| //===-- 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 LLVM_SUPPORT_MATHEXTRAS_H |
| #define LLVM_SUPPORT_MATHEXTRAS_H |
| |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Support/SwapByteOrder.h" |
| #include <cassert> |
| #include <cstring> |
| #include <type_traits> |
| |
| #ifdef _MSC_VER |
| #include <intrin.h> |
| #include <limits> |
| #endif |
| |
| 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 |
| }; |
| |
| /// \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> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| !std::numeric_limits<T>::is_signed, std::size_t>::type |
| countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) { |
| (void)ZB; |
| |
| 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; |
| } |
| |
| // Disable signed. |
| template <typename T> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| std::numeric_limits<T>::is_signed, std::size_t>::type |
| countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) LLVM_DELETED_FUNCTION; |
| |
| #if __GNUC__ >= 4 || _MSC_VER |
| template <> |
| inline std::size_t countTrailingZeros<uint32_t>(uint32_t Val, ZeroBehavior ZB) { |
| if (ZB != ZB_Undefined && Val == 0) |
| return 32; |
| |
| #if __has_builtin(__builtin_ctz) || __GNUC_PREREQ(4, 0) |
| return __builtin_ctz(Val); |
| #elif _MSC_VER |
| unsigned long Index; |
| _BitScanForward(&Index, Val); |
| return Index; |
| #endif |
| } |
| |
| #if !defined(_MSC_VER) || defined(_M_X64) |
| template <> |
| inline std::size_t countTrailingZeros<uint64_t>(uint64_t Val, ZeroBehavior ZB) { |
| if (ZB != ZB_Undefined && Val == 0) |
| return 64; |
| |
| #if __has_builtin(__builtin_ctzll) || __GNUC_PREREQ(4, 0) |
| return __builtin_ctzll(Val); |
| #elif _MSC_VER |
| unsigned long Index; |
| _BitScanForward64(&Index, Val); |
| return Index; |
| #endif |
| } |
| #endif |
| #endif |
| |
| /// \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> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| !std::numeric_limits<T>::is_signed, std::size_t>::type |
| countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) { |
| (void)ZB; |
| |
| 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; |
| } |
| |
| // Disable signed. |
| template <typename T> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| std::numeric_limits<T>::is_signed, std::size_t>::type |
| countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) LLVM_DELETED_FUNCTION; |
| |
| #if __GNUC__ >= 4 || _MSC_VER |
| template <> |
| inline std::size_t countLeadingZeros<uint32_t>(uint32_t Val, ZeroBehavior ZB) { |
| if (ZB != ZB_Undefined && Val == 0) |
| return 32; |
| |
| #if __has_builtin(__builtin_clz) || __GNUC_PREREQ(4, 0) |
| return __builtin_clz(Val); |
| #elif _MSC_VER |
| unsigned long Index; |
| _BitScanReverse(&Index, Val); |
| return Index ^ 31; |
| #endif |
| } |
| |
| #if !defined(_MSC_VER) || defined(_M_X64) |
| template <> |
| inline std::size_t countLeadingZeros<uint64_t>(uint64_t Val, ZeroBehavior ZB) { |
| if (ZB != ZB_Undefined && Val == 0) |
| return 64; |
| |
| #if __has_builtin(__builtin_clzll) || __GNUC_PREREQ(4, 0) |
| return __builtin_clzll(Val); |
| #elif _MSC_VER |
| unsigned long Index; |
| _BitScanReverse64(&Index, Val); |
| return Index ^ 63; |
| #endif |
| } |
| #endif |
| #endif |
| |
| /// \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> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| !std::numeric_limits<T>::is_signed, T>::type |
| findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) { |
| if (ZB == ZB_Max && Val == 0) |
| return std::numeric_limits<T>::max(); |
| |
| return countTrailingZeros(Val, ZB_Undefined); |
| } |
| |
| // Disable signed. |
| template <typename T> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| std::numeric_limits<T>::is_signed, T>::type |
| findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) LLVM_DELETED_FUNCTION; |
| |
| /// \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> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| !std::numeric_limits<T>::is_signed, T>::type |
| 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); |
| } |
| |
| // Disable signed. |
| template <typename T> |
| typename std::enable_if<std::numeric_limits<T>::is_integer && |
| std::numeric_limits<T>::is_signed, T>::type |
| findLastSet(T Val, ZeroBehavior ZB = ZB_Max) LLVM_DELETED_FUNCTION; |
| |
| /// \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. |
| 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. |
| 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. |
| 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> |
| 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<> |
| inline bool isInt<8>(int64_t x) { |
| return static_cast<int8_t>(x) == x; |
| } |
| template<> |
| inline bool isInt<16>(int64_t x) { |
| return static_cast<int16_t>(x) == x; |
| } |
| template<> |
| 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> |
| inline bool isShiftedInt(int64_t x) { |
| return isInt<N+S>(x) && (x % (1<<S) == 0); |
| } |
| |
| /// isUInt - Checks if an unsigned integer fits into the given bit width. |
| template<unsigned N> |
| inline bool isUInt(uint64_t x) { |
| return N >= 64 || x < (UINT64_C(1)<<(N)); |
| } |
| // Template specializations to get better code for common cases. |
| template<> |
| inline bool isUInt<8>(uint64_t x) { |
| return static_cast<uint8_t>(x) == x; |
| } |
| template<> |
| inline bool isUInt<16>(uint64_t x) { |
| return static_cast<uint16_t>(x) == x; |
| } |
| template<> |
| inline bool isUInt<32>(uint64_t x) { |
| return static_cast<uint32_t>(x) == x; |
| } |
| |
| /// isShiftedUInt<N,S> - Checks if a unsigned integer is an N bit number shifted |
| /// left by S. |
| template<unsigned N, unsigned S> |
| inline bool isShiftedUInt(uint64_t x) { |
| return isUInt<N+S>(x) && (x % (1<<S) == 0); |
| } |
| |
| /// isUIntN - Checks if an unsigned integer fits into the given (dynamic) |
| /// bit width. |
| inline bool isUIntN(unsigned N, uint64_t x) { |
| return x == (x & (~0ULL >> (64 - 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 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1))); |
| } |
| |
| /// isMask_32 - This function returns true if the argument is a sequence of ones |
| /// starting at the least significant bit with the remainder zero (32 bit |
| /// version). Ex. isMask_32(0x0000FFFFU) == true. |
| inline bool isMask_32(uint32_t Value) { |
| return Value && ((Value + 1) & Value) == 0; |
| } |
| |
| /// isMask_64 - This function returns true if the argument is a sequence of ones |
| /// starting at the least significant bit with the remainder zero (64 bit |
| /// version). |
| inline bool isMask_64(uint64_t Value) { |
| return Value && ((Value + 1) & Value) == 0; |
| } |
| |
| /// isShiftedMask_32 - This function returns true if the argument contains a |
| /// sequence of ones with the remainder zero (32 bit version.) |
| /// Ex. isShiftedMask_32(0x0000FF00U) == true. |
| inline bool isShiftedMask_32(uint32_t Value) { |
| return isMask_32((Value - 1) | Value); |
| } |
| |
| /// isShiftedMask_64 - This function returns true if the argument contains a |
| /// sequence of ones with the remainder zero (64 bit version.) |
| inline bool isShiftedMask_64(uint64_t Value) { |
| return 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.) |
| 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.) |
| 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 sys::SwapByteOrder_16(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 sys::SwapByteOrder_32(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 sys::SwapByteOrder_64(Value); |
| } |
| |
| /// CountLeadingOnes_32 - this function performs the operation of |
| /// counting the number of ones from the most significant bit to the first zero |
| /// bit. Ex. CountLeadingOnes_32(0xFF0FFF00) == 8. |
| /// Returns 32 if the word is all ones. |
| inline unsigned CountLeadingOnes_32(uint32_t Value) { |
| return countLeadingZeros(~Value); |
| } |
| |
| /// CountLeadingOnes_64 - This function performs the operation |
| /// of counting the number of ones from the most significant bit to the first |
| /// zero bit (64 bit edition.) |
| /// Returns 64 if the word is all ones. |
| inline unsigned CountLeadingOnes_64(uint64_t Value) { |
| return countLeadingZeros(~Value); |
| } |
| |
| /// CountTrailingOnes_32 - this function performs the operation of |
| /// counting the number of ones from the least significant bit to the first zero |
| /// bit. Ex. CountTrailingOnes_32(0x00FF00FF) == 8. |
| /// Returns 32 if the word is all ones. |
| inline unsigned CountTrailingOnes_32(uint32_t Value) { |
| return countTrailingZeros(~Value); |
| } |
| |
| /// CountTrailingOnes_64 - This function performs the operation |
| /// of counting the number of ones from the least significant bit to the first |
| /// zero bit (64 bit edition.) |
| /// Returns 64 if the word is all ones. |
| inline unsigned CountTrailingOnes_64(uint64_t Value) { |
| return countTrailingZeros(~Value); |
| } |
| |
| /// CountPopulation_32 - this function counts the number of set bits in a value. |
| /// Ex. CountPopulation(0xF000F000) = 8 |
| /// Returns 0 if the word is zero. |
| inline unsigned CountPopulation_32(uint32_t Value) { |
| #if __GNUC__ >= 4 |
| return __builtin_popcount(Value); |
| #else |
| uint32_t v = Value - ((Value >> 1) & 0x55555555); |
| v = (v & 0x33333333) + ((v >> 2) & 0x33333333); |
| return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; |
| #endif |
| } |
| |
| /// CountPopulation_64 - this function counts the number of set bits in a value, |
| /// (64 bit edition.) |
| inline unsigned CountPopulation_64(uint64_t Value) { |
| #if __GNUC__ >= 4 |
| return __builtin_popcountll(Value); |
| #else |
| uint64_t v = Value - ((Value >> 1) & 0x5555555555555555ULL); |
| v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL); |
| v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL; |
| return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56); |
| #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; |
| } |
| |
| /// Platform-independent wrappers for the C99 isnan() function. |
| int IsNAN(float f); |
| int IsNAN(double d); |
| |
| /// Platform-independent wrappers for the C99 isinf() function. |
| int IsInf(float f); |
| int IsInf(double d); |
| |
| /// MinAlign - A and B are either alignments or offsets. Return the minimum |
| /// alignment that may be assumed after adding the two together. |
| 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 Ptr to \c Alignment bytes, rounding up. |
| /// |
| /// Alignment should be a power of two. This method rounds up, so |
| /// AlignPtr(7, 4) == 8 and AlignPtr(8, 4) == 8. |
| inline char *alignPtr(char *Ptr, size_t Alignment) { |
| assert(Alignment && isPowerOf2_64((uint64_t)Alignment) && |
| "Alignment is not a power of two!"); |
| |
| return (char *)(((uintptr_t)Ptr + Alignment - 1) & |
| ~(uintptr_t)(Alignment - 1)); |
| } |
| |
| /// 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 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. |
| /// |
| /// Examples: |
| /// \code |
| /// RoundUpToAlignment(5, 8) = 8 |
| /// RoundUpToAlignment(17, 8) = 24 |
| /// RoundUpToAlignment(~0LL, 8) = 0 |
| /// \endcode |
| inline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align) { |
| return ((Value + Align - 1) / Align) * Align; |
| } |
| |
| /// 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 RoundUpToAlignment(Value, Align) - Value; |
| } |
| |
| /// abs64 - absolute value of a 64-bit int. Not all environments support |
| /// "abs" on whatever their name for the 64-bit int type is. The absolute |
| /// value of the largest negative number is undefined, as with "abs". |
| inline int64_t abs64(int64_t x) { |
| return (x < 0) ? -x : x; |
| } |
| |
| /// SignExtend32 - Sign extend B-bit number x to 32-bit int. |
| /// Usage int32_t r = SignExtend32<5>(x); |
| template <unsigned B> inline int32_t SignExtend32(uint32_t x) { |
| return int32_t(x << (32 - B)) >> (32 - B); |
| } |
| |
| /// \brief Sign extend number in the bottom B bits of X to a 32-bit int. |
| /// Requires 0 < B <= 32. |
| inline int32_t SignExtend32(uint32_t X, unsigned B) { |
| return int32_t(X << (32 - B)) >> (32 - B); |
| } |
| |
| /// SignExtend64 - Sign extend B-bit number x to 64-bit int. |
| /// Usage int64_t r = SignExtend64<5>(x); |
| template <unsigned B> inline int64_t SignExtend64(uint64_t x) { |
| return int64_t(x << (64 - B)) >> (64 - B); |
| } |
| |
| /// \brief Sign extend number in the bottom B bits of X to a 64-bit int. |
| /// Requires 0 < B <= 64. |
| inline int64_t SignExtend64(uint64_t X, unsigned B) { |
| return int64_t(X << (64 - B)) >> (64 - B); |
| } |
| |
| #if defined(_MSC_VER) |
| // Visual Studio defines the HUGE_VAL class of macros using purposeful |
| // constant arithmetic overflow, which it then warns on when encountered. |
| const float huge_valf = std::numeric_limits<float>::infinity(); |
| #else |
| const float huge_valf = HUGE_VALF; |
| #endif |
| } // End llvm namespace |
| |
| #endif |