//
// 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/System/DataTypes.h"
+#include "llvm/System/SwapByteOrder.h"
namespace llvm {
-// NOTE: The following support functions use the _32/_64 extensions instead of
+// 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.
return static_cast<uint32_t>(Value);
}
-/// is?Type - these functions produce optimal testing for integer data types.
-inline bool isInt8 (int64_t Value) {
- return static_cast<int8_t>(Value) == Value;
+/// 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)));
}
-inline bool isUInt8 (int64_t Value) {
- return static_cast<uint8_t>(Value) == Value;
+// Template specializations to get better code for common cases.
+template<>
+inline bool isInt<8>(int64_t x) {
+ return static_cast<int8_t>(x) == x;
}
-inline bool isInt16 (int64_t Value) {
- return static_cast<int16_t>(Value) == Value;
+template<>
+inline bool isInt<16>(int64_t x) {
+ return static_cast<int16_t>(x) == x;
}
-inline bool isUInt16(int64_t Value) {
- return static_cast<uint16_t>(Value) == Value;
+template<>
+inline bool isInt<32>(int64_t x) {
+ return static_cast<int32_t>(x) == x;
}
-inline bool isInt32 (int64_t Value) {
- return static_cast<int32_t>(Value) == Value;
+
+/// 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;
}
-inline bool isUInt32(int64_t Value) {
- return static_cast<uint32_t>(Value) == Value;
+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;
}
/// 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(uint32_t Value) {
+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) {
+inline bool isMask_64(uint64_t Value) {
return Value && ((Value + 1) & Value) == 0;
}
-/// isShiftedMask_32 - This function returns true if the argument contains a
+/// 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(uint32_t Value) {
+inline bool isShiftedMask_32(uint32_t Value) {
return isMask_32((Value - 1) | Value);
}
-/// isShiftedMask_64 - This function returns true if the argument contains a
+/// 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) {
+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
+/// 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));
/// ByteSwap_16 - This function returns a byte-swapped representation of the
/// 16-bit argument, Value.
inline uint16_t ByteSwap_16(uint16_t Value) {
-#if defined(_MSC_VER) && !defined(_DEBUG)
- // The DLL version of the runtime lacks these functions (bug!?), but in a
- // release build they're replaced with BSWAP instructions anyway.
- return _byteswap_ushort(Value);
-#else
- uint16_t Hi = Value << 8;
- uint16_t Lo = Value >> 8;
- return Hi | Lo;
-#endif
+ return sys::SwapByteOrder(Value);
}
/// ByteSwap_32 - This function returns a byte-swapped representation of the
/// 32-bit argument, Value.
inline uint32_t ByteSwap_32(uint32_t Value) {
-#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
- return __builtin_bswap32(Value);
-#elif defined(_MSC_VER) && !defined(_DEBUG)
- return _byteswap_ulong(Value);
-#else
- uint32_t Byte0 = Value & 0x000000FF;
- uint32_t Byte1 = Value & 0x0000FF00;
- uint32_t Byte2 = Value & 0x00FF0000;
- uint32_t Byte3 = Value & 0xFF000000;
- return (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24);
-#endif
+ return sys::SwapByteOrder(Value);
}
/// ByteSwap_64 - This function returns a byte-swapped representation of the
/// 64-bit argument, Value.
inline uint64_t ByteSwap_64(uint64_t Value) {
-#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
- return __builtin_bswap64(Value);
-#elif defined(_MSC_VER) && !defined(_DEBUG)
- return _byteswap_uint64(Value);
-#else
- uint64_t Hi = ByteSwap_32(uint32_t(Value));
- uint32_t Lo = ByteSwap_32(uint32_t(Value >> 32));
- return (Hi << 32) | Lo;
-#endif
+ return sys::SwapByteOrder(Value);
}
/// CountLeadingZeros_32 - this function performs the platform optimal form of
#else
if (!Value) return 32;
Count = 0;
- // bisecton method for count leading zeros
+ // bisection method for count leading zeros
for (unsigned Shift = 32 >> 1; Shift; Shift >>= 1) {
uint32_t Tmp = Value >> Shift;
if (Tmp) {
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
+/// 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) {
if (sizeof(long) == sizeof(int64_t)) {
if (!Value) return 64;
Count = 0;
- // bisecton method for count leading zeros
+ // bisection method for count leading zeros
for (unsigned Shift = 64 >> 1; Shift; Shift >>= 1) {
uint64_t Tmp = Value >> Shift;
if (Tmp) {
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.
#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
+/// 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) {
#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);
+}
+
/// CountPopulation_32 - this function counts the number of set bits in a value.
/// Ex. CountPopulation(0xF000F000) = 8
/// Returns 0 if the word is zero.
#endif
}
-/// Log2_32 - This function returns the floor log base 2 of the specified 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_32(Value);
}
-/// Log2_64 - This function returns the floor log base 2 of the specified 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 32-CountLeadingZeros_32(Value-1);
}
-/// Log2_64 - This function returns the ceil log base 2 of the specified value,
-/// 64 if the value is zero. (64 bit edition.)
+/// 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 A;
}
-
+
/// BitsToDouble - This function takes a 64-bit integer and returns the bit
/// equivalent double.
inline double BitsToDouble(uint64_t Bits) {
}
/// DoubleToBits - This function takes a double and returns the bit
-/// equivalent 64-bit integer.
+/// 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;
}
/// FloatToBits - This function takes a float and returns the bit
-/// equivalent 32-bit integer.
+/// 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;
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) {
+ // The largest power of 2 that divides both A and B.
+ return (A | B) & -(A | B);
+}
+
+/// 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) {
+ A |= (A >> 1);
+ A |= (A >> 2);
+ A |= (A >> 4);
+ A |= (A >> 8);
+ A |= (A >> 16);
+ A |= (A >> 32);
+ 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;
+}
+
+/// 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.
+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);
+}
+
+/// 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);
+}
+
} // End llvm namespace
#endif