X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FMathExtras.h;h=6a104e738fa7919b0f83bf89c60c3c7d642c8400;hp=d55fb80268adf398f8805631ed45f2797e51a5d2;hb=4f240010fdea1fcbe7dac3c8e9ebad082e4036c2;hpb=541ed9fd02ea48d2739f4a9dd681ba2d5da26886

diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h
index d55fb80268a..6a104e738fa 100644
--- a/include/llvm/Support/MathExtras.h
+++ b/include/llvm/Support/MathExtras.h
@@ -14,11 +14,240 @@
 #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
+};
+
+/// \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;
+
+  // 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;
+}
+
+// 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
+}
+
+#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
 
-// NOTE: The following support functions use the _32/_64 extensions instead of  
+/// \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();
+
+  // 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.
 
@@ -32,24 +261,74 @@ inline uint32_t Lo_32(uint64_t Value) {
   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; 
+/// 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;
 }
-inline bool isUInt8 (int64_t Value) { 
-  return static_cast<uint8_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 isInt16 (int64_t Value) { 
-  return static_cast<int16_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 isUInt16(int64_t Value) { 
-  return static_cast<uint16_t>(Value) == Value; 
+template<>
+inline bool isInt<16>(int64_t x) {
+  return static_cast<int16_t>(x) == x;
 }
-inline bool isInt32 (int64_t Value) { 
-  return static_cast<int32_t>(Value) == Value; 
+template<>
+inline bool isInt<32>(int64_t x) {
+  return static_cast<int32_t>(x) == x;
 }
-inline bool isUInt32(int64_t Value) { 
-  return static_cast<uint32_t>(Value) == Value; 
+
+/// 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
@@ -66,20 +345,20 @@ 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 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 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));
@@ -94,73 +373,19 @@ inline bool isPowerOf2_64(uint64_t Value) {
 /// 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_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) {
-#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_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) {
-#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
-}
-
-/// 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
-#if __GNUC__ >= 4
-  // PowerPC is defined for __builtin_clz(0)
-#if !defined(__ppc__) && !defined(__ppc64__)
-  if (!Value) return 32;
-#endif
-  Count = __builtin_clz(Value);
-#else
-  if (!Value) return 32;
-  Count = 0;
-  // bisecton 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;
-    }
-  }
-#endif
-  return Count;
+  return sys::SwapByteOrder_64(Value);
 }
 
 /// CountLeadingOnes_32 - this function performs the operation of
@@ -168,76 +393,15 @@ inline unsigned CountLeadingZeros_32(uint32_t Value) {
 /// 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;
-    // bisecton 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;
+  return countLeadingZeros(~Value);
 }
 
 /// CountLeadingOnes_64 - This function performs the operation
-/// of counting the number of ones from the most significant bit to the first 
+/// 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
+  return countLeadingZeros(~Value);
 }
 
 /// CountTrailingOnes_32 - this function performs the operation of
@@ -245,34 +409,15 @@ inline unsigned CountTrailingZeros_32(uint32_t Value) {
 /// 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) {
-#if __GNUC__ >= 4
-  return Value ? __builtin_ctzll(Value) : 64;
-#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];
-#endif
+  return countTrailingZeros(~Value);
 }
 
 /// CountTrailingOnes_64 - This function performs the operation
-/// of counting the number of ones from the least significant bit to the first 
+/// 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);
+  return countTrailingZeros(~Value);
 }
 
 /// CountPopulation_32 - this function counts the number of set bits in a value.
@@ -301,30 +446,30 @@ inline unsigned CountPopulation_64(uint64_t Value) {
 #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);
+  return 31 - countLeadingZeros(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 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 - 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 64 - countLeadingZeros(Value - 1);
 }
 
 /// GreatestCommonDivisor64 - Return the greatest common divisor of the two
@@ -337,7 +482,7 @@ inline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) {
   }
   return A;
 }
-  
+
 /// BitsToDouble - This function takes a 64-bit integer and returns the bit
 /// equivalent double.
 inline double BitsToDouble(uint64_t Bits) {
@@ -396,14 +541,37 @@ 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(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.
-static inline uint64_t NextPowerOf2(uint64_t A) {
+inline uint64_t NextPowerOf2(uint64_t A) {
   A |= (A >> 1);
   A |= (A >> 2);
   A |= (A >> 4);
@@ -412,7 +580,72 @@ static inline uint64_t NextPowerOf2(uint64_t A) {
   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