//
// 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.
//
//===----------------------------------------------------------------------===//
//
#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 <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
+};
-// 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 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;
-// 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<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;
}
-// 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 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
}
-// 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>(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();
-// 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<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 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 <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
projects / oota-llvm.git / blobdiff