Integrate llvm BitVector and MathExtras

This commit is contained in:
Jack Andersen 2016-12-09 16:32:20 -10:00
parent d42cf00a01
commit b12b858f3d
4 changed files with 1470 additions and 1 deletions

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hecl/extern/boo vendored

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Subproject commit 4c0c01f84f530cfbd6752d0047a6455e8d1886c4 Subproject commit fa45c6750a0d9d876341017a7e2b4915afa90369

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//===- llvm/ADT/BitVector.h - Bit vectors -----------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the BitVector class.
//
//===----------------------------------------------------------------------===//
#ifndef HECL_LLVM_ADT_BITVECTOR_H
#define HECL_LLVM_ADT_BITVECTOR_H
#include "MathExtras.hpp"
#include <algorithm>
#include <cassert>
#include <climits>
#include <cstdint>
#include <cstdlib>
#include <cstring>
namespace hecl {
namespace llvm {
class BitVector {
typedef unsigned long BitWord;
enum { BITWORD_SIZE = (unsigned)sizeof(BitWord) * CHAR_BIT };
static_assert(BITWORD_SIZE == 64 || BITWORD_SIZE == 32,
"Unsupported word size");
BitWord *Bits; // Actual bits.
unsigned Size; // Size of bitvector in bits.
unsigned Capacity; // Number of BitWords allocated in the Bits array.
public:
typedef unsigned size_type;
// Encapsulation of a single bit.
class reference {
friend class BitVector;
BitWord *WordRef;
unsigned BitPos;
reference(); // Undefined
public:
reference(BitVector &b, unsigned Idx) {
WordRef = &b.Bits[Idx / BITWORD_SIZE];
BitPos = Idx % BITWORD_SIZE;
}
reference(const reference&) = default;
reference &operator=(reference t) {
*this = bool(t);
return *this;
}
reference& operator=(bool t) {
if (t)
*WordRef |= BitWord(1) << BitPos;
else
*WordRef &= ~(BitWord(1) << BitPos);
return *this;
}
operator bool() const {
return ((*WordRef) & (BitWord(1) << BitPos)) != 0;
}
};
/// BitVector default ctor - Creates an empty bitvector.
BitVector() : Size(0), Capacity(0) {
Bits = nullptr;
}
/// BitVector ctor - Creates a bitvector of specified number of bits. All
/// bits are initialized to the specified value.
explicit BitVector(unsigned s, bool t = false) : Size(s) {
Capacity = NumBitWords(s);
Bits = (BitWord *)std::malloc(Capacity * sizeof(BitWord));
init_words(Bits, Capacity, t);
if (t)
clear_unused_bits();
}
/// BitVector copy ctor.
BitVector(const BitVector &RHS) : Size(RHS.size()) {
if (Size == 0) {
Bits = nullptr;
Capacity = 0;
return;
}
Capacity = NumBitWords(RHS.size());
Bits = (BitWord *)std::malloc(Capacity * sizeof(BitWord));
std::memcpy(Bits, RHS.Bits, Capacity * sizeof(BitWord));
}
BitVector(BitVector &&RHS)
: Bits(RHS.Bits), Size(RHS.Size), Capacity(RHS.Capacity) {
RHS.Bits = nullptr;
RHS.Size = RHS.Capacity = 0;
}
~BitVector() {
std::free(Bits);
}
/// empty - Tests whether there are no bits in this bitvector.
bool empty() const { return Size == 0; }
/// size - Returns the number of bits in this bitvector.
size_type size() const { return Size; }
/// count - Returns the number of bits which are set.
size_type count() const {
unsigned NumBits = 0;
for (unsigned i = 0; i < NumBitWords(size()); ++i)
NumBits += countPopulation(Bits[i]);
return NumBits;
}
/// any - Returns true if any bit is set.
bool any() const {
for (unsigned i = 0; i < NumBitWords(size()); ++i)
if (Bits[i] != 0)
return true;
return false;
}
/// all - Returns true if all bits are set.
bool all() const {
for (unsigned i = 0; i < Size / BITWORD_SIZE; ++i)
if (Bits[i] != ~0UL)
return false;
// If bits remain check that they are ones. The unused bits are always zero.
if (unsigned Remainder = Size % BITWORD_SIZE)
return Bits[Size / BITWORD_SIZE] == (1UL << Remainder) - 1;
return true;
}
/// none - Returns true if none of the bits are set.
bool none() const {
return !any();
}
/// find_first - Returns the index of the first set bit, -1 if none
/// of the bits are set.
int find_first() const {
for (unsigned i = 0; i < NumBitWords(size()); ++i)
if (Bits[i] != 0)
return i * BITWORD_SIZE + countTrailingZeros(Bits[i]);
return -1;
}
/// find_next - Returns the index of the next set bit following the
/// "Prev" bit. Returns -1 if the next set bit is not found.
int find_next(unsigned Prev) const {
++Prev;
if (Prev >= Size)
return -1;
unsigned WordPos = Prev / BITWORD_SIZE;
unsigned BitPos = Prev % BITWORD_SIZE;
BitWord Copy = Bits[WordPos];
// Mask off previous bits.
Copy &= ~0UL << BitPos;
if (Copy != 0)
return WordPos * BITWORD_SIZE + countTrailingZeros(Copy);
// Check subsequent words.
for (unsigned i = WordPos+1; i < NumBitWords(size()); ++i)
if (Bits[i] != 0)
return i * BITWORD_SIZE + countTrailingZeros(Bits[i]);
return -1;
}
/// find_first_contiguous - Returns the index of the first contiguous
/// set of bits of "Length", -1 if no contiguous bits found.
int find_first_contiguous(unsigned Length) const {
for (int idx = find_first(); idx != -1; idx = find_next(idx)) {
if (idx + Length > size())
return -1;
bool good = true;
for (int i = 0; i < Length; ++i) {
int ThisIdx = idx + i;
if (!test(ThisIdx)) {
good = false;
idx = ThisIdx;
break;
}
}
if (good)
return idx;
}
return -1;
}
/// clear - Clear all bits.
void clear() {
Size = 0;
}
/// resize - Grow or shrink the bitvector.
void resize(unsigned N, bool t = false) {
if (N > Capacity * BITWORD_SIZE) {
unsigned OldCapacity = Capacity;
grow(N);
init_words(&Bits[OldCapacity], (Capacity-OldCapacity), t);
}
// Set any old unused bits that are now included in the BitVector. This
// may set bits that are not included in the new vector, but we will clear
// them back out below.
if (N > Size)
set_unused_bits(t);
// Update the size, and clear out any bits that are now unused
unsigned OldSize = Size;
Size = N;
if (t || N < OldSize)
clear_unused_bits();
}
void reserve(unsigned N) {
if (N > Capacity * BITWORD_SIZE)
grow(N);
}
// Set, reset, flip
BitVector &set() {
init_words(Bits, Capacity, true);
clear_unused_bits();
return *this;
}
BitVector &set(unsigned Idx) {
assert(Bits && "Bits never allocated");
Bits[Idx / BITWORD_SIZE] |= BitWord(1) << (Idx % BITWORD_SIZE);
return *this;
}
/// set - Efficiently set a range of bits in [I, E)
BitVector &set(unsigned I, unsigned E) {
assert(I <= E && "Attempted to set backwards range!");
assert(E <= size() && "Attempted to set out-of-bounds range!");
if (I == E) return *this;
if (I / BITWORD_SIZE == E / BITWORD_SIZE) {
BitWord EMask = 1UL << (E % BITWORD_SIZE);
BitWord IMask = 1UL << (I % BITWORD_SIZE);
BitWord Mask = EMask - IMask;
Bits[I / BITWORD_SIZE] |= Mask;
return *this;
}
BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE);
Bits[I / BITWORD_SIZE] |= PrefixMask;
I = alignTo(I, BITWORD_SIZE);
for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE)
Bits[I / BITWORD_SIZE] = ~0UL;
BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;
if (I < E)
Bits[I / BITWORD_SIZE] |= PostfixMask;
return *this;
}
BitVector &reset() {
init_words(Bits, Capacity, false);
return *this;
}
BitVector &reset(unsigned Idx) {
Bits[Idx / BITWORD_SIZE] &= ~(BitWord(1) << (Idx % BITWORD_SIZE));
return *this;
}
/// reset - Efficiently reset a range of bits in [I, E)
BitVector &reset(unsigned I, unsigned E) {
assert(I <= E && "Attempted to reset backwards range!");
assert(E <= size() && "Attempted to reset out-of-bounds range!");
if (I == E) return *this;
if (I / BITWORD_SIZE == E / BITWORD_SIZE) {
BitWord EMask = 1UL << (E % BITWORD_SIZE);
BitWord IMask = 1UL << (I % BITWORD_SIZE);
BitWord Mask = EMask - IMask;
Bits[I / BITWORD_SIZE] &= ~Mask;
return *this;
}
BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE);
Bits[I / BITWORD_SIZE] &= ~PrefixMask;
I = alignTo(I, BITWORD_SIZE);
for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE)
Bits[I / BITWORD_SIZE] = 0UL;
BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;
if (I < E)
Bits[I / BITWORD_SIZE] &= ~PostfixMask;
return *this;
}
BitVector &flip() {
for (unsigned i = 0; i < NumBitWords(size()); ++i)
Bits[i] = ~Bits[i];
clear_unused_bits();
return *this;
}
BitVector &flip(unsigned Idx) {
Bits[Idx / BITWORD_SIZE] ^= BitWord(1) << (Idx % BITWORD_SIZE);
return *this;
}
// Indexing.
reference operator[](unsigned Idx) {
assert (Idx < Size && "Out-of-bounds Bit access.");
return reference(*this, Idx);
}
bool operator[](unsigned Idx) const {
assert (Idx < Size && "Out-of-bounds Bit access.");
BitWord Mask = BitWord(1) << (Idx % BITWORD_SIZE);
return (Bits[Idx / BITWORD_SIZE] & Mask) != 0;
}
bool test(unsigned Idx) const {
return (*this)[Idx];
}
/// Test if any common bits are set.
bool anyCommon(const BitVector &RHS) const {
unsigned ThisWords = NumBitWords(size());
unsigned RHSWords = NumBitWords(RHS.size());
for (unsigned i = 0, e = std::min(ThisWords, RHSWords); i != e; ++i)
if (Bits[i] & RHS.Bits[i])
return true;
return false;
}
// Comparison operators.
bool operator==(const BitVector &RHS) const {
unsigned ThisWords = NumBitWords(size());
unsigned RHSWords = NumBitWords(RHS.size());
unsigned i;
for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
if (Bits[i] != RHS.Bits[i])
return false;
// Verify that any extra words are all zeros.
if (i != ThisWords) {
for (; i != ThisWords; ++i)
if (Bits[i])
return false;
} else if (i != RHSWords) {
for (; i != RHSWords; ++i)
if (RHS.Bits[i])
return false;
}
return true;
}
bool operator!=(const BitVector &RHS) const {
return !(*this == RHS);
}
/// Intersection, union, disjoint union.
BitVector &operator&=(const BitVector &RHS) {
unsigned ThisWords = NumBitWords(size());
unsigned RHSWords = NumBitWords(RHS.size());
unsigned i;
for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
Bits[i] &= RHS.Bits[i];
// Any bits that are just in this bitvector become zero, because they aren't
// in the RHS bit vector. Any words only in RHS are ignored because they
// are already zero in the LHS.
for (; i != ThisWords; ++i)
Bits[i] = 0;
return *this;
}
/// reset - Reset bits that are set in RHS. Same as *this &= ~RHS.
BitVector &reset(const BitVector &RHS) {
unsigned ThisWords = NumBitWords(size());
unsigned RHSWords = NumBitWords(RHS.size());
unsigned i;
for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
Bits[i] &= ~RHS.Bits[i];
return *this;
}
/// test - Check if (This - RHS) is zero.
/// This is the same as reset(RHS) and any().
bool test(const BitVector &RHS) const {
unsigned ThisWords = NumBitWords(size());
unsigned RHSWords = NumBitWords(RHS.size());
unsigned i;
for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
if ((Bits[i] & ~RHS.Bits[i]) != 0)
return true;
for (; i != ThisWords ; ++i)
if (Bits[i] != 0)
return true;
return false;
}
BitVector &operator|=(const BitVector &RHS) {
if (size() < RHS.size())
resize(RHS.size());
for (size_t i = 0, e = NumBitWords(RHS.size()); i != e; ++i)
Bits[i] |= RHS.Bits[i];
return *this;
}
BitVector &operator^=(const BitVector &RHS) {
if (size() < RHS.size())
resize(RHS.size());
for (size_t i = 0, e = NumBitWords(RHS.size()); i != e; ++i)
Bits[i] ^= RHS.Bits[i];
return *this;
}
// Assignment operator.
const BitVector &operator=(const BitVector &RHS) {
if (this == &RHS) return *this;
Size = RHS.size();
unsigned RHSWords = NumBitWords(Size);
if (Size <= Capacity * BITWORD_SIZE) {
if (Size)
std::memcpy(Bits, RHS.Bits, RHSWords * sizeof(BitWord));
clear_unused_bits();
return *this;
}
// Grow the bitvector to have enough elements.
Capacity = RHSWords;
assert(Capacity > 0 && "negative capacity?");
BitWord *NewBits = (BitWord *)std::malloc(Capacity * sizeof(BitWord));
std::memcpy(NewBits, RHS.Bits, Capacity * sizeof(BitWord));
// Destroy the old bits.
std::free(Bits);
Bits = NewBits;
return *this;
}
const BitVector &operator=(BitVector &&RHS) {
if (this == &RHS) return *this;
std::free(Bits);
Bits = RHS.Bits;
Size = RHS.Size;
Capacity = RHS.Capacity;
RHS.Bits = nullptr;
RHS.Size = RHS.Capacity = 0;
return *this;
}
void swap(BitVector &RHS) {
std::swap(Bits, RHS.Bits);
std::swap(Size, RHS.Size);
std::swap(Capacity, RHS.Capacity);
}
//===--------------------------------------------------------------------===//
// Portable bit mask operations.
//===--------------------------------------------------------------------===//
//
// These methods all operate on arrays of uint32_t, each holding 32 bits. The
// fixed word size makes it easier to work with literal bit vector constants
// in portable code.
//
// The LSB in each word is the lowest numbered bit. The size of a portable
// bit mask is always a whole multiple of 32 bits. If no bit mask size is
// given, the bit mask is assumed to cover the entire BitVector.
/// setBitsInMask - Add '1' bits from Mask to this vector. Don't resize.
/// This computes "*this |= Mask".
void setBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<true, false>(Mask, MaskWords);
}
/// clearBitsInMask - Clear any bits in this vector that are set in Mask.
/// Don't resize. This computes "*this &= ~Mask".
void clearBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<false, false>(Mask, MaskWords);
}
/// setBitsNotInMask - Add a bit to this vector for every '0' bit in Mask.
/// Don't resize. This computes "*this |= ~Mask".
void setBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<true, true>(Mask, MaskWords);
}
/// clearBitsNotInMask - Clear a bit in this vector for every '0' bit in Mask.
/// Don't resize. This computes "*this &= Mask".
void clearBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<false, true>(Mask, MaskWords);
}
private:
unsigned NumBitWords(unsigned S) const {
return (S + BITWORD_SIZE-1) / BITWORD_SIZE;
}
// Set the unused bits in the high words.
void set_unused_bits(bool t = true) {
// Set high words first.
unsigned UsedWords = NumBitWords(Size);
if (Capacity > UsedWords)
init_words(&Bits[UsedWords], (Capacity-UsedWords), t);
// Then set any stray high bits of the last used word.
unsigned ExtraBits = Size % BITWORD_SIZE;
if (ExtraBits) {
BitWord ExtraBitMask = ~0UL << ExtraBits;
if (t)
Bits[UsedWords-1] |= ExtraBitMask;
else
Bits[UsedWords-1] &= ~ExtraBitMask;
}
}
// Clear the unused bits in the high words.
void clear_unused_bits() {
set_unused_bits(false);
}
void grow(unsigned NewSize) {
Capacity = std::max(NumBitWords(NewSize), Capacity * 2);
assert(Capacity > 0 && "realloc-ing zero space");
Bits = (BitWord *)std::realloc(Bits, Capacity * sizeof(BitWord));
clear_unused_bits();
}
void init_words(BitWord *B, unsigned NumWords, bool t) {
memset(B, 0 - (int)t, NumWords*sizeof(BitWord));
}
template<bool AddBits, bool InvertMask>
void applyMask(const uint32_t *Mask, unsigned MaskWords) {
static_assert(BITWORD_SIZE % 32 == 0, "Unsupported BitWord size.");
MaskWords = std::min(MaskWords, (size() + 31) / 32);
const unsigned Scale = BITWORD_SIZE / 32;
unsigned i;
for (i = 0; MaskWords >= Scale; ++i, MaskWords -= Scale) {
BitWord BW = Bits[i];
// This inner loop should unroll completely when BITWORD_SIZE > 32.
for (unsigned b = 0; b != BITWORD_SIZE; b += 32) {
uint32_t M = *Mask++;
if (InvertMask) M = ~M;
if (AddBits) BW |= BitWord(M) << b;
else BW &= ~(BitWord(M) << b);
}
Bits[i] = BW;
}
for (unsigned b = 0; MaskWords; b += 32, --MaskWords) {
uint32_t M = *Mask++;
if (InvertMask) M = ~M;
if (AddBits) Bits[i] |= BitWord(M) << b;
else Bits[i] &= ~(BitWord(M) << b);
}
if (AddBits)
clear_unused_bits();
}
public:
/// Return the size (in bytes) of the bit vector.
size_t getMemorySize() const { return Capacity * sizeof(BitWord); }
};
static inline size_t capacity_in_bytes(const BitVector &X) {
return X.getMemorySize();
}
} // end namespace llvm
} // end namespace hecl
namespace std {
/// Implement std::swap in terms of BitVector swap.
inline void
swap(hecl::llvm::BitVector &LHS, hecl::llvm::BitVector &RHS) {
LHS.swap(RHS);
}
} // end namespace std
#endif // LLVM_ADT_BITVECTOR_H

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//===-- llvm/Support/MathExtras.h - Useful math functions -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains some functions that are useful for math stuff.
//
//===----------------------------------------------------------------------===//
#ifndef HECL_LLVM_SUPPORT_MATHEXTRAS_H
#define HECL_LLVM_SUPPORT_MATHEXTRAS_H
/// \macro LLVM_GNUC_PREREQ
/// \brief Extend the default __GNUC_PREREQ even if glibc's features.h isn't
/// available.
#ifndef LLVM_GNUC_PREREQ
# if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
# define LLVM_GNUC_PREREQ(maj, min, patch) \
((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >= \
((maj) << 20) + ((min) << 10) + (patch))
# elif defined(__GNUC__) && defined(__GNUC_MINOR__)
# define LLVM_GNUC_PREREQ(maj, min, patch) \
((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10))
# else
# define LLVM_GNUC_PREREQ(maj, min, patch) 0
# endif
#endif
#include "hecl.hpp"
#include <algorithm>
#include <cassert>
#include <cstring>
#include <type_traits>
#include <limits>
#ifdef _MSC_VER
#include <intrin.h>
#endif
#ifdef __ANDROID_NDK__
#include <android/api-level.h>
#endif
namespace hecl {
namespace llvm {
/// \brief The behavior an operation has on an input of 0.
enum ZeroBehavior {
/// \brief The returned value is undefined.
ZB_Undefined,
/// \brief The returned value is numeric_limits<T>::max()
ZB_Max,
/// \brief The returned value is numeric_limits<T>::digits
ZB_Width
};
namespace detail {
template <typename T, std::size_t SizeOfT> struct TrailingZerosCounter {
static std::size_t count(T Val, ZeroBehavior) {
if (!Val)
return std::numeric_limits<T>::digits;
if (Val & 0x1)
return 0;
// Bisection method.
std::size_t ZeroBits = 0;
T Shift = std::numeric_limits<T>::digits >> 1;
T Mask = std::numeric_limits<T>::max() >> Shift;
while (Shift) {
if ((Val & Mask) == 0) {
Val >>= Shift;
ZeroBits |= Shift;
}
Shift >>= 1;
Mask >>= Shift;
}
return ZeroBits;
}
};
#if __GNUC__ >= 4 || defined(_MSC_VER)
template <typename T> struct TrailingZerosCounter<T, 4> {
static std::size_t count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 32;
#if __has_builtin(__builtin_ctz) || LLVM_GNUC_PREREQ(4, 0, 0)
return __builtin_ctz(Val);
#elif defined(_MSC_VER)
unsigned long Index;
_BitScanForward(&Index, Val);
return Index;
#endif
}
};
#if !defined(_MSC_VER) || defined(_M_X64)
template <typename T> struct TrailingZerosCounter<T, 8> {
static std::size_t count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 64;
#if __has_builtin(__builtin_ctzll) || LLVM_GNUC_PREREQ(4, 0, 0)
return __builtin_ctzll(Val);
#elif defined(_MSC_VER)
unsigned long Index;
_BitScanForward64(&Index, Val);
return Index;
#endif
}
};
#endif
#endif
} // namespace detail
/// \brief Count number of 0's from the least significant bit to the most
/// stopping at the first 1.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
/// valid arguments.
template <typename T>
std::size_t countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
static_assert(std::numeric_limits<T>::is_integer &&
!std::numeric_limits<T>::is_signed,
"Only unsigned integral types are allowed.");
return detail::TrailingZerosCounter<T, sizeof(T)>::count(Val, ZB);
}
namespace detail {
template <typename T, std::size_t SizeOfT> struct LeadingZerosCounter {
static std::size_t count(T Val, ZeroBehavior) {
if (!Val)
return std::numeric_limits<T>::digits;
// Bisection method.
std::size_t ZeroBits = 0;
for (T Shift = std::numeric_limits<T>::digits >> 1; Shift; Shift >>= 1) {
T Tmp = Val >> Shift;
if (Tmp)
Val = Tmp;
else
ZeroBits |= Shift;
}
return ZeroBits;
}
};
#if __GNUC__ >= 4 || defined(_MSC_VER)
template <typename T> struct LeadingZerosCounter<T, 4> {
static std::size_t count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 32;
#if __has_builtin(__builtin_clz) || LLVM_GNUC_PREREQ(4, 0, 0)
return __builtin_clz(Val);
#elif defined(_MSC_VER)
unsigned long Index;
_BitScanReverse(&Index, Val);
return Index ^ 31;
#endif
}
};
#if !defined(_MSC_VER) || defined(_M_X64)
template <typename T> struct LeadingZerosCounter<T, 8> {
static std::size_t count(T Val, ZeroBehavior ZB) {
if (ZB != ZB_Undefined && Val == 0)
return 64;
#if __has_builtin(__builtin_clzll) || LLVM_GNUC_PREREQ(4, 0, 0)
return __builtin_clzll(Val);
#elif defined(_MSC_VER)
unsigned long Index;
_BitScanReverse64(&Index, Val);
return Index ^ 63;
#endif
}
};
#endif
#endif
} // namespace detail
/// \brief Count number of 0's from the most significant bit to the least
/// stopping at the first 1.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
/// valid arguments.
template <typename T>
std::size_t countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
static_assert(std::numeric_limits<T>::is_integer &&
!std::numeric_limits<T>::is_signed,
"Only unsigned integral types are allowed.");
return detail::LeadingZerosCounter<T, sizeof(T)>::count(Val, ZB);
}
/// \brief Get the index of the first set bit starting from the least
/// significant bit.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
/// valid arguments.
template <typename T> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) {
if (ZB == ZB_Max && Val == 0)
return std::numeric_limits<T>::max();
return countTrailingZeros(Val, ZB_Undefined);
}
/// \brief Get the index of the last set bit starting from the least
/// significant bit.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
/// valid arguments.
template <typename T> T findLastSet(T Val, ZeroBehavior ZB = ZB_Max) {
if (ZB == ZB_Max && Val == 0)
return std::numeric_limits<T>::max();
// Use ^ instead of - because both gcc and llvm can remove the associated ^
// in the __builtin_clz intrinsic on x86.
return countLeadingZeros(Val, ZB_Undefined) ^
(std::numeric_limits<T>::digits - 1);
}
/// \brief Macro compressed bit reversal table for 256 bits.
///
/// http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
static const unsigned char BitReverseTable256[256] = {
#define R2(n) n, n + 2 * 64, n + 1 * 64, n + 3 * 64
#define R4(n) R2(n), R2(n + 2 * 16), R2(n + 1 * 16), R2(n + 3 * 16)
#define R6(n) R4(n), R4(n + 2 * 4), R4(n + 1 * 4), R4(n + 3 * 4)
R6(0), R6(2), R6(1), R6(3)
#undef R2
#undef R4
#undef R6
};
/// \brief Reverse the bits in \p Val.
template <typename T>
T reverseBits(T Val) {
unsigned char in[sizeof(Val)];
unsigned char out[sizeof(Val)];
std::memcpy(in, &Val, sizeof(Val));
for (unsigned i = 0; i < sizeof(Val); ++i)
out[(sizeof(Val) - i) - 1] = BitReverseTable256[in[i]];
std::memcpy(&Val, out, sizeof(Val));
return Val;
}
// NOTE: The following support functions use the _32/_64 extensions instead of
// type overloading so that signed and unsigned integers can be used without
// ambiguity.
/// Hi_32 - This function returns the high 32 bits of a 64 bit value.
constexpr inline uint32_t Hi_32(uint64_t Value) {
return static_cast<uint32_t>(Value >> 32);
}
/// Lo_32 - This function returns the low 32 bits of a 64 bit value.
constexpr inline uint32_t Lo_32(uint64_t Value) {
return static_cast<uint32_t>(Value);
}
/// Make_64 - This functions makes a 64-bit integer from a high / low pair of
/// 32-bit integers.
constexpr inline uint64_t Make_64(uint32_t High, uint32_t Low) {
return ((uint64_t)High << 32) | (uint64_t)Low;
}
/// isInt - Checks if an integer fits into the given bit width.
template <unsigned N> constexpr inline bool isInt(int64_t x) {
return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1)));
}
// Template specializations to get better code for common cases.
template <> constexpr inline bool isInt<8>(int64_t x) {
return static_cast<int8_t>(x) == x;
}
template <> constexpr inline bool isInt<16>(int64_t x) {
return static_cast<int16_t>(x) == x;
}
template <> constexpr inline bool isInt<32>(int64_t x) {
return static_cast<int32_t>(x) == x;
}
/// isShiftedInt<N,S> - Checks if a signed integer is an N bit number shifted
/// left by S.
template <unsigned N, unsigned S>
constexpr inline bool isShiftedInt(int64_t x) {
static_assert(
N > 0, "isShiftedInt<0> doesn't make sense (refers to a 0-bit number.");
static_assert(N + S <= 64, "isShiftedInt<N, S> with N + S > 64 is too wide.");
return isInt<N + S>(x) && (x % (UINT64_C(1) << S) == 0);
}
/// isUInt - Checks if an unsigned integer fits into the given bit width.
///
/// This is written as two functions rather than as simply
///
/// return N >= 64 || X < (UINT64_C(1) << N);
///
/// to keep MSVC from (incorrectly) warning on isUInt<64> that we're shifting
/// left too many places.
template <unsigned N>
constexpr inline typename std::enable_if<(N < 64), bool>::type
isUInt(uint64_t X) {
static_assert(N > 0, "isUInt<0> doesn't make sense");
return X < (UINT64_C(1) << (N));
}
template <unsigned N>
constexpr inline typename std::enable_if<N >= 64, bool>::type
isUInt(uint64_t X) {
return true;
}
// Template specializations to get better code for common cases.
template <> constexpr inline bool isUInt<8>(uint64_t x) {
return static_cast<uint8_t>(x) == x;
}
template <> constexpr inline bool isUInt<16>(uint64_t x) {
return static_cast<uint16_t>(x) == x;
}
template <> constexpr inline bool isUInt<32>(uint64_t x) {
return static_cast<uint32_t>(x) == x;
}
/// Checks if a unsigned integer is an N bit number shifted left by S.
template <unsigned N, unsigned S>
constexpr inline bool isShiftedUInt(uint64_t x) {
static_assert(
N > 0, "isShiftedUInt<0> doesn't make sense (refers to a 0-bit number)");
static_assert(N + S <= 64,
"isShiftedUInt<N, S> with N + S > 64 is too wide.");
// Per the two static_asserts above, S must be strictly less than 64. So
// 1 << S is not undefined behavior.
return isUInt<N + S>(x) && (x % (UINT64_C(1) << S) == 0);
}
/// Gets the maximum value for a N-bit unsigned integer.
inline uint64_t maxUIntN(uint64_t N) {
assert(N > 0 && N <= 64 && "integer width out of range");
// uint64_t(1) << 64 is undefined behavior, so we can't do
// (uint64_t(1) << N) - 1
// without checking first that N != 64. But this works and doesn't have a
// branch.
return UINT64_MAX >> (64 - N);
}
/// Gets the minimum value for a N-bit signed integer.
inline int64_t minIntN(int64_t N) {
assert(N > 0 && N <= 64 && "integer width out of range");
return -(UINT64_C(1)<<(N-1));
}
/// Gets the maximum value for a N-bit signed integer.
inline int64_t maxIntN(int64_t N) {
assert(N > 0 && N <= 64 && "integer width out of range");
// This relies on two's complement wraparound when N == 64, so we convert to
// int64_t only at the very end to avoid UB.
return (UINT64_C(1) << (N - 1)) - 1;
}
/// isUIntN - Checks if an unsigned integer fits into the given (dynamic)
/// bit width.
inline bool isUIntN(unsigned N, uint64_t x) {
return N >= 64 || x <= maxUIntN(N);
}
/// isIntN - Checks if an signed integer fits into the given (dynamic)
/// bit width.
inline bool isIntN(unsigned N, int64_t x) {
return N >= 64 || (minIntN(N) <= x && x <= maxIntN(N));
}
/// isMask_32 - This function returns true if the argument is a non-empty
/// sequence of ones starting at the least significant bit with the remainder
/// zero (32 bit version). Ex. isMask_32(0x0000FFFFU) == true.
constexpr inline bool isMask_32(uint32_t Value) {
return Value && ((Value + 1) & Value) == 0;
}
/// isMask_64 - This function returns true if the argument is a non-empty
/// sequence of ones starting at the least significant bit with the remainder
/// zero (64 bit version).
constexpr inline bool isMask_64(uint64_t Value) {
return Value && ((Value + 1) & Value) == 0;
}
/// isShiftedMask_32 - This function returns true if the argument contains a
/// non-empty sequence of ones with the remainder zero (32 bit version.)
/// Ex. isShiftedMask_32(0x0000FF00U) == true.
constexpr inline bool isShiftedMask_32(uint32_t Value) {
return Value && isMask_32((Value - 1) | Value);
}
/// isShiftedMask_64 - This function returns true if the argument contains a
/// non-empty sequence of ones with the remainder zero (64 bit version.)
constexpr inline bool isShiftedMask_64(uint64_t Value) {
return Value && isMask_64((Value - 1) | Value);
}
/// isPowerOf2_32 - This function returns true if the argument is a power of
/// two > 0. Ex. isPowerOf2_32(0x00100000U) == true (32 bit edition.)
constexpr inline bool isPowerOf2_32(uint32_t Value) {
return Value && !(Value & (Value - 1));
}
/// isPowerOf2_64 - This function returns true if the argument is a power of two
/// > 0 (64 bit edition.)
constexpr inline bool isPowerOf2_64(uint64_t Value) {
return Value && !(Value & (Value - int64_t(1L)));
}
/// ByteSwap_16 - This function returns a byte-swapped representation of the
/// 16-bit argument, Value.
inline uint16_t ByteSwap_16(uint16_t Value) {
return hecl::bswap16(Value);
}
/// ByteSwap_32 - This function returns a byte-swapped representation of the
/// 32-bit argument, Value.
inline uint32_t ByteSwap_32(uint32_t Value) {
return hecl::bswap32(Value);
}
/// ByteSwap_64 - This function returns a byte-swapped representation of the
/// 64-bit argument, Value.
inline uint64_t ByteSwap_64(uint64_t Value) {
return hecl::bswap64(Value);
}
/// \brief Count the number of ones from the most significant bit to the first
/// zero bit.
///
/// Ex. CountLeadingOnes(0xFF0FFF00) == 8.
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of all ones. Only ZB_Width and
/// ZB_Undefined are valid arguments.
template <typename T>
std::size_t countLeadingOnes(T Value, ZeroBehavior ZB = ZB_Width) {
static_assert(std::numeric_limits<T>::is_integer &&
!std::numeric_limits<T>::is_signed,
"Only unsigned integral types are allowed.");
return countLeadingZeros(~Value, ZB);
}
/// \brief Count the number of ones from the least significant bit to the first
/// zero bit.
///
/// Ex. countTrailingOnes(0x00FF00FF) == 8.
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of all ones. Only ZB_Width and
/// ZB_Undefined are valid arguments.
template <typename T>
std::size_t countTrailingOnes(T Value, ZeroBehavior ZB = ZB_Width) {
static_assert(std::numeric_limits<T>::is_integer &&
!std::numeric_limits<T>::is_signed,
"Only unsigned integral types are allowed.");
return countTrailingZeros(~Value, ZB);
}
namespace detail {
template <typename T, std::size_t SizeOfT> struct PopulationCounter {
static unsigned count(T Value) {
// Generic version, forward to 32 bits.
static_assert(SizeOfT <= 4, "Not implemented!");
#if __GNUC__ >= 4
return __builtin_popcount(Value);
#else
uint32_t v = Value;
v = v - ((v >> 1) & 0x55555555);
v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
#endif
}
};
template <typename T> struct PopulationCounter<T, 8> {
static unsigned count(T Value) {
#if __GNUC__ >= 4
return __builtin_popcountll(Value);
#else
uint64_t v = Value;
v = v - ((v >> 1) & 0x5555555555555555ULL);
v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL);
v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL;
return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56);
#endif
}
};
} // namespace detail
/// \brief Count the number of set bits in a value.
/// Ex. countPopulation(0xF000F000) = 8
/// Returns 0 if the word is zero.
template <typename T>
inline unsigned countPopulation(T Value) {
static_assert(std::numeric_limits<T>::is_integer &&
!std::numeric_limits<T>::is_signed,
"Only unsigned integral types are allowed.");
return detail::PopulationCounter<T, sizeof(T)>::count(Value);
}
/// Log2 - This function returns the log base 2 of the specified value
inline double Log2(double Value) {
#if defined(__ANDROID_API__) && __ANDROID_API__ < 18
return __builtin_log(Value) / __builtin_log(2.0);
#else
return log2(Value);
#endif
}
/// Log2_32 - This function returns the floor log base 2 of the specified value,
/// -1 if the value is zero. (32 bit edition.)
/// Ex. Log2_32(32) == 5, Log2_32(1) == 0, Log2_32(0) == -1, Log2_32(6) == 2
inline unsigned Log2_32(uint32_t Value) {
return 31 - countLeadingZeros(Value);
}
/// Log2_64 - This function returns the floor log base 2 of the specified value,
/// -1 if the value is zero. (64 bit edition.)
inline unsigned Log2_64(uint64_t Value) {
return 63 - countLeadingZeros(Value);
}
/// Log2_32_Ceil - This function returns the ceil log base 2 of the specified
/// value, 32 if the value is zero. (32 bit edition).
/// Ex. Log2_32_Ceil(32) == 5, Log2_32_Ceil(1) == 0, Log2_32_Ceil(6) == 3
inline unsigned Log2_32_Ceil(uint32_t Value) {
return 32 - countLeadingZeros(Value - 1);
}
/// Log2_64_Ceil - This function returns the ceil log base 2 of the specified
/// value, 64 if the value is zero. (64 bit edition.)
inline unsigned Log2_64_Ceil(uint64_t Value) {
return 64 - countLeadingZeros(Value - 1);
}
/// GreatestCommonDivisor64 - Return the greatest common divisor of the two
/// values using Euclid's algorithm.
inline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) {
while (B) {
uint64_t T = B;
B = A % B;
A = T;
}
return A;
}
/// BitsToDouble - This function takes a 64-bit integer and returns the bit
/// equivalent double.
inline double BitsToDouble(uint64_t Bits) {
union {
uint64_t L;
double D;
} T;
T.L = Bits;
return T.D;
}
/// BitsToFloat - This function takes a 32-bit integer and returns the bit
/// equivalent float.
inline float BitsToFloat(uint32_t Bits) {
union {
uint32_t I;
float F;
} T;
T.I = Bits;
return T.F;
}
/// DoubleToBits - This function takes a double and returns the bit
/// equivalent 64-bit integer. Note that copying doubles around
/// changes the bits of NaNs on some hosts, notably x86, so this
/// routine cannot be used if these bits are needed.
inline uint64_t DoubleToBits(double Double) {
union {
uint64_t L;
double D;
} T;
T.D = Double;
return T.L;
}
/// FloatToBits - This function takes a float and returns the bit
/// equivalent 32-bit integer. Note that copying floats around
/// changes the bits of NaNs on some hosts, notably x86, so this
/// routine cannot be used if these bits are needed.
inline uint32_t FloatToBits(float Float) {
union {
uint32_t I;
float F;
} T;
T.F = Float;
return T.I;
}
/// MinAlign - A and B are either alignments or offsets. Return the minimum
/// alignment that may be assumed after adding the two together.
constexpr inline uint64_t MinAlign(uint64_t A, uint64_t B) {
// The largest power of 2 that divides both A and B.
//
// Replace "-Value" by "1+~Value" in the following commented code to avoid
// MSVC warning C4146
// return (A | B) & -(A | B);
return (A | B) & (1 + ~(A | B));
}
/// \brief Aligns \c Addr to \c Alignment bytes, rounding up.
///
/// Alignment should be a power of two. This method rounds up, so
/// alignAddr(7, 4) == 8 and alignAddr(8, 4) == 8.
inline uintptr_t alignAddr(const void *Addr, size_t Alignment) {
assert(Alignment && isPowerOf2_64((uint64_t)Alignment) &&
"Alignment is not a power of two!");
assert((uintptr_t)Addr + Alignment - 1 >= (uintptr_t)Addr);
return (((uintptr_t)Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1));
}
/// \brief Returns the necessary adjustment for aligning \c Ptr to \c Alignment
/// bytes, rounding up.
inline size_t alignmentAdjustment(const void *Ptr, size_t Alignment) {
return alignAddr(Ptr, Alignment) - (uintptr_t)Ptr;
}
/// NextPowerOf2 - Returns the next power of two (in 64-bits)
/// that is strictly greater than A. Returns zero on overflow.
inline uint64_t NextPowerOf2(uint64_t A) {
A |= (A >> 1);
A |= (A >> 2);
A |= (A >> 4);
A |= (A >> 8);
A |= (A >> 16);
A |= (A >> 32);
return A + 1;
}
/// Returns the power of two which is less than or equal to the given value.
/// Essentially, it is a floor operation across the domain of powers of two.
inline uint64_t PowerOf2Floor(uint64_t A) {
if (!A) return 0;
return 1ull << (63 - countLeadingZeros(A, ZB_Undefined));
}
/// Returns the power of two which is greater than or equal to the given value.
/// Essentially, it is a ceil operation across the domain of powers of two.
inline uint64_t PowerOf2Ceil(uint64_t A) {
if (!A)
return 0;
return NextPowerOf2(A - 1);
}
/// Returns the next integer (mod 2**64) that is greater than or equal to
/// \p Value and is a multiple of \p Align. \p Align must be non-zero.
///
/// If non-zero \p Skew is specified, the return value will be a minimal
/// integer that is greater than or equal to \p Value and equal to
/// \p Align * N + \p Skew for some integer N. If \p Skew is larger than
/// \p Align, its value is adjusted to '\p Skew mod \p Align'.
///
/// Examples:
/// \code
/// alignTo(5, 8) = 8
/// alignTo(17, 8) = 24
/// alignTo(~0LL, 8) = 0
/// alignTo(321, 255) = 510
///
/// alignTo(5, 8, 7) = 7
/// alignTo(17, 8, 1) = 17
/// alignTo(~0LL, 8, 3) = 3
/// alignTo(321, 255, 42) = 552
/// \endcode
inline uint64_t alignTo(uint64_t Value, uint64_t Align, uint64_t Skew = 0) {
assert(Align != 0u && "Align can't be 0.");
Skew %= Align;
return (Value + Align - 1 - Skew) / Align * Align + Skew;
}
/// Returns the next integer (mod 2**64) that is greater than or equal to
/// \p Value and is a multiple of \c Align. \c Align must be non-zero.
template <uint64_t Align> constexpr inline uint64_t alignTo(uint64_t Value) {
static_assert(Align != 0u, "Align must be non-zero");
return (Value + Align - 1) / Align * Align;
}
/// \c alignTo for contexts where a constant expression is required.
/// \sa alignTo
///
/// \todo FIXME: remove when \c constexpr becomes really \c constexpr
template <uint64_t Align>
struct AlignTo {
static_assert(Align != 0u, "Align must be non-zero");
template <uint64_t Value>
struct from_value {
static const uint64_t value = (Value + Align - 1) / Align * Align;
};
};
/// Returns the largest uint64_t less than or equal to \p Value and is
/// \p Skew mod \p Align. \p Align must be non-zero
inline uint64_t alignDown(uint64_t Value, uint64_t Align, uint64_t Skew = 0) {
assert(Align != 0u && "Align can't be 0.");
Skew %= Align;
return (Value - Skew) / Align * Align + Skew;
}
/// Returns the offset to the next integer (mod 2**64) that is greater than
/// or equal to \p Value and is a multiple of \p Align. \p Align must be
/// non-zero.
inline uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align) {
return alignTo(Value, Align) - Value;
}
/// Sign-extend the number in the bottom B bits of X to a 32-bit integer.
/// Requires 0 < B <= 32.
template <unsigned B> constexpr inline int32_t SignExtend32(uint32_t X) {
static_assert(B > 0, "Bit width can't be 0.");
static_assert(B <= 32, "Bit width out of range.");
return int32_t(X << (32 - B)) >> (32 - B);
}
/// Sign-extend the number in the bottom B bits of X to a 32-bit integer.
/// Requires 0 < B < 32.
inline int32_t SignExtend32(uint32_t X, unsigned B) {
assert(B > 0 && "Bit width can't be 0.");
assert(B <= 32 && "Bit width out of range.");
return int32_t(X << (32 - B)) >> (32 - B);
}
/// Sign-extend the number in the bottom B bits of X to a 64-bit integer.
/// Requires 0 < B < 64.
template <unsigned B> constexpr inline int64_t SignExtend64(uint64_t x) {
static_assert(B > 0, "Bit width can't be 0.");
static_assert(B <= 64, "Bit width out of range.");
return int64_t(x << (64 - B)) >> (64 - B);
}
/// Sign-extend the number in the bottom B bits of X to a 64-bit integer.
/// Requires 0 < B < 64.
inline int64_t SignExtend64(uint64_t X, unsigned B) {
assert(B > 0 && "Bit width can't be 0.");
assert(B <= 64 && "Bit width out of range.");
return int64_t(X << (64 - B)) >> (64 - B);
}
/// Subtract two unsigned integers, X and Y, of type T and return the absolute
/// value of the result.
template <typename T>
typename std::enable_if<std::is_unsigned<T>::value, T>::type
AbsoluteDifference(T X, T Y) {
return std::max(X, Y) - std::min(X, Y);
}
/// Add two unsigned integers, X and Y, of type T. Clamp the result to the
/// maximum representable value of T on overflow. ResultOverflowed indicates if
/// the result is larger than the maximum representable value of type T.
template <typename T>
typename std::enable_if<std::is_unsigned<T>::value, T>::type
SaturatingAdd(T X, T Y, bool *ResultOverflowed = nullptr) {
bool Dummy;
bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy;
// Hacker's Delight, p. 29
T Z = X + Y;
Overflowed = (Z < X || Z < Y);
if (Overflowed)
return std::numeric_limits<T>::max();
else
return Z;
}
/// Multiply two unsigned integers, X and Y, of type T. Clamp the result to the
/// maximum representable value of T on overflow. ResultOverflowed indicates if
/// the result is larger than the maximum representable value of type T.
template <typename T>
typename std::enable_if<std::is_unsigned<T>::value, T>::type
SaturatingMultiply(T X, T Y, bool *ResultOverflowed = nullptr) {
bool Dummy;
bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy;
// Hacker's Delight, p. 30 has a different algorithm, but we don't use that
// because it fails for uint16_t (where multiplication can have undefined
// behavior due to promotion to int), and requires a division in addition
// to the multiplication.
Overflowed = false;
// Log2(Z) would be either Log2Z or Log2Z + 1.
// Special case: if X or Y is 0, Log2_64 gives -1, and Log2Z
// will necessarily be less than Log2Max as desired.
int Log2Z = Log2_64(X) + Log2_64(Y);
const T Max = std::numeric_limits<T>::max();
int Log2Max = Log2_64(Max);
if (Log2Z < Log2Max) {
return X * Y;
}
if (Log2Z > Log2Max) {
Overflowed = true;
return Max;
}
// We're going to use the top bit, and maybe overflow one
// bit past it. Multiply all but the bottom bit then add
// that on at the end.
T Z = (X >> 1) * Y;
if (Z & ~(Max >> 1)) {
Overflowed = true;
return Max;
}
Z <<= 1;
if (X & 1)
return SaturatingAdd(Z, Y, ResultOverflowed);
return Z;
}
/// Multiply two unsigned integers, X and Y, and add the unsigned integer, A to
/// the product. Clamp the result to the maximum representable value of T on
/// overflow. ResultOverflowed indicates if the result is larger than the
/// maximum representable value of type T.
template <typename T>
typename std::enable_if<std::is_unsigned<T>::value, T>::type
SaturatingMultiplyAdd(T X, T Y, T A, bool *ResultOverflowed = nullptr) {
bool Dummy;
bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy;
T Product = SaturatingMultiply(X, Y, &Overflowed);
if (Overflowed)
return Product;
return SaturatingAdd(A, Product, &Overflowed);
}
/// Use this rather than HUGE_VALF; the latter causes warnings on MSVC.
extern const float huge_valf;
} // End llvm namespace
} // End hecl namespace
#endif

View File

@ -47,6 +47,8 @@ add_library(hecl-common
../include/hecl/Database.hpp ../include/hecl/Database.hpp
../include/hecl/Runtime.hpp ../include/hecl/Runtime.hpp
../include/hecl/ClientProcess.hpp ../include/hecl/ClientProcess.hpp
../include/hecl/BitVector.hpp
../include/hecl/MathExtras.hpp
ClientProcess.cpp ClientProcess.cpp
atdna_HMDLMeta.cpp atdna_HMDLMeta.cpp
atdna_Frontend.cpp atdna_Frontend.cpp