X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FAPInt.cpp;h=23f89bb66f9e562204cd136d5ed21c9ad5f414a4;hb=c0d892732d3b19af18a1dda15dd3aaa65ddddcd4;hp=02778b2fc7c799510001d477db1d9d8fbd4615fe;hpb=c67df0c462db55a7fcac0361ed084a907d6df59c;p=oota-llvm.git diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp index 02778b2fc7c..23f89bb66f9 100644 --- a/lib/Support/APInt.cpp +++ b/lib/Support/APInt.cpp @@ -162,7 +162,7 @@ APInt& APInt::operator=(uint64_t RHS) { return clearUnusedBits(); } -/// Profile - This method 'profiles' an APInt for use with FoldingSet. +/// This method 'profiles' an APInt for use with FoldingSet. void APInt::Profile(FoldingSetNodeID& ID) const { ID.AddInteger(BitWidth); @@ -176,7 +176,7 @@ void APInt::Profile(FoldingSetNodeID& ID) const { ID.AddInteger(pVal[i]); } -/// add_1 - This function adds a single "digit" integer, y, to the multiple +/// This function adds a single "digit" integer, y, to the multiple /// "digit" integer array, x[]. x[] is modified to reflect the addition and /// 1 is returned if there is a carry out, otherwise 0 is returned. /// @returns the carry of the addition. @@ -202,7 +202,7 @@ APInt& APInt::operator++() { return clearUnusedBits(); } -/// sub_1 - This function subtracts a single "digit" (64-bit word), y, from +/// This function subtracts a single "digit" (64-bit word), y, from /// the multi-digit integer array, x[], propagating the borrowed 1 value until /// no further borrowing is neeeded or it runs out of "digits" in x. The result /// is 1 if "borrowing" exhausted the digits in x, or 0 if x was not exhausted. @@ -231,7 +231,7 @@ APInt& APInt::operator--() { return clearUnusedBits(); } -/// add - This function adds the integer array x to the integer array Y and +/// This function adds the integer array x to the integer array Y and /// places the result in dest. /// @returns the carry out from the addition /// @brief General addition of 64-bit integer arrays @@ -672,12 +672,20 @@ hash_code llvm::hash_value(const APInt &Arg) { return hash_combine_range(Arg.pVal, Arg.pVal + Arg.getNumWords()); } -/// HiBits - This function returns the high "numBits" bits of this APInt. +bool APInt::isSplat(unsigned SplatSizeInBits) const { + assert(getBitWidth() % SplatSizeInBits == 0 && + "SplatSizeInBits must divide width!"); + // We can check that all parts of an integer are equal by making use of a + // little trick: rotate and check if it's still the same value. + return *this == rotl(SplatSizeInBits); +} + +/// This function returns the high "numBits" bits of this APInt. APInt APInt::getHiBits(unsigned numBits) const { return APIntOps::lshr(*this, BitWidth - numBits); } -/// LoBits - This function returns the low "numBits" bits of this APInt. +/// This function returns the low "numBits" bits of this APInt. APInt APInt::getLoBits(unsigned numBits) const { return APIntOps::lshr(APIntOps::shl(*this, BitWidth - numBits), BitWidth - numBits); @@ -713,7 +721,7 @@ unsigned APInt::countLeadingZerosSlowCase() const { unsigned APInt::countLeadingOnes() const { if (isSingleWord()) - return CountLeadingOnes_64(VAL << (APINT_BITS_PER_WORD - BitWidth)); + return llvm::countLeadingOnes(VAL << (APINT_BITS_PER_WORD - BitWidth)); unsigned highWordBits = BitWidth % APINT_BITS_PER_WORD; unsigned shift; @@ -724,13 +732,13 @@ unsigned APInt::countLeadingOnes() const { shift = APINT_BITS_PER_WORD - highWordBits; } int i = getNumWords() - 1; - unsigned Count = CountLeadingOnes_64(pVal[i] << shift); + unsigned Count = llvm::countLeadingOnes(pVal[i] << shift); if (Count == highWordBits) { for (i--; i >= 0; --i) { if (pVal[i] == -1ULL) Count += APINT_BITS_PER_WORD; else { - Count += CountLeadingOnes_64(pVal[i]); + Count += llvm::countLeadingOnes(pVal[i]); break; } } @@ -756,14 +764,14 @@ unsigned APInt::countTrailingOnesSlowCase() const { for (; i < getNumWords() && pVal[i] == -1ULL; ++i) Count += APINT_BITS_PER_WORD; if (i < getNumWords()) - Count += CountTrailingOnes_64(pVal[i]); + Count += llvm::countTrailingOnes(pVal[i]); return std::min(Count, BitWidth); } unsigned APInt::countPopulationSlowCase() const { unsigned Count = 0; for (unsigned i = 0; i < getNumWords(); ++i) - Count += CountPopulation_64(pVal[i]); + Count += llvm::countPopulation(pVal[i]); return Count; } @@ -853,7 +861,7 @@ APInt llvm::APIntOps::RoundDoubleToAPInt(double Double, unsigned width) { return isNeg ? -Tmp : Tmp; } -/// RoundToDouble - This function converts this APInt to a double. +/// This function converts this APInt to a double. /// The layout for double is as following (IEEE Standard 754): /// -------------------------------------- /// | Sign Exponent Fraction Bias | @@ -1310,13 +1318,8 @@ APInt APInt::sqrt() const { // libc sqrt function which will probably use a hardware sqrt computation. // This should be faster than the algorithm below. if (magnitude < 52) { -#if HAVE_ROUND return APInt(BitWidth, uint64_t(::round(::sqrt(double(isSingleWord()?VAL:pVal[0]))))); -#else - return APInt(BitWidth, - uint64_t(::sqrt(double(isSingleWord()?VAL:pVal[0])) + 0.5)); -#endif } // Okay, all the short cuts are exhausted. We must compute it. The following @@ -1508,21 +1511,18 @@ static void KnuthDiv(unsigned *u, unsigned *v, unsigned *q, unsigned* r, assert(u && "Must provide dividend"); assert(v && "Must provide divisor"); assert(q && "Must provide quotient"); - assert(u != v && u != q && v != q && "Must us different memory"); + assert(u != v && u != q && v != q && "Must use different memory"); assert(n>1 && "n must be > 1"); - // Knuth uses the value b as the base of the number system. In our case b - // is 2^31 so we just set it to -1u. - uint64_t b = uint64_t(1) << 32; + // b denotes the base of the number system. In our case b is 2^32. + LLVM_CONSTEXPR uint64_t b = uint64_t(1) << 32; -#if 0 DEBUG(dbgs() << "KnuthDiv: m=" << m << " n=" << n << '\n'); DEBUG(dbgs() << "KnuthDiv: original:"); DEBUG(for (int i = m+n; i >=0; i--) dbgs() << " " << u[i]); DEBUG(dbgs() << " by"); DEBUG(for (int i = n; i >0; i--) dbgs() << " " << v[i-1]); DEBUG(dbgs() << '\n'); -#endif // D1. [Normalize.] Set d = b / (v[n-1] + 1) and multiply all the digits of // u and v by d. Note that we have taken Knuth's advice here to use a power // of 2 value for d such that d * v[n-1] >= b/2 (b is the base). A power of @@ -1547,13 +1547,12 @@ static void KnuthDiv(unsigned *u, unsigned *v, unsigned *q, unsigned* r, } } u[m+n] = u_carry; -#if 0 + DEBUG(dbgs() << "KnuthDiv: normal:"); DEBUG(for (int i = m+n; i >=0; i--) dbgs() << " " << u[i]); DEBUG(dbgs() << " by"); DEBUG(for (int i = n; i >0; i--) dbgs() << " " << v[i-1]); DEBUG(dbgs() << '\n'); -#endif // D2. [Initialize j.] Set j to m. This is the loop counter over the places. int j = m; @@ -1583,44 +1582,23 @@ static void KnuthDiv(unsigned *u, unsigned *v, unsigned *q, unsigned* r, // (u[j+n]u[j+n-1]..u[j]) - qp * (v[n-1]...v[1]v[0]). This computation // consists of a simple multiplication by a one-place number, combined with // a subtraction. - bool isNeg = false; - for (unsigned i = 0; i < n; ++i) { - uint64_t u_tmp = uint64_t(u[j+i]) | (uint64_t(u[j+i+1]) << 32); - uint64_t subtrahend = uint64_t(qp) * uint64_t(v[i]); - bool borrow = subtrahend > u_tmp; - DEBUG(dbgs() << "KnuthDiv: u_tmp == " << u_tmp - << ", subtrahend == " << subtrahend - << ", borrow = " << borrow << '\n'); - - uint64_t result = u_tmp - subtrahend; - unsigned k = j + i; - u[k++] = (unsigned)(result & (b-1)); // subtract low word - u[k++] = (unsigned)(result >> 32); // subtract high word - while (borrow && k <= m+n) { // deal with borrow to the left - borrow = u[k] == 0; - u[k]--; - k++; - } - isNeg |= borrow; - DEBUG(dbgs() << "KnuthDiv: u[j+i] == " << u[j+i] << ", u[j+i+1] == " << - u[j+i+1] << '\n'); - } - DEBUG(dbgs() << "KnuthDiv: after subtraction:"); - DEBUG(for (int i = m+n; i >=0; i--) dbgs() << " " << u[i]); - DEBUG(dbgs() << '\n'); // The digits (u[j+n]...u[j]) should be kept positive; if the result of // this step is actually negative, (u[j+n]...u[j]) should be left as the // true value plus b**(n+1), namely as the b's complement of // the true value, and a "borrow" to the left should be remembered. - // - if (isNeg) { - bool carry = true; // true because b's complement is "complement + 1" - for (unsigned i = 0; i <= m+n; ++i) { - u[i] = ~u[i] + carry; // b's complement - carry = carry && u[i] == 0; - } + int64_t borrow = 0; + for (unsigned i = 0; i < n; ++i) { + uint64_t p = uint64_t(qp) * uint64_t(v[i]); + int64_t subres = int64_t(u[j+i]) - borrow - (unsigned)p; + u[j+i] = (unsigned)subres; + borrow = (p >> 32) - (subres >> 32); + DEBUG(dbgs() << "KnuthDiv: u[j+i] = " << u[j+i] + << ", borrow = " << borrow << '\n'); } - DEBUG(dbgs() << "KnuthDiv: after complement:"); + bool isNeg = u[j+n] < borrow; + u[j+n] -= (unsigned)borrow; + + DEBUG(dbgs() << "KnuthDiv: after subtraction:"); DEBUG(for (int i = m+n; i >=0; i--) dbgs() << " " << u[i]); DEBUG(dbgs() << '\n'); @@ -1644,7 +1622,7 @@ static void KnuthDiv(unsigned *u, unsigned *v, unsigned *q, unsigned* r, u[j+n] += carry; } DEBUG(dbgs() << "KnuthDiv: after correction:"); - DEBUG(for (int i = m+n; i >=0; i--) dbgs() <<" " << u[i]); + DEBUG(for (int i = m+n; i >=0; i--) dbgs() << " " << u[i]); DEBUG(dbgs() << "\nKnuthDiv: digit result = " << q[j] << '\n'); // D7. [Loop on j.] Decrease j by one. Now if j >= 0, go back to D3. @@ -1677,9 +1655,7 @@ static void KnuthDiv(unsigned *u, unsigned *v, unsigned *q, unsigned* r, } DEBUG(dbgs() << '\n'); } -#if 0 DEBUG(dbgs() << '\n'); -#endif } void APInt::divide(const APInt LHS, unsigned lhsWords, @@ -1803,6 +1779,8 @@ void APInt::divide(const APInt LHS, unsigned lhsWords, // The quotient is in Q. Reconstitute the quotient into Quotient's low // order words. + // This case is currently dead as all users of divide() handle trivial cases + // earlier. if (lhsWords == 1) { uint64_t tmp = uint64_t(Q[0]) | (uint64_t(Q[1]) << (APINT_BITS_PER_WORD / 2)); @@ -1956,6 +1934,18 @@ APInt APInt::srem(const APInt &RHS) const { void APInt::udivrem(const APInt &LHS, const APInt &RHS, APInt &Quotient, APInt &Remainder) { + assert(LHS.BitWidth == RHS.BitWidth && "Bit widths must be the same"); + + // First, deal with the easy case + if (LHS.isSingleWord()) { + assert(RHS.VAL != 0 && "Divide by zero?"); + uint64_t QuotVal = LHS.VAL / RHS.VAL; + uint64_t RemVal = LHS.VAL % RHS.VAL; + Quotient = APInt(LHS.BitWidth, QuotVal); + Remainder = APInt(LHS.BitWidth, RemVal); + return; + } + // Get some size facts about the dividend and divisor unsigned lhsBits = LHS.getActiveBits(); unsigned lhsWords = !lhsBits ? 0 : (APInt::whichWord(lhsBits - 1) + 1); @@ -2064,19 +2054,29 @@ APInt APInt::umul_ov(const APInt &RHS, bool &Overflow) const { return Res; } -APInt APInt::sshl_ov(unsigned ShAmt, bool &Overflow) const { - Overflow = ShAmt >= getBitWidth(); +APInt APInt::sshl_ov(const APInt &ShAmt, bool &Overflow) const { + Overflow = ShAmt.uge(getBitWidth()); if (Overflow) - ShAmt = getBitWidth()-1; + return APInt(BitWidth, 0); if (isNonNegative()) // Don't allow sign change. - Overflow = ShAmt >= countLeadingZeros(); + Overflow = ShAmt.uge(countLeadingZeros()); else - Overflow = ShAmt >= countLeadingOnes(); + Overflow = ShAmt.uge(countLeadingOnes()); return *this << ShAmt; } +APInt APInt::ushl_ov(const APInt &ShAmt, bool &Overflow) const { + Overflow = ShAmt.uge(getBitWidth()); + if (Overflow) + return APInt(BitWidth, 0); + + Overflow = ShAmt.ugt(countLeadingZeros()); + + return *this << ShAmt; +} + @@ -2259,9 +2259,8 @@ void APInt::toString(SmallVectorImpl &Str, unsigned Radix, std::reverse(Str.begin()+StartDig, Str.end()); } -/// toString - This returns the APInt as a std::string. Note that this is an -/// inefficient method. It is better to pass in a SmallVector/SmallString -/// to the methods above. +/// Returns the APInt as a std::string. Note that this is an inefficient method. +/// It is better to pass in a SmallVector/SmallString to the methods above. std::string APInt::toString(unsigned Radix = 10, bool Signed = true) const { SmallString<40> S; toString(S, Radix, Signed, /* formatAsCLiteral = */false); @@ -2274,13 +2273,13 @@ void APInt::dump() const { this->toStringUnsigned(U); this->toStringSigned(S); dbgs() << "APInt(" << BitWidth << "b, " - << U.str() << "u " << S.str() << "s)"; + << U << "u " << S << "s)"; } void APInt::print(raw_ostream &OS, bool isSigned) const { SmallString<40> S; this->toString(S, 10, isSigned, /* formatAsCLiteral = */false); - OS << S.str(); + OS << S; } // This implements a variety of operations on a representation of