X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FMathExtras.h;h=b7b3c02dcfe76be2cf9572cb4308f4aed4dc9905;hp=f660d48d862023b067effd1866dce26ad7126d0c;hb=156d5ee497ef9b6b08bad403f66c52bb15887db9;hpb=49e6a9bc94a115d674502009b396c1a22fb1b1a1

diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h
index f660d48d862..b7b3c02dcfe 100644
--- a/include/llvm/Support/MathExtras.h
+++ b/include/llvm/Support/MathExtras.h
@@ -2,8 +2,8 @@
 //
 //                     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.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -14,74 +14,344 @@
 #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>
 
-namespace llvm {
+#ifdef _MSC_VER
+#include <intrin.h>
+#endif
+
+#ifdef __ANDROID_NDK__
+#include <android/api-level.h>
+#endif
 
-// NOTE: The following support functions use the _32/_64 extensions instead of  
+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
+};
+
+namespace detail {
+template <typename T, std::size_t SizeOfT> struct TrailingZerosCounter {
+  static std::size_t count(T Val, ZeroBehavior) {
+    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;
+  }
+};
+
+#if __GNUC__ >= 4 || _MSC_VER
+template <typename T> struct TrailingZerosCounter<T, 4> {
+  static std::size_t count(T Val, ZeroBehavior ZB) {
+    if (ZB != ZB_Undefined && Val == 0)
+      return 32;
+
+#if __has_builtin(__builtin_ctz) || LLVM_GNUC_PREREQ(4, 0, 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 <typename T> struct TrailingZerosCounter<T, 8> {
+  static std::size_t count(T Val, ZeroBehavior ZB) {
+    if (ZB != ZB_Undefined && Val == 0)
+      return 64;
+
+#if __has_builtin(__builtin_ctzll) || LLVM_GNUC_PREREQ(4, 0, 0)
+    return __builtin_ctzll(Val);
+#elif _MSC_VER
+    unsigned long Index;
+    _BitScanForward64(&Index, Val);
+    return Index;
+#endif
+  }
+};
+#endif
+#endif
+} // namespace detail
+
+/// \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>
+std::size_t countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
+  static_assert(std::numeric_limits<T>::is_integer &&
+                    !std::numeric_limits<T>::is_signed,
+                "Only unsigned integral types are allowed.");
+  return detail::TrailingZerosCounter<T, sizeof(T)>::count(Val, ZB);
+}
+
+namespace detail {
+template <typename T, std::size_t SizeOfT> struct LeadingZerosCounter {
+  static std::size_t count(T Val, ZeroBehavior) {
+    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;
+  }
+};
+
+#if __GNUC__ >= 4 || _MSC_VER
+template <typename T> struct LeadingZerosCounter<T, 4> {
+  static std::size_t count(T Val, ZeroBehavior ZB) {
+    if (ZB != ZB_Undefined && Val == 0)
+      return 32;
+
+#if __has_builtin(__builtin_clz) || LLVM_GNUC_PREREQ(4, 0, 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 <typename T> struct LeadingZerosCounter<T, 8> {
+  static std::size_t count(T Val, ZeroBehavior ZB) {
+    if (ZB != ZB_Undefined && Val == 0)
+      return 64;
+
+#if __has_builtin(__builtin_clzll) || LLVM_GNUC_PREREQ(4, 0, 0)
+    return __builtin_clzll(Val);
+#elif _MSC_VER
+    unsigned long Index;
+    _BitScanReverse64(&Index, Val);
+    return Index ^ 63;
+#endif
+  }
+};
+#endif
+#endif
+} // namespace detail
+
+/// \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>
+std::size_t countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
+  static_assert(std::numeric_limits<T>::is_integer &&
+                    !std::numeric_limits<T>::is_signed,
+                "Only unsigned integral types are allowed.");
+  return detail::LeadingZerosCounter<T, sizeof(T)>::count(Val, ZB);
+}
+
+/// \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> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) {
+  if (ZB == ZB_Max && Val == 0)
+    return std::numeric_limits<T>::max();
+
+  return countTrailingZeros(Val, ZB_Undefined);
+}
+
+/// \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> T 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);
+}
+
+/// \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 unsigned Hi_32(uint64_t Value) {
-  return static_cast<unsigned>(Value >> 32);
+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 unsigned Lo_32(uint64_t Value) {
-  return static_cast<unsigned>(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);
 }
 
-/// is?Type - these functions produce optimal testing for integer data types.
-inline bool isInt8  (int64_t Value) { 
-  return static_cast<signed char>(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 isUInt8 (int64_t Value) { 
-  return static_cast<unsigned char>(Value) == Value; 
+template<>
+inline bool isUInt<16>(uint64_t x) {
+  return static_cast<uint16_t>(x) == x;
 }
-inline bool isInt16 (int64_t Value) { 
-  return static_cast<signed short>(Value) == Value; 
+template<>
+inline bool isUInt<32>(uint64_t x) {
+  return static_cast<uint32_t>(x) == x;
 }
-inline bool isUInt16(int64_t Value) { 
-  return static_cast<unsigned short>(Value) == Value; 
+
+/// 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);
 }
-inline bool isInt32 (int64_t Value) { 
-  return static_cast<signed int>(Value) == Value; 
+
+/// isUIntN - Checks if an unsigned integer fits into the given (dynamic)
+/// bit width.
+inline bool isUIntN(unsigned N, uint64_t x) {
+  return N >= 64 || x < (UINT64_C(1)<<(N));
 }
-inline bool isUInt32(int64_t Value) { 
-  return static_cast<unsigned int>(Value) == Value; 
+
+/// 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 const bool isMask_32(unsigned Value) {
+/// isMask_32 - This function returns true if the argument is a non-empty
+/// 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 non-empty
+/// 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.)
+/// isShiftedMask_32 - This function returns true if the argument contains a
+/// non-empty 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);
+inline bool isShiftedMask_32(uint32_t Value) {
+  return Value && 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) {
-  return isMask_64((Value - 1) | Value);
+/// isShiftedMask_64 - This function returns true if the argument contains a
+/// non-empty sequence of ones with the remainder zero (64 bit version.)
+inline bool isShiftedMask_64(uint64_t Value) {
+  return Value && 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(unsigned Value) {
+inline bool isPowerOf2_32(uint32_t Value) {
   return Value && !(Value & (Value - 1));
 }
 
@@ -93,163 +363,129 @@ inline bool isPowerOf2_64(uint64_t 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;
+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 unsigned ByteSwap_32(unsigned Value) {
-  unsigned Byte0 = Value & 0x000000FF;
-  unsigned Byte1 = Value & 0x0000FF00;
-  unsigned Byte2 = Value & 0x00FF0000;
-  unsigned Byte3 = Value & 0xFF000000;
-  return (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24);
+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) {
-  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.
-inline unsigned CountLeadingZeros_32(unsigned Value) {
-  unsigned Count; // result
+  return sys::SwapByteOrder_64(Value);
+}
+
+/// \brief Count the number of ones from the most significant bit to the first
+/// zero bit.
+///
+/// Ex. CountLeadingOnes(0xFF0FFF00) == 8.
+/// Only unsigned integral types are allowed.
+///
+/// \param ZB the behavior on an input of all ones. Only ZB_Width and
+/// ZB_Undefined are valid arguments.
+template <typename T>
+std::size_t countLeadingOnes(T Value, ZeroBehavior ZB = ZB_Width) {
+  static_assert(std::numeric_limits<T>::is_integer &&
+                    !std::numeric_limits<T>::is_signed,
+                "Only unsigned integral types are allowed.");
+  return countLeadingZeros(~Value, ZB);
+}
+
+/// \brief Count the number of ones from the least significant bit to the first
+/// zero bit.
+///
+/// Ex. countTrailingOnes(0x00FF00FF) == 8.
+/// Only unsigned integral types are allowed.
+///
+/// \param ZB the behavior on an input of all ones. Only ZB_Width and
+/// ZB_Undefined are valid arguments.
+template <typename T>
+std::size_t countTrailingOnes(T Value, ZeroBehavior ZB = ZB_Width) {
+  static_assert(std::numeric_limits<T>::is_integer &&
+                    !std::numeric_limits<T>::is_signed,
+                "Only unsigned integral types are allowed.");
+  return countTrailingZeros(~Value, ZB);
+}
+
+namespace detail {
+template <typename T, std::size_t SizeOfT> struct PopulationCounter {
+  static unsigned count(T Value) {
+    // Generic version, forward to 32 bits.
+    static_assert(SizeOfT <= 4, "Not implemented!");
 #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;
+    v = v - ((v >> 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
+template <typename T> struct PopulationCounter<T, 8> {
+  static unsigned count(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;
+    v = v - ((v >> 1) & 0x5555555555555555ULL);
+    v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL);
+    v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL;
+    return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56);
 #endif
-  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.
-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.
-inline unsigned CountTrailingZeros_64(uint64_t Value) {
-  return 64 - CountLeadingZeros_64(~Value & (Value - 1));
-}
+  }
+};
+} // namespace detail
 
-/// CountPopulation_32 - this function counts the number of set bits in a value.
-/// Ex. CountPopulation(0xF000F000) = 8
+/// \brief Count 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);
-  t = ((x >> 2) & 0x33333333);
-  x = (x & 0x33333333) + t;
-  x = (x + (x >> 4)) & 0x0F0F0F0F;
-  x = x + (x << 8);
-  x = x + (x << 16);
-  return x >> 24;
-}
-
-/// 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));
+template <typename T>
+inline unsigned countPopulation(T Value) {
+  static_assert(std::numeric_limits<T>::is_integer &&
+                    !std::numeric_limits<T>::is_signed,
+                "Only unsigned integral types are allowed.");
+  return detail::PopulationCounter<T, sizeof(T)>::count(Value);
+}
+
+/// Log2 - This function returns the log base 2 of the specified value
+inline double Log2(double Value) {
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 18
+  return __builtin_log(Value) / __builtin_log(2.0);
+#else
+  return log2(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(unsigned Value) {
-    return 31 - CountLeadingZeros_32(Value);
+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, 
+/// 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(unsigned Value) {
-  return 32-CountLeadingZeros_32(Value-1);
+inline unsigned Log2_32_Ceil(uint32_t Value) {
+  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
@@ -262,7 +498,7 @@ 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) {
@@ -286,7 +522,9 @@ inline float BitsToFloat(uint32_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;
@@ -297,7 +535,9 @@ inline uint64_t DoubleToBits(double Double) {
 }
 
 /// 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;
@@ -307,14 +547,139 @@ 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 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(const 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(const 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.
+///
+/// If non-zero \p Skew is specified, the return value will be a minimal
+/// integer that is greater than or equal to \p Value and equal to
+/// \p Align * N + \p Skew for some integer N. If \p Skew is larger than
+/// \p Align, its value is adjusted to '\p Skew mod \p Align'.
+///
+/// Examples:
+/// \code
+///   RoundUpToAlignment(5, 8) = 8
+///   RoundUpToAlignment(17, 8) = 24
+///   RoundUpToAlignment(~0LL, 8) = 0
+///   RoundUpToAlignment(321, 255) = 510
+///
+///   RoundUpToAlignment(5, 8, 7) = 7
+///   RoundUpToAlignment(17, 8, 1) = 17
+///   RoundUpToAlignment(~0LL, 8, 3) = 3
+///   RoundUpToAlignment(321, 255, 42) = 552
+/// \endcode
+inline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align,
+                                   uint64_t Skew = 0) {
+  Skew %= Align;
+  return (Value + Align - 1 - Skew) / Align * Align + Skew;
+}
+
+/// 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;
+}
+
+/// 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);
+}
+
+/// \brief Add two unsigned integers, X and Y, of type T.
+/// Clamp the result to the maximum representable value of T on overflow.
+template <typename T>
+typename std::enable_if<std::is_unsigned<T>::value, T>::type
+SaturatingAdd(T X, T Y) {
+  // Hacker's Delight, p. 29
+  T Z = X + Y;
+  if (Z < X || Z < Y)
+    return std::numeric_limits<T>::max();
+  else
+    return Z;
+}
+
+/// \brief Multiply two unsigned integers, X and Y, of type T.
+/// Clamp the result to the maximum representable value of T on overflow.
+template <typename T>
+typename std::enable_if<std::is_unsigned<T>::value, T>::type
+SaturatingMultiply(T X, T Y) {
+  // Hacker's Delight, p. 30
+  T Z = X * Y;
+  if (Y != 0 && Z / Y != X)
+    return std::numeric_limits<T>::max();
+  else
+    return Z;
+}
+
+extern const float huge_valf;
 } // End llvm namespace
 
 #endif