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=ff41608f5f5178df0dbf17f2cd83187c438ea986;hb=156d5ee497ef9b6b08bad403f66c52bb15887db9;hpb=20d7ed198978f871e91fde66e3b9a4a73a7c5396 diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h index ff41608f5f5..b7b3c02dcfe 100644 --- a/include/llvm/Support/MathExtras.h +++ b/include/llvm/Support/MathExtras.h @@ -16,13 +16,16 @@ #include "llvm/Support/Compiler.h" #include "llvm/Support/SwapByteOrder.h" -#include "llvm/Support/type_traits.h" - +#include #include +#include #ifdef _MSC_VER #include -#include +#endif + +#ifdef __ANDROID_NDK__ +#include #endif namespace llvm { @@ -36,78 +39,66 @@ enum ZeroBehavior { 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 enable_if_c::is_integer && - !std::numeric_limits::is_signed, std::size_t>::type -countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) { - (void)ZB; - - if (!Val) - return std::numeric_limits::digits; - if (Val & 0x1) - return 0; - - // Bisection method. - std::size_t ZeroBits = 0; - T Shift = std::numeric_limits::digits >> 1; - T Mask = std::numeric_limits::max() >> Shift; - while (Shift) { - if ((Val & Mask) == 0) { - Val >>= Shift; - ZeroBits |= Shift; +namespace detail { +template struct TrailingZerosCounter { + static std::size_t count(T Val, ZeroBehavior) { + if (!Val) + return std::numeric_limits::digits; + if (Val & 0x1) + return 0; + + // Bisection method. + std::size_t ZeroBits = 0; + T Shift = std::numeric_limits::digits >> 1; + T Mask = std::numeric_limits::max() >> Shift; + while (Shift) { + if ((Val & Mask) == 0) { + Val >>= Shift; + ZeroBits |= Shift; + } + Shift >>= 1; + Mask >>= Shift; } - Shift >>= 1; - Mask >>= Shift; + return ZeroBits; } - return ZeroBits; -} - -// Disable signed. -template -typename enable_if_c::is_integer && - std::numeric_limits::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 Val, ZeroBehavior ZB) { - if (ZB != ZB_Undefined && Val == 0) - return 32; +template struct TrailingZerosCounter { + static std::size_t count(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); +#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; + unsigned long Index; + _BitScanForward(&Index, Val); + return Index; #endif -} + } +}; #if !defined(_MSC_VER) || defined(_M_X64) -template <> -inline std::size_t countTrailingZeros(uint64_t Val, ZeroBehavior ZB) { - if (ZB != ZB_Undefined && Val == 0) - return 64; +template struct TrailingZerosCounter { + static std::size_t count(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); +#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; + unsigned long Index; + _BitScanForward64(&Index, Val); + return Index; #endif -} + } +}; #endif #endif +} // namespace detail -/// \brief Count number of 0's from the most significant bit to the least +/// \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. @@ -115,63 +106,81 @@ inline std::size_t countTrailingZeros(uint64_t Val, ZeroBehavior ZB) { /// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are /// valid arguments. template -typename enable_if_c::is_integer && - !std::numeric_limits::is_signed, std::size_t>::type -countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) { - (void)ZB; - - if (!Val) - return std::numeric_limits::digits; - - // Bisection method. - std::size_t ZeroBits = 0; - for (T Shift = std::numeric_limits::digits >> 1; Shift; Shift >>= 1) { - T Tmp = Val >> Shift; - if (Tmp) - Val = Tmp; - else - ZeroBits |= Shift; +std::size_t countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) { + static_assert(std::numeric_limits::is_integer && + !std::numeric_limits::is_signed, + "Only unsigned integral types are allowed."); + return detail::TrailingZerosCounter::count(Val, ZB); +} + +namespace detail { +template struct LeadingZerosCounter { + static std::size_t count(T Val, ZeroBehavior) { + if (!Val) + return std::numeric_limits::digits; + + // Bisection method. + std::size_t ZeroBits = 0; + for (T Shift = std::numeric_limits::digits >> 1; Shift; Shift >>= 1) { + T Tmp = Val >> Shift; + if (Tmp) + Val = Tmp; + else + ZeroBits |= Shift; + } + return ZeroBits; } - return ZeroBits; -} - -// Disable signed. -template -typename enable_if_c::is_integer && - std::numeric_limits::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 Val, ZeroBehavior ZB) { - if (ZB != ZB_Undefined && Val == 0) - return 32; +template struct LeadingZerosCounter { + static std::size_t count(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); +#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; + 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 Val, ZeroBehavior ZB) { - if (ZB != ZB_Undefined && Val == 0) - return 64; +template struct LeadingZerosCounter { + static std::size_t count(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); +#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; + 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 +std::size_t countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) { + static_assert(std::numeric_limits::is_integer && + !std::numeric_limits::is_signed, + "Only unsigned integral types are allowed."); + return detail::LeadingZerosCounter::count(Val, ZB); +} /// \brief Get the index of the first set bit starting from the least /// significant bit. @@ -180,22 +189,13 @@ inline std::size_t countLeadingZeros(uint64_t Val, ZeroBehavior ZB) { /// /// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are /// valid arguments. -template -typename enable_if_c::is_integer && - !std::numeric_limits::is_signed, T>::type -findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) { +template T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) { if (ZB == ZB_Max && Val == 0) return std::numeric_limits::max(); return countTrailingZeros(Val, ZB_Undefined); } -// Disable signed. -template -typename enable_if_c::is_integer && - std::numeric_limits::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. /// @@ -203,10 +203,7 @@ findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) LLVM_DELETED_FUNCTION; /// /// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are /// valid arguments. -template -typename enable_if_c::is_integer && - !std::numeric_limits::is_signed, T>::type -findLastSet(T Val, ZeroBehavior ZB = ZB_Max) { +template T findLastSet(T Val, ZeroBehavior ZB = ZB_Max) { if (ZB == ZB_Max && Val == 0) return std::numeric_limits::max(); @@ -216,12 +213,6 @@ findLastSet(T Val, ZeroBehavior ZB = ZB_Max) { (std::numeric_limits::digits - 1); } -// Disable signed. -template -typename enable_if_c::is_integer && - std::numeric_limits::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 @@ -230,6 +221,9 @@ static const unsigned char BitReverseTable256[256] = { #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. @@ -258,6 +252,12 @@ inline uint32_t Lo_32(uint64_t Value) { return static_cast(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 inline bool isInt(int64_t x) { @@ -313,7 +313,7 @@ inline bool isShiftedUInt(uint64_t x) { /// 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))); + return N >= 64 || x < (UINT64_C(1)<<(N)); } /// isIntN - Checks if an signed integer fits into the given (dynamic) @@ -322,31 +322,31 @@ 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. +/// 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). +/// 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.) +/// non-empty 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); + 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.) +/// non-empty sequence of ones with the remainder zero (64 bit version.) inline bool isShiftedMask_64(uint64_t Value) { - return isMask_64((Value - 1) | Value); + return Value && isMask_64((Value - 1) | Value); } /// isPowerOf2_32 - This function returns true if the argument is a power of @@ -379,61 +379,86 @@ inline uint64_t ByteSwap_64(uint64_t Value) { return sys::SwapByteOrder_64(Value); } -/// 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(~Value); -} - -/// 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(~Value); -} - -/// 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(~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 +std::size_t countLeadingOnes(T Value, ZeroBehavior ZB = ZB_Width) { + static_assert(std::numeric_limits::is_integer && + !std::numeric_limits::is_signed, + "Only unsigned integral types are allowed."); + return countLeadingZeros(~Value, ZB); } -/// 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(~Value); -} +/// \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 +std::size_t countTrailingOnes(T Value, ZeroBehavior ZB = ZB_Width) { + static_assert(std::numeric_limits::is_integer && + !std::numeric_limits::is_signed, + "Only unsigned integral types are allowed."); + return countTrailingZeros(~Value, ZB); +} + +namespace detail { +template struct PopulationCounter { + static unsigned count(T Value) { + // Generic version, forward to 32 bits. + static_assert(SizeOfT <= 4, "Not implemented!"); +#if __GNUC__ >= 4 + return __builtin_popcount(Value); +#else + uint32_t v = Value; + v = v - ((v >> 1) & 0x55555555); + v = (v & 0x33333333) + ((v >> 2) & 0x33333333); + return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; +#endif + } +}; -/// 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(uint32_t Value) { +template struct PopulationCounter { + static unsigned count(T Value) { #if __GNUC__ >= 4 - return __builtin_popcount(Value); + return __builtin_popcountll(Value); #else - uint32_t v = Value - ((Value >> 1) & 0x55555555); - v = (v & 0x33333333) + ((v >> 2) & 0x33333333); - return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; + 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 + } +}; +} // namespace detail + +/// \brief Count the number of set bits in a value. +/// Ex. countPopulation(0xF000F000) = 8 +/// Returns 0 if the word is zero. +template +inline unsigned countPopulation(T Value) { + static_assert(std::numeric_limits::is_integer && + !std::numeric_limits::is_signed, + "Only unsigned integral types are allowed."); + return detail::PopulationCounter::count(Value); } -/// CountPopulation_64 - this function counts the number of set bits in a value, -/// (64 bit edition.) -inline unsigned CountPopulation_64(uint64_t Value) { -#if __GNUC__ >= 4 - return __builtin_popcountll(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 - uint64_t v = Value - ((Value >> 1) & 0x5555555555555555ULL); - v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL); - v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL; - return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56); + return log2(Value); #endif } @@ -522,25 +547,36 @@ 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 + // 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) { @@ -553,17 +589,37 @@ inline uint64_t NextPowerOf2(uint64_t A) { 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) { - return ((Value + Align - 1) / Align) * Align; +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 @@ -573,13 +629,6 @@ 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 inline int32_t SignExtend32(uint32_t x) { @@ -604,13 +653,33 @@ 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::infinity(); -#else - const float huge_valf = HUGE_VALF; -#endif +/// \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 std::enable_if::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::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 std::enable_if::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::max(); + else + return Z; +} + +extern const float huge_valf; } // End llvm namespace #endif