1551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer//===-- llvm/Support/MathExtras.h - Useful math functions -------*- C++ -*-===// 263b3afa98460ce38a1c48d3c44ef6edfdaf37b77Misha Brukman// 3b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// The LLVM Compiler Infrastructure 4b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell// 57ed47a13356daed2a34cd2209a31f92552e3bdd8Chris Lattner// This file is distributed under the University of Illinois Open Source 67ed47a13356daed2a34cd2209a31f92552e3bdd8Chris Lattner// License. See LICENSE.TXT for details. 763b3afa98460ce38a1c48d3c44ef6edfdaf37b77Misha Brukman// 8b2109ce97881269a610fa4afbcbca350e975174dJohn Criswell//===----------------------------------------------------------------------===// 954ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner// 1054ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner// This file contains some functions that are useful for math stuff. 1154ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner// 1254ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner//===----------------------------------------------------------------------===// 13cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 14551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#ifndef LLVM_SUPPORT_MATHEXTRAS_H 15551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#define LLVM_SUPPORT_MATHEXTRAS_H 16cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 17a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#include "llvm/Support/Compiler.h" 181f6efa3996dd1929fbc129203ce5009b620e6969Michael J. Spencer#include "llvm/Support/SwapByteOrder.h" 1936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include <cassert> 2036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#include <cstring> 2136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include <type_traits> 22cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 23c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer#ifdef _MSC_VER 24eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman#include <intrin.h> 25c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer#endif 26c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer 27d0fde30ce850b78371fd1386338350591f9ff494Brian Gaekenamespace llvm { 2836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief The behavior an operation has on an input of 0. 2936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerenum ZeroBehavior { 3036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is undefined. 3136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Undefined, 3236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is numeric_limits<T>::max() 3336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Max, 3436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is numeric_limits<T>::digits 3536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Width 3636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer}; 3736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 38ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesnamespace detail { 39ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T, std::size_t SizeOfT> struct TrailingZerosCounter { 40ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior) { 41ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (!Val) 42ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return std::numeric_limits<T>::digits; 43ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (Val & 0x1) 44ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 0; 45ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 46ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // Bisection method. 47ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines std::size_t ZeroBits = 0; 48ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines T Shift = std::numeric_limits<T>::digits >> 1; 49ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines T Mask = std::numeric_limits<T>::max() >> Shift; 50ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines while (Shift) { 51ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if ((Val & Mask) == 0) { 52ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Val >>= Shift; 53ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines ZeroBits |= Shift; 54ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 55ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Shift >>= 1; 56ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Mask >>= Shift; 5736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 58ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return ZeroBits; 5936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 60ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 6136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 6236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#if __GNUC__ >= 4 || _MSC_VER 63ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct TrailingZerosCounter<T, 4> { 64ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 65ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 66ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 32; 6736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 6837ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_ctz) || LLVM_GNUC_PREREQ(4, 0, 0) 69ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_ctz(Val); 7036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 71ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 72ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanForward(&Index, Val); 73ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index; 7436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 75ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 76ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 7736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 78a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#if !defined(_MSC_VER) || defined(_M_X64) 79ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct TrailingZerosCounter<T, 8> { 80ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 81ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 82ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 64; 8336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 8437ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_ctzll) || LLVM_GNUC_PREREQ(4, 0, 0) 85ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_ctzll(Val); 8636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 87ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 88ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanForward64(&Index, Val); 89ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index; 9036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 91ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 92ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 9336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 94a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#endif 95ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} // namespace detail 9636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 97ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count number of 0's from the least significant bit to the most 9836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// stopping at the first 1. 9936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 10036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 10136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 10236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are 10336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 10436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 105ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) { 106ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 107ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 108ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 109ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return detail::TrailingZerosCounter<T, sizeof(T)>::count(Val, ZB); 110ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} 111ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 112ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesnamespace detail { 113ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T, std::size_t SizeOfT> struct LeadingZerosCounter { 114ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior) { 115ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (!Val) 116ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return std::numeric_limits<T>::digits; 117ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 118ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // Bisection method. 119ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines std::size_t ZeroBits = 0; 120ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines for (T Shift = std::numeric_limits<T>::digits >> 1; Shift; Shift >>= 1) { 121ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines T Tmp = Val >> Shift; 122ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (Tmp) 123ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Val = Tmp; 124ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines else 125ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines ZeroBits |= Shift; 126ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 127ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return ZeroBits; 12836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 129ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 13036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 13136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#if __GNUC__ >= 4 || _MSC_VER 132ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct LeadingZerosCounter<T, 4> { 133ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 134ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 135ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 32; 13636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 13737ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_clz) || LLVM_GNUC_PREREQ(4, 0, 0) 138ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_clz(Val); 13936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 140ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 141ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanReverse(&Index, Val); 142ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index ^ 31; 14336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 144ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 145ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 14636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 147a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#if !defined(_MSC_VER) || defined(_M_X64) 148ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct LeadingZerosCounter<T, 8> { 149ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 150ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 151ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 64; 15236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 15337ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_clzll) || LLVM_GNUC_PREREQ(4, 0, 0) 154ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_clzll(Val); 15536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 156ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 157ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanReverse64(&Index, Val); 158ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index ^ 63; 15936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 160ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 161ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 16236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 163a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#endif 164ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} // namespace detail 165ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 166ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count number of 0's from the most significant bit to the least 167ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// stopping at the first 1. 168ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 169ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Only unsigned integral types are allowed. 170ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 171ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are 172ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// valid arguments. 173ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 174ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) { 175ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 176ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 177ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 178ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return detail::LeadingZerosCounter<T, sizeof(T)>::count(Val, ZB); 179ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} 18036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 18136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Get the index of the first set bit starting from the least 18236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// significant bit. 18336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 18436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 18536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 18636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are 18736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 188ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) { 18936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB == ZB_Max && Val == 0) 19036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::max(); 19136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 19236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return countTrailingZeros(Val, ZB_Undefined); 19336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 19436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 19536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Get the index of the last set bit starting from the least 19636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// significant bit. 19736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 19836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 19936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 20036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are 20136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 202ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> T findLastSet(T Val, ZeroBehavior ZB = ZB_Max) { 20336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB == ZB_Max && Val == 0) 20436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::max(); 20536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 20636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // Use ^ instead of - because both gcc and llvm can remove the associated ^ 20736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // in the __builtin_clz intrinsic on x86. 20836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return countLeadingZeros(Val, ZB_Undefined) ^ 20936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer (std::numeric_limits<T>::digits - 1); 21036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 21136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 21236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Macro compressed bit reversal table for 256 bits. 21336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 21436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable 21536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerstatic const unsigned char BitReverseTable256[256] = { 21636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R2(n) n, n + 2 * 64, n + 1 * 64, n + 3 * 64 21736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R4(n) R2(n), R2(n + 2 * 16), R2(n + 1 * 16), R2(n + 3 * 16) 21836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R6(n) R4(n), R4(n + 2 * 4), R4(n + 1 * 4), R4(n + 3 * 4) 21936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer R6(0), R6(2), R6(1), R6(3) 220c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines#undef R2 221c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines#undef R4 222c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines#undef R6 22336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer}; 22436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 22536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Reverse the bits in \p Val. 22636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 22736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencerT reverseBits(T Val) { 22836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned char in[sizeof(Val)]; 22936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned char out[sizeof(Val)]; 23036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::memcpy(in, &Val, sizeof(Val)); 23136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer for (unsigned i = 0; i < sizeof(Val); ++i) 23236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer out[(sizeof(Val) - i) - 1] = BitReverseTable256[in[i]]; 23336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::memcpy(&Val, out, sizeof(Val)); 23436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return Val; 23536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 236d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 237fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman// NOTE: The following support functions use the _32/_64 extensions instead of 23889bfcd34cbd2f4c6bb2cafff0a5c2bff147fae11Chris Lattner// type overloading so that signed and unsigned integers can be used without 23989bfcd34cbd2f4c6bb2cafff0a5c2bff147fae11Chris Lattner// ambiguity. 24088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 24149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Hi_32 - This function returns the high 32 bits of a 64 bit value. 242c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t Hi_32(uint64_t Value) { 243c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Cohen return static_cast<uint32_t>(Value >> 32); 24488c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 24588c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 24649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Lo_32 - This function returns the low 32 bits of a 64 bit value. 247c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t Lo_32(uint64_t Value) { 248c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Cohen return static_cast<uint32_t>(Value); 24988c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 25088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 251c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines/// Make_64 - This functions makes a 64-bit integer from a high / low pair of 252c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines/// 32-bit integers. 253c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hinesinline uint64_t Make_64(uint32_t High, uint32_t Low) { 254c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines return ((uint64_t)High << 32) | (uint64_t)Low; 255c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines} 256c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines 25734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer/// isInt - Checks if an integer fits into the given bit width. 258d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesentemplate<unsigned N> 259d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Oleseninline bool isInt(int64_t x) { 260d4c00c0f558193b492aed9ab6aacf84bf1d3fb4eJakob Stoklund Olesen return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1))); 261d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen} 26234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer// Template specializations to get better code for common cases. 26334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 26434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<8>(int64_t x) { 26534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int8_t>(x) == x; 26634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 26734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 26834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<16>(int64_t x) { 26934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int16_t>(x) == x; 27034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 27134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 27234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<32>(int64_t x) { 27334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int32_t>(x) == x; 27434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 275d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen 276b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// isShiftedInt<N,S> - Checks if a signed integer is an N bit number shifted 277b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// left by S. 278b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicumtemplate<unsigned N, unsigned S> 279b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicuminline bool isShiftedInt(int64_t x) { 280b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum return isInt<N+S>(x) && (x % (1<<S) == 0); 281b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum} 282b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum 28334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer/// isUInt - Checks if an unsigned integer fits into the given bit width. 284d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesentemplate<unsigned N> 28534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt(uint64_t x) { 28666f1f30725eb20760069823ec015234cce6b887cReid Kleckner return N >= 64 || x < (UINT64_C(1)<<(N)); 287d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen} 28834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer// Template specializations to get better code for common cases. 28934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 29034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<8>(uint64_t x) { 29134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint8_t>(x) == x; 29234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 29334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 29434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<16>(uint64_t x) { 29534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint16_t>(x) == x; 29634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 29734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 29834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<32>(uint64_t x) { 29934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint32_t>(x) == x; 30034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 301d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen 302b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// isShiftedUInt<N,S> - Checks if a unsigned integer is an N bit number shifted 303b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// left by S. 304b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicumtemplate<unsigned N, unsigned S> 305b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicuminline bool isShiftedUInt(uint64_t x) { 306b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum return isUInt<N+S>(x) && (x % (1<<S) == 0); 307b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum} 308b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum 3095005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman/// isUIntN - Checks if an unsigned integer fits into the given (dynamic) 3105005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman/// bit width. 3115005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohmaninline bool isUIntN(unsigned N, uint64_t x) { 3125005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman return x == (x & (~0ULL >> (64 - N))); 3135005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman} 3145005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman 315c42a7754bb6249c33c509e6fa6e8b3c9344e72d8Rafael Espindola/// isIntN - Checks if an signed integer fits into the given (dynamic) 316b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola/// bit width. 317b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindolainline bool isIntN(unsigned N, int64_t x) { 318b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1))); 319b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola} 320b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola 3212c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// isMask_32 - This function returns true if the argument is a non-empty 3222c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// sequence of ones starting at the least significant bit with the remainder 3232c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// zero (32 bit version). Ex. isMask_32(0x0000FFFFU) == true. 32418a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isMask_32(uint32_t Value) { 32588c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && ((Value + 1) & Value) == 0; 32688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 32788c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 3282c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// isMask_64 - This function returns true if the argument is a non-empty 3292c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// sequence of ones starting at the least significant bit with the remainder 3302c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// zero (64 bit version). 33118a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isMask_64(uint64_t Value) { 33288c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && ((Value + 1) & Value) == 0; 33388c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 33488c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 335fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isShiftedMask_32 - This function returns true if the argument contains a 3362c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// non-empty sequence of ones with the remainder zero (32 bit version.) 33749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. isShiftedMask_32(0x0000FF00U) == true. 33818a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isShiftedMask_32(uint32_t Value) { 3392c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar return Value && isMask_32((Value - 1) | Value); 34088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 34188c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 342fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isShiftedMask_64 - This function returns true if the argument contains a 3432c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar/// non-empty sequence of ones with the remainder zero (64 bit version.) 34418a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isShiftedMask_64(uint64_t Value) { 3452c3e0051c31c3f5b2328b447eadf1cf9c4427442Pirama Arumuga Nainar return Value && isMask_64((Value - 1) | Value); 34688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 34788c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 348fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isPowerOf2_32 - This function returns true if the argument is a power of 34949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// two > 0. Ex. isPowerOf2_32(0x00100000U) == true (32 bit edition.) 350c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline bool isPowerOf2_32(uint32_t Value) { 35188c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && !(Value & (Value - 1)); 35288c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 35388c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 35449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// isPowerOf2_64 - This function returns true if the argument is a power of two 35549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// > 0 (64 bit edition.) 35688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattnerinline bool isPowerOf2_64(uint64_t Value) { 35719b7e0e0cabfa6dfc559c64e3d6ed053832c4047Reid Spencer return Value && !(Value & (Value - int64_t(1L))); 35888c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 35988c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 36049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_16 - This function returns a byte-swapped representation of the 36149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 16-bit argument, Value. 362c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint16_t ByteSwap_16(uint16_t Value) { 3633afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_16(Value); 3646fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3656fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 36649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_32 - This function returns a byte-swapped representation of the 36749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 32-bit argument, Value. 368c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t ByteSwap_32(uint32_t Value) { 3693afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_32(Value); 3706fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3716fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 37249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_64 - This function returns a byte-swapped representation of the 37349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 64-bit argument, Value. 3746fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begemaninline uint64_t ByteSwap_64(uint64_t Value) { 3753afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_64(Value); 3766fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3776fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 378ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count the number of ones from the most significant bit to the first 379ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// zero bit. 380ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 381ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Ex. CountLeadingOnes(0xFF0FFF00) == 8. 382ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Only unsigned integral types are allowed. 383ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 384ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \param ZB the behavior on an input of all ones. Only ZB_Width and 385ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// ZB_Undefined are valid arguments. 386ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 387ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countLeadingOnes(T Value, ZeroBehavior ZB = ZB_Width) { 388ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 389ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 390ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 391ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return countLeadingZeros(~Value, ZB); 392ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman} 393ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman 394ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count the number of ones from the least significant bit to the first 395ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// zero bit. 396ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 397ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Ex. countTrailingOnes(0x00FF00FF) == 8. 398ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Only unsigned integral types are allowed. 399ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 400ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \param ZB the behavior on an input of all ones. Only ZB_Width and 401ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// ZB_Undefined are valid arguments. 402ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 403ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countTrailingOnes(T Value, ZeroBehavior ZB = ZB_Width) { 404ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 405ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 406ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 407ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return countTrailingZeros(~Value, ZB); 408ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} 409ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 410ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesnamespace detail { 411ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T, std::size_t SizeOfT> struct PopulationCounter { 412ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static unsigned count(T Value) { 413ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // Generic version, forward to 32 bits. 414ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(SizeOfT <= 4, "Not implemented!"); 4152a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#if __GNUC__ >= 4 416ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_popcount(Value); 4172a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#else 418ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines uint32_t v = Value; 419ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = v - ((v >> 1) & 0x55555555); 420ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = (v & 0x33333333) + ((v >> 2) & 0x33333333); 421ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; 4222a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#endif 423ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 424ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 42516d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 426ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct PopulationCounter<T, 8> { 427ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static unsigned count(T Value) { 4282a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#if __GNUC__ >= 4 429ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_popcountll(Value); 4302a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#else 431ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines uint64_t v = Value; 432ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = v - ((v >> 1) & 0x5555555555555555ULL); 433ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL); 434ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL; 435ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56); 4362a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#endif 437ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 438ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 439ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} // namespace detail 440ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 441ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count the number of set bits in a value. 442ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Ex. countPopulation(0xF000F000) = 8 443ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Returns 0 if the word is zero. 444ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 445ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesinline unsigned countPopulation(T Value) { 446ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 447ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 448ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 449ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return detail::PopulationCounter<T, sizeof(T)>::count(Value); 45016d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 45116d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 452fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// Log2_32 - This function returns the floor log base 2 of the specified value, 45349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// -1 if the value is zero. (32 bit edition.) 45449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. Log2_32(32) == 5, Log2_32(1) == 0, Log2_32(0) == -1, Log2_32(6) == 2 455c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline unsigned Log2_32(uint32_t Value) { 456c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 31 - countLeadingZeros(Value); 45716d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 45854ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner 459fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// Log2_64 - This function returns the floor log base 2 of the specified value, 46049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// -1 if the value is zero. (64 bit edition.) 4612be12faabb3ce2d2d3979c73ac65d466fdea5ec5Chris Lattnerinline unsigned Log2_64(uint64_t Value) { 462c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 63 - countLeadingZeros(Value); 463cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner} 464cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 46549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Log2_32_Ceil - This function returns the ceil log base 2 of the specified 46649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// value, 32 if the value is zero. (32 bit edition). 46749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. Log2_32_Ceil(32) == 5, Log2_32_Ceil(1) == 0, Log2_32_Ceil(6) == 3 468c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline unsigned Log2_32_Ceil(uint32_t Value) { 469c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 32 - countLeadingZeros(Value - 1); 4700683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner} 4710683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner 47255b42513e1548554bfacc72d48ec3483c73fddf9Dan Gohman/// Log2_64_Ceil - This function returns the ceil log base 2 of the specified 47355b42513e1548554bfacc72d48ec3483c73fddf9Dan Gohman/// value, 64 if the value is zero. (64 bit edition.) 4740683c8cad920d241d44b126972d5cdd164dcc213Chris Lattnerinline unsigned Log2_64_Ceil(uint64_t Value) { 475c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 64 - countLeadingZeros(Value - 1); 4760683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner} 4770683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner 47849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// GreatestCommonDivisor64 - Return the greatest common divisor of the two 47949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// values using Euclid's algorithm. 48049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattnerinline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) { 48149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner while (B) { 48249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner uint64_t T = B; 48349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner B = A % B; 48449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner A = T; 48549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner } 48649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner return A; 48749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner} 488fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman 48949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// BitsToDouble - This function takes a 64-bit integer and returns the bit 49049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// equivalent double. 49159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskeyinline double BitsToDouble(uint64_t Bits) { 49259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 49359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey uint64_t L; 49459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey double D; 49559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 49659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.L = Bits; 49759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.D; 49859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 49959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 50049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// BitsToFloat - This function takes a 32-bit integer and returns the bit 50149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// equivalent float. 502104338913500d007996056ad092e195009883a84Jim Laskeyinline float BitsToFloat(uint32_t Bits) { 50359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 504104338913500d007996056ad092e195009883a84Jim Laskey uint32_t I; 50559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey float F; 50659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 50759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.I = Bits; 50859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.F; 50959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 51059b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 51149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// DoubleToBits - This function takes a double and returns the bit 512541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// equivalent 64-bit integer. Note that copying doubles around 513541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// changes the bits of NaNs on some hosts, notably x86, so this 514541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// routine cannot be used if these bits are needed. 51559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskeyinline uint64_t DoubleToBits(double Double) { 51659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 51759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey uint64_t L; 51859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey double D; 51959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 52059b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.D = Double; 52159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.L; 52259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 52359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 52449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// FloatToBits - This function takes a float and returns the bit 525541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// equivalent 32-bit integer. Note that copying floats around 526541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// changes the bits of NaNs on some hosts, notably x86, so this 527541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// routine cannot be used if these bits are needed. 528104338913500d007996056ad092e195009883a84Jim Laskeyinline uint32_t FloatToBits(float Float) { 52959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 530104338913500d007996056ad092e195009883a84Jim Laskey uint32_t I; 53159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey float F; 53259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 53359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.F = Float; 53459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.I; 53559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 53659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 537fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands/// MinAlign - A and B are either alignments or offsets. Return the minimum 538fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands/// alignment that may be assumed after adding the two together. 539305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline uint64_t MinAlign(uint64_t A, uint64_t B) { 540fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands // The largest power of 2 that divides both A and B. 541b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // 542b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // Replace "-Value" by "1+~Value" in the following commented code to avoid 543b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // MSVC warning C4146 544b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // return (A | B) & -(A | B); 545b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman return (A | B) & (1 + ~(A | B)); 546fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands} 547d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson 54837ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// \brief Aligns \c Addr to \c Alignment bytes, rounding up. 54936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// 55036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// Alignment should be a power of two. This method rounds up, so 55137ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// alignAddr(7, 4) == 8 and alignAddr(8, 4) == 8. 55237ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hinesinline uintptr_t alignAddr(void *Addr, size_t Alignment) { 55336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines assert(Alignment && isPowerOf2_64((uint64_t)Alignment) && 55436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines "Alignment is not a power of two!"); 55536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 55637ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines assert((uintptr_t)Addr + Alignment - 1 >= (uintptr_t)Addr); 55737ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines 55837ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines return (((uintptr_t)Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1)); 55937ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines} 56037ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines 56137ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// \brief Returns the necessary adjustment for aligning \c Ptr to \c Alignment 56237ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// bytes, rounding up. 56337ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hinesinline size_t alignmentAdjustment(void *Ptr, size_t Alignment) { 56437ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines return alignAddr(Ptr, Alignment) - (uintptr_t)Ptr; 56536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines} 56636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 567d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson/// NextPowerOf2 - Returns the next power of two (in 64-bits) 568d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson/// that is strictly greater than A. Returns zero on overflow. 569305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline uint64_t NextPowerOf2(uint64_t A) { 570d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 1); 571d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 2); 572d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 4); 573d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 8); 574d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 16); 575d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 32); 576d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson return A + 1; 577d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson} 578e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar 57936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// Returns the power of two which is less than or equal to the given value. 58036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// Essentially, it is a floor operation across the domain of powers of two. 58136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hinesinline uint64_t PowerOf2Floor(uint64_t A) { 58236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (!A) return 0; 58336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines return 1ull << (63 - countLeadingZeros(A, ZB_Undefined)); 58436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines} 58536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 5862d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// Returns the next integer (mod 2**64) that is greater than or equal to 5872d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \p Value and is a multiple of \p Align. \p Align must be non-zero. 588e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar/// 589e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar/// Examples: 5902d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \code 5912d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// RoundUpToAlignment(5, 8) = 8 5922d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// RoundUpToAlignment(17, 8) = 24 5932d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// RoundUpToAlignment(~0LL, 8) = 0 59437ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// RoundUpToAlignment(321, 255) = 510 5952d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \endcode 596e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbarinline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align) { 59737ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines return (Value + Align - 1) / Align * Align; 598e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar} 599fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman 6002d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// Returns the offset to the next integer (mod 2**64) that is greater than 6012d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// or equal to \p Value and is a multiple of \p Align. \p Align must be 6022d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// non-zero. 603eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbarinline uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align) { 604eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar return RoundUpToAlignment(Value, Align) - Value; 605eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar} 606eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar 607b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// SignExtend32 - Sign extend B-bit number x to 32-bit int. 608b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// Usage int32_t r = SignExtend32<5>(x); 609adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesentemplate <unsigned B> inline int32_t SignExtend32(uint32_t x) { 610adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesen return int32_t(x << (32 - B)) >> (32 - B); 611b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen} 612b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen 6131144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// \brief Sign extend number in the bottom B bits of X to a 32-bit int. 6141144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// Requires 0 < B <= 32. 6151144af3c9b4da48cd581156e05b24261c8de366aRichard Smithinline int32_t SignExtend32(uint32_t X, unsigned B) { 6161144af3c9b4da48cd581156e05b24261c8de366aRichard Smith return int32_t(X << (32 - B)) >> (32 - B); 6171144af3c9b4da48cd581156e05b24261c8de366aRichard Smith} 6181144af3c9b4da48cd581156e05b24261c8de366aRichard Smith 619b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// SignExtend64 - Sign extend B-bit number x to 64-bit int. 620b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// Usage int64_t r = SignExtend64<5>(x); 621adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesentemplate <unsigned B> inline int64_t SignExtend64(uint64_t x) { 622adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesen return int64_t(x << (64 - B)) >> (64 - B); 623b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen} 624b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen 6251144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// \brief Sign extend number in the bottom B bits of X to a 64-bit int. 6261144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// Requires 0 < B <= 64. 6271144af3c9b4da48cd581156e05b24261c8de366aRichard Smithinline int64_t SignExtend64(uint64_t X, unsigned B) { 6281144af3c9b4da48cd581156e05b24261c8de366aRichard Smith return int64_t(X << (64 - B)) >> (64 - B); 6291144af3c9b4da48cd581156e05b24261c8de366aRichard Smith} 6301144af3c9b4da48cd581156e05b24261c8de366aRichard Smith 63137ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hinesextern const float huge_valf; 632d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke} // End llvm namespace 633d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 63454ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner#endif 635