APInt.cpp revision b5ca2cd5095b61c17f89edc10bf2fc63a7e22824
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 integer 11// constant values and provide a variety of arithmetic operations on them. 12// 13//===----------------------------------------------------------------------===// 14 15#define DEBUG_TYPE "apint" 16#include "llvm/ADT/APInt.h" 17#include "llvm/DerivedTypes.h" 18#include "llvm/Support/Debug.h" 19#include "llvm/Support/MathExtras.h" 20#include <cstring> 21#include <cstdlib> 22#ifndef NDEBUG 23#include <iomanip> 24#endif 25 26using namespace llvm; 27 28/// A utility function for allocating memory, checking for allocation failures, 29/// and ensuring the contents are zeroed. 30inline static uint64_t* getClearedMemory(uint32_t numWords) { 31 uint64_t * result = new uint64_t[numWords]; 32 assert(result && "APInt memory allocation fails!"); 33 memset(result, 0, numWords * sizeof(uint64_t)); 34 return result; 35} 36 37/// A utility function for allocating memory and checking for allocation 38/// failure. The content is not zeroed. 39inline static uint64_t* getMemory(uint32_t numWords) { 40 uint64_t * result = new uint64_t[numWords]; 41 assert(result && "APInt memory allocation fails!"); 42 return result; 43} 44 45APInt::APInt(uint32_t numBits, uint64_t val) : BitWidth(numBits), VAL(0) { 46 assert(BitWidth >= IntegerType::MIN_INT_BITS && "bitwidth too small"); 47 assert(BitWidth <= IntegerType::MAX_INT_BITS && "bitwidth too large"); 48 if (isSingleWord()) 49 VAL = val; 50 else { 51 pVal = getClearedMemory(getNumWords()); 52 pVal[0] = val; 53 } 54 clearUnusedBits(); 55} 56 57APInt::APInt(uint32_t numBits, uint32_t numWords, uint64_t bigVal[]) 58 : BitWidth(numBits), VAL(0) { 59 assert(BitWidth >= IntegerType::MIN_INT_BITS && "bitwidth too small"); 60 assert(BitWidth <= IntegerType::MAX_INT_BITS && "bitwidth too large"); 61 assert(bigVal && "Null pointer detected!"); 62 if (isSingleWord()) 63 VAL = bigVal[0]; 64 else { 65 // Get memory, cleared to 0 66 pVal = getClearedMemory(getNumWords()); 67 // Calculate the number of words to copy 68 uint32_t words = std::min<uint32_t>(numWords, getNumWords()); 69 // Copy the words from bigVal to pVal 70 memcpy(pVal, bigVal, words * APINT_WORD_SIZE); 71 } 72 // Make sure unused high bits are cleared 73 clearUnusedBits(); 74} 75 76APInt::APInt(uint32_t numbits, const char StrStart[], uint32_t slen, 77 uint8_t radix) 78 : BitWidth(numbits), VAL(0) { 79 fromString(numbits, StrStart, slen, radix); 80} 81 82APInt::APInt(uint32_t numbits, const std::string& Val, uint8_t radix) 83 : BitWidth(numbits), VAL(0) { 84 assert(!Val.empty() && "String empty?"); 85 fromString(numbits, Val.c_str(), Val.size(), radix); 86} 87 88APInt::APInt(const APInt& that) 89 : BitWidth(that.BitWidth), VAL(0) { 90 if (isSingleWord()) 91 VAL = that.VAL; 92 else { 93 pVal = getMemory(getNumWords()); 94 memcpy(pVal, that.pVal, getNumWords() * APINT_WORD_SIZE); 95 } 96} 97 98APInt::~APInt() { 99 if (!isSingleWord() && pVal) 100 delete [] pVal; 101} 102 103APInt& APInt::operator=(const APInt& RHS) { 104 // Don't do anything for X = X 105 if (this == &RHS) 106 return *this; 107 108 // If the bitwidths are the same, we can avoid mucking with memory 109 if (BitWidth == RHS.getBitWidth()) { 110 if (isSingleWord()) 111 VAL = RHS.VAL; 112 else 113 memcpy(pVal, RHS.pVal, getNumWords() * APINT_WORD_SIZE); 114 return *this; 115 } 116 117 if (isSingleWord()) 118 if (RHS.isSingleWord()) 119 VAL = RHS.VAL; 120 else { 121 VAL = 0; 122 pVal = getMemory(RHS.getNumWords()); 123 memcpy(pVal, RHS.pVal, RHS.getNumWords() * APINT_WORD_SIZE); 124 } 125 else if (getNumWords() == RHS.getNumWords()) 126 memcpy(pVal, RHS.pVal, RHS.getNumWords() * APINT_WORD_SIZE); 127 else if (RHS.isSingleWord()) { 128 delete [] pVal; 129 VAL = RHS.VAL; 130 } else { 131 delete [] pVal; 132 pVal = getMemory(RHS.getNumWords()); 133 memcpy(pVal, RHS.pVal, RHS.getNumWords() * APINT_WORD_SIZE); 134 } 135 BitWidth = RHS.BitWidth; 136 return clearUnusedBits(); 137} 138 139APInt& APInt::operator=(uint64_t RHS) { 140 if (isSingleWord()) 141 VAL = RHS; 142 else { 143 pVal[0] = RHS; 144 memset(pVal+1, 0, (getNumWords() - 1) * APINT_WORD_SIZE); 145 } 146 return clearUnusedBits(); 147} 148 149/// add_1 - This function adds a single "digit" integer, y, to the multiple 150/// "digit" integer array, x[]. x[] is modified to reflect the addition and 151/// 1 is returned if there is a carry out, otherwise 0 is returned. 152/// @returns the carry of the addition. 153static bool add_1(uint64_t dest[], uint64_t x[], uint32_t len, uint64_t y) { 154 for (uint32_t i = 0; i < len; ++i) { 155 dest[i] = y + x[i]; 156 if (dest[i] < y) 157 y = 1; // Carry one to next digit. 158 else { 159 y = 0; // No need to carry so exit early 160 break; 161 } 162 } 163 return y; 164} 165 166/// @brief Prefix increment operator. Increments the APInt by one. 167APInt& APInt::operator++() { 168 if (isSingleWord()) 169 ++VAL; 170 else 171 add_1(pVal, pVal, getNumWords(), 1); 172 return clearUnusedBits(); 173} 174 175/// sub_1 - This function subtracts a single "digit" (64-bit word), y, from 176/// the multi-digit integer array, x[], propagating the borrowed 1 value until 177/// no further borrowing is neeeded or it runs out of "digits" in x. The result 178/// is 1 if "borrowing" exhausted the digits in x, or 0 if x was not exhausted. 179/// In other words, if y > x then this function returns 1, otherwise 0. 180/// @returns the borrow out of the subtraction 181static bool sub_1(uint64_t x[], uint32_t len, uint64_t y) { 182 for (uint32_t i = 0; i < len; ++i) { 183 uint64_t X = x[i]; 184 x[i] -= y; 185 if (y > X) 186 y = 1; // We have to "borrow 1" from next "digit" 187 else { 188 y = 0; // No need to borrow 189 break; // Remaining digits are unchanged so exit early 190 } 191 } 192 return bool(y); 193} 194 195/// @brief Prefix decrement operator. Decrements the APInt by one. 196APInt& APInt::operator--() { 197 if (isSingleWord()) 198 --VAL; 199 else 200 sub_1(pVal, getNumWords(), 1); 201 return clearUnusedBits(); 202} 203 204/// add - This function adds the integer array x to the integer array Y and 205/// places the result in dest. 206/// @returns the carry out from the addition 207/// @brief General addition of 64-bit integer arrays 208static bool add(uint64_t *dest, const uint64_t *x, const uint64_t *y, 209 uint32_t len) { 210 bool carry = false; 211 for (uint32_t i = 0; i< len; ++i) { 212 uint64_t limit = std::min(x[i],y[i]); // must come first in case dest == x 213 dest[i] = x[i] + y[i] + carry; 214 carry = dest[i] < limit || (carry && dest[i] == limit); 215 } 216 return carry; 217} 218 219/// Adds the RHS APint to this APInt. 220/// @returns this, after addition of RHS. 221/// @brief Addition assignment operator. 222APInt& APInt::operator+=(const APInt& RHS) { 223 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 224 if (isSingleWord()) 225 VAL += RHS.VAL; 226 else { 227 add(pVal, pVal, RHS.pVal, getNumWords()); 228 } 229 return clearUnusedBits(); 230} 231 232/// Subtracts the integer array y from the integer array x 233/// @returns returns the borrow out. 234/// @brief Generalized subtraction of 64-bit integer arrays. 235static bool sub(uint64_t *dest, const uint64_t *x, const uint64_t *y, 236 uint32_t len) { 237 bool borrow = false; 238 for (uint32_t i = 0; i < len; ++i) { 239 uint64_t x_tmp = borrow ? x[i] - 1 : x[i]; 240 borrow = y[i] > x_tmp || (borrow && x[i] == 0); 241 dest[i] = x_tmp - y[i]; 242 } 243 return borrow; 244} 245 246/// Subtracts the RHS APInt from this APInt 247/// @returns this, after subtraction 248/// @brief Subtraction assignment operator. 249APInt& APInt::operator-=(const APInt& RHS) { 250 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 251 if (isSingleWord()) 252 VAL -= RHS.VAL; 253 else 254 sub(pVal, pVal, RHS.pVal, getNumWords()); 255 return clearUnusedBits(); 256} 257 258/// Multiplies an integer array, x by a a uint64_t integer and places the result 259/// into dest. 260/// @returns the carry out of the multiplication. 261/// @brief Multiply a multi-digit APInt by a single digit (64-bit) integer. 262static uint64_t mul_1(uint64_t dest[], uint64_t x[], uint32_t len, uint64_t y) { 263 // Split y into high 32-bit part (hy) and low 32-bit part (ly) 264 uint64_t ly = y & 0xffffffffULL, hy = y >> 32; 265 uint64_t carry = 0; 266 267 // For each digit of x. 268 for (uint32_t i = 0; i < len; ++i) { 269 // Split x into high and low words 270 uint64_t lx = x[i] & 0xffffffffULL; 271 uint64_t hx = x[i] >> 32; 272 // hasCarry - A flag to indicate if there is a carry to the next digit. 273 // hasCarry == 0, no carry 274 // hasCarry == 1, has carry 275 // hasCarry == 2, no carry and the calculation result == 0. 276 uint8_t hasCarry = 0; 277 dest[i] = carry + lx * ly; 278 // Determine if the add above introduces carry. 279 hasCarry = (dest[i] < carry) ? 1 : 0; 280 carry = hx * ly + (dest[i] >> 32) + (hasCarry ? (1ULL << 32) : 0); 281 // The upper limit of carry can be (2^32 - 1)(2^32 - 1) + 282 // (2^32 - 1) + 2^32 = 2^64. 283 hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0); 284 285 carry += (lx * hy) & 0xffffffffULL; 286 dest[i] = (carry << 32) | (dest[i] & 0xffffffffULL); 287 carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0) + 288 (carry >> 32) + ((lx * hy) >> 32) + hx * hy; 289 } 290 return carry; 291} 292 293/// Multiplies integer array x by integer array y and stores the result into 294/// the integer array dest. Note that dest's size must be >= xlen + ylen. 295/// @brief Generalized multiplicate of integer arrays. 296static void mul(uint64_t dest[], uint64_t x[], uint32_t xlen, uint64_t y[], 297 uint32_t ylen) { 298 dest[xlen] = mul_1(dest, x, xlen, y[0]); 299 for (uint32_t i = 1; i < ylen; ++i) { 300 uint64_t ly = y[i] & 0xffffffffULL, hy = y[i] >> 32; 301 uint64_t carry = 0, lx = 0, hx = 0; 302 for (uint32_t j = 0; j < xlen; ++j) { 303 lx = x[j] & 0xffffffffULL; 304 hx = x[j] >> 32; 305 // hasCarry - A flag to indicate if has carry. 306 // hasCarry == 0, no carry 307 // hasCarry == 1, has carry 308 // hasCarry == 2, no carry and the calculation result == 0. 309 uint8_t hasCarry = 0; 310 uint64_t resul = carry + lx * ly; 311 hasCarry = (resul < carry) ? 1 : 0; 312 carry = (hasCarry ? (1ULL << 32) : 0) + hx * ly + (resul >> 32); 313 hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0); 314 315 carry += (lx * hy) & 0xffffffffULL; 316 resul = (carry << 32) | (resul & 0xffffffffULL); 317 dest[i+j] += resul; 318 carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0)+ 319 (carry >> 32) + (dest[i+j] < resul ? 1 : 0) + 320 ((lx * hy) >> 32) + hx * hy; 321 } 322 dest[i+xlen] = carry; 323 } 324} 325 326APInt& APInt::operator*=(const APInt& RHS) { 327 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 328 if (isSingleWord()) { 329 VAL *= RHS.VAL; 330 clearUnusedBits(); 331 return *this; 332 } 333 334 // Get some bit facts about LHS and check for zero 335 uint32_t lhsBits = getActiveBits(); 336 uint32_t lhsWords = !lhsBits ? 0 : whichWord(lhsBits - 1) + 1; 337 if (!lhsWords) 338 // 0 * X ===> 0 339 return *this; 340 341 // Get some bit facts about RHS and check for zero 342 uint32_t rhsBits = RHS.getActiveBits(); 343 uint32_t rhsWords = !rhsBits ? 0 : whichWord(rhsBits - 1) + 1; 344 if (!rhsWords) { 345 // X * 0 ===> 0 346 clear(); 347 return *this; 348 } 349 350 // Allocate space for the result 351 uint32_t destWords = rhsWords + lhsWords; 352 uint64_t *dest = getMemory(destWords); 353 354 // Perform the long multiply 355 mul(dest, pVal, lhsWords, RHS.pVal, rhsWords); 356 357 // Copy result back into *this 358 clear(); 359 uint32_t wordsToCopy = destWords >= getNumWords() ? getNumWords() : destWords; 360 memcpy(pVal, dest, wordsToCopy * APINT_WORD_SIZE); 361 362 // delete dest array and return 363 delete[] dest; 364 return *this; 365} 366 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 379APInt& APInt::operator|=(const APInt& RHS) { 380 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 381 if (isSingleWord()) { 382 VAL |= RHS.VAL; 383 return *this; 384 } 385 uint32_t numWords = getNumWords(); 386 for (uint32_t i = 0; i < numWords; ++i) 387 pVal[i] |= RHS.pVal[i]; 388 return *this; 389} 390 391APInt& APInt::operator^=(const APInt& RHS) { 392 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 393 if (isSingleWord()) { 394 VAL ^= RHS.VAL; 395 this->clearUnusedBits(); 396 return *this; 397 } 398 uint32_t numWords = getNumWords(); 399 for (uint32_t i = 0; i < numWords; ++i) 400 pVal[i] ^= RHS.pVal[i]; 401 return clearUnusedBits(); 402} 403 404APInt APInt::operator&(const APInt& RHS) const { 405 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 406 if (isSingleWord()) 407 return APInt(getBitWidth(), VAL & RHS.VAL); 408 409 uint32_t numWords = getNumWords(); 410 uint64_t* val = getMemory(numWords); 411 for (uint32_t i = 0; i < numWords; ++i) 412 val[i] = pVal[i] & RHS.pVal[i]; 413 return APInt(val, getBitWidth()); 414} 415 416APInt APInt::operator|(const APInt& RHS) const { 417 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 418 if (isSingleWord()) 419 return APInt(getBitWidth(), VAL | RHS.VAL); 420 421 uint32_t numWords = getNumWords(); 422 uint64_t *val = getMemory(numWords); 423 for (uint32_t i = 0; i < numWords; ++i) 424 val[i] = pVal[i] | RHS.pVal[i]; 425 return APInt(val, getBitWidth()); 426} 427 428APInt APInt::operator^(const APInt& RHS) const { 429 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 430 if (isSingleWord()) 431 return APInt(BitWidth, VAL ^ RHS.VAL); 432 433 uint32_t numWords = getNumWords(); 434 uint64_t *val = getMemory(numWords); 435 for (uint32_t i = 0; i < numWords; ++i) 436 val[i] = pVal[i] ^ RHS.pVal[i]; 437 438 // 0^0==1 so clear the high bits in case they got set. 439 return APInt(val, getBitWidth()).clearUnusedBits(); 440} 441 442bool APInt::operator !() const { 443 if (isSingleWord()) 444 return !VAL; 445 446 for (uint32_t i = 0; i < getNumWords(); ++i) 447 if (pVal[i]) 448 return false; 449 return true; 450} 451 452APInt APInt::operator*(const APInt& RHS) const { 453 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 454 if (isSingleWord()) 455 return APInt(BitWidth, VAL * RHS.VAL); 456 APInt Result(*this); 457 Result *= RHS; 458 return Result.clearUnusedBits(); 459} 460 461APInt APInt::operator+(const APInt& RHS) const { 462 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 463 if (isSingleWord()) 464 return APInt(BitWidth, VAL + RHS.VAL); 465 APInt Result(BitWidth, 0); 466 add(Result.pVal, this->pVal, RHS.pVal, getNumWords()); 467 return Result.clearUnusedBits(); 468} 469 470APInt APInt::operator-(const APInt& RHS) const { 471 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 472 if (isSingleWord()) 473 return APInt(BitWidth, VAL - RHS.VAL); 474 APInt Result(BitWidth, 0); 475 sub(Result.pVal, this->pVal, RHS.pVal, getNumWords()); 476 return Result.clearUnusedBits(); 477} 478 479bool APInt::operator[](uint32_t bitPosition) const { 480 return (maskBit(bitPosition) & 481 (isSingleWord() ? VAL : pVal[whichWord(bitPosition)])) != 0; 482} 483 484bool APInt::operator==(const APInt& RHS) const { 485 assert(BitWidth == RHS.BitWidth && "Comparison requires equal bit widths"); 486 if (isSingleWord()) 487 return VAL == RHS.VAL; 488 489 // Get some facts about the number of bits used in the two operands. 490 uint32_t n1 = getActiveBits(); 491 uint32_t n2 = RHS.getActiveBits(); 492 493 // If the number of bits isn't the same, they aren't equal 494 if (n1 != n2) 495 return false; 496 497 // If the number of bits fits in a word, we only need to compare the low word. 498 if (n1 <= APINT_BITS_PER_WORD) 499 return pVal[0] == RHS.pVal[0]; 500 501 // Otherwise, compare everything 502 for (int i = whichWord(n1 - 1); i >= 0; --i) 503 if (pVal[i] != RHS.pVal[i]) 504 return false; 505 return true; 506} 507 508bool APInt::operator==(uint64_t Val) const { 509 if (isSingleWord()) 510 return VAL == Val; 511 512 uint32_t n = getActiveBits(); 513 if (n <= APINT_BITS_PER_WORD) 514 return pVal[0] == Val; 515 else 516 return false; 517} 518 519bool APInt::ult(const APInt& RHS) const { 520 assert(BitWidth == RHS.BitWidth && "Bit widths must be same for comparison"); 521 if (isSingleWord()) 522 return VAL < RHS.VAL; 523 524 // Get active bit length of both operands 525 uint32_t n1 = getActiveBits(); 526 uint32_t n2 = RHS.getActiveBits(); 527 528 // If magnitude of LHS is less than RHS, return true. 529 if (n1 < n2) 530 return true; 531 532 // If magnitude of RHS is greather than LHS, return false. 533 if (n2 < n1) 534 return false; 535 536 // If they bot fit in a word, just compare the low order word 537 if (n1 <= APINT_BITS_PER_WORD && n2 <= APINT_BITS_PER_WORD) 538 return pVal[0] < RHS.pVal[0]; 539 540 // Otherwise, compare all words 541 uint32_t topWord = whichWord(std::max(n1,n2)-1); 542 for (int i = topWord; i >= 0; --i) { 543 if (pVal[i] > RHS.pVal[i]) 544 return false; 545 if (pVal[i] < RHS.pVal[i]) 546 return true; 547 } 548 return false; 549} 550 551bool APInt::slt(const APInt& RHS) const { 552 assert(BitWidth == RHS.BitWidth && "Bit widths must be same for comparison"); 553 if (isSingleWord()) { 554 int64_t lhsSext = (int64_t(VAL) << (64-BitWidth)) >> (64-BitWidth); 555 int64_t rhsSext = (int64_t(RHS.VAL) << (64-BitWidth)) >> (64-BitWidth); 556 return lhsSext < rhsSext; 557 } 558 559 APInt lhs(*this); 560 APInt rhs(RHS); 561 bool lhsNeg = isNegative(); 562 bool rhsNeg = rhs.isNegative(); 563 if (lhsNeg) { 564 // Sign bit is set so perform two's complement to make it positive 565 lhs.flip(); 566 lhs++; 567 } 568 if (rhsNeg) { 569 // Sign bit is set so perform two's complement to make it positive 570 rhs.flip(); 571 rhs++; 572 } 573 574 // Now we have unsigned values to compare so do the comparison if necessary 575 // based on the negativeness of the values. 576 if (lhsNeg) 577 if (rhsNeg) 578 return lhs.ugt(rhs); 579 else 580 return true; 581 else if (rhsNeg) 582 return false; 583 else 584 return lhs.ult(rhs); 585} 586 587APInt& APInt::set(uint32_t bitPosition) { 588 if (isSingleWord()) 589 VAL |= maskBit(bitPosition); 590 else 591 pVal[whichWord(bitPosition)] |= maskBit(bitPosition); 592 return *this; 593} 594 595APInt& APInt::set() { 596 if (isSingleWord()) { 597 VAL = -1ULL; 598 return clearUnusedBits(); 599 } 600 601 // Set all the bits in all the words. 602 for (uint32_t i = 0; i < getNumWords() - 1; ++i) 603 pVal[i] = -1ULL; 604 // Clear the unused ones 605 return clearUnusedBits(); 606} 607 608/// Set the given bit to 0 whose position is given as "bitPosition". 609/// @brief Set a given bit to 0. 610APInt& APInt::clear(uint32_t bitPosition) { 611 if (isSingleWord()) 612 VAL &= ~maskBit(bitPosition); 613 else 614 pVal[whichWord(bitPosition)] &= ~maskBit(bitPosition); 615 return *this; 616} 617 618/// @brief Set every bit to 0. 619APInt& APInt::clear() { 620 if (isSingleWord()) 621 VAL = 0; 622 else 623 memset(pVal, 0, getNumWords() * APINT_WORD_SIZE); 624 return *this; 625} 626 627/// @brief Bitwise NOT operator. Performs a bitwise logical NOT operation on 628/// this APInt. 629APInt APInt::operator~() const { 630 APInt Result(*this); 631 Result.flip(); 632 return Result; 633} 634 635/// @brief Toggle every bit to its opposite value. 636APInt& APInt::flip() { 637 if (isSingleWord()) { 638 VAL ^= -1ULL; 639 return clearUnusedBits(); 640 } 641 for (uint32_t i = 0; i < getNumWords(); ++i) 642 pVal[i] ^= -1ULL; 643 return clearUnusedBits(); 644} 645 646/// Toggle a given bit to its opposite value whose position is given 647/// as "bitPosition". 648/// @brief Toggles a given bit to its opposite value. 649APInt& APInt::flip(uint32_t bitPosition) { 650 assert(bitPosition < BitWidth && "Out of the bit-width range!"); 651 if ((*this)[bitPosition]) clear(bitPosition); 652 else set(bitPosition); 653 return *this; 654} 655 656uint64_t APInt::getHashValue() const { 657 // Put the bit width into the low order bits. 658 uint64_t hash = BitWidth; 659 660 // Add the sum of the words to the hash. 661 if (isSingleWord()) 662 hash += VAL << 6; // clear separation of up to 64 bits 663 else 664 for (uint32_t i = 0; i < getNumWords(); ++i) 665 hash += pVal[i] << 6; // clear sepration of up to 64 bits 666 return hash; 667} 668 669/// HiBits - This function returns the high "numBits" bits of this APInt. 670APInt APInt::getHiBits(uint32_t numBits) const { 671 return APIntOps::lshr(*this, BitWidth - numBits); 672} 673 674/// LoBits - This function returns the low "numBits" bits of this APInt. 675APInt APInt::getLoBits(uint32_t numBits) const { 676 return APIntOps::lshr(APIntOps::shl(*this, BitWidth - numBits), 677 BitWidth - numBits); 678} 679 680bool APInt::isPowerOf2() const { 681 return (!!*this) && !(*this & (*this - APInt(BitWidth,1))); 682} 683 684uint32_t APInt::countLeadingZeros() const { 685 uint32_t Count = 0; 686 if (isSingleWord()) 687 Count = CountLeadingZeros_64(VAL); 688 else { 689 for (uint32_t i = getNumWords(); i > 0u; --i) { 690 if (pVal[i-1] == 0) 691 Count += APINT_BITS_PER_WORD; 692 else { 693 Count += CountLeadingZeros_64(pVal[i-1]); 694 break; 695 } 696 } 697 } 698 uint32_t remainder = BitWidth % APINT_BITS_PER_WORD; 699 if (remainder) 700 Count -= APINT_BITS_PER_WORD - remainder; 701 return Count; 702} 703 704static uint32_t countLeadingOnes_64(uint64_t V, uint32_t skip) { 705 uint32_t Count = 0; 706 if (skip) 707 V <<= skip; 708 while (V && (V & (1ULL << 63))) { 709 Count++; 710 V <<= 1; 711 } 712 return Count; 713} 714 715uint32_t APInt::countLeadingOnes() const { 716 if (isSingleWord()) 717 return countLeadingOnes_64(VAL, APINT_BITS_PER_WORD - BitWidth); 718 719 uint32_t highWordBits = BitWidth % APINT_BITS_PER_WORD; 720 uint32_t shift = (highWordBits == 0 ? 0 : APINT_BITS_PER_WORD - highWordBits); 721 int i = getNumWords() - 1; 722 uint32_t Count = countLeadingOnes_64(pVal[i], shift); 723 if (Count == highWordBits) { 724 for (i--; i >= 0; --i) { 725 if (pVal[i] == -1ULL) 726 Count += APINT_BITS_PER_WORD; 727 else { 728 Count += countLeadingOnes_64(pVal[i], 0); 729 break; 730 } 731 } 732 } 733 return Count; 734} 735 736uint32_t APInt::countTrailingZeros() const { 737 if (isSingleWord()) 738 return CountTrailingZeros_64(VAL); 739 uint32_t Count = 0; 740 uint32_t i = 0; 741 for (; i < getNumWords() && pVal[i] == 0; ++i) 742 Count += APINT_BITS_PER_WORD; 743 if (i < getNumWords()) 744 Count += CountTrailingZeros_64(pVal[i]); 745 return Count; 746} 747 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 757APInt APInt::byteSwap() const { 758 assert(BitWidth >= 16 && BitWidth % 16 == 0 && "Cannot byteswap!"); 759 if (BitWidth == 16) 760 return APInt(BitWidth, ByteSwap_16(VAL)); 761 else if (BitWidth == 32) 762 return APInt(BitWidth, ByteSwap_32(VAL)); 763 else if (BitWidth == 48) { 764 uint64_t Tmp1 = ((VAL >> 32) << 16) | (VAL & 0xFFFF); 765 Tmp1 = ByteSwap_32(Tmp1); 766 uint64_t Tmp2 = (VAL >> 16) & 0xFFFF; 767 Tmp2 = ByteSwap_16(Tmp2); 768 return 769 APInt(BitWidth, 770 (Tmp1 & 0xff) | ((Tmp1<<16) & 0xffff00000000ULL) | (Tmp2 << 16)); 771 } else if (BitWidth == 64) 772 return APInt(BitWidth, ByteSwap_64(VAL)); 773 else { 774 APInt Result(BitWidth, 0); 775 char *pByte = (char*)Result.pVal; 776 for (uint32_t i = 0; i < BitWidth / APINT_WORD_SIZE / 2; ++i) { 777 char Tmp = pByte[i]; 778 pByte[i] = pByte[BitWidth / APINT_WORD_SIZE - 1 - i]; 779 pByte[BitWidth / APINT_WORD_SIZE - i - 1] = Tmp; 780 } 781 return Result; 782 } 783} 784 785APInt llvm::APIntOps::GreatestCommonDivisor(const APInt& API1, 786 const APInt& API2) { 787 APInt A = API1, B = API2; 788 while (!!B) { 789 APInt T = B; 790 B = APIntOps::urem(A, B); 791 A = T; 792 } 793 return A; 794} 795 796APInt llvm::APIntOps::RoundDoubleToAPInt(double Double, uint32_t width) { 797 union { 798 double D; 799 uint64_t I; 800 } T; 801 T.D = Double; 802 803 // Get the sign bit from the highest order bit 804 bool isNeg = T.I >> 63; 805 806 // Get the 11-bit exponent and adjust for the 1023 bit bias 807 int64_t exp = ((T.I >> 52) & 0x7ff) - 1023; 808 809 // If the exponent is negative, the value is < 0 so just return 0. 810 if (exp < 0) 811 return APInt(width, 0u); 812 813 // Extract the mantissa by clearing the top 12 bits (sign + exponent). 814 uint64_t mantissa = (T.I & (~0ULL >> 12)) | 1ULL << 52; 815 816 // If the exponent doesn't shift all bits out of the mantissa 817 if (exp < 52) 818 return isNeg ? -APInt(width, mantissa >> (52 - exp)) : 819 APInt(width, mantissa >> (52 - exp)); 820 821 // If the client didn't provide enough bits for us to shift the mantissa into 822 // then the result is undefined, just return 0 823 if (width <= exp - 52) 824 return APInt(width, 0); 825 826 // Otherwise, we have to shift the mantissa bits up to the right location 827 APInt Tmp(width, mantissa); 828 Tmp = Tmp.shl(exp - 52); 829 return isNeg ? -Tmp : Tmp; 830} 831 832/// RoundToDouble - This function convert this APInt to a double. 833/// The layout for double is as following (IEEE Standard 754): 834/// -------------------------------------- 835/// | Sign Exponent Fraction Bias | 836/// |-------------------------------------- | 837/// | 1[63] 11[62-52] 52[51-00] 1023 | 838/// -------------------------------------- 839double APInt::roundToDouble(bool isSigned) const { 840 841 // Handle the simple case where the value is contained in one uint64_t. 842 if (isSingleWord() || getActiveBits() <= APINT_BITS_PER_WORD) { 843 if (isSigned) { 844 int64_t sext = (int64_t(VAL) << (64-BitWidth)) >> (64-BitWidth); 845 return double(sext); 846 } else 847 return double(VAL); 848 } 849 850 // Determine if the value is negative. 851 bool isNeg = isSigned ? (*this)[BitWidth-1] : false; 852 853 // Construct the absolute value if we're negative. 854 APInt Tmp(isNeg ? -(*this) : (*this)); 855 856 // Figure out how many bits we're using. 857 uint32_t n = Tmp.getActiveBits(); 858 859 // The exponent (without bias normalization) is just the number of bits 860 // we are using. Note that the sign bit is gone since we constructed the 861 // absolute value. 862 uint64_t exp = n; 863 864 // Return infinity for exponent overflow 865 if (exp > 1023) { 866 if (!isSigned || !isNeg) 867 return double(1.0E300 * 1.0E300); // positive infinity 868 else 869 return double(-1.0E300 * 1.0E300); // negative infinity 870 } 871 exp += 1023; // Increment for 1023 bias 872 873 // Number of bits in mantissa is 52. To obtain the mantissa value, we must 874 // extract the high 52 bits from the correct words in pVal. 875 uint64_t mantissa; 876 unsigned hiWord = whichWord(n-1); 877 if (hiWord == 0) { 878 mantissa = Tmp.pVal[0]; 879 if (n > 52) 880 mantissa >>= n - 52; // shift down, we want the top 52 bits. 881 } else { 882 assert(hiWord > 0 && "huh?"); 883 uint64_t hibits = Tmp.pVal[hiWord] << (52 - n % APINT_BITS_PER_WORD); 884 uint64_t lobits = Tmp.pVal[hiWord-1] >> (11 + n % APINT_BITS_PER_WORD); 885 mantissa = hibits | lobits; 886 } 887 888 // The leading bit of mantissa is implicit, so get rid of it. 889 uint64_t sign = isNeg ? (1ULL << (APINT_BITS_PER_WORD - 1)) : 0; 890 union { 891 double D; 892 uint64_t I; 893 } T; 894 T.I = sign | (exp << 52) | mantissa; 895 return T.D; 896} 897 898// Truncate to new width. 899APInt &APInt::trunc(uint32_t width) { 900 assert(width < BitWidth && "Invalid APInt Truncate request"); 901 assert(width >= IntegerType::MIN_INT_BITS && "Can't truncate to 0 bits"); 902 uint32_t wordsBefore = getNumWords(); 903 BitWidth = width; 904 uint32_t wordsAfter = getNumWords(); 905 if (wordsBefore != wordsAfter) { 906 if (wordsAfter == 1) { 907 uint64_t *tmp = pVal; 908 VAL = pVal[0]; 909 delete [] tmp; 910 } else { 911 uint64_t *newVal = getClearedMemory(wordsAfter); 912 for (uint32_t i = 0; i < wordsAfter; ++i) 913 newVal[i] = pVal[i]; 914 delete [] pVal; 915 pVal = newVal; 916 } 917 } 918 return clearUnusedBits(); 919} 920 921// Sign extend to a new width. 922APInt &APInt::sext(uint32_t width) { 923 assert(width > BitWidth && "Invalid APInt SignExtend request"); 924 assert(width <= IntegerType::MAX_INT_BITS && "Too many bits"); 925 // If the sign bit isn't set, this is the same as zext. 926 if (!isNegative()) { 927 zext(width); 928 return *this; 929 } 930 931 // The sign bit is set. First, get some facts 932 uint32_t wordsBefore = getNumWords(); 933 uint32_t wordBits = BitWidth % APINT_BITS_PER_WORD; 934 BitWidth = width; 935 uint32_t wordsAfter = getNumWords(); 936 937 // Mask the high order word appropriately 938 if (wordsBefore == wordsAfter) { 939 uint32_t newWordBits = width % APINT_BITS_PER_WORD; 940 // The extension is contained to the wordsBefore-1th word. 941 uint64_t mask = (~0ULL >> (APINT_BITS_PER_WORD - newWordBits)) << wordBits; 942 if (wordsBefore == 1) 943 VAL |= mask; 944 else 945 pVal[wordsBefore-1] |= mask; 946 clearUnusedBits(); 947 return *this; 948 } 949 950 uint64_t mask = wordBits == 0 ? 0 : ~0ULL << wordBits; 951 uint64_t *newVal = getMemory(wordsAfter); 952 if (wordsBefore == 1) 953 newVal[0] = VAL | mask; 954 else { 955 for (uint32_t i = 0; i < wordsBefore; ++i) 956 newVal[i] = pVal[i]; 957 newVal[wordsBefore-1] |= mask; 958 } 959 for (uint32_t i = wordsBefore; i < wordsAfter; i++) 960 newVal[i] = -1ULL; 961 if (wordsBefore != 1) 962 delete [] pVal; 963 pVal = newVal; 964 return clearUnusedBits(); 965} 966 967// Zero extend to a new width. 968APInt &APInt::zext(uint32_t width) { 969 assert(width > BitWidth && "Invalid APInt ZeroExtend request"); 970 assert(width <= IntegerType::MAX_INT_BITS && "Too many bits"); 971 uint32_t wordsBefore = getNumWords(); 972 BitWidth = width; 973 uint32_t wordsAfter = getNumWords(); 974 if (wordsBefore != wordsAfter) { 975 uint64_t *newVal = getClearedMemory(wordsAfter); 976 if (wordsBefore == 1) 977 newVal[0] = VAL; 978 else 979 for (uint32_t i = 0; i < wordsBefore; ++i) 980 newVal[i] = pVal[i]; 981 if (wordsBefore != 1) 982 delete [] pVal; 983 pVal = newVal; 984 } 985 return *this; 986} 987 988/// Arithmetic right-shift this APInt by shiftAmt. 989/// @brief Arithmetic right-shift function. 990APInt APInt::ashr(uint32_t shiftAmt) const { 991 assert(shiftAmt <= BitWidth && "Invalid shift amount"); 992 if (isSingleWord()) { 993 if (shiftAmt == BitWidth) 994 return APInt(BitWidth, 0); // undefined 995 else { 996 uint32_t SignBit = APINT_BITS_PER_WORD - BitWidth; 997 return APInt(BitWidth, 998 (((int64_t(VAL) << SignBit) >> SignBit) >> shiftAmt)); 999 } 1000 } 1001 1002 // If all the bits were shifted out, the result is 0 or -1. This avoids issues 1003 // with shifting by the size of the integer type, which produces undefined 1004 // results. 1005 if (shiftAmt == BitWidth) 1006 if (isNegative()) 1007 return APInt(BitWidth, -1ULL); 1008 else 1009 return APInt(BitWidth, 0); 1010 1011 // Create some space for the result. 1012 uint64_t * val = new uint64_t[getNumWords()]; 1013 1014 // If we are shifting less than a word, compute the shift with a simple carry 1015 if (shiftAmt < APINT_BITS_PER_WORD) { 1016 uint64_t carry = 0; 1017 for (int i = getNumWords()-1; i >= 0; --i) { 1018 val[i] = (pVal[i] >> shiftAmt) | carry; 1019 carry = pVal[i] << (APINT_BITS_PER_WORD - shiftAmt); 1020 } 1021 return APInt(val, BitWidth).clearUnusedBits(); 1022 } 1023 1024 // Compute some values needed by the remaining shift algorithms 1025 uint32_t wordShift = shiftAmt % APINT_BITS_PER_WORD; 1026 uint32_t offset = shiftAmt / APINT_BITS_PER_WORD; 1027 1028 // If we are shifting whole words, just move whole words 1029 if (wordShift == 0) { 1030 for (uint32_t i = 0; i < getNumWords() - offset; ++i) 1031 val[i] = pVal[i+offset]; 1032 for (uint32_t i = getNumWords()-offset; i < getNumWords(); i++) 1033 val[i] = (isNegative() ? -1ULL : 0); 1034 return APInt(val,BitWidth).clearUnusedBits(); 1035 } 1036 1037 // Shift the low order words 1038 uint32_t breakWord = getNumWords() - offset -1; 1039 for (uint32_t i = 0; i < breakWord; ++i) 1040 val[i] = (pVal[i+offset] >> wordShift) | 1041 (pVal[i+offset+1] << (APINT_BITS_PER_WORD - wordShift)); 1042 // Shift the break word. 1043 uint32_t SignBit = APINT_BITS_PER_WORD - (BitWidth % APINT_BITS_PER_WORD); 1044 val[breakWord] = uint64_t( 1045 (((int64_t(pVal[breakWord+offset]) << SignBit) >> SignBit) >> wordShift)); 1046 1047 // Remaining words are 0 or -1 1048 for (uint32_t i = breakWord+1; i < getNumWords(); ++i) 1049 val[i] = (isNegative() ? -1ULL : 0); 1050 return APInt(val, BitWidth).clearUnusedBits(); 1051} 1052 1053/// Logical right-shift this APInt by shiftAmt. 1054/// @brief Logical right-shift function. 1055APInt APInt::lshr(uint32_t shiftAmt) const { 1056 if (isSingleWord()) 1057 if (shiftAmt == BitWidth) 1058 return APInt(BitWidth, 0); 1059 else 1060 return APInt(BitWidth, this->VAL >> shiftAmt); 1061 1062 // If all the bits were shifted out, the result is 0. This avoids issues 1063 // with shifting by the size of the integer type, which produces undefined 1064 // results. We define these "undefined results" to always be 0. 1065 if (shiftAmt == BitWidth) 1066 return APInt(BitWidth, 0); 1067 1068 // Create some space for the result. 1069 uint64_t * val = new uint64_t[getNumWords()]; 1070 1071 // If we are shifting less than a word, compute the shift with a simple carry 1072 if (shiftAmt < APINT_BITS_PER_WORD) { 1073 uint64_t carry = 0; 1074 for (int i = getNumWords()-1; i >= 0; --i) { 1075 val[i] = (pVal[i] >> shiftAmt) | carry; 1076 carry = pVal[i] << (APINT_BITS_PER_WORD - shiftAmt); 1077 } 1078 return APInt(val, BitWidth).clearUnusedBits(); 1079 } 1080 1081 // Compute some values needed by the remaining shift algorithms 1082 uint32_t wordShift = shiftAmt % APINT_BITS_PER_WORD; 1083 uint32_t offset = shiftAmt / APINT_BITS_PER_WORD; 1084 1085 // If we are shifting whole words, just move whole words 1086 if (wordShift == 0) { 1087 for (uint32_t i = 0; i < getNumWords() - offset; ++i) 1088 val[i] = pVal[i+offset]; 1089 for (uint32_t i = getNumWords()-offset; i < getNumWords(); i++) 1090 val[i] = 0; 1091 return APInt(val,BitWidth).clearUnusedBits(); 1092 } 1093 1094 // Shift the low order words 1095 uint32_t breakWord = getNumWords() - offset -1; 1096 for (uint32_t i = 0; i < breakWord; ++i) 1097 val[i] = (pVal[i+offset] >> wordShift) | 1098 (pVal[i+offset+1] << (APINT_BITS_PER_WORD - wordShift)); 1099 // Shift the break word. 1100 val[breakWord] = pVal[breakWord+offset] >> wordShift; 1101 1102 // Remaining words are 0 1103 for (uint32_t i = breakWord+1; i < getNumWords(); ++i) 1104 val[i] = 0; 1105 return APInt(val, BitWidth).clearUnusedBits(); 1106} 1107 1108/// Left-shift this APInt by shiftAmt. 1109/// @brief Left-shift function. 1110APInt APInt::shl(uint32_t shiftAmt) const { 1111 assert(shiftAmt <= BitWidth && "Invalid shift amount"); 1112 if (isSingleWord()) { 1113 if (shiftAmt == BitWidth) 1114 return APInt(BitWidth, 0); // avoid undefined shift results 1115 return APInt(BitWidth, VAL << shiftAmt); 1116 } 1117 1118 // If all the bits were shifted out, the result is 0. This avoids issues 1119 // with shifting by the size of the integer type, which produces undefined 1120 // results. We define these "undefined results" to always be 0. 1121 if (shiftAmt == BitWidth) 1122 return APInt(BitWidth, 0); 1123 1124 // Create some space for the result. 1125 uint64_t * val = new uint64_t[getNumWords()]; 1126 1127 // If we are shifting less than a word, do it the easy way 1128 if (shiftAmt < APINT_BITS_PER_WORD) { 1129 uint64_t carry = 0; 1130 for (uint32_t i = 0; i < getNumWords(); i++) { 1131 val[i] = pVal[i] << shiftAmt | carry; 1132 carry = pVal[i] >> (APINT_BITS_PER_WORD - shiftAmt); 1133 } 1134 return APInt(val, BitWidth).clearUnusedBits(); 1135 } 1136 1137 // Compute some values needed by the remaining shift algorithms 1138 uint32_t wordShift = shiftAmt % APINT_BITS_PER_WORD; 1139 uint32_t offset = shiftAmt / APINT_BITS_PER_WORD; 1140 1141 // If we are shifting whole words, just move whole words 1142 if (wordShift == 0) { 1143 for (uint32_t i = 0; i < offset; i++) 1144 val[i] = 0; 1145 for (uint32_t i = offset; i < getNumWords(); i++) 1146 val[i] = pVal[i-offset]; 1147 return APInt(val,BitWidth).clearUnusedBits(); 1148 } 1149 1150 // Copy whole words from this to Result. 1151 uint32_t i = getNumWords() - 1; 1152 for (; i > offset; --i) 1153 val[i] = pVal[i-offset] << wordShift | 1154 pVal[i-offset-1] >> (APINT_BITS_PER_WORD - wordShift); 1155 val[offset] = pVal[0] << wordShift; 1156 for (i = 0; i < offset; ++i) 1157 val[i] = 0; 1158 return APInt(val, BitWidth).clearUnusedBits(); 1159} 1160 1161 1162// Square Root - this method computes and returns the square root of "this". 1163// Three mechanisms are used for computation. For small values (<= 5 bits), 1164// a table lookup is done. This gets some performance for common cases. For 1165// values using less than 52 bits, the value is converted to double and then 1166// the libc sqrt function is called. The result is rounded and then converted 1167// back to a uint64_t which is then used to construct the result. Finally, 1168// the Babylonian method for computing square roots is used. 1169APInt APInt::sqrt() const { 1170 1171 // Determine the magnitude of the value. 1172 uint32_t magnitude = getActiveBits(); 1173 1174 // Use a fast table for some small values. This also gets rid of some 1175 // rounding errors in libc sqrt for small values. 1176 if (magnitude <= 5) { 1177 static uint8_t results[32] = { 1178 /* 0 */ 0, 1179 /* 1- 2 */ 1, 1, 1180 /* 3- 6 */ 2, 2, 2, 2, 1181 /* 7-12 */ 3, 3, 3, 3, 3, 3, 1182 /* 13-20 */ 4, 4, 4, 4, 4, 4, 4, 4, 1183 /* 21-30 */ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 1184 /* 31 */ 6 1185 }; 1186 return APInt(BitWidth, results[ (isSingleWord() ? VAL : pVal[0]) ]); 1187 } 1188 1189 // If the magnitude of the value fits in less than 52 bits (the precision of 1190 // an IEEE double precision floating point value), then we can use the 1191 // libc sqrt function which will probably use a hardware sqrt computation. 1192 // This should be faster than the algorithm below. 1193 if (magnitude < 52) 1194 return APInt(BitWidth, 1195 uint64_t(::round(::sqrt(double(isSingleWord()?VAL:pVal[0]))))); 1196 1197 // Okay, all the short cuts are exhausted. We must compute it. The following 1198 // is a classical Babylonian method for computing the square root. This code 1199 // was adapted to APINt from a wikipedia article on such computations. 1200 // See http://www.wikipedia.org/ and go to the page named 1201 // Calculate_an_integer_square_root. 1202 uint32_t nbits = BitWidth, i = 4; 1203 APInt testy(BitWidth, 16); 1204 APInt x_old(BitWidth, 1); 1205 APInt x_new(BitWidth, 0); 1206 APInt two(BitWidth, 2); 1207 1208 // Select a good starting value using binary logarithms. 1209 for (;; i += 2, testy = testy.shl(2)) 1210 if (i >= nbits || this->ule(testy)) { 1211 x_old = x_old.shl(i / 2); 1212 break; 1213 } 1214 1215 // Use the Babylonian method to arrive at the integer square root: 1216 for (;;) { 1217 x_new = (this->udiv(x_old) + x_old).udiv(two); 1218 if (x_old.ule(x_new)) 1219 break; 1220 x_old = x_new; 1221 } 1222 1223 // Make sure we return the closest approximation 1224 APInt square(x_old * x_old); 1225 APInt nextSquare((x_old + 1) * (x_old +1)); 1226 if (this->ult(square)) 1227 return x_old; 1228 else if (this->ule(nextSquare)) 1229 if ((nextSquare - *this).ult(*this - square)) 1230 return x_old + 1; 1231 else 1232 return x_old; 1233 else 1234 assert(0 && "Error in APInt::sqrt computation"); 1235 return x_old + 1; 1236} 1237 1238/// Implementation of Knuth's Algorithm D (Division of nonnegative integers) 1239/// from "Art of Computer Programming, Volume 2", section 4.3.1, p. 272. The 1240/// variables here have the same names as in the algorithm. Comments explain 1241/// the algorithm and any deviation from it. 1242static void KnuthDiv(uint32_t *u, uint32_t *v, uint32_t *q, uint32_t* r, 1243 uint32_t m, uint32_t n) { 1244 assert(u && "Must provide dividend"); 1245 assert(v && "Must provide divisor"); 1246 assert(q && "Must provide quotient"); 1247 assert(u != v && u != q && v != q && "Must us different memory"); 1248 assert(n>1 && "n must be > 1"); 1249 1250 // Knuth uses the value b as the base of the number system. In our case b 1251 // is 2^31 so we just set it to -1u. 1252 uint64_t b = uint64_t(1) << 32; 1253 1254 DEBUG(cerr << "KnuthDiv: m=" << m << " n=" << n << '\n'); 1255 DEBUG(cerr << "KnuthDiv: original:"); 1256 DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << std::setbase(16) << u[i]); 1257 DEBUG(cerr << " by"); 1258 DEBUG(for (int i = n; i >0; i--) cerr << " " << std::setbase(16) << v[i-1]); 1259 DEBUG(cerr << '\n'); 1260 // D1. [Normalize.] Set d = b / (v[n-1] + 1) and multiply all the digits of 1261 // u and v by d. Note that we have taken Knuth's advice here to use a power 1262 // of 2 value for d such that d * v[n-1] >= b/2 (b is the base). A power of 1263 // 2 allows us to shift instead of multiply and it is easy to determine the 1264 // shift amount from the leading zeros. We are basically normalizing the u 1265 // and v so that its high bits are shifted to the top of v's range without 1266 // overflow. Note that this can require an extra word in u so that u must 1267 // be of length m+n+1. 1268 uint32_t shift = CountLeadingZeros_32(v[n-1]); 1269 uint32_t v_carry = 0; 1270 uint32_t u_carry = 0; 1271 if (shift) { 1272 for (uint32_t i = 0; i < m+n; ++i) { 1273 uint32_t u_tmp = u[i] >> (32 - shift); 1274 u[i] = (u[i] << shift) | u_carry; 1275 u_carry = u_tmp; 1276 } 1277 for (uint32_t i = 0; i < n; ++i) { 1278 uint32_t v_tmp = v[i] >> (32 - shift); 1279 v[i] = (v[i] << shift) | v_carry; 1280 v_carry = v_tmp; 1281 } 1282 } 1283 u[m+n] = u_carry; 1284 DEBUG(cerr << "KnuthDiv: normal:"); 1285 DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << std::setbase(16) << u[i]); 1286 DEBUG(cerr << " by"); 1287 DEBUG(for (int i = n; i >0; i--) cerr << " " << std::setbase(16) << v[i-1]); 1288 DEBUG(cerr << '\n'); 1289 1290 // D2. [Initialize j.] Set j to m. This is the loop counter over the places. 1291 int j = m; 1292 do { 1293 DEBUG(cerr << "KnuthDiv: quotient digit #" << j << '\n'); 1294 // D3. [Calculate q'.]. 1295 // Set qp = (u[j+n]*b + u[j+n-1]) / v[n-1]. (qp=qprime=q') 1296 // Set rp = (u[j+n]*b + u[j+n-1]) % v[n-1]. (rp=rprime=r') 1297 // Now test if qp == b or qp*v[n-2] > b*rp + u[j+n-2]; if so, decrease 1298 // qp by 1, inrease rp by v[n-1], and repeat this test if rp < b. The test 1299 // on v[n-2] determines at high speed most of the cases in which the trial 1300 // value qp is one too large, and it eliminates all cases where qp is two 1301 // too large. 1302 uint64_t dividend = ((uint64_t(u[j+n]) << 32) + u[j+n-1]); 1303 DEBUG(cerr << "KnuthDiv: dividend == " << dividend << '\n'); 1304 uint64_t qp = dividend / v[n-1]; 1305 uint64_t rp = dividend % v[n-1]; 1306 if (qp == b || qp*v[n-2] > b*rp + u[j+n-2]) { 1307 qp--; 1308 rp += v[n-1]; 1309 if (rp < b && (qp == b || qp*v[n-2] > b*rp + u[j+n-2])) 1310 qp--; 1311 } 1312 DEBUG(cerr << "KnuthDiv: qp == " << qp << ", rp == " << rp << '\n'); 1313 1314 // D4. [Multiply and subtract.] Replace (u[j+n]u[j+n-1]...u[j]) with 1315 // (u[j+n]u[j+n-1]..u[j]) - qp * (v[n-1]...v[1]v[0]). This computation 1316 // consists of a simple multiplication by a one-place number, combined with 1317 // a subtraction. 1318 bool isNeg = false; 1319 for (uint32_t i = 0; i < n; ++i) { 1320 uint64_t u_tmp = uint64_t(u[j+i]) | (uint64_t(u[j+i+1]) << 32); 1321 uint64_t subtrahend = uint64_t(qp) * uint64_t(v[i]); 1322 bool borrow = subtrahend > u_tmp; 1323 DEBUG(cerr << "KnuthDiv: u_tmp == " << u_tmp 1324 << ", subtrahend == " << subtrahend 1325 << ", borrow = " << borrow << '\n'); 1326 1327 uint64_t result = u_tmp - subtrahend; 1328 uint32_t k = j + i; 1329 u[k++] = result & (b-1); // subtract low word 1330 u[k++] = result >> 32; // subtract high word 1331 while (borrow && k <= m+n) { // deal with borrow to the left 1332 borrow = u[k] == 0; 1333 u[k]--; 1334 k++; 1335 } 1336 isNeg |= borrow; 1337 DEBUG(cerr << "KnuthDiv: u[j+i] == " << u[j+i] << ", u[j+i+1] == " << 1338 u[j+i+1] << '\n'); 1339 } 1340 DEBUG(cerr << "KnuthDiv: after subtraction:"); 1341 DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << u[i]); 1342 DEBUG(cerr << '\n'); 1343 // The digits (u[j+n]...u[j]) should be kept positive; if the result of 1344 // this step is actually negative, (u[j+n]...u[j]) should be left as the 1345 // true value plus b**(n+1), namely as the b's complement of 1346 // the true value, and a "borrow" to the left should be remembered. 1347 // 1348 if (isNeg) { 1349 bool carry = true; // true because b's complement is "complement + 1" 1350 for (uint32_t i = 0; i <= m+n; ++i) { 1351 u[i] = ~u[i] + carry; // b's complement 1352 carry = carry && u[i] == 0; 1353 } 1354 } 1355 DEBUG(cerr << "KnuthDiv: after complement:"); 1356 DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << u[i]); 1357 DEBUG(cerr << '\n'); 1358 1359 // D5. [Test remainder.] Set q[j] = qp. If the result of step D4 was 1360 // negative, go to step D6; otherwise go on to step D7. 1361 q[j] = qp; 1362 if (isNeg) { 1363 // D6. [Add back]. The probability that this step is necessary is very 1364 // small, on the order of only 2/b. Make sure that test data accounts for 1365 // this possibility. Decrease q[j] by 1 1366 q[j]--; 1367 // and add (0v[n-1]...v[1]v[0]) to (u[j+n]u[j+n-1]...u[j+1]u[j]). 1368 // A carry will occur to the left of u[j+n], and it should be ignored 1369 // since it cancels with the borrow that occurred in D4. 1370 bool carry = false; 1371 for (uint32_t i = 0; i < n; i++) { 1372 uint32_t limit = std::min(u[j+i],v[i]); 1373 u[j+i] += v[i] + carry; 1374 carry = u[j+i] < limit || (carry && u[j+i] == limit); 1375 } 1376 u[j+n] += carry; 1377 } 1378 DEBUG(cerr << "KnuthDiv: after correction:"); 1379 DEBUG(for (int i = m+n; i >=0; i--) cerr <<" " << u[i]); 1380 DEBUG(cerr << "\nKnuthDiv: digit result = " << q[j] << '\n'); 1381 1382 // D7. [Loop on j.] Decrease j by one. Now if j >= 0, go back to D3. 1383 } while (--j >= 0); 1384 1385 DEBUG(cerr << "KnuthDiv: quotient:"); 1386 DEBUG(for (int i = m; i >=0; i--) cerr <<" " << q[i]); 1387 DEBUG(cerr << '\n'); 1388 1389 // D8. [Unnormalize]. Now q[...] is the desired quotient, and the desired 1390 // remainder may be obtained by dividing u[...] by d. If r is non-null we 1391 // compute the remainder (urem uses this). 1392 if (r) { 1393 // The value d is expressed by the "shift" value above since we avoided 1394 // multiplication by d by using a shift left. So, all we have to do is 1395 // shift right here. In order to mak 1396 if (shift) { 1397 uint32_t carry = 0; 1398 DEBUG(cerr << "KnuthDiv: remainder:"); 1399 for (int i = n-1; i >= 0; i--) { 1400 r[i] = (u[i] >> shift) | carry; 1401 carry = u[i] << (32 - shift); 1402 DEBUG(cerr << " " << r[i]); 1403 } 1404 } else { 1405 for (int i = n-1; i >= 0; i--) { 1406 r[i] = u[i]; 1407 DEBUG(cerr << " " << r[i]); 1408 } 1409 } 1410 DEBUG(cerr << '\n'); 1411 } 1412 DEBUG(cerr << std::setbase(10) << '\n'); 1413} 1414 1415void APInt::divide(const APInt LHS, uint32_t lhsWords, 1416 const APInt &RHS, uint32_t rhsWords, 1417 APInt *Quotient, APInt *Remainder) 1418{ 1419 assert(lhsWords >= rhsWords && "Fractional result"); 1420 1421 // First, compose the values into an array of 32-bit words instead of 1422 // 64-bit words. This is a necessity of both the "short division" algorithm 1423 // and the the Knuth "classical algorithm" which requires there to be native 1424 // operations for +, -, and * on an m bit value with an m*2 bit result. We 1425 // can't use 64-bit operands here because we don't have native results of 1426 // 128-bits. Furthremore, casting the 64-bit values to 32-bit values won't 1427 // work on large-endian machines. 1428 uint64_t mask = ~0ull >> (sizeof(uint32_t)*8); 1429 uint32_t n = rhsWords * 2; 1430 uint32_t m = (lhsWords * 2) - n; 1431 1432 // Allocate space for the temporary values we need either on the stack, if 1433 // it will fit, or on the heap if it won't. 1434 uint32_t SPACE[128]; 1435 uint32_t *U = 0; 1436 uint32_t *V = 0; 1437 uint32_t *Q = 0; 1438 uint32_t *R = 0; 1439 if ((Remainder?4:3)*n+2*m+1 <= 128) { 1440 U = &SPACE[0]; 1441 V = &SPACE[m+n+1]; 1442 Q = &SPACE[(m+n+1) + n]; 1443 if (Remainder) 1444 R = &SPACE[(m+n+1) + n + (m+n)]; 1445 } else { 1446 U = new uint32_t[m + n + 1]; 1447 V = new uint32_t[n]; 1448 Q = new uint32_t[m+n]; 1449 if (Remainder) 1450 R = new uint32_t[n]; 1451 } 1452 1453 // Initialize the dividend 1454 memset(U, 0, (m+n+1)*sizeof(uint32_t)); 1455 for (unsigned i = 0; i < lhsWords; ++i) { 1456 uint64_t tmp = (LHS.getNumWords() == 1 ? LHS.VAL : LHS.pVal[i]); 1457 U[i * 2] = tmp & mask; 1458 U[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8); 1459 } 1460 U[m+n] = 0; // this extra word is for "spill" in the Knuth algorithm. 1461 1462 // Initialize the divisor 1463 memset(V, 0, (n)*sizeof(uint32_t)); 1464 for (unsigned i = 0; i < rhsWords; ++i) { 1465 uint64_t tmp = (RHS.getNumWords() == 1 ? RHS.VAL : RHS.pVal[i]); 1466 V[i * 2] = tmp & mask; 1467 V[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8); 1468 } 1469 1470 // initialize the quotient and remainder 1471 memset(Q, 0, (m+n) * sizeof(uint32_t)); 1472 if (Remainder) 1473 memset(R, 0, n * sizeof(uint32_t)); 1474 1475 // Now, adjust m and n for the Knuth division. n is the number of words in 1476 // the divisor. m is the number of words by which the dividend exceeds the 1477 // divisor (i.e. m+n is the length of the dividend). These sizes must not 1478 // contain any zero words or the Knuth algorithm fails. 1479 for (unsigned i = n; i > 0 && V[i-1] == 0; i--) { 1480 n--; 1481 m++; 1482 } 1483 for (unsigned i = m+n; i > 0 && U[i-1] == 0; i--) 1484 m--; 1485 1486 // If we're left with only a single word for the divisor, Knuth doesn't work 1487 // so we implement the short division algorithm here. This is much simpler 1488 // and faster because we are certain that we can divide a 64-bit quantity 1489 // by a 32-bit quantity at hardware speed and short division is simply a 1490 // series of such operations. This is just like doing short division but we 1491 // are using base 2^32 instead of base 10. 1492 assert(n != 0 && "Divide by zero?"); 1493 if (n == 1) { 1494 uint32_t divisor = V[0]; 1495 uint32_t remainder = 0; 1496 for (int i = m+n-1; i >= 0; i--) { 1497 uint64_t partial_dividend = uint64_t(remainder) << 32 | U[i]; 1498 if (partial_dividend == 0) { 1499 Q[i] = 0; 1500 remainder = 0; 1501 } else if (partial_dividend < divisor) { 1502 Q[i] = 0; 1503 remainder = partial_dividend; 1504 } else if (partial_dividend == divisor) { 1505 Q[i] = 1; 1506 remainder = 0; 1507 } else { 1508 Q[i] = partial_dividend / divisor; 1509 remainder = partial_dividend - (Q[i] * divisor); 1510 } 1511 } 1512 if (R) 1513 R[0] = remainder; 1514 } else { 1515 // Now we're ready to invoke the Knuth classical divide algorithm. In this 1516 // case n > 1. 1517 KnuthDiv(U, V, Q, R, m, n); 1518 } 1519 1520 // If the caller wants the quotient 1521 if (Quotient) { 1522 // Set up the Quotient value's memory. 1523 if (Quotient->BitWidth != LHS.BitWidth) { 1524 if (Quotient->isSingleWord()) 1525 Quotient->VAL = 0; 1526 else 1527 delete [] Quotient->pVal; 1528 Quotient->BitWidth = LHS.BitWidth; 1529 if (!Quotient->isSingleWord()) 1530 Quotient->pVal = getClearedMemory(Quotient->getNumWords()); 1531 } else 1532 Quotient->clear(); 1533 1534 // The quotient is in Q. Reconstitute the quotient into Quotient's low 1535 // order words. 1536 if (lhsWords == 1) { 1537 uint64_t tmp = 1538 uint64_t(Q[0]) | (uint64_t(Q[1]) << (APINT_BITS_PER_WORD / 2)); 1539 if (Quotient->isSingleWord()) 1540 Quotient->VAL = tmp; 1541 else 1542 Quotient->pVal[0] = tmp; 1543 } else { 1544 assert(!Quotient->isSingleWord() && "Quotient APInt not large enough"); 1545 for (unsigned i = 0; i < lhsWords; ++i) 1546 Quotient->pVal[i] = 1547 uint64_t(Q[i*2]) | (uint64_t(Q[i*2+1]) << (APINT_BITS_PER_WORD / 2)); 1548 } 1549 } 1550 1551 // If the caller wants the remainder 1552 if (Remainder) { 1553 // Set up the Remainder value's memory. 1554 if (Remainder->BitWidth != RHS.BitWidth) { 1555 if (Remainder->isSingleWord()) 1556 Remainder->VAL = 0; 1557 else 1558 delete [] Remainder->pVal; 1559 Remainder->BitWidth = RHS.BitWidth; 1560 if (!Remainder->isSingleWord()) 1561 Remainder->pVal = getClearedMemory(Remainder->getNumWords()); 1562 } else 1563 Remainder->clear(); 1564 1565 // The remainder is in R. Reconstitute the remainder into Remainder's low 1566 // order words. 1567 if (rhsWords == 1) { 1568 uint64_t tmp = 1569 uint64_t(R[0]) | (uint64_t(R[1]) << (APINT_BITS_PER_WORD / 2)); 1570 if (Remainder->isSingleWord()) 1571 Remainder->VAL = tmp; 1572 else 1573 Remainder->pVal[0] = tmp; 1574 } else { 1575 assert(!Remainder->isSingleWord() && "Remainder APInt not large enough"); 1576 for (unsigned i = 0; i < rhsWords; ++i) 1577 Remainder->pVal[i] = 1578 uint64_t(R[i*2]) | (uint64_t(R[i*2+1]) << (APINT_BITS_PER_WORD / 2)); 1579 } 1580 } 1581 1582 // Clean up the memory we allocated. 1583 if (U != &SPACE[0]) { 1584 delete [] U; 1585 delete [] V; 1586 delete [] Q; 1587 delete [] R; 1588 } 1589} 1590 1591APInt APInt::udiv(const APInt& RHS) const { 1592 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 1593 1594 // First, deal with the easy case 1595 if (isSingleWord()) { 1596 assert(RHS.VAL != 0 && "Divide by zero?"); 1597 return APInt(BitWidth, VAL / RHS.VAL); 1598 } 1599 1600 // Get some facts about the LHS and RHS number of bits and words 1601 uint32_t rhsBits = RHS.getActiveBits(); 1602 uint32_t rhsWords = !rhsBits ? 0 : (APInt::whichWord(rhsBits - 1) + 1); 1603 assert(rhsWords && "Divided by zero???"); 1604 uint32_t lhsBits = this->getActiveBits(); 1605 uint32_t lhsWords = !lhsBits ? 0 : (APInt::whichWord(lhsBits - 1) + 1); 1606 1607 // Deal with some degenerate cases 1608 if (!lhsWords) 1609 // 0 / X ===> 0 1610 return APInt(BitWidth, 0); 1611 else if (lhsWords < rhsWords || this->ult(RHS)) { 1612 // X / Y ===> 0, iff X < Y 1613 return APInt(BitWidth, 0); 1614 } else if (*this == RHS) { 1615 // X / X ===> 1 1616 return APInt(BitWidth, 1); 1617 } else if (lhsWords == 1 && rhsWords == 1) { 1618 // All high words are zero, just use native divide 1619 return APInt(BitWidth, this->pVal[0] / RHS.pVal[0]); 1620 } 1621 1622 // We have to compute it the hard way. Invoke the Knuth divide algorithm. 1623 APInt Quotient(1,0); // to hold result. 1624 divide(*this, lhsWords, RHS, rhsWords, &Quotient, 0); 1625 return Quotient; 1626} 1627 1628APInt APInt::urem(const APInt& RHS) const { 1629 assert(BitWidth == RHS.BitWidth && "Bit widths must be the same"); 1630 if (isSingleWord()) { 1631 assert(RHS.VAL != 0 && "Remainder by zero?"); 1632 return APInt(BitWidth, VAL % RHS.VAL); 1633 } 1634 1635 // Get some facts about the LHS 1636 uint32_t lhsBits = getActiveBits(); 1637 uint32_t lhsWords = !lhsBits ? 0 : (whichWord(lhsBits - 1) + 1); 1638 1639 // Get some facts about the RHS 1640 uint32_t rhsBits = RHS.getActiveBits(); 1641 uint32_t rhsWords = !rhsBits ? 0 : (APInt::whichWord(rhsBits - 1) + 1); 1642 assert(rhsWords && "Performing remainder operation by zero ???"); 1643 1644 // Check the degenerate cases 1645 if (lhsWords == 0) { 1646 // 0 % Y ===> 0 1647 return APInt(BitWidth, 0); 1648 } else if (lhsWords < rhsWords || this->ult(RHS)) { 1649 // X % Y ===> X, iff X < Y 1650 return *this; 1651 } else if (*this == RHS) { 1652 // X % X == 0; 1653 return APInt(BitWidth, 0); 1654 } else if (lhsWords == 1) { 1655 // All high words are zero, just use native remainder 1656 return APInt(BitWidth, pVal[0] % RHS.pVal[0]); 1657 } 1658 1659 // We have to compute it the hard way. Invoke the Knute divide algorithm. 1660 APInt Remainder(1,0); 1661 divide(*this, lhsWords, RHS, rhsWords, 0, &Remainder); 1662 return Remainder; 1663} 1664 1665void APInt::fromString(uint32_t numbits, const char *str, uint32_t slen, 1666 uint8_t radix) { 1667 // Check our assumptions here 1668 assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) && 1669 "Radix should be 2, 8, 10, or 16!"); 1670 assert(str && "String is null?"); 1671 bool isNeg = str[0] == '-'; 1672 if (isNeg) 1673 str++, slen--; 1674 assert(slen <= numbits || radix != 2 && "Insufficient bit width"); 1675 assert(slen*3 <= numbits || radix != 8 && "Insufficient bit width"); 1676 assert(slen*4 <= numbits || radix != 16 && "Insufficient bit width"); 1677 assert((slen*64)/20 <= numbits || radix != 10 && "Insufficient bit width"); 1678 1679 // Allocate memory 1680 if (!isSingleWord()) 1681 pVal = getClearedMemory(getNumWords()); 1682 1683 // Figure out if we can shift instead of multiply 1684 uint32_t shift = (radix == 16 ? 4 : radix == 8 ? 3 : radix == 2 ? 1 : 0); 1685 1686 // Set up an APInt for the digit to add outside the loop so we don't 1687 // constantly construct/destruct it. 1688 APInt apdigit(getBitWidth(), 0); 1689 APInt apradix(getBitWidth(), radix); 1690 1691 // Enter digit traversal loop 1692 for (unsigned i = 0; i < slen; i++) { 1693 // Get a digit 1694 uint32_t digit = 0; 1695 char cdigit = str[i]; 1696 if (isdigit(cdigit)) 1697 digit = cdigit - '0'; 1698 else if (isxdigit(cdigit)) 1699 if (cdigit >= 'a') 1700 digit = cdigit - 'a' + 10; 1701 else if (cdigit >= 'A') 1702 digit = cdigit - 'A' + 10; 1703 else 1704 assert(0 && "huh?"); 1705 else 1706 assert(0 && "Invalid character in digit string"); 1707 1708 // Shift or multiple the value by the radix 1709 if (shift) 1710 this->shl(shift); 1711 else 1712 *this *= apradix; 1713 1714 // Add in the digit we just interpreted 1715 if (apdigit.isSingleWord()) 1716 apdigit.VAL = digit; 1717 else 1718 apdigit.pVal[0] = digit; 1719 *this += apdigit; 1720 } 1721 // If its negative, put it in two's complement form 1722 if (isNeg) { 1723 (*this)--; 1724 this->flip(); 1725 } 1726} 1727 1728std::string APInt::toString(uint8_t radix, bool wantSigned) const { 1729 assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) && 1730 "Radix should be 2, 8, 10, or 16!"); 1731 static const char *digits[] = { 1732 "0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F" 1733 }; 1734 std::string result; 1735 uint32_t bits_used = getActiveBits(); 1736 if (isSingleWord()) { 1737 char buf[65]; 1738 const char *format = (radix == 10 ? (wantSigned ? "%lld" : "%llu") : 1739 (radix == 16 ? "%llX" : (radix == 8 ? "%llo" : 0))); 1740 if (format) { 1741 if (wantSigned) { 1742 int64_t sextVal = (int64_t(VAL) << (APINT_BITS_PER_WORD-BitWidth)) >> 1743 (APINT_BITS_PER_WORD-BitWidth); 1744 sprintf(buf, format, sextVal); 1745 } else 1746 sprintf(buf, format, VAL); 1747 } else { 1748 memset(buf, 0, 65); 1749 uint64_t v = VAL; 1750 while (bits_used) { 1751 uint32_t bit = v & 1; 1752 bits_used--; 1753 buf[bits_used] = digits[bit][0]; 1754 v >>=1; 1755 } 1756 } 1757 result = buf; 1758 return result; 1759 } 1760 1761 if (radix != 10) { 1762 uint64_t mask = radix - 1; 1763 uint32_t shift = (radix == 16 ? 4 : radix == 8 ? 3 : 1); 1764 uint32_t nibbles = APINT_BITS_PER_WORD / shift; 1765 for (uint32_t i = 0; i < getNumWords(); ++i) { 1766 uint64_t value = pVal[i]; 1767 for (uint32_t j = 0; j < nibbles; ++j) { 1768 result.insert(0, digits[ value & mask ]); 1769 value >>= shift; 1770 } 1771 } 1772 return result; 1773 } 1774 1775 APInt tmp(*this); 1776 APInt divisor(4, radix); 1777 APInt zero(tmp.getBitWidth(), 0); 1778 size_t insert_at = 0; 1779 if (wantSigned && tmp[BitWidth-1]) { 1780 // They want to print the signed version and it is a negative value 1781 // Flip the bits and add one to turn it into the equivalent positive 1782 // value and put a '-' in the result. 1783 tmp.flip(); 1784 tmp++; 1785 result = "-"; 1786 insert_at = 1; 1787 } 1788 if (tmp == APInt(tmp.getBitWidth(), 0)) 1789 result = "0"; 1790 else while (tmp.ne(zero)) { 1791 APInt APdigit(1,0); 1792 APInt tmp2(tmp.getBitWidth(), 0); 1793 divide(tmp, tmp.getNumWords(), divisor, divisor.getNumWords(), &tmp2, 1794 &APdigit); 1795 uint32_t digit = APdigit.getZExtValue(); 1796 assert(digit < radix && "divide failed"); 1797 result.insert(insert_at,digits[digit]); 1798 tmp = tmp2; 1799 } 1800 1801 return result; 1802} 1803 1804#ifndef NDEBUG 1805void APInt::dump() const 1806{ 1807 cerr << "APInt(" << BitWidth << ")=" << std::setbase(16); 1808 if (isSingleWord()) 1809 cerr << VAL; 1810 else for (unsigned i = getNumWords(); i > 0; i--) { 1811 cerr << pVal[i-1] << " "; 1812 } 1813 cerr << " U(" << this->toString(10) << ") S(" << this->toStringSigned(10) 1814 << ")\n" << std::setbase(10); 1815} 1816#endif 1817