#ifndef LLVM_SUPPORT_MATHEXTRAS_H
#define LLVM_SUPPORT_MATHEXTRAS_H
-#include "llvm/System/SwapByteOrder.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/SwapByteOrder.h"
+#include <cassert>
+#include <cstring>
+#include <type_traits>
+
+#ifdef _MSC_VER
+#include <intrin.h>
+#endif
+
+#ifdef __ANDROID_NDK__
+#include <android/api-level.h>
+#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
+};
+
+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 || _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 _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 _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 || _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 _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 _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
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 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);
+ return N >= 64 || x < (UINT64_C(1)<<(N));
}
// Template specializations to get better code for common cases.
template<>
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)));
+ return N >= 64 || x < (UINT64_C(1)<<(N));
}
-/// 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.
+/// 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 non-empty
+/// 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).
+/// 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).
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.)
+/// non-empty 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);
+ return Value && 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.)
+/// non-empty sequence of ones with the remainder zero (64 bit version.)
inline bool isShiftedMask_64(uint64_t Value) {
- return isMask_64((Value - 1) | Value);
+ return Value && isMask_64((Value - 1) | Value);
}
/// isPowerOf2_32 - This function returns true if the argument is a power of
return sys::SwapByteOrder_64(Value);
}
-/// 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(uint32_t Value) {
- unsigned Count; // result
+/// \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
- // 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;
- // bisection method for count leading zeros
- for (unsigned Shift = 32 >> 1; Shift; Shift >>= 1) {
- uint32_t Tmp = Value >> Shift;
- if (Tmp) {
- Value = Tmp;
- } else {
- Count |= Shift;
- }
- }
+ uint32_t v = Value;
+ v = v - ((v >> 1) & 0x55555555);
+ v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
+ return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
#endif
- return Count;
-}
-
-/// 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_32(~Value);
-}
-
-/// 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
-#if __GNUC__ >= 4
- // PowerPC is defined for __builtin_clzll(0)
-#if !defined(__ppc__) && !defined(__ppc64__)
- if (!Value) return 64;
-#endif
- Count = __builtin_clzll(Value);
-#else
- if (sizeof(long) == sizeof(int64_t)) {
- if (!Value) return 64;
- Count = 0;
- // bisection method for count leading zeros
- for (unsigned Shift = 64 >> 1; Shift; Shift >>= 1) {
- uint64_t Tmp = Value >> Shift;
- if (Tmp) {
- Value = Tmp;
- } else {
- Count |= Shift;
- }
- }
- } else {
- // get hi portion
- uint32_t 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
- uint32_t Lo = Lo_32(Value);
- // same as 32 bit value
- Count = CountLeadingZeros_32(Lo)+32;
- }
}
-#endif
- return Count;
-}
-
-/// 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_64(~Value);
-}
-
-/// CountTrailingZeros_32 - this function performs the platform optimal form of
-/// counting the number of zeros from the least significant bit to the first one
-/// bit. Ex. CountTrailingZeros_32(0xFF00FF00) == 8.
-/// Returns 32 if the word is zero.
-inline unsigned CountTrailingZeros_32(uint32_t Value) {
-#if __GNUC__ >= 4
- return Value ? __builtin_ctz(Value) : 32;
-#else
- static const unsigned Mod37BitPosition[] = {
- 32, 0, 1, 26, 2, 23, 27, 0, 3, 16, 24, 30, 28, 11, 0, 13,
- 4, 7, 17, 0, 25, 22, 31, 15, 29, 10, 12, 6, 0, 21, 14, 9,
- 5, 20, 8, 19, 18
- };
- return Mod37BitPosition[(-Value & Value) % 37];
-#endif
-}
+};
-/// 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_32(~Value);
-}
-
-/// CountTrailingZeros_64 - This function performs the platform optimal form
-/// of counting the number of zeros from the least significant bit to the first
-/// one bit (64 bit edition.)
-/// Returns 64 if the word is zero.
-inline unsigned CountTrailingZeros_64(uint64_t Value) {
+template <typename T> struct PopulationCounter<T, 8> {
+ static unsigned count(T Value) {
#if __GNUC__ >= 4
- return Value ? __builtin_ctzll(Value) : 64;
+ return __builtin_popcountll(Value);
#else
- static const unsigned Mod67Position[] = {
- 64, 0, 1, 39, 2, 15, 40, 23, 3, 12, 16, 59, 41, 19, 24, 54,
- 4, 64, 13, 10, 17, 62, 60, 28, 42, 30, 20, 51, 25, 44, 55,
- 47, 5, 32, 65, 38, 14, 22, 11, 58, 18, 53, 63, 9, 61, 27,
- 29, 50, 43, 46, 31, 37, 21, 57, 52, 8, 26, 49, 45, 36, 56,
- 7, 48, 35, 6, 34, 33, 0
- };
- return Mod67Position[(-Value & Value) % 67];
+ 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
-}
-
-/// 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_64(~Value);
-}
+ }
+};
+} // namespace detail
-/// CountPopulation_32 - this function counts the number of set bits in a value.
-/// Ex. CountPopulation(0xF000F000) = 8
+/// \brief Count 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);
+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
- 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);
+ return log2(Value);
#endif
}
/// -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_32(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_64(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_32(Value-1);
+ 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_64(Value-1);
+ return 64 - countLeadingZeros(Value - 1);
}
/// GreatestCommonDivisor64 - Return the greatest common divisor of the two
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.
-static inline uint64_t MinAlign(uint64_t A, uint64_t B) {
+inline uint64_t MinAlign(uint64_t A, uint64_t B) {
// The largest power of 2 that divides both A and B.
- return (A | B) & -(A | 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.
-static inline uint64_t NextPowerOf2(uint64_t A) {
+inline uint64_t NextPowerOf2(uint64_t A) {
A |= (A >> 1);
A |= (A >> 2);
A |= (A >> 4);
return A + 1;
}
-/// RoundUpToAlignment - Returns the next integer (mod 2**64) that is
-/// greater than or equal to \arg Value and is a multiple of \arg
-/// Align. Align must be non-zero.
-///
-/// Examples:
-/// RoundUpToAlignment(5, 8) = 8
-/// RoundUpToAlignment(17, 8) = 24
-/// RoundUpToAlignment(~0LL, 8) = 0
-inline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align) {
- return ((Value + Align - 1) / Align) * Align;
+/// 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));
}
-/// OffsetToAlignment - Return the offset to the next integer (mod 2**64) that
-/// is greater than or equal to \arg Value and is a multiple of \arg
-/// Align. Align must be non-zero.
+/// 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
+/// RoundUpToAlignment(5, 8) = 8
+/// RoundUpToAlignment(17, 8) = 24
+/// RoundUpToAlignment(~0LL, 8) = 0
+/// RoundUpToAlignment(321, 255) = 510
+///
+/// RoundUpToAlignment(5, 8, 7) = 7
+/// RoundUpToAlignment(17, 8, 1) = 17
+/// RoundUpToAlignment(~0LL, 8, 3) = 3
+/// RoundUpToAlignment(321, 255, 42) = 552
+/// \endcode
+inline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align,
+ uint64_t Skew = 0) {
+ Skew %= Align;
+ return (Value + Align - 1 - 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 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);
+}
+
+/// \brief Add two unsigned integers, X and Y, of type T.
+/// Clamp the result to the maximum representable value of T on overflow.
+template <typename T>
+typename std::enable_if<std::is_unsigned<T>::value, T>::type
+SaturatingAdd(T X, T Y) {
+ // Hacker's Delight, p. 29
+ T Z = X + Y;
+ if (Z < X || Z < Y)
+ return std::numeric_limits<T>::max();
+ else
+ return Z;
+}
+
+/// \brief Multiply two unsigned integers, X and Y, of type T.
+/// Clamp the result to the maximum representable value of T on overflow.
+template <typename T>
+typename std::enable_if<std::is_unsigned<T>::value, T>::type
+SaturatingMultiply(T X, T Y) {
+ // Hacker's Delight, p. 30
+ T Z = X * Y;
+ if (Y != 0 && Z / Y != X)
+ return std::numeric_limits<T>::max();
+ else
+ return Z;
+}
+
+extern const float huge_valf;
} // End llvm namespace
#endif
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