X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FMathExtras.h;h=6a104e738fa7919b0f83bf89c60c3c7d642c8400;hp=8e7ad58efd06d80a3753b18e2240b50f93856709;hb=4f240010fdea1fcbe7dac3c8e9ebad082e4036c2;hpb=865dc8f64f50b72dbc8acb7851e606357f9d81f1 diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h index 8e7ad58efd0..6a104e738fa 100644 --- a/include/llvm/Support/MathExtras.h +++ b/include/llvm/Support/MathExtras.h @@ -2,8 +2,8 @@ // // The LLVM Compiler Infrastructure // -// This file was developed by the LLVM research group and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // @@ -14,167 +14,638 @@ #ifndef LLVM_SUPPORT_MATHEXTRAS_H #define LLVM_SUPPORT_MATHEXTRAS_H -#include "llvm/Support/DataTypes.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/SwapByteOrder.h" +#include +#include +#include + +#ifdef _MSC_VER +#include +#include +#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::max() + ZB_Max, + /// \brief The returned value is numeric_limits::digits + ZB_Width +}; -// 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. +/// \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 std::enable_if::is_integer && + !std::numeric_limits::is_signed, std::size_t>::type +countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) { + (void)ZB; + if (!Val) + return std::numeric_limits::digits; + if (Val & 0x1) + return 0; -// Hi_32 - This function returns the high 32 bits of a 64 bit value. -inline unsigned Hi_32(uint64_t Value) { - return (unsigned)(Value >> 32); + // Bisection method. + std::size_t ZeroBits = 0; + T Shift = std::numeric_limits::digits >> 1; + T Mask = std::numeric_limits::max() >> Shift; + while (Shift) { + if ((Val & Mask) == 0) { + Val >>= Shift; + ZeroBits |= Shift; + } + Shift >>= 1; + Mask >>= Shift; + } + return ZeroBits; } -// Lo_32 - This function returns the low 32 bits of a 64 bit value. -inline unsigned Lo_32(uint64_t Value) { - return (unsigned)Value; +// Disable signed. +template +typename std::enable_if::is_integer && + std::numeric_limits::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 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 } -// is?Type - these functions produce optimal testing for integer data types. -inline bool isInt8 (int Value) { return ( signed char )Value == Value; } -inline bool isUInt8 (int Value) { return (unsigned char )Value == Value; } -inline bool isInt16 (int Value) { return ( signed short)Value == Value; } -inline bool isUInt16(int Value) { return (unsigned short)Value == Value; } -inline bool isInt32 (int64_t Value) { return ( signed int )Value == Value; } -inline bool isUInt32(int64_t Value) { return (unsigned int )Value == Value; } +#if !defined(_MSC_VER) || defined(_M_X64) +template <> +inline std::size_t countTrailingZeros(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 std::enable_if::is_integer && + !std::numeric_limits::is_signed, std::size_t>::type +countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) { + (void)ZB; + + if (!Val) + return std::numeric_limits::digits; + + // Bisection method. + std::size_t ZeroBits = 0; + for (T Shift = std::numeric_limits::digits >> 1; Shift; Shift >>= 1) { + T Tmp = Val >> Shift; + if (Tmp) + Val = Tmp; + else + ZeroBits |= Shift; + } + return ZeroBits; +} + +// Disable signed. +template +typename std::enable_if::is_integer && + std::numeric_limits::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 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 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 std::enable_if::is_integer && + !std::numeric_limits::is_signed, T>::type +findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) { + if (ZB == ZB_Max && Val == 0) + return std::numeric_limits::max(); + + return countTrailingZeros(Val, ZB_Undefined); +} + +// Disable signed. +template +typename std::enable_if::is_integer && + std::numeric_limits::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 std::enable_if::is_integer && + !std::numeric_limits::is_signed, T>::type +findLastSet(T Val, ZeroBehavior ZB = ZB_Max) { + if (ZB == ZB_Max && Val == 0) + return std::numeric_limits::max(); -// 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 const bool isMask_32(unsigned Value) { + // 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::digits - 1); +} + +// Disable signed. +template +typename std::enable_if::is_integer && + std::numeric_limits::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 +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(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(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 +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(x) == x; +} +template<> +inline bool isInt<16>(int64_t x) { + return static_cast(x) == x; +} +template<> +inline bool isInt<32>(int64_t x) { + return static_cast(x) == x; +} + +/// isShiftedInt - Checks if a signed integer is an N bit number shifted +/// left by S. +template +inline bool isShiftedInt(int64_t x) { + return isInt(x) && (x % (1< +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(x) == x; +} +template<> +inline bool isUInt<16>(uint64_t x) { + return static_cast(x) == x; +} +template<> +inline bool isUInt<32>(uint64_t x) { + return static_cast(x) == x; +} + +/// isShiftedUInt - Checks if a unsigned integer is an N bit number shifted +/// left by S. +template +inline bool isShiftedUInt(uint64_t x) { + return isUInt(x) && (x % (1<> (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 const bool isMask_64(uint64_t Value) { +/// 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 const bool isShiftedMask_32(unsigned Value) { +/// 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 const bool isShiftedMask_64(uint64_t 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(unsigned 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.) +/// 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 - 1LL)); -} - -// CountLeadingZeros_32 - this function performs the platform optimal form of -// counting the number of zeros from the most significant bit to the first one -// bit. Ex. CountLeadingZeros_32(0x00F000FF) == 8. -// Returns 32 if the word is zero. -// CountLeadingZeros_32 - this function performs the platform optimal form -// of counting the number of zeros from the most significant bit to the first -// one bit. Ex. CountLeadingZeros_32(0x00F000FF) == 8. -// Returns 32 if the word is zero. -inline unsigned CountLeadingZeros_32(unsigned Value) { - unsigned Count; // result + 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 - // PowerPC is defined for __builtin_clz(0) -#if !defined(__ppc__) && !defined(__ppc64__) - if (!Value) return 32; -#endif - Count = __builtin_clz(Value); + return __builtin_popcount(Value); #else - if (!Value) return 32; - Count = 0; - // bisecton method for count leading zeros - for (unsigned Shift = 32 >> 1; Shift; Shift >>= 1) { - unsigned Tmp = Value >> Shift; - if (Tmp) { - Value = Tmp; - } else { - Count |= Shift; - } - } + uint32_t v = Value - ((Value >> 1) & 0x55555555); + v = (v & 0x33333333) + ((v >> 2) & 0x33333333); + return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; #endif - return Count; } -// CountLeadingZeros_64 - This function performs the platform optimal form -// of counting the number of zeros from the most significant bit to the first one bit -// (64 bit edition.) -// Returns 64 if the word is zero. -inline unsigned CountLeadingZeros_64(uint64_t Value) { - unsigned Count; // result +/// 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 - // PowerPC is defined for __builtin_clzll(0) -#if defined(__ppc__) || defined(__ppc64__) - if (!Value) return 64; -#endif - Count = __builtin_clzll(Value); + return __builtin_popcountll(Value); #else - if (sizeof(long) == sizeof(int64_t)) { - if (!Value) return 64; - Count = 0; - // bisecton method for count leading zeros - for (uint64_t Shift = 64 >> 1; Shift; Shift >>= 1) { - uint64_t Tmp = Value >> Shift; - if (Tmp) { - Value = Tmp; - } else { - Count |= Shift; - } - } - } else { - // get hi portion - unsigned Hi = Hi_32(Value); - - // if some bits in hi portion - if (Hi) { - // leading zeros in hi portion plus all bits in lo portion - Count = CountLeadingZeros_32(Hi); - } else { - // get lo portion - unsigned Lo = Lo_32(Value); - // same as 32 bit value - Count = CountLeadingZeros_32(Lo)+32; - } - } + 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 - return Count; } -// 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 -inline unsigned Log2_32(unsigned Value) { - return 31 - CountLeadingZeros_32(Value); +/// 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; +} -// 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(unsigned Value) { - return 63 - CountLeadingZeros_64(Value); +/// 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; } -// Platform-independent wrappers for the C99 isnan() function. -int IsNAN (float f); -int IsNAN (double 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; +} -// Platform-independent wrappers for the C99 isinf() function. -int IsInf (float f); -int IsInf (double d); +/// 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 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(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(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 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 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 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::infinity(); +#else + const float huge_valf = HUGE_VALF; +#endif } // End llvm namespace #endif