Doxgenate comments.

Add GreatestCommonDivisor64


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32661 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 84 insertions, 74 deletions

diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h
index 76447b2..f660d48 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<unsigned>(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<unsigned>(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<signed char>(Value) == Value; 
 }
-inline bool isUInt8 (int64_t Value)     { 
+inline bool isUInt8 (int64_t Value) { 
   return static_cast<unsigned char>(Value) == Value; 
 }
-inline bool isInt16 (int64_t Value)     { 
+inline bool isInt16 (int64_t Value) { 
   return static_cast<signed short>(Value) == Value; 
 }
-inline bool isUInt16(int64_t Value)     { 
+inline bool isUInt16(int64_t Value) { 
   return static_cast<unsigned short>(Value) == Value; 
 }
 inline bool isInt32 (int64_t Value) { 
@@ -54,54 +52,55 @@ inline bool isUInt32(int64_t Value) {
   return static_cast<unsigned int>(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