From 49e6a9bc94a115d674502009b396c1a22fb1b1a1 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 19 Dec 2006 01:11:32 +0000 Subject: [PATCH] Doxgenate comments. Add GreatestCommonDivisor64 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32661 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Support/MathExtras.h | 158 ++++++++++++++++-------------- 1 file changed, 84 insertions(+), 74 deletions(-) diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h index 76447b21ebf..f660d48d862 100644 --- a/include/llvm/Support/MathExtras.h +++ b/include/llvm/Support/MathExtras.h @@ -15,7 +15,6 @@ #define LLVM_SUPPORT_MATHEXTRAS_H #include "llvm/Support/DataTypes.h" -#include "llvm/System/IncludeFile.h" namespace llvm { @@ -23,28 +22,27 @@ namespace llvm { // 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. +/// Hi_32 - This function returns the high 32 bits of a 64 bit value. inline unsigned Hi_32(uint64_t Value) { return static_cast(Value >> 32); } -// Lo_32 - This function returns the low 32 bits of a 64 bit value. +/// Lo_32 - This function returns the low 32 bits of a 64 bit value. inline unsigned Lo_32(uint64_t Value) { return static_cast(Value); } -// is?Type - these functions produce optimal testing for integer data types. -inline bool isInt8 (int64_t Value) { +/// is?Type - these functions produce optimal testing for integer data types. +inline bool isInt8 (int64_t Value) { return static_cast(Value) == Value; } -inline bool isUInt8 (int64_t Value) { +inline bool isUInt8 (int64_t Value) { return static_cast(Value) == Value; } -inline bool isInt16 (int64_t Value) { +inline bool isInt16 (int64_t Value) { return static_cast(Value) == Value; } -inline bool isUInt16(int64_t Value) { +inline bool isUInt16(int64_t Value) { return static_cast(Value) == Value; } inline bool isInt32 (int64_t Value) { @@ -54,54 +52,55 @@ inline bool isUInt32(int64_t Value) { return static_cast(Value) == Value; } -// 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. +/// 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) { 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 sequence of ones +/// starting at the least significant bit with the remainder zero (64 bit +/// version). inline const 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. +/// 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) { 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.) +/// 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) { 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.) +/// 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) { 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 - int64_t(1L))); } -// ByteSwap_16 - This function returns a byte-swapped representation of the -// 16-bit argument, Value. +/// ByteSwap_16 - This function returns a byte-swapped representation of the +/// 16-bit argument, Value. inline unsigned short ByteSwap_16(unsigned short Value) { unsigned short Hi = Value << 8; unsigned short Lo = Value >> 8; return Hi | Lo; } -// ByteSwap_32 - This function returns a byte-swapped representation of the -// 32-bit argument, Value. +/// ByteSwap_32 - This function returns a byte-swapped representation of the +/// 32-bit argument, Value. inline unsigned ByteSwap_32(unsigned Value) { unsigned Byte0 = Value & 0x000000FF; unsigned Byte1 = Value & 0x0000FF00; @@ -110,18 +109,18 @@ inline unsigned ByteSwap_32(unsigned Value) { return (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24); } -// ByteSwap_64 - This function returns a byte-swapped representation of the -// 64-bit argument, Value. +/// ByteSwap_64 - This function returns a byte-swapped representation of the +/// 64-bit argument, Value. inline uint64_t ByteSwap_64(uint64_t Value) { uint64_t Hi = ByteSwap_32(unsigned(Value)); uint64_t Lo = ByteSwap_32(unsigned(Value >> 32)); return (Hi << 32) | Lo; } -// 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 #if __GNUC__ >= 4 @@ -146,10 +145,10 @@ inline unsigned CountLeadingZeros_32(unsigned Value) { 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. +/// 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 @@ -190,25 +189,25 @@ inline unsigned CountLeadingZeros_64(uint64_t Value) { return Count; } -// 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. +/// 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(unsigned Value) { return 32 - CountLeadingZeros_32(~Value & (Value - 1)); } -// 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. +/// 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) { return 64 - CountLeadingZeros_64(~Value & (Value - 1)); } -// CountPopulation_32 - this function counts the number of set bits in a value. -// Ex. CountPopulation(0xF000F000) = 8 -// Returns 0 if the word is zero. +/// 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(unsigned Value) { unsigned x, t; x = Value - ((Value >> 1) & 0x55555555); @@ -220,41 +219,52 @@ inline unsigned CountPopulation_32(unsigned Value) { return x >> 24; } -// CountPopulation_64 - this function counts the number of set bits in a value, -// (64 bit edition.) +/// CountPopulation_64 - this function counts the number of set bits in a value, +/// (64 bit edition.) inline unsigned CountPopulation_64(uint64_t Value) { return CountPopulation_32(unsigned(Value >> 32)) + CountPopulation_32(unsigned(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 +/// 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(unsigned Value) { return 31 - CountLeadingZeros_32(Value); } -// Log2_64 - This function returns the floor log base 2 of the specified value, -// -1 if the value is zero. (64 bit edition.) +/// 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); } -// 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 +/// 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(unsigned 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 - 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); } -// BitsToDouble - This function takes a 64-bit integer and returns the bit -// equivalent double. +/// 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; @@ -264,8 +274,8 @@ inline double BitsToDouble(uint64_t Bits) { return T.D; } -// BitsToFloat - This function takes a 32-bit integer and returns the bit -// equivalent float. +/// BitsToFloat - This function takes a 32-bit integer and returns the bit +/// equivalent float. inline float BitsToFloat(uint32_t Bits) { union { uint32_t I; @@ -275,8 +285,8 @@ inline float BitsToFloat(uint32_t Bits) { return T.F; } -// DoubleToBits - This function takes a double and returns the bit -// equivalent 64-bit integer. +/// DoubleToBits - This function takes a double and returns the bit +/// equivalent 64-bit integer. inline uint64_t DoubleToBits(double Double) { union { uint64_t L; @@ -286,8 +296,8 @@ inline uint64_t DoubleToBits(double Double) { return T.L; } -// FloatToBits - This function takes a float and returns the bit -// equivalent 32-bit integer. +/// FloatToBits - This function takes a float and returns the bit +/// equivalent 32-bit integer. inline uint32_t FloatToBits(float Float) { union { uint32_t I; @@ -297,13 +307,13 @@ inline uint32_t FloatToBits(float 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 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); +/// Platform-independent wrappers for the C99 isinf() function. +int IsInf(float f); +int IsInf(double d); } // End llvm namespace -- 2.34.1