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" 19de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar#include <algorithm> 2036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include <cassert> 2136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#include <cstring> 2236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include <type_traits> 23de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar#include <limits> 24cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 25c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer#ifdef _MSC_VER 26eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman#include <intrin.h> 27c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer#endif 28c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer 296948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar#ifdef __ANDROID_NDK__ 306948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar#include <android/api-level.h> 316948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar#endif 326948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar 33d0fde30ce850b78371fd1386338350591f9ff494Brian Gaekenamespace llvm { 3436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief The behavior an operation has on an input of 0. 3536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerenum ZeroBehavior { 3636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is undefined. 3736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Undefined, 3836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is numeric_limits<T>::max() 3936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Max, 4036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is numeric_limits<T>::digits 4136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Width 4236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer}; 4336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 44ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesnamespace detail { 45ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T, std::size_t SizeOfT> struct TrailingZerosCounter { 46ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior) { 47ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (!Val) 48ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return std::numeric_limits<T>::digits; 49ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (Val & 0x1) 50ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 0; 51ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 52ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // Bisection method. 53ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines std::size_t ZeroBits = 0; 54ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines T Shift = std::numeric_limits<T>::digits >> 1; 55ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines T Mask = std::numeric_limits<T>::max() >> Shift; 56ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines while (Shift) { 57ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if ((Val & Mask) == 0) { 58ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Val >>= Shift; 59ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines ZeroBits |= Shift; 60ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 61ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Shift >>= 1; 62ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Mask >>= Shift; 6336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 64ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return ZeroBits; 6536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 66ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 6736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 68f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar#if __GNUC__ >= 4 || defined(_MSC_VER) 69ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct TrailingZerosCounter<T, 4> { 70ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 71ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 72ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 32; 7336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 7437ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_ctz) || LLVM_GNUC_PREREQ(4, 0, 0) 75ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_ctz(Val); 76f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar#elif defined(_MSC_VER) 77ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 78ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanForward(&Index, Val); 79ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index; 8036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 81ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 82ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 8336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 84a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#if !defined(_MSC_VER) || defined(_M_X64) 85ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct TrailingZerosCounter<T, 8> { 86ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 87ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 88ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 64; 8936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 9037ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_ctzll) || LLVM_GNUC_PREREQ(4, 0, 0) 91ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_ctzll(Val); 92f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar#elif defined(_MSC_VER) 93ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 94ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanForward64(&Index, Val); 95ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index; 9636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 97ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 98ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 9936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 100a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#endif 101ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} // namespace detail 10236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 103ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count number of 0's from the least significant bit to the most 10436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// stopping at the first 1. 10536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 10636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 10736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 10836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are 10936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 11036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 111ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) { 112ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 113ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 114ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 115ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return detail::TrailingZerosCounter<T, sizeof(T)>::count(Val, ZB); 116ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} 117ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 118ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesnamespace detail { 119ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T, std::size_t SizeOfT> struct LeadingZerosCounter { 120ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior) { 121ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (!Val) 122ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return std::numeric_limits<T>::digits; 123ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 124ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // Bisection method. 125ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines std::size_t ZeroBits = 0; 126ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines for (T Shift = std::numeric_limits<T>::digits >> 1; Shift; Shift >>= 1) { 127ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines T Tmp = Val >> Shift; 128ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (Tmp) 129ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines Val = Tmp; 130ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines else 131ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines ZeroBits |= Shift; 132ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 133ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return ZeroBits; 13436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 135ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 13636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 137f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar#if __GNUC__ >= 4 || defined(_MSC_VER) 138ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct LeadingZerosCounter<T, 4> { 139ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 140ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 141ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 32; 14236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 14337ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_clz) || LLVM_GNUC_PREREQ(4, 0, 0) 144ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_clz(Val); 145f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar#elif defined(_MSC_VER) 146ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 147ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanReverse(&Index, Val); 148ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index ^ 31; 14936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 150ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 151ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 15236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 153a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#if !defined(_MSC_VER) || defined(_M_X64) 154ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct LeadingZerosCounter<T, 8> { 155ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static std::size_t count(T Val, ZeroBehavior ZB) { 156ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines if (ZB != ZB_Undefined && Val == 0) 157ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return 64; 15836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 15937ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines#if __has_builtin(__builtin_clzll) || LLVM_GNUC_PREREQ(4, 0, 0) 160ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_clzll(Val); 161f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar#elif defined(_MSC_VER) 162ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines unsigned long Index; 163ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines _BitScanReverse64(&Index, Val); 164ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return Index ^ 63; 16536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 166ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 167ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 16836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 169a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#endif 170ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} // namespace detail 171ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 172ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count number of 0's from the most significant bit to the least 173ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// stopping at the first 1. 174ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 175ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Only unsigned integral types are allowed. 176ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 177ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are 178ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// valid arguments. 179ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 180ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) { 181ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 182ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 183ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 184ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return detail::LeadingZerosCounter<T, sizeof(T)>::count(Val, ZB); 185ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} 18636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 18736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Get the index of the first set bit starting from the least 18836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// significant bit. 18936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 19036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 19136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 19236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are 19336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 194ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) { 19536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB == ZB_Max && Val == 0) 19636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::max(); 19736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 19836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return countTrailingZeros(Val, ZB_Undefined); 19936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 20036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 20136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Get the index of the last set bit starting from the least 20236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// significant bit. 20336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 20436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 20536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 20636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are 20736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 208ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> T findLastSet(T Val, ZeroBehavior ZB = ZB_Max) { 20936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB == ZB_Max && Val == 0) 21036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::max(); 21136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 21236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // Use ^ instead of - because both gcc and llvm can remove the associated ^ 21336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // in the __builtin_clz intrinsic on x86. 21436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return countLeadingZeros(Val, ZB_Undefined) ^ 21536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer (std::numeric_limits<T>::digits - 1); 21636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 21736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 21836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Macro compressed bit reversal table for 256 bits. 21936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 22036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable 22136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerstatic const unsigned char BitReverseTable256[256] = { 22236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R2(n) n, n + 2 * 64, n + 1 * 64, n + 3 * 64 22336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R4(n) R2(n), R2(n + 2 * 16), R2(n + 1 * 16), R2(n + 3 * 16) 22436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R6(n) R4(n), R4(n + 2 * 4), R4(n + 1 * 4), R4(n + 3 * 4) 22536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer R6(0), R6(2), R6(1), R6(3) 226c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines#undef R2 227c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines#undef R4 228c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines#undef R6 22936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer}; 23036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 23136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Reverse the bits in \p Val. 23236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 23336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencerT reverseBits(T Val) { 23436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned char in[sizeof(Val)]; 23536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned char out[sizeof(Val)]; 23636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::memcpy(in, &Val, sizeof(Val)); 23736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer for (unsigned i = 0; i < sizeof(Val); ++i) 23836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer out[(sizeof(Val) - i) - 1] = BitReverseTable256[in[i]]; 23936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::memcpy(&Val, out, sizeof(Val)); 24036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return Val; 24136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 242d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 243fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman// NOTE: The following support functions use the _32/_64 extensions instead of 24489bfcd34cbd2f4c6bb2cafff0a5c2bff147fae11Chris Lattner// type overloading so that signed and unsigned integers can be used without 24589bfcd34cbd2f4c6bb2cafff0a5c2bff147fae11Chris Lattner// ambiguity. 24688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 24749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Hi_32 - This function returns the high 32 bits of a 64 bit value. 248c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t Hi_32(uint64_t Value) { 249c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Cohen return static_cast<uint32_t>(Value >> 32); 25088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 25188c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 25249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Lo_32 - This function returns the low 32 bits of a 64 bit value. 253c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t Lo_32(uint64_t Value) { 254c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Cohen return static_cast<uint32_t>(Value); 25588c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 25688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 257c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines/// Make_64 - This functions makes a 64-bit integer from a high / low pair of 258c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines/// 32-bit integers. 259c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hinesinline uint64_t Make_64(uint32_t High, uint32_t Low) { 260c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines return ((uint64_t)High << 32) | (uint64_t)Low; 261c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines} 262c6a4f5e819217e1e12c458aed8e7b122e23a3a58Stephen Hines 26334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer/// isInt - Checks if an integer fits into the given bit width. 264d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesentemplate<unsigned N> 265d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Oleseninline bool isInt(int64_t x) { 266d4c00c0f558193b492aed9ab6aacf84bf1d3fb4eJakob Stoklund Olesen return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1))); 267d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen} 26834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer// Template specializations to get better code for common cases. 26934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 27034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<8>(int64_t x) { 27134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int8_t>(x) == x; 27234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 27334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 27434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<16>(int64_t x) { 27534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int16_t>(x) == x; 27634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 27734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 27834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<32>(int64_t x) { 27934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int32_t>(x) == x; 28034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 281d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen 282b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// isShiftedInt<N,S> - Checks if a signed integer is an N bit number shifted 283b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// left by S. 284b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicumtemplate<unsigned N, unsigned S> 285b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicuminline bool isShiftedInt(int64_t x) { 286b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum return isInt<N+S>(x) && (x % (1<<S) == 0); 287b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum} 288b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum 28934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer/// isUInt - Checks if an unsigned integer fits into the given bit width. 290d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesentemplate<unsigned N> 29134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt(uint64_t x) { 29266f1f30725eb20760069823ec015234cce6b887cReid Kleckner return N >= 64 || x < (UINT64_C(1)<<(N)); 293d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen} 29434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer// Template specializations to get better code for common cases. 29534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 29634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<8>(uint64_t x) { 29734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint8_t>(x) == x; 29834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 29934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 30034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<16>(uint64_t x) { 30134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint16_t>(x) == x; 30234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 30334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 30434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<32>(uint64_t x) { 30534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint32_t>(x) == x; 30634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 307d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen 308b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// isShiftedUInt<N,S> - Checks if a unsigned integer is an N bit number shifted 309b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// left by S. 310b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicumtemplate<unsigned N, unsigned S> 311b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicuminline bool isShiftedUInt(uint64_t x) { 312b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum return isUInt<N+S>(x) && (x % (1<<S) == 0); 313b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum} 314b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum 315de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// Gets the maximum value for a N-bit unsigned integer. 316de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainarinline uint64_t maxUIntN(uint64_t N) { 317de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar assert(N > 0 && N <= 64 && "integer width out of range"); 318de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 319de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return (UINT64_C(1) << N) - 1; 320de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar} 321de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 322de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// Gets the minimum value for a N-bit signed integer. 323de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainarinline int64_t minIntN(int64_t N) { 324de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar assert(N > 0 && N <= 64 && "integer width out of range"); 325de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 326de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return -(INT64_C(1)<<(N-1)); 327de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar} 328de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 329de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// Gets the maximum value for a N-bit signed integer. 330de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainarinline int64_t maxIntN(int64_t N) { 331de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar assert(N > 0 && N <= 64 && "integer width out of range"); 332de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 333de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return (INT64_C(1)<<(N-1)) - 1; 334de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar} 335de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 3365005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman/// isUIntN - Checks if an unsigned integer fits into the given (dynamic) 3375005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman/// bit width. 3385005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohmaninline bool isUIntN(unsigned N, uint64_t x) { 339de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return N >= 64 || x <= maxUIntN(N); 3405005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman} 3415005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman 342c42a7754bb6249c33c509e6fa6e8b3c9344e72d8Rafael Espindola/// isIntN - Checks if an signed integer fits into the given (dynamic) 343b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola/// bit width. 344b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindolainline bool isIntN(unsigned N, int64_t x) { 345de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return N >= 64 || (minIntN(N) <= x && x <= maxIntN(N)); 346b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola} 347b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola 3480c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// isMask_32 - This function returns true if the argument is a non-empty 3490c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// sequence of ones starting at the least significant bit with the remainder 3500c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// zero (32 bit version). Ex. isMask_32(0x0000FFFFU) == true. 35118a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isMask_32(uint32_t Value) { 35288c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && ((Value + 1) & Value) == 0; 35388c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 35488c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 3550c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// isMask_64 - This function returns true if the argument is a non-empty 3560c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// sequence of ones starting at the least significant bit with the remainder 3570c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// zero (64 bit version). 35818a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isMask_64(uint64_t Value) { 35988c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && ((Value + 1) & Value) == 0; 36088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 36188c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 362fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isShiftedMask_32 - This function returns true if the argument contains a 3630c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// non-empty sequence of ones with the remainder zero (32 bit version.) 36449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. isShiftedMask_32(0x0000FF00U) == true. 36518a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isShiftedMask_32(uint32_t Value) { 3660c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar return Value && isMask_32((Value - 1) | Value); 36788c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 36888c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 369fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isShiftedMask_64 - This function returns true if the argument contains a 3700c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar/// non-empty sequence of ones with the remainder zero (64 bit version.) 37118a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isShiftedMask_64(uint64_t Value) { 3720c7f116bb6950ef819323d855415b2f2b0aad987Pirama Arumuga Nainar return Value && isMask_64((Value - 1) | Value); 37388c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 37488c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 375fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isPowerOf2_32 - This function returns true if the argument is a power of 37649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// two > 0. Ex. isPowerOf2_32(0x00100000U) == true (32 bit edition.) 377c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline bool isPowerOf2_32(uint32_t Value) { 37888c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && !(Value & (Value - 1)); 37988c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 38088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 38149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// isPowerOf2_64 - This function returns true if the argument is a power of two 38249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// > 0 (64 bit edition.) 38388c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattnerinline bool isPowerOf2_64(uint64_t Value) { 38419b7e0e0cabfa6dfc559c64e3d6ed053832c4047Reid Spencer return Value && !(Value & (Value - int64_t(1L))); 38588c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 38688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 38749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_16 - This function returns a byte-swapped representation of the 38849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 16-bit argument, Value. 389c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint16_t ByteSwap_16(uint16_t Value) { 3903afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_16(Value); 3916fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3926fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 39349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_32 - This function returns a byte-swapped representation of the 39449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 32-bit argument, Value. 395c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t ByteSwap_32(uint32_t Value) { 3963afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_32(Value); 3976fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3986fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 39949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_64 - This function returns a byte-swapped representation of the 40049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 64-bit argument, Value. 4016fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begemaninline uint64_t ByteSwap_64(uint64_t Value) { 4023afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_64(Value); 4036fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 4046fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 405ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count the number of ones from the most significant bit to the first 406ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// zero bit. 407ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 408ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Ex. CountLeadingOnes(0xFF0FFF00) == 8. 409ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Only unsigned integral types are allowed. 410ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 411ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \param ZB the behavior on an input of all ones. Only ZB_Width and 412ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// ZB_Undefined are valid arguments. 413ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 414ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countLeadingOnes(T Value, ZeroBehavior ZB = ZB_Width) { 415ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 416ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 417ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 418ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return countLeadingZeros(~Value, ZB); 419ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman} 420ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman 421ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count the number of ones from the least significant bit to the first 422ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// zero bit. 423ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 424ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Ex. countTrailingOnes(0x00FF00FF) == 8. 425ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Only unsigned integral types are allowed. 426ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// 427ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \param ZB the behavior on an input of all ones. Only ZB_Width and 428ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// ZB_Undefined are valid arguments. 429ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 430ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesstd::size_t countTrailingOnes(T Value, ZeroBehavior ZB = ZB_Width) { 431ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 432ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 433ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 434ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return countTrailingZeros(~Value, ZB); 435ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} 436ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 437ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesnamespace detail { 438ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T, std::size_t SizeOfT> struct PopulationCounter { 439ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static unsigned count(T Value) { 440ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines // Generic version, forward to 32 bits. 441ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(SizeOfT <= 4, "Not implemented!"); 4422a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#if __GNUC__ >= 4 443ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_popcount(Value); 4442a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#else 445ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines uint32_t v = Value; 446ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = v - ((v >> 1) & 0x55555555); 447ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = (v & 0x33333333) + ((v >> 2) & 0x33333333); 448ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; 4492a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#endif 450ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 451ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 45216d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 453ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> struct PopulationCounter<T, 8> { 454ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static unsigned count(T Value) { 4552a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#if __GNUC__ >= 4 456ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return __builtin_popcountll(Value); 4572a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#else 458ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines uint64_t v = Value; 459ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = v - ((v >> 1) & 0x5555555555555555ULL); 460ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL); 461ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL; 462ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56); 4632a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#endif 464ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines } 465ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines}; 466ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines} // namespace detail 467ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines 468ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// \brief Count the number of set bits in a value. 469ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Ex. countPopulation(0xF000F000) = 8 470ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines/// Returns 0 if the word is zero. 471ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinestemplate <typename T> 472ebe69fe11e48d322045d5949c83283927a0d790bStephen Hinesinline unsigned countPopulation(T Value) { 473ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines static_assert(std::numeric_limits<T>::is_integer && 474ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines !std::numeric_limits<T>::is_signed, 475ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines "Only unsigned integral types are allowed."); 476ebe69fe11e48d322045d5949c83283927a0d790bStephen Hines return detail::PopulationCounter<T, sizeof(T)>::count(Value); 47716d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 47816d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 4796948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar/// Log2 - This function returns the log base 2 of the specified value 4806948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainarinline double Log2(double Value) { 4816948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar#if defined(__ANDROID_API__) && __ANDROID_API__ < 18 4826948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar return __builtin_log(Value) / __builtin_log(2.0); 4836948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar#else 4846948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar return log2(Value); 4856948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar#endif 4866948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar} 4876948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainar 488fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// Log2_32 - This function returns the floor log base 2 of the specified value, 48949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// -1 if the value is zero. (32 bit edition.) 49049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. Log2_32(32) == 5, Log2_32(1) == 0, Log2_32(0) == -1, Log2_32(6) == 2 491c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline unsigned Log2_32(uint32_t Value) { 492c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 31 - countLeadingZeros(Value); 49316d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 49454ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner 495fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// Log2_64 - This function returns the floor log base 2 of the specified value, 49649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// -1 if the value is zero. (64 bit edition.) 4972be12faabb3ce2d2d3979c73ac65d466fdea5ec5Chris Lattnerinline unsigned Log2_64(uint64_t Value) { 498c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 63 - countLeadingZeros(Value); 499cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner} 500cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 50149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Log2_32_Ceil - This function returns the ceil log base 2 of the specified 50249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// value, 32 if the value is zero. (32 bit edition). 50349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. Log2_32_Ceil(32) == 5, Log2_32_Ceil(1) == 0, Log2_32_Ceil(6) == 3 504c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline unsigned Log2_32_Ceil(uint32_t Value) { 505c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 32 - countLeadingZeros(Value - 1); 5060683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner} 5070683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner 50855b42513e1548554bfacc72d48ec3483c73fddf9Dan Gohman/// Log2_64_Ceil - This function returns the ceil log base 2 of the specified 50955b42513e1548554bfacc72d48ec3483c73fddf9Dan Gohman/// value, 64 if the value is zero. (64 bit edition.) 5100683c8cad920d241d44b126972d5cdd164dcc213Chris Lattnerinline unsigned Log2_64_Ceil(uint64_t Value) { 511c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 64 - countLeadingZeros(Value - 1); 5120683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner} 5130683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner 51449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// GreatestCommonDivisor64 - Return the greatest common divisor of the two 51549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// values using Euclid's algorithm. 51649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattnerinline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) { 51749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner while (B) { 51849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner uint64_t T = B; 51949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner B = A % B; 52049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner A = T; 52149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner } 52249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner return A; 52349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner} 524fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman 52549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// BitsToDouble - This function takes a 64-bit integer and returns the bit 52649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// equivalent double. 52759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskeyinline double BitsToDouble(uint64_t Bits) { 52859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 52959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey uint64_t L; 53059b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey double D; 53159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 53259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.L = Bits; 53359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.D; 53459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 53559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 53649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// BitsToFloat - This function takes a 32-bit integer and returns the bit 53749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// equivalent float. 538104338913500d007996056ad092e195009883a84Jim Laskeyinline float BitsToFloat(uint32_t Bits) { 53959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 540104338913500d007996056ad092e195009883a84Jim Laskey uint32_t I; 54159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey float F; 54259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 54359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.I = Bits; 54459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.F; 54559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 54659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 54749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// DoubleToBits - This function takes a double and returns the bit 548541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// equivalent 64-bit integer. Note that copying doubles around 549541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// changes the bits of NaNs on some hosts, notably x86, so this 550541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// routine cannot be used if these bits are needed. 55159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskeyinline uint64_t DoubleToBits(double Double) { 55259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 55359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey uint64_t L; 55459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey double D; 55559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 55659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.D = Double; 55759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.L; 55859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 55959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 56049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// FloatToBits - This function takes a float and returns the bit 561541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// equivalent 32-bit integer. Note that copying floats around 562541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// changes the bits of NaNs on some hosts, notably x86, so this 563541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// routine cannot be used if these bits are needed. 564104338913500d007996056ad092e195009883a84Jim Laskeyinline uint32_t FloatToBits(float Float) { 56559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 566104338913500d007996056ad092e195009883a84Jim Laskey uint32_t I; 56759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey float F; 56859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 56959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.F = Float; 57059b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.I; 57159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 57259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 573fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands/// MinAlign - A and B are either alignments or offsets. Return the minimum 574fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands/// alignment that may be assumed after adding the two together. 575305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline uint64_t MinAlign(uint64_t A, uint64_t B) { 576fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands // The largest power of 2 that divides both A and B. 577b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // 578f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // Replace "-Value" by "1+~Value" in the following commented code to avoid 579b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // MSVC warning C4146 580b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // return (A | B) & -(A | B); 581b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman return (A | B) & (1 + ~(A | B)); 582fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands} 583d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson 58437ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// \brief Aligns \c Addr to \c Alignment bytes, rounding up. 58536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// 58636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// Alignment should be a power of two. This method rounds up, so 58737ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// alignAddr(7, 4) == 8 and alignAddr(8, 4) == 8. 5886948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainarinline uintptr_t alignAddr(const void *Addr, size_t Alignment) { 58936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines assert(Alignment && isPowerOf2_64((uint64_t)Alignment) && 59036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines "Alignment is not a power of two!"); 59136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 59237ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines assert((uintptr_t)Addr + Alignment - 1 >= (uintptr_t)Addr); 59337ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines 59437ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines return (((uintptr_t)Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1)); 59537ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines} 59637ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines 59737ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// \brief Returns the necessary adjustment for aligning \c Ptr to \c Alignment 59837ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines/// bytes, rounding up. 5996948897e478cbd66626159776a8017b3c18579b9Pirama Arumuga Nainarinline size_t alignmentAdjustment(const void *Ptr, size_t Alignment) { 60037ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hines return alignAddr(Ptr, Alignment) - (uintptr_t)Ptr; 60136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines} 60236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 603d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson/// NextPowerOf2 - Returns the next power of two (in 64-bits) 604d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson/// that is strictly greater than A. Returns zero on overflow. 605305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline uint64_t NextPowerOf2(uint64_t A) { 606d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 1); 607d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 2); 608d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 4); 609d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 8); 610d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 16); 611d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 32); 612d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson return A + 1; 613d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson} 614e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar 61536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// Returns the power of two which is less than or equal to the given value. 61636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines/// Essentially, it is a floor operation across the domain of powers of two. 61736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hinesinline uint64_t PowerOf2Floor(uint64_t A) { 61836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (!A) return 0; 61936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines return 1ull << (63 - countLeadingZeros(A, ZB_Undefined)); 62036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines} 62136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 6222d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// Returns the next integer (mod 2**64) that is greater than or equal to 6232d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \p Value and is a multiple of \p Align. \p Align must be non-zero. 624e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar/// 625f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// If non-zero \p Skew is specified, the return value will be a minimal 626f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// integer that is greater than or equal to \p Value and equal to 627f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// \p Align * N + \p Skew for some integer N. If \p Skew is larger than 628f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// \p Align, its value is adjusted to '\p Skew mod \p Align'. 629f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// 630e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar/// Examples: 6312d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \code 632de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(5, 8) = 8 633de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(17, 8) = 24 634de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(~0LL, 8) = 0 635de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(321, 255) = 510 636f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// 637de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(5, 8, 7) = 7 638de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(17, 8, 1) = 17 639de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(~0LL, 8, 3) = 3 640de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// alignTo(321, 255, 42) = 552 6412d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \endcode 642de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainarinline uint64_t alignTo(uint64_t Value, uint64_t Align, uint64_t Skew = 0) { 643f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar Skew %= Align; 644f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return (Value + Align - 1 - Skew) / Align * Align + Skew; 645e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar} 646fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman 647de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// Returns the largest uint64_t less than or equal to \p Value and is 648de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// \p Skew mod \p Align. \p Align must be non-zero 649de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainarinline uint64_t alignDown(uint64_t Value, uint64_t Align, uint64_t Skew = 0) { 650de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar Skew %= Align; 651de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return (Value - Skew) / Align * Align + Skew; 652de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar} 653de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 6542d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// Returns the offset to the next integer (mod 2**64) that is greater than 6552d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// or equal to \p Value and is a multiple of \p Align. \p Align must be 6562d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// non-zero. 657eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbarinline uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align) { 658de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return alignTo(Value, Align) - Value; 659eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar} 660eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar 661b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// SignExtend32 - Sign extend B-bit number x to 32-bit int. 662b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// Usage int32_t r = SignExtend32<5>(x); 663adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesentemplate <unsigned B> inline int32_t SignExtend32(uint32_t x) { 664adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesen return int32_t(x << (32 - B)) >> (32 - B); 665b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen} 666b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen 6671144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// \brief Sign extend number in the bottom B bits of X to a 32-bit int. 6681144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// Requires 0 < B <= 32. 6691144af3c9b4da48cd581156e05b24261c8de366aRichard Smithinline int32_t SignExtend32(uint32_t X, unsigned B) { 6701144af3c9b4da48cd581156e05b24261c8de366aRichard Smith return int32_t(X << (32 - B)) >> (32 - B); 6711144af3c9b4da48cd581156e05b24261c8de366aRichard Smith} 6721144af3c9b4da48cd581156e05b24261c8de366aRichard Smith 673b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// SignExtend64 - Sign extend B-bit number x to 64-bit int. 674b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// Usage int64_t r = SignExtend64<5>(x); 675adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesentemplate <unsigned B> inline int64_t SignExtend64(uint64_t x) { 676adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesen return int64_t(x << (64 - B)) >> (64 - B); 677b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen} 678b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen 6791144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// \brief Sign extend number in the bottom B bits of X to a 64-bit int. 6801144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// Requires 0 < B <= 64. 6811144af3c9b4da48cd581156e05b24261c8de366aRichard Smithinline int64_t SignExtend64(uint64_t X, unsigned B) { 6821144af3c9b4da48cd581156e05b24261c8de366aRichard Smith return int64_t(X << (64 - B)) >> (64 - B); 6831144af3c9b4da48cd581156e05b24261c8de366aRichard Smith} 6841144af3c9b4da48cd581156e05b24261c8de366aRichard Smith 685de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// \brief Subtract two unsigned integers, X and Y, of type T and return their 686de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// absolute value. 687de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainartemplate <typename T> 688de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainartypename std::enable_if<std::is_unsigned<T>::value, T>::type 689de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga NainarAbsoluteDifference(T X, T Y) { 690de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return std::max(X, Y) - std::min(X, Y); 691de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar} 692de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 693f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// \brief Add two unsigned integers, X and Y, of type T. 694f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// Clamp the result to the maximum representable value of T on overflow. 695f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// ResultOverflowed indicates if the result is larger than the maximum 696f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// representable value of type T. 697f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainartemplate <typename T> 698f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainartypename std::enable_if<std::is_unsigned<T>::value, T>::type 699f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga NainarSaturatingAdd(T X, T Y, bool *ResultOverflowed = nullptr) { 700f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar bool Dummy; 701f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy; 702f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // Hacker's Delight, p. 29 703f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar T Z = X + Y; 704f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar Overflowed = (Z < X || Z < Y); 705f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar if (Overflowed) 706f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return std::numeric_limits<T>::max(); 707f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar else 708f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return Z; 709f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar} 710f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar 711f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// \brief Multiply two unsigned integers, X and Y, of type T. 712f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// Clamp the result to the maximum representable value of T on overflow. 713f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// ResultOverflowed indicates if the result is larger than the maximum 714f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar/// representable value of type T. 715f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainartemplate <typename T> 716f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainartypename std::enable_if<std::is_unsigned<T>::value, T>::type 717f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga NainarSaturatingMultiply(T X, T Y, bool *ResultOverflowed = nullptr) { 718f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar bool Dummy; 719f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy; 720f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar 721f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // Hacker's Delight, p. 30 has a different algorithm, but we don't use that 722f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // because it fails for uint16_t (where multiplication can have undefined 723f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // behavior due to promotion to int), and requires a division in addition 724f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // to the multiplication. 725f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar 726f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar Overflowed = false; 727f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar 728f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // Log2(Z) would be either Log2Z or Log2Z + 1. 729f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // Special case: if X or Y is 0, Log2_64 gives -1, and Log2Z 730f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // will necessarily be less than Log2Max as desired. 731f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar int Log2Z = Log2_64(X) + Log2_64(Y); 732f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar const T Max = std::numeric_limits<T>::max(); 733f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar int Log2Max = Log2_64(Max); 734f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar if (Log2Z < Log2Max) { 735f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return X * Y; 736f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar } 737f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar if (Log2Z > Log2Max) { 738f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar Overflowed = true; 739f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return Max; 740f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar } 741f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar 742f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // We're going to use the top bit, and maybe overflow one 743f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // bit past it. Multiply all but the bottom bit then add 744f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar // that on at the end. 745f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar T Z = (X >> 1) * Y; 746f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar if (Z & ~(Max >> 1)) { 747f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar Overflowed = true; 748f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return Max; 749f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar } 750f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar Z <<= 1; 751f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar if (X & 1) 752f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return SaturatingAdd(Z, Y, ResultOverflowed); 753f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar 754f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar return Z; 755f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar} 756f3ef5332fa3f4d5ec72c178a2b19dac363a19383Pirama Arumuga Nainar 757de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// \brief Multiply two unsigned integers, X and Y, and add the unsigned 758de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// integer, A to the product. Clamp the result to the maximum representable 759de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// value of T on overflow. ResultOverflowed indicates if the result is larger 760de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// than the maximum representable value of type T. 761de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// Note that this is purely a convenience function as there is no distinction 762de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar/// where overflow occurred in a 'fused' multiply-add for unsigned numbers. 763de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainartemplate <typename T> 764de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainartypename std::enable_if<std::is_unsigned<T>::value, T>::type 765de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga NainarSaturatingMultiplyAdd(T X, T Y, T A, bool *ResultOverflowed = nullptr) { 766de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar bool Dummy; 767de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar bool &Overflowed = ResultOverflowed ? *ResultOverflowed : Dummy; 768de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 769de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar T Product = SaturatingMultiply(X, Y, &Overflowed); 770de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar if (Overflowed) 771de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return Product; 772de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 773de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar return SaturatingAdd(A, Product, &Overflowed); 774de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar} 775de2d8694e25a814696358e95141f4b1aa4d8847ePirama Arumuga Nainar 77637ed9c199ca639565f6ce88105f9e39e898d82d0Stephen Hinesextern const float huge_valf; 777d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke} // End llvm namespace 778d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 77954ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner#endif 780