0) + 268 (carry >> 32) + ((lx * hy) >> 32) + hx * hy; 269 } 270 271 return carry; 272} 273 274/// mul - This function multiplies integer array x[] by integer array y[] and 275/// stores the result into integer array dest[]. 276/// Note the array dest[]'s size should no less than xlen + ylen. 277static void mul(uint64_t dest[], uint64_t x[], uint32_t xlen, 278 uint64_t y[], uint32_t ylen) { 279 dest[xlen] = mul_1(dest, x, xlen, y[0]); 280 281 for (uint32_t i = 1; i < ylen; ++i) { 282 uint64_t ly = y[i] & 0xffffffffULL, hy = y[i] >> 32; 283 uint64_t carry = 0, lx = 0, hx = 0; 284 for (uint32_t j = 0; j < xlen; ++j) { 285 lx = x[j] & 0xffffffffULL; 286 hx = x[j] >> 32; 287 // hasCarry - A flag to indicate if has carry. 288 // hasCarry == 0, no carry 289 // hasCarry == 1, has carry 290 // hasCarry == 2, no carry and the calculation result == 0. 291 uint8_t hasCarry = 0; 292 uint64_t resul = carry + lx * ly; 293 hasCarry = (resul < carry) ? 1 : 0; 294 carry = (hasCarry ? (1ULL << 32) : 0) + hx * ly + (resul >> 32); 295 hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0); 296 297 carry += (lx * hy) & 0xffffffffULL; 298 resul = (carry << 32) | (resul & 0xffffffffULL); 299 dest[i+j] += resul; 300 carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0)+ 301 (carry >> 32) + (dest[i+j] < resul ? 1 : 0) + 302 ((lx * hy) >> 32) + hx * hy; 303 } 304 dest[i+xlen] = carry; 305 } 306} 307 308/// @brief Multiplication assignment operator. Multiplies this APInt by the 309/// given APInt& RHS and assigns the result to this APInt. 310APInt& APInt::operator*=(const APInt& RHS) { 311 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 312 if (isSingleWord()) { 313 VAL *= RHS.VAL; 314 clearUnusedBits(); 315 return *this; 316 } 317 318 // Get some bit facts about LHS and check for zero 319 uint32_t lhsBits = getActiveBits(); 320 uint32_t lhsWords = !lhsBits ? 0 : whichWord(lhsBits - 1) + 1; 321 if (!lhsWords) 322 // 0 * X ===> 0 323 return *this; 324 325 // Get some bit facts about RHS and check for zero 326 uint32_t rhsBits = RHS.getActiveBits(); 327 uint32_t rhsWords = !rhsBits ? 0 : whichWord(rhsBits - 1) + 1; 328 if (!rhsWords) { 329 // X * 0 ===> 0 330 clear(); 331 return *this; 332 } 333 334 // Allocate space for the result 335 uint32_t destWords = rhsWords + lhsWords; 336 uint64_t *dest = getMemory(destWords); 337 338 // Perform the long multiply 339 mul(dest, pVal, lhsWords, RHS.pVal, rhsWords); 340 341 // Copy result back into *this 342 clear(); 343 uint32_t wordsToCopy = destWords >= getNumWords() ? getNumWords() : destWords; 344 memcpy(pVal, dest, wordsToCopy * APINT_WORD_SIZE); 345 346 // delete dest array and return 347 delete[] dest; 348 return *this; 349} 350 351/// @brief Bitwise AND assignment operator. Performs bitwise AND operation on 352/// this APInt and the given APInt& RHS, assigns the result to this APInt. 353APInt& APInt::operator&=(const APInt& RHS) { 354 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 355 if (isSingleWord()) { 356 VAL &= RHS.VAL; 357 return *this; 358 } 359 uint32_t numWords = getNumWords(); 360 for (uint32_t i = 0; i < numWords; ++i) 361 pVal[i] &= RHS.pVal[i]; 362 return *this; 363} 364 365/// @brief Bitwise OR assignment operator. Performs bitwise OR operation on 366/// this APInt and the given APInt& RHS, assigns the result to this APInt. 367APInt& APInt::operator|=(const APInt& RHS) { 368 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 369 if (isSingleWord()) { 370 VAL |= RHS.VAL; 371 return *this; 372 } 373 uint32_t numWords = getNumWords(); 374 for (uint32_t i = 0; i < numWords; ++i) 375 pVal[i] |= RHS.pVal[i]; 376 return *this; 377} 378 379/// @brief Bitwise XOR assignment operator. Performs bitwise XOR operation on 380/// this APInt and the given APInt& RHS, assigns the result to this APInt. 381APInt& APInt::operator^=(const APInt& RHS) { 382 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 383 if (isSingleWord()) { 384 VAL ^= RHS.VAL; 385 this->clearUnusedBits(); 386 return *this; 387 } 388 uint32_t numWords = getNumWords(); 389 for (uint32_t i = 0; i < numWords; ++i) 390 pVal[i] ^= RHS.pVal[i]; 391 this->clearUnusedBits(); 392 return *this; 393} 394 395/// @brief Bitwise AND operator. Performs bitwise AND operation on this APInt 396/// and the given APInt& RHS. 397APInt APInt::operator&(const APInt& RHS) const { 398 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 399 if (isSingleWord()) 400 return APInt(getBitWidth(), VAL & RHS.VAL); 401 402 APInt Result(*this); 403 uint32_t numWords = getNumWords(); 404 for (uint32_t i = 0; i < numWords; ++i) 405 Result.pVal[i] &= RHS.pVal[i]; 406 return Result; 407} 408 409/// @brief Bitwise OR operator. Performs bitwise OR operation on this APInt 410/// and the given APInt& RHS. 411APInt APInt::operator|(const APInt& RHS) const { 412 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 413 if (isSingleWord()) 414 return APInt(getBitWidth(), VAL | RHS.VAL); 415 416 APInt Result(*this); 417 uint32_t numWords = getNumWords(); 418 for (uint32_t i = 0; i < numWords; ++i) 419 Result.pVal[i] |= RHS.pVal[i]; 420 return Result; 421} 422 423/// @brief Bitwise XOR operator. Performs bitwise XOR operation on this APInt 424/// and the given APInt& RHS. 425APInt APInt::operator^(const APInt& RHS) const { 426 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 427 if (isSingleWord()) { 428 APInt Result(BitWidth, VAL ^ RHS.VAL); 429 Result.clearUnusedBits(); 430 return Result; 431 } 432 APInt Result(*this); 433 uint32_t numWords = getNumWords(); 434 for (uint32_t i = 0; i < numWords; ++i) 435 Result.pVal[i] ^= RHS.pVal[i]; 436 return Result; 437} 438 439/// @brief Logical negation operator. Performs logical negation operation on 440/// this APInt. 441bool APInt::operator !() const { 442 if (isSingleWord()) 443 return !VAL; 444 445 for (uint32_t i = 0; i < getNumWords(); ++i) 446 if (pVal[i]) 447 return false; 448 return true; 449} 450 451/// @brief Multiplication operator. Multiplies this APInt by the given APInt& 452/// RHS. 453APInt APInt::operator*(const APInt& RHS) const { 454 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 455 if (isSingleWord()) { 456 APInt Result(BitWidth, VAL * RHS.VAL); 457 Result.clearUnusedBits(); 458 return Result; 459 } 460 APInt Result(*this); 461 Result *= RHS; 462 Result.clearUnusedBits(); 463 return Result; 464} 465 466/// @brief Addition operator. Adds this APInt by the given APInt& RHS. 467APInt APInt::operator+(const APInt& RHS) const { 468 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 469 if (isSingleWord()) { 470 APInt Result(BitWidth, VAL + RHS.VAL); 471 Result.clearUnusedBits(); 472 return Result; 473 } 474 APInt Result(BitWidth, 0); 475 add(Result.pVal, this->pVal, RHS.pVal, getNumWords()); 476 Result.clearUnusedBits(); 477 return Result; 478} 479 480/// @brief Subtraction operator. Subtracts this APInt by the given APInt& RHS 481APInt APInt::operator-(const APInt& RHS) const { 482 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 483 if (isSingleWord()) { 484 APInt Result(BitWidth, VAL - RHS.VAL); 485 Result.clearUnusedBits(); 486 return Result; 487 } 488 APInt Result(BitWidth, 0); 489 sub(Result.pVal, this->pVal, RHS.pVal, getNumWords()); 490 Result.clearUnusedBits(); 491 return Result; 492} 493 494/// @brief Array-indexing support. 495bool APInt::operator[](uint32_t bitPosition) const { 496 return (maskBit(bitPosition) & (isSingleWord() ? 497 VAL : pVal[whichWord(bitPosition)])) != 0; 498} 499 500/// @brief Equality operator. Compare this APInt with the given APInt& RHS 501/// for the validity of the equality relationship. 502bool APInt::operator==(const APInt& RHS) const { 503 if (isSingleWord()) 504 return VAL == RHS.VAL; 505 506 uint32_t n1 = getActiveBits(); 507 uint32_t n2 = RHS.getActiveBits(); 508 if (n1 != n2) 509 return false; 510 511 if (n1 <= APINT_BITS_PER_WORD) 512 return pVal[0] == RHS.pVal[0]; 513 514 for (int i = whichWord(n1 - 1); i >= 0; --i) 515 if (pVal[i] != RHS.pVal[i]) 516 return false; 517 return true; 518} 519 520/// @brief Equality operator. Compare this APInt with the given uint64_t value 521/// for the validity of the equality relationship. 522bool APInt::operator==(uint64_t Val) const { 523 if (isSingleWord()) 524 return VAL == Val; 525 526 uint32_t n = getActiveBits(); 527 if (n <= APINT_BITS_PER_WORD) 528 return pVal[0] == Val; 529 else 530 return false; 531} 532 533/// @brief Unsigned less than comparison 534bool APInt::ult(const APInt& RHS) const { 535 assert(BitWidth == RHS.BitWidth && "Bit widths must be same for comparison"); 536 if (isSingleWord()) 537 return VAL < RHS.VAL; 538 else { 539 uint32_t n1 = getActiveBits(); 540 uint32_t n2 = RHS.getActiveBits(); 541 if (n1 < n2) 542 return true; 543 else if (n2 < n1) 544 return false; 545 else if (n1 <= APINT_BITS_PER_WORD && n2 <= APINT_BITS_PER_WORD) 546 return pVal[0] < RHS.pVal[0]; 547 for (int i = whichWord(n1 - 1); i >= 0; --i) { 548 if (pVal[i] > RHS.pVal[i]) return false; 549 else if (pVal[i] < RHS.pVal[i]) return true; 550 } 551 } 552 return false; 553} 554 555/// @brief Signed less than comparison 556bool APInt::slt(const APInt& RHS) const { 557 assert(BitWidth == RHS.BitWidth && "Bit widths must be same for comparison"); 558 if (isSingleWord()) { 559 int64_t lhsSext = (int64_t(VAL) << (64-BitWidth)) >> (64-BitWidth); 560 int64_t rhsSext = (int64_t(RHS.VAL) << (64-BitWidth)) >> (64-BitWidth); 561 return lhsSext < rhsSext; 562 } 563 564 APInt lhs(*this); 565 APInt rhs(*this); 566 bool lhsNegative = false; 567 bool rhsNegative = false; 568 if (lhs[BitWidth-1]) { 569 lhsNegative = true; 570 lhs.flip(); 571 lhs++; 572 } 573 if (rhs[BitWidth-1]) { 574 rhsNegative = true; 575 rhs.flip(); 576 rhs++; 577 } 578 if (lhsNegative) 579 if (rhsNegative) 580 return !lhs.ult(rhs); 581 else 582 return true; 583 else if (rhsNegative) 584 return false; 585 else 586 return lhs.ult(rhs); 587} 588 589/// Set the given bit to 1 whose poition is given as "bitPosition". 590/// @brief Set a given bit to 1. 591APInt& APInt::set(uint32_t bitPosition) { 592 if (isSingleWord()) VAL |= maskBit(bitPosition); 593 else pVal[whichWord(bitPosition)] |= maskBit(bitPosition); 594 return *this; 595} 596 597/// @brief Set every bit to 1. 598APInt& APInt::set() { 599 if (isSingleWord()) 600 VAL = ~0ULL >> (APINT_BITS_PER_WORD - BitWidth); 601 else { 602 for (uint32_t i = 0; i < getNumWords() - 1; ++i) 603 pVal[i] = -1ULL; 604 pVal[getNumWords() - 1] = ~0ULL >> 605 (APINT_BITS_PER_WORD - BitWidth % APINT_BITS_PER_WORD); 606 } 607 return *this; 608} 609 610/// Set the given bit to 0 whose position is given as "bitPosition". 611/// @brief Set a given bit to 0. 612APInt& APInt::clear(uint32_t bitPosition) { 613 if (isSingleWord()) 614 VAL &= ~maskBit(bitPosition); 615 else 616 pVal[whichWord(bitPosition)] &= ~maskBit(bitPosition); 617 return *this; 618} 619 620/// @brief Set every bit to 0. 621APInt& APInt::clear() { 622 if (isSingleWord()) 623 VAL = 0; 624 else 625 memset(pVal, 0, getNumWords() * APINT_WORD_SIZE); 626 return *this; 627} 628 629/// @brief Bitwise NOT operator. Performs a bitwise logical NOT operation on 630/// this APInt. 631APInt APInt::operator~() const { 632 APInt API(*this); 633 API.flip(); 634 return API; 635} 636 637/// @brief Toggle every bit to its opposite value. 638APInt& APInt::flip() { 639 if (isSingleWord()) VAL = (~(VAL << 640 (APINT_BITS_PER_WORD - BitWidth))) >> (APINT_BITS_PER_WORD - BitWidth); 641 else { 642 uint32_t i = 0; 643 for (; i < getNumWords() - 1; ++i) 644 pVal[i] = ~pVal[i]; 645 uint32_t offset = 646 APINT_BITS_PER_WORD - (BitWidth - APINT_BITS_PER_WORD * (i - 1)); 647 pVal[i] = (~(pVal[i] << offset)) >> offset; 648 } 649 return *this; 650} 651 652/// Toggle a given bit to its opposite value whose position is given 653/// as "bitPosition". 654/// @brief Toggles a given bit to its opposite value. 655APInt& APInt::flip(uint32_t bitPosition) { 656 assert(bitPosition < BitWidth && "Out of the bit-width range!"); 657 if ((*this)[bitPosition]) clear(bitPosition); 658 else set(bitPosition); 659 return *this; 660} 661 662/// getMaxValue - This function returns the largest value 663/// for an APInt of the specified bit-width and if isSign == true, 664/// it should be largest signed value, otherwise unsigned value. 665APInt APInt::getMaxValue(uint32_t numBits, bool isSign) { 666 APInt Result(numBits, 0); 667 Result.set(); 668 if (isSign) 669 Result.clear(numBits - 1); 670 return Result; 671} 672 673/// getMinValue - This function returns the smallest value for 674/// an APInt of the given bit-width and if isSign == true, 675/// it should be smallest signed value, otherwise zero. 676APInt APInt::getMinValue(uint32_t numBits, bool isSign) { 677 APInt Result(numBits, 0); 678 if (isSign) 679 Result.set(numBits - 1); 680 return Result; 681} 682 683/// getAllOnesValue - This function returns an all-ones value for 684/// an APInt of the specified bit-width. 685APInt APInt::getAllOnesValue(uint32_t numBits) { 686 return getMaxValue(numBits, false); 687} 688 689/// getNullValue - This function creates an '0' value for an 690/// APInt of the specified bit-width. 691APInt APInt::getNullValue(uint32_t numBits) { 692 return getMinValue(numBits, false); 693} 694 695/// HiBits - This function returns the high "numBits" bits of this APInt. 696APInt APInt::getHiBits(uint32_t numBits) const { 697 return APIntOps::lshr(*this, BitWidth - numBits); 698} 699 700/// LoBits - This function returns the low "numBits" bits of this APInt. 701APInt APInt::getLoBits(uint32_t numBits) const { 702 return APIntOps::lshr(APIntOps::shl(*this, BitWidth - numBits), 703 BitWidth - numBits); 704} 705 706bool APInt::isPowerOf2() const { 707 return (!!*this) && !(*this & (*this - APInt(BitWidth,1))); 708} 709 710/// countLeadingZeros - This function is a APInt version corresponding to 711/// llvm/include/llvm/Support/MathExtras.h's function 712/// countLeadingZeros_{32, 64}. It performs platform optimal form of counting 713/// the number of zeros from the most significant bit to the first one bit. 714/// @returns numWord() * 64 if the value is zero. 715uint32_t APInt::countLeadingZeros() const { 716 uint32_t Count = 0; 717 if (isSingleWord()) 718 Count = CountLeadingZeros_64(VAL); 719 else { 720 for (uint32_t i = getNumWords(); i > 0u; --i) { 721 if (pVal[i-1] == 0) 722 Count += APINT_BITS_PER_WORD; 723 else { 724 Count += CountLeadingZeros_64(pVal[i-1]); 725 break; 726 } 727 } 728 } 729 return Count - (APINT_BITS_PER_WORD - (BitWidth % APINT_BITS_PER_WORD)); 730} 731 732/// countTrailingZeros - This function is a APInt version corresponding to 733/// llvm/include/llvm/Support/MathExtras.h's function 734/// countTrailingZeros_{32, 64}. It performs platform optimal form of counting 735/// the number of zeros from the least significant bit to the first one bit. 736/// @returns numWord() * 64 if the value is zero. 737uint32_t APInt::countTrailingZeros() const { 738 if (isSingleWord()) 739 return CountTrailingZeros_64(VAL); 740 APInt Tmp( ~(*this) & ((*this) - APInt(BitWidth,1)) ); 741 return getNumWords() * APINT_BITS_PER_WORD - Tmp.countLeadingZeros(); 742} 743 744/// countPopulation - This function is a APInt version corresponding to 745/// llvm/include/llvm/Support/MathExtras.h's function 746/// countPopulation_{32, 64}. It counts the number of set bits in a value. 747/// @returns 0 if the value is zero. 748uint32_t APInt::countPopulation() const { 749 if (isSingleWord()) 750 return CountPopulation_64(VAL); 751 uint32_t Count = 0; 752 for (uint32_t i = 0; i < getNumWords(); ++i) 753 Count += CountPopulation_64(pVal[i]); 754 return Count; 755} 756 757 758/// byteSwap - This function returns a byte-swapped representation of the 759/// this APInt. 760APInt APInt::byteSwap() const { 761 assert(BitWidth >= 16 && BitWidth % 16 == 0 && "Cannot byteswap!"); 762 if (BitWidth == 16) 763 return APInt(BitWidth, ByteSwap_16(VAL)); 764 else if (BitWidth == 32) 765 return APInt(BitWidth, ByteSwap_32(VAL)); 766 else if (BitWidth == 48) { 767 uint64_t Tmp1 = ((VAL >> 32) << 16) | (VAL & 0xFFFF); 768 Tmp1 = ByteSwap_32(Tmp1); 769 uint64_t Tmp2 = (VAL >> 16) & 0xFFFF; 770 Tmp2 = ByteSwap_16(Tmp2); 771 return 772 APInt(BitWidth, 773 (Tmp1 & 0xff) | ((Tmp1<<16) & 0xffff00000000ULL) | (Tmp2 << 16)); 774 } else if (BitWidth == 64) 775 return APInt(BitWidth, ByteSwap_64(VAL)); 776 else { 777 APInt Result(BitWidth, 0); 778 char *pByte = (char*)Result.pVal; 779 for (uint32_t i = 0; i < BitWidth / APINT_WORD_SIZE / 2; ++i) { 780 char Tmp = pByte[i]; 781 pByte[i] = pByte[BitWidth / APINT_WORD_SIZE - 1 - i]; 782 pByte[BitWidth / APINT_WORD_SIZE - i - 1] = Tmp; 783 } 784 return Result; 785 } 786} 787 788/// GreatestCommonDivisor - This function returns the greatest common 789/// divisor of the two APInt values using Enclid's algorithm. 790APInt llvm::APIntOps::GreatestCommonDivisor(const APInt& API1, 791 const APInt& API2) { 792 APInt A = API1, B = API2; 793 while (!!B) { 794 APInt T = B; 795 B = APIntOps::urem(A, B); 796 A = T; 797 } 798 return A; 799} 800 801/// DoubleRoundToAPInt - This function convert a double value to 802/// a APInt value. 803APInt llvm::APIntOps::RoundDoubleToAPInt(double Double) { 804 union { 805 double D; 806 uint64_t I; 807 } T; 808 T.D = Double; 809 bool isNeg = T.I >> 63; 810 int64_t exp = ((T.I >> 52) & 0x7ff) - 1023; 811 if (exp < 0) 812 return APInt(64ull, 0u); 813 uint64_t mantissa = ((T.I << 12) >> 12) | (1ULL << 52); 814 if (exp < 52) 815 return isNeg ? -APInt(64u, mantissa >> (52 - exp)) : 816 APInt(64u, mantissa >> (52 - exp)); 817 APInt Tmp(exp + 1, mantissa); 818 Tmp = Tmp.shl(exp - 52); 819 return isNeg ? -Tmp : Tmp; 820} 821 822/// RoundToDouble - This function convert this APInt to a double. 823/// The layout for double is as following (IEEE Standard 754): 824/// -------------------------------------- 825/// | Sign Exponent Fraction Bias | 826/// |-------------------------------------- | 827/// | 1[63] 11[62-52] 52[51-00] 1023 | 828/// -------------------------------------- 829double APInt::roundToDouble(bool isSigned) const { 830 831 // Handle the simple case where the value is contained in one uint64_t. 832 if (isSingleWord() || getActiveBits() <= APINT_BITS_PER_WORD) { 833 if (isSigned) { 834 int64_t sext = (int64_t(VAL) << (64-BitWidth)) >> (64-BitWidth); 835 return double(sext); 836 } else 837 return double(VAL); 838 } 839 840 // Determine if the value is negative. 841 bool isNeg = isSigned ? (*this)[BitWidth-1] : false; 842 843 // Construct the absolute value if we're negative. 844 APInt Tmp(isNeg ? -(*this) : (*this)); 845 846 // Figure out how many bits we're using. 847 uint32_t n = Tmp.getActiveBits(); 848 849 // The exponent (without bias normalization) is just the number of bits 850 // we are using. Note that the sign bit is gone since we constructed the 851 // absolute value. 852 uint64_t exp = n; 853 854 // Return infinity for exponent overflow 855 if (exp > 1023) { 856 if (!isSigned || !isNeg) 857 return double(1.0E300 * 1.0E300); // positive infinity 858 else 859 return double(-1.0E300 * 1.0E300); // negative infinity 860 } 861 exp += 1023; // Increment for 1023 bias 862 863 // Number of bits in mantissa is 52. To obtain the mantissa value, we must 864 // extract the high 52 bits from the correct words in pVal. 865 uint64_t mantissa; 866 unsigned hiWord = whichWord(n-1); 867 if (hiWord == 0) { 868 mantissa = Tmp.pVal[0]; 869 if (n > 52) 870 mantissa >>= n - 52; // shift down, we want the top 52 bits. 871 } else { 872 assert(hiWord > 0 && "huh?"); 873 uint64_t hibits = Tmp.pVal[hiWord] << (52 - n % APINT_BITS_PER_WORD); 874 uint64_t lobits = Tmp.pVal[hiWord-1] >> (11 + n % APINT_BITS_PER_WORD); 875 mantissa = hibits | lobits; 876 } 877 878 // The leading bit of mantissa is implicit, so get rid of it. 879 uint64_t sign = isNeg ? (1ULL << (APINT_BITS_PER_WORD - 1)) : 0; 880 union { 881 double D; 882 uint64_t I; 883 } T; 884 T.I = sign | (exp << 52) | mantissa; 885 return T.D; 886} 887 888// Truncate to new width. 889void APInt::trunc(uint32_t width) { 890 assert(width < BitWidth && "Invalid APInt Truncate request"); 891} 892 893// Sign extend to a new width. 894void APInt::sext(uint32_t width) { 895 assert(width > BitWidth && "Invalid APInt SignExtend request"); 896} 897 898// Zero extend to a new width. 899void APInt::zext(uint32_t width) { 900 assert(width > BitWidth && "Invalid APInt ZeroExtend request"); 901} 902 903/// Arithmetic right-shift this APInt by shiftAmt. 904/// @brief Arithmetic right-shift function. 905APInt APInt::ashr(uint32_t shiftAmt) const { 906 APInt API(*this); 907 if (API.isSingleWord()) 908 API.VAL = 909 (((int64_t(API.VAL) << (APINT_BITS_PER_WORD - API.BitWidth)) >> 910 (APINT_BITS_PER_WORD - API.BitWidth)) >> shiftAmt) & 911 (~uint64_t(0UL) >> (APINT_BITS_PER_WORD - API.BitWidth)); 912 else { 913 if (shiftAmt >= API.BitWidth) { 914 memset(API.pVal, API[API.BitWidth-1] ? 1 : 0, 915 (API.getNumWords()-1) * APINT_WORD_SIZE); 916 API.pVal[API.getNumWords() - 1] = 917 ~uint64_t(0UL) >> 918 (APINT_BITS_PER_WORD - API.BitWidth % APINT_BITS_PER_WORD); 919 } else { 920 uint32_t i = 0; 921 for (; i < API.BitWidth - shiftAmt; ++i) 922 if (API[i+shiftAmt]) 923 API.set(i); 924 else 925 API.clear(i); 926 for (; i < API.BitWidth; ++i) 927 if (API[API.BitWidth-1]) 928 API.set(i); 929 else API.clear(i); 930 } 931 } 932 return API; 933} 934 935/// Logical right-shift this APInt by shiftAmt. 936/// @brief Logical right-shift function. 937APInt APInt::lshr(uint32_t shiftAmt) const { 938 APInt API(*this); 939 if (API.isSingleWord()) 940 API.VAL >>= shiftAmt; 941 else { 942 if (shiftAmt >= API.BitWidth) 943 memset(API.pVal, 0, API.getNumWords() * APINT_WORD_SIZE); 944 uint32_t i = 0; 945 for (i = 0; i < API.BitWidth - shiftAmt; ++i) 946 if (API[i+shiftAmt]) API.set(i); 947 else API.clear(i); 948 for (; i < API.BitWidth; ++i) 949 API.clear(i); 950 } 951 return API; 952} 953 954/// Left-shift this APInt by shiftAmt. 955/// @brief Left-shift function. 956APInt APInt::shl(uint32_t shiftAmt) const { 957 APInt API(*this); 958 if (API.isSingleWord()) 959 API.VAL <<= shiftAmt; 960 else if (shiftAmt >= API.BitWidth) 961 memset(API.pVal, 0, API.getNumWords() * APINT_WORD_SIZE); 962 else { 963 if (uint32_t offset = shiftAmt / APINT_BITS_PER_WORD) { 964 for (uint32_t i = API.getNumWords() - 1; i > offset - 1; --i) 965 API.pVal[i] = API.pVal[i-offset]; 966 memset(API.pVal, 0, offset * APINT_WORD_SIZE); 967 } 968 shiftAmt %= APINT_BITS_PER_WORD; 969 uint32_t i; 970 for (i = API.getNumWords() - 1; i > 0; --i) 971 API.pVal[i] = (API.pVal[i] << shiftAmt) | 972 (API.pVal[i-1] >> (APINT_BITS_PER_WORD - shiftAmt)); 973 API.pVal[i] <<= shiftAmt; 974 } 975 API.clearUnusedBits(); 976 return API; 977} 978 979#if 0 980/// subMul - This function substracts x[len-1:0] * y from 981/// dest[offset+len-1:offset], and returns the most significant 982/// word of the product, minus the borrow-out from the subtraction. 983static uint32_t subMul(uint32_t dest[], uint32_t offset, 984 uint32_t x[], uint32_t len, uint32_t y) { 985 uint64_t yl = (uint64_t) y & 0xffffffffL; 986 uint32_t carry = 0; 987 uint32_t j = 0; 988 do { 989 uint64_t prod = ((uint64_t) x[j] & 0xffffffffUL) * yl; 990 uint32_t prod_low = (uint32_t) prod; 991 uint32_t prod_high = (uint32_t) (prod >> 32); 992 prod_low += carry; 993 carry = (prod_low < carry ? 1 : 0) + prod_high; 994 uint32_t x_j = dest[offset+j]; 995 prod_low = x_j - prod_low; 996 if (prod_low > x_j) ++carry; 997 dest[offset+j] = prod_low; 998 } while (++j < len); 999 return carry; 1000} 1001 1002/// unitDiv - This function divides N by D, 1003/// and returns (remainder << 32) | quotient. 1004/// Assumes (N >> 32) < D. 1005static uint64_t unitDiv(uint64_t N, uint32_t D) { 1006 uint64_t q, r; // q: quotient, r: remainder. 1007 uint64_t a1 = N >> 32; // a1: high 32-bit part of N. 1008 uint64_t a0 = N & 0xffffffffL; // a0: low 32-bit part of N 1009 if (a1 < ((D - a1 - (a0 >> 31)) & 0xffffffffL)) { 1010 q = N / D; 1011 r = N % D; 1012 } 1013 else { 1014 // Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d 1015 uint64_t c = N - ((uint64_t) D << 31); 1016 // Divide (c1*2^32 + c0) by d 1017 q = c / D; 1018 r = c % D; 1019 // Add 2^31 to quotient 1020 q += 1 << 31; 1021 } 1022 1023 return (r << 32) | (q & 0xFFFFFFFFl); 1024} 1025 1026#endif 1027 1028/// div - This is basically Knuth's formulation of the classical algorithm. 1029/// Correspondance with Knuth's notation: 1030/// Knuth's u[0:m+n] == zds[nx:0]. 1031/// Knuth's v[1:n] == y[ny-1:0] 1032/// Knuth's n == ny. 1033/// Knuth's m == nx-ny. 1034/// Our nx == Knuth's m+n. 1035/// Could be re-implemented using gmp's mpn_divrem: 1036/// zds[nx] = mpn_divrem (&zds[ny], 0, zds, nx, y, ny). 1037 1038/// Implementation of Knuth's Algorithm D (Division of nonnegative integers) 1039/// from "Art of Computer Programming, Volume 2", section 4.3.1, p. 272. The 1040/// variables here have the same names as in the algorithm. Comments explain 1041/// the algorithm and any deviation from it. 1042static void KnuthDiv(uint32_t *u, uint32_t *v, uint32_t *q, uint32_t* r, 1043 uint32_t m, uint32_t n) { 1044 assert(u && "Must provide dividend"); 1045 assert(v && "Must provide divisor"); 1046 assert(q && "Must provide quotient"); 1047 assert(n>1 && "n must be > 1"); 1048 1049 // Knuth uses the value b as the base of the number system. In our case b 1050 // is 2^31 so we just set it to -1u. 1051 uint64_t b = uint64_t(1) << 32; 1052 1053 // D1. [Normalize.] Set d = b / (v[n-1] + 1) and multiply all the digits of 1054 // u and v by d. Note that we have taken Knuth's advice here to use a power 1055 // of 2 value for d such that d * v[n-1] >= b/2 (b is the base). A power of 1056 // 2 allows us to shift instead of multiply and it is easy to determine the 1057 // shift amount from the leading zeros. We are basically normalizing the u 1058 // and v so that its high bits are shifted to the top of v's range without 1059 // overflow. Note that this can require an extra word in u so that u must 1060 // be of length m+n+1. 1061 uint32_t shift = CountLeadingZeros_32(v[n-1]); 1062 uint32_t v_carry = 0; 1063 uint32_t u_carry = 0; 1064 if (shift) { 1065 for (uint32_t i = 0; i < m+n; ++i) { 1066 uint32_t u_tmp = u[i] >> (32 - shift); 1067 u[i] = (u[i] << shift) | u_carry; 1068 u_carry = u_tmp; 1069 } 1070 for (uint32_t i = 0; i < n; ++i) { 1071 uint32_t v_tmp = v[i] >> (32 - shift); 1072 v[i] = (v[i] << shift) | v_carry; 1073 v_carry = v_tmp; 1074 } 1075 } 1076 u[m+n] = u_carry; 1077 1078 // D2. [Initialize j.] Set j to m. This is the loop counter over the places. 1079 int j = m; 1080 do { 1081 // D3. [Calculate q'.]. 1082 // Set qp = (u[j+n]*b + u[j+n-1]) / v[n-1]. (qp=qprime=q') 1083 // Set rp = (u[j+n]*b + u[j+n-1]) % v[n-1]. (rp=rprime=r') 1084 // Now test if qp == b or qp*v[n-2] > b*rp + u[j+n-2]; if so, decrease 1085 // qp by 1, inrease rp by v[n-1], and repeat this test if rp < b. The test 1086 // on v[n-2] determines at high speed most of the cases in which the trial 1087 // value qp is one too large, and it eliminates all cases where qp is two 1088 // too large. 1089 uint64_t qp = ((uint64_t(u[j+n]) << 32) | uint64_t(u[j+n-1])) / v[n-1]; 1090 uint64_t rp = ((uint64_t(u[j+n]) << 32) | uint64_t(u[j+n-1])) % v[n-1]; 1091 if (qp == b || qp*v[n-2] > b*rp + u[j+n-2]) { 1092 qp--; 1093 rp += v[n-1]; 1094 } 1095 if (rp < b) 1096 if (qp == b || qp*v[n-2] > b*rp + u[j+n-2]) { 1097 qp--; 1098 rp += v[n-1]; 1099 } 1100 1101 // D4. [Multiply and subtract.] Replace u with u - q*v (for each word). 1102 uint32_t borrow = 0; 1103 for (uint32_t i = 0; i < n; i++) { 1104 uint32_t save = u[j+i]; 1105 u[j+i] = uint64_t(u[j+i]) - (qp * v[i]) - borrow; 1106 if (u[j+i] > save) { 1107 borrow = 1; 1108 u[j+i+1] += b; 1109 } else { 1110 borrow = 0; 1111 } 1112 } 1113 if (borrow) 1114 u[j+n] += 1; 1115 1116 // D5. [Test remainder.] Set q[j] = qp. If the result of step D4 was 1117 // negative, go to step D6; otherwise go on to step D7. 1118 q[j] = qp; 1119 if (borrow) { 1120 // D6. [Add back]. The probability that this step is necessary is very 1121 // small, on the order of only 2/b. Make sure that test data accounts for 1122 // this possibility. Decreate qj by 1 and add v[...] to u[...]. A carry 1123 // will occur to the left of u[j+n], and it should be ignored since it 1124 // cancels with the borrow that occurred in D4. 1125 uint32_t carry = 0; 1126 for (uint32_t i = 0; i < n; i++) { 1127 uint32_t save = u[j+i]; 1128 u[j+i] += v[i] + carry; 1129 carry = u[j+i] < save; 1130 } 1131 } 1132 1133 // D7. [Loop on j.] Decreate j by one. Now if j >= 0, go back to D3. 1134 j--; 1135 } while (j >= 0); 1136 1137 // D8. [Unnormalize]. Now q[...] is the desired quotient, and the desired 1138 // remainder may be obtained by dividing u[...] by d. If r is non-null we 1139 // compute the remainder (urem uses this). 1140 if (r) { 1141 // The value d is expressed by the "shift" value above since we avoided 1142 // multiplication by d by using a shift left. So, all we have to do is 1143 // shift right here. In order to mak 1144 uint32_t mask = ~0u >> (32 - shift); 1145 uint32_t carry = 0; 1146 for (int i = n-1; i >= 0; i--) { 1147 uint32_t save = u[i] & mask; 1148 r[i] = (u[i] >> shift) | carry; 1149 carry = save; 1150 } 1151 } 1152} 1153 1154// This function makes calling KnuthDiv a little more convenient. It uses 1155// APInt parameters instead of uint32_t* parameters. It can also divide APInt 1156// values of different widths. 1157void APInt::divide(const APInt LHS, uint32_t lhsWords, 1158 const APInt &RHS, uint32_t rhsWords, 1159 APInt *Quotient, APInt *Remainder) 1160{ 1161 assert(lhsWords >= rhsWords && "Fractional result"); 1162 1163 // First, compose the values into an array of 32-bit words instead of 1164 // 64-bit words. This is a necessity of both the "short division" algorithm 1165 // and the the Knuth "classical algorithm" which requires there to be native 1166 // operations for +, -, and * on an m bit value with an m*2 bit result. We 1167 // can't use 64-bit operands here because we don't have native results of 1168 // 128-bits. Furthremore, casting the 64-bit values to 32-bit values won't 1169 // work on large-endian machines. 1170 uint64_t mask = ~0ull >> (sizeof(uint32_t)*8); 1171 uint32_t n = rhsWords * 2; 1172 uint32_t m = (lhsWords * 2) - n; 1173 // FIXME: allocate space on stack if m and n are sufficiently small. 1174 uint32_t *U = new uint32_t[m + n + 1]; 1175 memset(U, 0, (m+n+1)*sizeof(uint32_t)); 1176 for (unsigned i = 0; i < lhsWords; ++i) { 1177 uint64_t tmp = (lhsWords == 1 ? LHS.VAL : LHS.pVal[i]); 1178 U[i * 2] = tmp & mask; 1179 U[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8); 1180 } 1181 U[m+n] = 0; // this extra word is for "spill" in the Knuth algorithm. 1182 1183 uint32_t *V = new uint32_t[n]; 1184 memset(V, 0, (n)*sizeof(uint32_t)); 1185 for (unsigned i = 0; i < rhsWords; ++i) { 1186 uint64_t tmp = (rhsWords == 1 ? RHS.VAL : RHS.pVal[i]); 1187 V[i * 2] = tmp & mask; 1188 V[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8); 1189 } 1190 1191 // Set up the quotient and remainder 1192 uint32_t *Q = new uint32_t[m+n]; 1193 memset(Q, 0, (m+n) * sizeof(uint32_t)); 1194 uint32_t *R = 0; 1195 if (Remainder) { 1196 R = new uint32_t[n]; 1197 memset(R, 0, n * sizeof(uint32_t)); 1198 } 1199 1200 // Now, adjust m and n for the Knuth division. n is the number of words in 1201 // the divisor. m is the number of words by which the dividend exceeds the 1202 // divisor (i.e. m+n is the length of the dividend). These sizes must not 1203 // contain any zero words or the Knuth algorithm fails. 1204 for (unsigned i = n; i > 0 && V[i-1] == 0; i--) { 1205 n--; 1206 m++; 1207 } 1208 for (unsigned i = m+n; i > 0 && U[i-1] == 0; i--) 1209 m--; 1210 1211 // If we're left with only a single word for the divisor, Knuth doesn't work 1212 // so we implement the short division algorithm here. This is much simpler 1213 // and faster because we are certain that we can divide a 64-bit quantity 1214 // by a 32-bit quantity at hardware speed and short division is simply a 1215 // series of such operations. This is just like doing short division but we 1216 // are using base 2^32 instead of base 10. 1217 assert(n != 0 && "Divide by zero?"); 1218 if (n == 1) { 1219 uint32_t divisor = V[0]; 1220 uint32_t remainder = 0; 1221 for (int i = m+n-1; i >= 0; i--) { 1222 uint64_t partial_dividend = uint64_t(remainder) << 32 | U[i]; 1223 if (partial_dividend == 0) { 1224 Q[i] = 0; 1225 remainder = 0; 1226 } else if (partial_dividend < divisor) { 1227 Q[i] = 0; 1228 remainder = partial_dividend; 1229 } else if (partial_dividend == divisor) { 1230 Q[i] = 1; 1231 remainder = 0; 1232 } else { 1233 Q[i] = partial_dividend / divisor; 1234 remainder = partial_dividend - (Q[i] * divisor); 1235 } 1236 } 1237 if (R) 1238 R[0] = remainder; 1239 } else { 1240 // Now we're ready to invoke the Knuth classical divide algorithm. In this 1241 // case n > 1. 1242 KnuthDiv(U, V, Q, R, m, n); 1243 } 1244 1245 // If the caller wants the quotient 1246 if (Quotient) { 1247 // Set up the Quotient value's memory. 1248 if (Quotient->BitWidth != LHS.BitWidth) { 1249 if (Quotient->isSingleWord()) 1250 Quotient->VAL = 0; 1251 else 1252 delete Quotient->pVal; 1253 Quotient->BitWidth = LHS.BitWidth; 1254 if (!Quotient->isSingleWord()) 1255 Quotient->pVal = getClearedMemory(Quotient->getNumWords()); 1256 } else 1257 Quotient->clear(); 1258 1259 // The quotient is in Q. Reconstitute the quotient into Quotient's low 1260 // order words. 1261 if (lhsWords == 1) { 1262 uint64_t tmp = 1263 uint64_t(Q[0]) | (uint64_t(Q[1]) << (APINT_BITS_PER_WORD / 2)); 1264 if (Quotient->isSingleWord()) 1265 Quotient->VAL = tmp; 1266 else 1267 Quotient->pVal[0] = tmp; 1268 } else { 1269 assert(!Quotient->isSingleWord() && "Quotient APInt not large enough"); 1270 for (unsigned i = 0; i < lhsWords; ++i) 1271 Quotient->pVal[i] = 1272 uint64_t(Q[i*2]) | (uint64_t(Q[i*2+1]) << (APINT_BITS_PER_WORD / 2)); 1273 } 1274 } 1275 1276 // If the caller wants the remainder 1277 if (Remainder) { 1278 // Set up the Remainder value's memory. 1279 if (Remainder->BitWidth != RHS.BitWidth) { 1280 if (Remainder->isSingleWord()) 1281 Remainder->VAL = 0; 1282 else 1283 delete Remainder->pVal; 1284 Remainder->BitWidth = RHS.BitWidth; 1285 if (!Remainder->isSingleWord()) 1286 Remainder->pVal = getClearedMemory(Remainder->getNumWords()); 1287 } else 1288 Remainder->clear(); 1289 1290 // The remainder is in R. Reconstitute the remainder into Remainder's low 1291 // order words. 1292 if (rhsWords == 1) { 1293 uint64_t tmp = 1294 uint64_t(R[0]) | (uint64_t(R[1]) << (APINT_BITS_PER_WORD / 2)); 1295 if (Remainder->isSingleWord()) 1296 Remainder->VAL = tmp; 1297 else 1298 Remainder->pVal[0] = tmp; 1299 } else { 1300 assert(!Remainder->isSingleWord() && "Remainder APInt not large enough"); 1301 for (unsigned i = 0; i < rhsWords; ++i) 1302 Remainder->pVal[i] = 1303 uint64_t(R[i*2]) | (uint64_t(R[i*2+1]) << (APINT_BITS_PER_WORD / 2)); 1304 } 1305 } 1306 1307 // Clean up the memory we allocated. 1308 delete [] U; 1309 delete [] V; 1310 delete [] Q; 1311 delete [] R; 1312} 1313 1314/// Unsigned divide this APInt by APInt RHS. 1315/// @brief Unsigned division function for APInt. 1316APInt APInt::udiv(const APInt& RHS) const { 1317 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 1318 1319 // First, deal with the easy case 1320 if (isSingleWord()) { 1321 assert(RHS.VAL != 0 && "Divide by zero?"); 1322 return APInt(BitWidth, VAL / RHS.VAL); 1323 } 1324 1325 // Get some facts about the LHS and RHS number of bits and words 1326 uint32_t rhsBits = RHS.getActiveBits(); 1327 uint32_t rhsWords = !rhsBits ? 0 : (APInt::whichWord(rhsBits - 1) + 1); 1328 assert(rhsWords && "Divided by zero???"); 1329 uint32_t lhsBits = this->getActiveBits(); 1330 uint32_t lhsWords = !lhsBits ? 0 : (APInt::whichWord(lhsBits - 1) + 1); 1331 1332 // Deal with some degenerate cases 1333 if (!lhsWords) 1334 // 0 / X ===> 0 1335 return APInt(BitWidth, 0); 1336 else if (lhsWords < rhsWords || this->ult(RHS)) { 1337 // X / Y ===> 0, iff X < Y 1338 return APInt(BitWidth, 0); 1339 } else if (*this == RHS) { 1340 // X / X ===> 1 1341 return APInt(BitWidth, 1); 1342 } else if (lhsWords == 1 && rhsWords == 1) { 1343 // All high words are zero, just use native divide 1344 return APInt(BitWidth, this->pVal[0] / RHS.pVal[0]); 1345 } 1346 1347 // We have to compute it the hard way. Invoke the Knuth divide algorithm. 1348 APInt Quotient(1,0); // to hold result. 1349 divide(*this, lhsWords, RHS, rhsWords, &Quotient, 0); 1350 return Quotient; 1351} 1352 1353/// Unsigned remainder operation on APInt. 1354/// @brief Function for unsigned remainder operation. 1355APInt APInt::urem(const APInt& RHS) const { 1356 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 1357 if (isSingleWord()) { 1358 assert(RHS.VAL != 0 && "Remainder by zero?"); 1359 return APInt(BitWidth, VAL % RHS.VAL); 1360 } 1361 1362 // Get some facts about the LHS 1363 uint32_t lhsBits = getActiveBits(); 1364 uint32_t lhsWords = !lhsBits ? 0 : (whichWord(lhsBits - 1) + 1); 1365 1366 // Get some facts about the RHS 1367 uint32_t rhsBits = RHS.getActiveBits(); 1368 uint32_t rhsWords = !rhsBits ? 0 : (APInt::whichWord(rhsBits - 1) + 1); 1369 assert(rhsWords && "Performing remainder operation by zero ???"); 1370 1371 // Check the degenerate cases 1372 if (lhsWords == 0) { 1373 // 0 % Y ===> 0 1374 return APInt(BitWidth, 0); 1375 } else if (lhsWords < rhsWords || this->ult(RHS)) { 1376 // X % Y ===> X, iff X < Y 1377 return *this; 1378 } else if (*this == RHS) { 1379 // X % X == 0; 1380 return APInt(BitWidth, 0); 1381 } else if (lhsWords == 1) { 1382 // All high words are zero, just use native remainder 1383 return APInt(BitWidth, pVal[0] % RHS.pVal[0]); 1384 } 1385 1386 // We have to compute it the hard way. Invoke the Knute divide algorithm. 1387 APInt Remainder(1,0); 1388 divide(*this, lhsWords, RHS, rhsWords, 0, &Remainder); 1389 return Remainder; 1390} 1391 1392/// @brief Converts a char array into an integer. 1393void APInt::fromString(uint32_t numbits, const char *str, uint32_t slen, 1394 uint8_t radix) { 1395 // Check our assumptions here 1396 assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) && 1397 "Radix should be 2, 8, 10, or 16!"); 1398 assert(str && "String is null?"); 1399 assert(slen <= numbits || radix != 2 && "Insufficient bit width"); 1400 assert(slen*3 <= numbits || radix != 8 && "Insufficient bit width"); 1401 assert(slen*4 <= numbits || radix != 16 && "Insufficient bit width"); 1402 assert((slen*64)/20 <= numbits || radix != 10 && "Insufficient bit width"); 1403 1404 // Allocate memory 1405 if (!isSingleWord()) 1406 pVal = getClearedMemory(getNumWords()); 1407 1408 // Figure out if we can shift instead of multiply 1409 uint32_t shift = (radix == 16 ? 4 : radix == 8 ? 3 : radix == 2 ? 1 : 0); 1410 1411 // Set up an APInt for the digit to add outside the loop so we don't 1412 // constantly construct/destruct it. 1413 APInt apdigit(getBitWidth(), 0); 1414 APInt apradix(getBitWidth(), radix); 1415 1416 // Enter digit traversal loop 1417 for (unsigned i = 0; i < slen; i++) { 1418 // Get a digit 1419 uint32_t digit = 0; 1420 char cdigit = str[i]; 1421 if (isdigit(cdigit)) 1422 digit = cdigit - '0'; 1423 else if (isxdigit(cdigit)) 1424 if (cdigit >= 'a') 1425 digit = cdigit - 'a' + 10; 1426 else if (cdigit >= 'A') 1427 digit = cdigit - 'A' + 10; 1428 else 1429 assert(0 && "huh?"); 1430 else 1431 assert(0 && "Invalid character in digit string"); 1432 1433 // Shift or multiple the value by the radix 1434 if (shift) 1435 this->shl(shift); 1436 else 1437 *this *= apradix; 1438 1439 // Add in the digit we just interpreted 1440 apdigit.pVal[0] = digit; 1441 *this += apdigit; 1442 } 1443} 1444 1445/// to_string - This function translates the APInt into a string. 1446std::string APInt::toString(uint8_t radix, bool wantSigned) const { 1447 assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) && 1448 "Radix should be 2, 8, 10, or 16!"); 1449 static const char *digits[] = { 1450 "0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F" 1451 }; 1452 std::string result; 1453 uint32_t bits_used = getActiveBits(); 1454 if (isSingleWord()) { 1455 char buf[65]; 1456 const char *format = (radix == 10 ? (wantSigned ? "%lld" : "%llu") : 1457 (radix == 16 ? "%llX" : (radix == 8 ? "%llo" : 0))); 1458 if (format) { 1459 if (wantSigned) { 1460 int64_t sextVal = (int64_t(VAL) << (APINT_BITS_PER_WORD-BitWidth)) >> 1461 (APINT_BITS_PER_WORD-BitWidth); 1462 sprintf(buf, format, sextVal); 1463 } else 1464 sprintf(buf, format, VAL); 1465 } else { 1466 memset(buf, 0, 65); 1467 uint64_t v = VAL; 1468 while (bits_used) { 1469 uint32_t bit = v & 1; 1470 bits_used--; 1471 buf[bits_used] = digits[bit][0]; 1472 v >>=1; 1473 } 1474 } 1475 result = buf; 1476 return result; 1477 } 1478 1479 if (radix != 10) { 1480 uint64_t mask = radix - 1; 1481 uint32_t shift = (radix == 16 ? 4 : radix == 8 ? 3 : 1); 1482 uint32_t nibbles = APINT_BITS_PER_WORD / shift; 1483 for (uint32_t i = 0; i < getNumWords(); ++i) { 1484 uint64_t value = pVal[i]; 1485 for (uint32_t j = 0; j < nibbles; ++j) { 1486 result.insert(0, digits[ value & mask ]); 1487 value >>= shift; 1488 } 1489 } 1490 return result; 1491 } 1492 1493 APInt tmp(*this); 1494 APInt divisor(4, radix); 1495 APInt zero(tmp.getBitWidth(), 0); 1496 size_t insert_at = 0; 1497 if (wantSigned && tmp[BitWidth-1]) { 1498 // They want to print the signed version and it is a negative value 1499 // Flip the bits and add one to turn it into the equivalent positive 1500 // value and put a '-' in the result. 1501 tmp.flip(); 1502 tmp++; 1503 result = "-"; 1504 insert_at = 1; 1505 } 1506 if (tmp == APInt(tmp.getBitWidth(), 0)) 1507 result = "0"; 1508 else while (tmp.ne(zero)) { 1509 APInt APdigit(1,0); 1510 APInt tmp2(tmp.getBitWidth(), 0); 1511 divide(tmp, tmp.getNumWords(), divisor, divisor.getNumWords(), &tmp2, 1512 &APdigit); 1513 uint32_t digit = APdigit.getValue(); 1514 assert(digit < radix && "divide failed"); 1515 result.insert(insert_at,digits[digit]); 1516 tmp = tmp2; 1517 } 1518 1519 return result; 1520} 1521 1522#ifndef NDEBUG 1523void APInt::dump() const 1524{ 1525 std::cerr << "APInt(" << BitWidth << ")=" << std::setbase(16); 1526 if (isSingleWord()) 1527 std::cerr << VAL; 1528 else for (unsigned i = getNumWords(); i > 0; i--) { 1529 std::cerr << pVal[i-1] << " "; 1530 } 1531 std::cerr << " (" << this->toString(10, false) << ")\n" << std::setbase(10); 1532} 1533#endif 1534