MathExtras.h revision eb3602472026dc029beb45ccbe09bc84162ba949
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" 1936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#include "llvm/Support/type_traits.h" 2036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 2136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#include <cstring> 22cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 23c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer#ifdef _MSC_VER 24eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman#include <intrin.h> 25eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman#include <limits> 26c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer#endif 27c8b909ae499e5b0d7e38ba5c54c35e98c936300bMichael J. Spencer 28d0fde30ce850b78371fd1386338350591f9ff494Brian Gaekenamespace llvm { 2936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief The behavior an operation has on an input of 0. 3036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerenum ZeroBehavior { 3136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is undefined. 3236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Undefined, 3336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is numeric_limits<T>::max() 3436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Max, 3536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer /// \brief The returned value is numeric_limits<T>::digits 3636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZB_Width 3736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer}; 3836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 3936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Count number of 0's from the least significant bit to the most 4036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// stopping at the first 1. 4136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 4236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 4336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 4436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are 4536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 4636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 4736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 4836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer !std::numeric_limits<T>::is_signed, std::size_t>::type 493018f0ddd4677eadf33af4284b8fa41ed929a2f0Dmitri GribenkocountTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) { 503018f0ddd4677eadf33af4284b8fa41ed929a2f0Dmitri Gribenko (void)ZB; 513018f0ddd4677eadf33af4284b8fa41ed929a2f0Dmitri Gribenko 5236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (!Val) 5336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::digits; 5436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (Val & 0x1) 5536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return 0; 5636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 5736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // Bisection method. 5836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::size_t ZeroBits = 0; 5936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer T Shift = std::numeric_limits<T>::digits >> 1; 6036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer T Mask = std::numeric_limits<T>::max() >> Shift; 6136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer while (Shift) { 6236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if ((Val & Mask) == 0) { 6336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer Val >>= Shift; 6436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZeroBits |= Shift; 6536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 6636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer Shift >>= 1; 6736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer Mask >>= Shift; 6836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 6936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return ZeroBits; 7036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 7136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 7236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer// Disable signed. 7336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 7436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 7536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::numeric_limits<T>::is_signed, std::size_t>::type 7636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencercountTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) LLVM_DELETED_FUNCTION; 7736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 7836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#if __GNUC__ >= 4 || _MSC_VER 7936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <> 8036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerinline std::size_t countTrailingZeros<uint32_t>(uint32_t Val, ZeroBehavior ZB) { 8136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB != ZB_Undefined && Val == 0) 8236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return 32; 8336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 84ae8e3cfbca31cddac5a891b1d5606399dd4fefe0Reid Kleckner#if __has_builtin(__builtin_ctz) || __GNUC_PREREQ(4, 0) 8536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return __builtin_ctz(Val); 8636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 8736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned long Index; 8836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer _BitScanForward(&Index, Val); 8936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return Index; 9036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 9136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 9236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 93a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#if !defined(_MSC_VER) || defined(_M_X64) 9436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <> 9536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerinline std::size_t countTrailingZeros<uint64_t>(uint64_t Val, ZeroBehavior ZB) { 9636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB != ZB_Undefined && Val == 0) 9736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return 64; 9836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 99ae8e3cfbca31cddac5a891b1d5606399dd4fefe0Reid Kleckner#if __has_builtin(__builtin_ctzll) || __GNUC_PREREQ(4, 0) 10036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return __builtin_ctzll(Val); 10136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 10236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned long Index; 10336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer _BitScanForward64(&Index, Val); 10436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return Index; 10536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 10636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 10736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 108a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#endif 10936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 11036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Count number of 0's from the most significant bit to the least 11136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// stopping at the first 1. 11236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 11336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 11436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 11536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are 11636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 11736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 11836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 11936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer !std::numeric_limits<T>::is_signed, std::size_t>::type 1203018f0ddd4677eadf33af4284b8fa41ed929a2f0Dmitri GribenkocountLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) { 1213018f0ddd4677eadf33af4284b8fa41ed929a2f0Dmitri Gribenko (void)ZB; 1223018f0ddd4677eadf33af4284b8fa41ed929a2f0Dmitri Gribenko 12336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (!Val) 12436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::digits; 12536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 12636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // Bisection method. 12736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::size_t ZeroBits = 0; 12836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer for (T Shift = std::numeric_limits<T>::digits >> 1; Shift; Shift >>= 1) { 12936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer T Tmp = Val >> Shift; 13036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (Tmp) 13136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer Val = Tmp; 13236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer else 13336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer ZeroBits |= Shift; 13436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer } 13536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return ZeroBits; 13636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 13736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 13836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer// Disable signed. 13936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 14036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 14136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::numeric_limits<T>::is_signed, std::size_t>::type 14236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencercountLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) LLVM_DELETED_FUNCTION; 14336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 14436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#if __GNUC__ >= 4 || _MSC_VER 14536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <> 14636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerinline std::size_t countLeadingZeros<uint32_t>(uint32_t Val, ZeroBehavior ZB) { 14736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB != ZB_Undefined && Val == 0) 14836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return 32; 14936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 150ae8e3cfbca31cddac5a891b1d5606399dd4fefe0Reid Kleckner#if __has_builtin(__builtin_clz) || __GNUC_PREREQ(4, 0) 15136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return __builtin_clz(Val); 15236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 15336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned long Index; 15436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer _BitScanReverse(&Index, Val); 15536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return Index ^ 31; 15636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 15736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 15836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 159a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#if !defined(_MSC_VER) || defined(_M_X64) 16036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <> 16136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerinline std::size_t countLeadingZeros<uint64_t>(uint64_t Val, ZeroBehavior ZB) { 16236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB != ZB_Undefined && Val == 0) 16336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return 64; 16436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 165ae8e3cfbca31cddac5a891b1d5606399dd4fefe0Reid Kleckner#if __has_builtin(__builtin_clzll) || __GNUC_PREREQ(4, 0) 16636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return __builtin_clzll(Val); 16736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#elif _MSC_VER 16836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned long Index; 16936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer _BitScanReverse64(&Index, Val); 17036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return Index ^ 63; 17136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 17236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 17336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#endif 174a0cfb8f21baf94fb8c40ff90bfc043de1ef700ecMichael J. Spencer#endif 17536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 17636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Get the index of the first set bit starting from the least 17736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// significant bit. 17836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 17936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 18036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 18136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are 18236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 18336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 18436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 185927d8dcb47a50b4471f5619733fb8196fa1e52eaBenjamin Kramer !std::numeric_limits<T>::is_signed, T>::type 18636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencerfindFirstSet(T Val, ZeroBehavior ZB = ZB_Max) { 18736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB == ZB_Max && Val == 0) 18836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::max(); 18936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 19036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return countTrailingZeros(Val, ZB_Undefined); 19136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 19236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 19336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer// Disable signed. 19436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 19536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 196927d8dcb47a50b4471f5619733fb8196fa1e52eaBenjamin Kramer std::numeric_limits<T>::is_signed, T>::type 19736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencerfindFirstSet(T Val, ZeroBehavior ZB = ZB_Max) LLVM_DELETED_FUNCTION; 19836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 19936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Get the index of the last set bit starting from the least 20036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// significant bit. 20136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 20236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// Only unsigned integral types are allowed. 20336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 20436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are 20536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// valid arguments. 20636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 20736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 208927d8dcb47a50b4471f5619733fb8196fa1e52eaBenjamin Kramer !std::numeric_limits<T>::is_signed, T>::type 20936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencerfindLastSet(T Val, ZeroBehavior ZB = ZB_Max) { 21036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer if (ZB == ZB_Max && Val == 0) 21136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return std::numeric_limits<T>::max(); 21236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 21336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // Use ^ instead of - because both gcc and llvm can remove the associated ^ 21436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer // in the __builtin_clz intrinsic on x86. 21536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return countLeadingZeros(Val, ZB_Undefined) ^ 21636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer (std::numeric_limits<T>::digits - 1); 21736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 21836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 21936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer// Disable signed. 22036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 22136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertypename enable_if_c<std::numeric_limits<T>::is_integer && 222927d8dcb47a50b4471f5619733fb8196fa1e52eaBenjamin Kramer std::numeric_limits<T>::is_signed, T>::type 22336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencerfindLastSet(T Val, ZeroBehavior ZB = ZB_Max) LLVM_DELETED_FUNCTION; 22436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 22536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Macro compressed bit reversal table for 256 bits. 22636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// 22736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable 22836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencerstatic const unsigned char BitReverseTable256[256] = { 22936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R2(n) n, n + 2 * 64, n + 1 * 64, n + 3 * 64 23036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R4(n) R2(n), R2(n + 2 * 16), R2(n + 1 * 16), R2(n + 3 * 16) 23136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer#define R6(n) R4(n), R4(n + 2 * 4), R4(n + 1 * 4), R4(n + 3 * 4) 23236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer R6(0), R6(2), R6(1), R6(3) 23336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer}; 23436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer 23536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer/// \brief Reverse the bits in \p Val. 23636fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencertemplate <typename T> 23736fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. SpencerT reverseBits(T Val) { 23836fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned char in[sizeof(Val)]; 23936fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer unsigned char out[sizeof(Val)]; 24036fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::memcpy(in, &Val, sizeof(Val)); 24136fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer for (unsigned i = 0; i < sizeof(Val); ++i) 24236fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer out[(sizeof(Val) - i) - 1] = BitReverseTable256[in[i]]; 24336fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer std::memcpy(&Val, out, sizeof(Val)); 24436fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer return Val; 24536fe3f2b5651882b12e24b49dc7818ebb1a5d79fMichael J. Spencer} 246d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 247fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman// NOTE: The following support functions use the _32/_64 extensions instead of 24889bfcd34cbd2f4c6bb2cafff0a5c2bff147fae11Chris Lattner// type overloading so that signed and unsigned integers can be used without 24989bfcd34cbd2f4c6bb2cafff0a5c2bff147fae11Chris Lattner// ambiguity. 25088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 25149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Hi_32 - This function returns the high 32 bits of a 64 bit value. 252c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t Hi_32(uint64_t Value) { 253c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Cohen return static_cast<uint32_t>(Value >> 32); 25488c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 25588c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 25649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Lo_32 - This function returns the low 32 bits of a 64 bit value. 257c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t Lo_32(uint64_t Value) { 258c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Cohen return static_cast<uint32_t>(Value); 25988c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 26088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 26134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer/// isInt - Checks if an integer fits into the given bit width. 262d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesentemplate<unsigned N> 263d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Oleseninline bool isInt(int64_t x) { 264d4c00c0f558193b492aed9ab6aacf84bf1d3fb4eJakob Stoklund Olesen return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1))); 265d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen} 26634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer// Template specializations to get better code for common cases. 26734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 26834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<8>(int64_t x) { 26934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int8_t>(x) == x; 27034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 27134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 27234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<16>(int64_t x) { 27334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int16_t>(x) == x; 27434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 27534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 27634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isInt<32>(int64_t x) { 27734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<int32_t>(x) == x; 27834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 279d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen 280b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// isShiftedInt<N,S> - Checks if a signed integer is an N bit number shifted 281b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// left by S. 282b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicumtemplate<unsigned N, unsigned S> 283b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicuminline bool isShiftedInt(int64_t x) { 284b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum return isInt<N+S>(x) && (x % (1<<S) == 0); 285b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum} 286b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum 28734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer/// isUInt - Checks if an unsigned integer fits into the given bit width. 288d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesentemplate<unsigned N> 28934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt(uint64_t x) { 29066f1f30725eb20760069823ec015234cce6b887cReid Kleckner return N >= 64 || x < (UINT64_C(1)<<(N)); 291d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen} 29234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer// Template specializations to get better code for common cases. 29334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 29434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<8>(uint64_t x) { 29534247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint8_t>(x) == x; 29634247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 29734247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 29834247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<16>(uint64_t x) { 29934247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint16_t>(x) == x; 30034247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 30134247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramertemplate<> 30234247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramerinline bool isUInt<32>(uint64_t x) { 30334247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer return static_cast<uint32_t>(x) == x; 30434247a0f356edf45ae3ad9ce04e1f90a77c6dba7Benjamin Kramer} 305d6eb635d1a1317fc3d218056ec77ec242c2413cbJakob Stoklund Olesen 306b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// isShiftedUInt<N,S> - Checks if a unsigned integer is an N bit number shifted 307b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum/// left by S. 308b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicumtemplate<unsigned N, unsigned S> 309b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicuminline bool isShiftedUInt(uint64_t x) { 310b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum return isUInt<N+S>(x) && (x % (1<<S) == 0); 311b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum} 312b4b54153ad760c69a00a08531abef4ed434a5092Tony Linthicum 3135005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman/// isUIntN - Checks if an unsigned integer fits into the given (dynamic) 3145005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman/// bit width. 3155005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohmaninline bool isUIntN(unsigned N, uint64_t x) { 3165005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman return x == (x & (~0ULL >> (64 - N))); 3175005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman} 3185005e27f9714f0eaa5b8b7a5a1f6751afa163f07Dan Gohman 319c42a7754bb6249c33c509e6fa6e8b3c9344e72d8Rafael Espindola/// isIntN - Checks if an signed integer fits into the given (dynamic) 320b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola/// bit width. 321b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindolainline bool isIntN(unsigned N, int64_t x) { 322b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1))); 323b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola} 324b35d56c2fe39064a33d0e4e7faf5464b6d8a7352Rafael Espindola 32549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// isMask_32 - This function returns true if the argument is a sequence of ones 32649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// starting at the least significant bit with the remainder zero (32 bit 32749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// version). Ex. isMask_32(0x0000FFFFU) == true. 32818a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isMask_32(uint32_t Value) { 32988c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && ((Value + 1) & Value) == 0; 33088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 33188c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 33249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// isMask_64 - This function returns true if the argument is a sequence of ones 33349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// starting at the least significant bit with the remainder zero (64 bit 33449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// version). 33518a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isMask_64(uint64_t Value) { 33688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && ((Value + 1) & Value) == 0; 33788c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 33888c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 339fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isShiftedMask_32 - This function returns true if the argument contains a 34049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// sequence of ones with the remainder zero (32 bit version.) 34149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. isShiftedMask_32(0x0000FF00U) == true. 34218a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isShiftedMask_32(uint32_t Value) { 34388c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return isMask_32((Value - 1) | Value); 34488c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 34588c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 346fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isShiftedMask_64 - This function returns true if the argument contains a 34749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// sequence of ones with the remainder zero (64 bit version.) 34818a4c74136a9919dc3235d03c0e060f32d01f3b0Chris Lattnerinline bool isShiftedMask_64(uint64_t Value) { 34988c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return isMask_64((Value - 1) | Value); 35088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 35188c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 352fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// isPowerOf2_32 - This function returns true if the argument is a power of 35349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// two > 0. Ex. isPowerOf2_32(0x00100000U) == true (32 bit edition.) 354c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline bool isPowerOf2_32(uint32_t Value) { 35588c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner return Value && !(Value & (Value - 1)); 35688c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 35788c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 35849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// isPowerOf2_64 - This function returns true if the argument is a power of two 35949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// > 0 (64 bit edition.) 36088c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattnerinline bool isPowerOf2_64(uint64_t Value) { 36119b7e0e0cabfa6dfc559c64e3d6ed053832c4047Reid Spencer return Value && !(Value & (Value - int64_t(1L))); 36288c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner} 36388c606eb0cc5415ed367c24e073f7bb478501d34Chris Lattner 36449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_16 - This function returns a byte-swapped representation of the 36549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 16-bit argument, Value. 366c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint16_t ByteSwap_16(uint16_t Value) { 3673afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_16(Value); 3686fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3696fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 37049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_32 - This function returns a byte-swapped representation of the 37149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 32-bit argument, Value. 372c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline uint32_t ByteSwap_32(uint32_t Value) { 3733afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_32(Value); 3746fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3756fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 37649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// ByteSwap_64 - This function returns a byte-swapped representation of the 37749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// 64-bit argument, Value. 3786fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begemaninline uint64_t ByteSwap_64(uint64_t Value) { 3793afc385042fb0d121e9454347f975e4f1a5f5bfdChris Lattner return sys::SwapByteOrder_64(Value); 3806fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman} 3816fb3bd6a658940287789198d3207b0da04c0a4e6Nate Begeman 382ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// CountLeadingOnes_32 - this function performs the operation of 383ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// counting the number of ones from the most significant bit to the first zero 384ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// bit. Ex. CountLeadingOnes_32(0xFF0FFF00) == 8. 385ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// Returns 32 if the word is all ones. 386ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohmaninline unsigned CountLeadingOnes_32(uint32_t Value) { 3873b77151a61d2985ad5b29ee3d05b34d553322c2aMichael J. Spencer return countLeadingZeros(~Value); 388e265504e82310266271fa2329b6ef8115bbe8244Chris Lattner} 389e265504e82310266271fa2329b6ef8115bbe8244Chris Lattner 390ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// CountLeadingOnes_64 - This function performs the operation 391fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// of counting the number of ones from the most significant bit to the first 392ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// zero bit (64 bit edition.) 393ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// Returns 64 if the word is all ones. 394ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohmaninline unsigned CountLeadingOnes_64(uint64_t Value) { 3953b77151a61d2985ad5b29ee3d05b34d553322c2aMichael J. Spencer return countLeadingZeros(~Value); 39616d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 39716d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 398ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// CountTrailingOnes_32 - this function performs the operation of 399ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// counting the number of ones from the least significant bit to the first zero 400ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// bit. Ex. CountTrailingOnes_32(0x00FF00FF) == 8. 401ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// Returns 32 if the word is all ones. 402ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohmaninline unsigned CountTrailingOnes_32(uint32_t Value) { 4033b77151a61d2985ad5b29ee3d05b34d553322c2aMichael J. Spencer return countTrailingZeros(~Value); 40416d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 40516d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 406ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// CountTrailingOnes_64 - This function performs the operation 407fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// of counting the number of ones from the least significant bit to the first 408ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// zero bit (64 bit edition.) 409ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman/// Returns 64 if the word is all ones. 410ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohmaninline unsigned CountTrailingOnes_64(uint64_t Value) { 411c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return countTrailingZeros(~Value); 412ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman} 413ca2a0e1062545651efd20dca1f647b864ede4a39Dan Gohman 41449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// CountPopulation_32 - this function counts the number of set bits in a value. 41549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. CountPopulation(0xF000F000) = 8 41649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Returns 0 if the word is zero. 4172a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Andersoninline unsigned CountPopulation_32(uint32_t Value) { 4182a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#if __GNUC__ >= 4 4192a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson return __builtin_popcount(Value); 4202a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#else 421e6efc859398498c3a08a3f36e82c63a706ae0d7eAnton Korobeynikov uint32_t v = Value - ((Value >> 1) & 0x55555555); 422e6efc859398498c3a08a3f36e82c63a706ae0d7eAnton Korobeynikov v = (v & 0x33333333) + ((v >> 2) & 0x33333333); 423e6efc859398498c3a08a3f36e82c63a706ae0d7eAnton Korobeynikov return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; 4242a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#endif 42516d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 42616d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 42749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// CountPopulation_64 - this function counts the number of set bits in a value, 42849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// (64 bit edition.) 42916d6ea526482e733fe3bc63929e94c9e88b6708dNate Begemaninline unsigned CountPopulation_64(uint64_t Value) { 4302a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#if __GNUC__ >= 4 4312a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson return __builtin_popcountll(Value); 4322a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#else 433e6efc859398498c3a08a3f36e82c63a706ae0d7eAnton Korobeynikov uint64_t v = Value - ((Value >> 1) & 0x5555555555555555ULL); 434e6efc859398498c3a08a3f36e82c63a706ae0d7eAnton Korobeynikov v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL); 435e6efc859398498c3a08a3f36e82c63a706ae0d7eAnton Korobeynikov v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL; 436ca5183d445954a9b2a570d6bbba1bc2b00ad6442Jeff Cohen return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56); 4372a934cb6072bb0840b39e899e02ad9dea95b18dcOwen Anderson#endif 43816d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 43916d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman 440fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// Log2_32 - This function returns the floor log base 2 of the specified value, 44149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// -1 if the value is zero. (32 bit edition.) 44249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. Log2_32(32) == 5, Log2_32(1) == 0, Log2_32(0) == -1, Log2_32(6) == 2 443c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline unsigned Log2_32(uint32_t Value) { 444c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 31 - countLeadingZeros(Value); 44516d6ea526482e733fe3bc63929e94c9e88b6708dNate Begeman} 44654ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner 447fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman/// Log2_64 - This function returns the floor log base 2 of the specified value, 44849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// -1 if the value is zero. (64 bit edition.) 4492be12faabb3ce2d2d3979c73ac65d466fdea5ec5Chris Lattnerinline unsigned Log2_64(uint64_t Value) { 450c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 63 - countLeadingZeros(Value); 451cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner} 452cee8f9ae67104576b2028125b56e9ba4856a1d66Chris Lattner 45349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Log2_32_Ceil - This function returns the ceil log base 2 of the specified 45449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// value, 32 if the value is zero. (32 bit edition). 45549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Ex. Log2_32_Ceil(32) == 5, Log2_32_Ceil(1) == 0, Log2_32_Ceil(6) == 3 456c3c395cf5e401328836e81c18cb70eef1b9ea5acJeff Coheninline unsigned Log2_32_Ceil(uint32_t Value) { 457c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 32 - countLeadingZeros(Value - 1); 4580683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner} 4590683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner 46055b42513e1548554bfacc72d48ec3483c73fddf9Dan Gohman/// Log2_64_Ceil - This function returns the ceil log base 2 of the specified 46155b42513e1548554bfacc72d48ec3483c73fddf9Dan Gohman/// value, 64 if the value is zero. (64 bit edition.) 4620683c8cad920d241d44b126972d5cdd164dcc213Chris Lattnerinline unsigned Log2_64_Ceil(uint64_t Value) { 463c6af2432c802d241c8fffbe0371c023e6c58844eMichael J. Spencer return 64 - countLeadingZeros(Value - 1); 4640683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner} 4650683c8cad920d241d44b126972d5cdd164dcc213Chris Lattner 46649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// GreatestCommonDivisor64 - Return the greatest common divisor of the two 46749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// values using Euclid's algorithm. 46849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattnerinline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) { 46949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner while (B) { 47049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner uint64_t T = B; 47149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner B = A % B; 47249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner A = T; 47349e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner } 47449e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner return A; 47549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner} 476fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman 47749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// BitsToDouble - This function takes a 64-bit integer and returns the bit 47849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// equivalent double. 47959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskeyinline double BitsToDouble(uint64_t Bits) { 48059b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 48159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey uint64_t L; 48259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey double D; 48359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 48459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.L = Bits; 48559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.D; 48659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 48759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 48849e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// BitsToFloat - This function takes a 32-bit integer and returns the bit 48949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// equivalent float. 490104338913500d007996056ad092e195009883a84Jim Laskeyinline float BitsToFloat(uint32_t Bits) { 49159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 492104338913500d007996056ad092e195009883a84Jim Laskey uint32_t I; 49359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey float F; 49459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 49559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.I = Bits; 49659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.F; 49759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 49859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 49949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// DoubleToBits - This function takes a double and returns the bit 500541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// equivalent 64-bit integer. Note that copying doubles around 501541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// changes the bits of NaNs on some hosts, notably x86, so this 502541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// routine cannot be used if these bits are needed. 50359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskeyinline uint64_t DoubleToBits(double Double) { 50459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 50559b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey uint64_t L; 50659b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey double D; 50759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 50859b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.D = Double; 50959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.L; 51059b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 51159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 51249e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// FloatToBits - This function takes a float and returns the bit 513541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// equivalent 32-bit integer. Note that copying floats around 514541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// changes the bits of NaNs on some hosts, notably x86, so this 515541ed9fd02ea48d2739f4a9dd681ba2d5da26886Dale Johannesen/// routine cannot be used if these bits are needed. 516104338913500d007996056ad092e195009883a84Jim Laskeyinline uint32_t FloatToBits(float Float) { 51759b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey union { 518104338913500d007996056ad092e195009883a84Jim Laskey uint32_t I; 51959b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey float F; 52059b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey } T; 52159b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey T.F = Float; 52259b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey return T.I; 52359b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey} 52459b8fcfa5f736dff4a08ebcac032935b6fd92f34Jim Laskey 52549e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Platform-independent wrappers for the C99 isnan() function. 52649e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattnerint IsNAN(float f); 52749e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattnerint IsNAN(double d); 5287764f4b2e0e550dc23f3c536f236f9abf86879dcBrian Gaeke 52949e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattner/// Platform-independent wrappers for the C99 isinf() function. 53049e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattnerint IsInf(float f); 53149e6a9bc94a115d674502009b396c1a22fb1b1a1Chris Lattnerint IsInf(double d); 532a7d03b466a41e68e11480ae6ca275140fe4c4507Brian Gaeke 533fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands/// MinAlign - A and B are either alignments or offsets. Return the minimum 534fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands/// alignment that may be assumed after adding the two together. 535305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline uint64_t MinAlign(uint64_t A, uint64_t B) { 536fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands // The largest power of 2 that divides both A and B. 537b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // 538b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // Replace "-Value" by "1+~Value" in the following commented code to avoid 539b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // MSVC warning C4146 540b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman // return (A | B) & -(A | B); 541b3508821533854b1879e7d6a83824b4ba84ce633Aaron Ballman return (A | B) & (1 + ~(A | B)); 542fd617d0143a158bc1c996445262d409280e7b0ccDuncan Sands} 543d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson 544d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson/// NextPowerOf2 - Returns the next power of two (in 64-bits) 545d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson/// that is strictly greater than A. Returns zero on overflow. 546305b515c2787f47adecbe120e4b4bef55c5e5525Chandler Carruthinline uint64_t NextPowerOf2(uint64_t A) { 547d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 1); 548d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 2); 549d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 4); 550d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 8); 551d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 16); 552d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson A |= (A >> 32); 553d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson return A + 1; 554d98a45d29a6047bd47d3a3cd83c13ac0dac851fbOwen Anderson} 555e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar 5562d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// Returns the next integer (mod 2**64) that is greater than or equal to 5572d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \p Value and is a multiple of \p Align. \p Align must be non-zero. 558e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar/// 559e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar/// Examples: 5602d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \code 5612d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// RoundUpToAlignment(5, 8) = 8 5622d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// RoundUpToAlignment(17, 8) = 24 5632d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// RoundUpToAlignment(~0LL, 8) = 0 5642d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// \endcode 565e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbarinline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align) { 566e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar return ((Value + Align - 1) / Align) * Align; 567e2a8dfefe5740377dbc323a84337c45d37410ea8Daniel Dunbar} 568fe2cce63aa26d0916fa7be32c6bf7fa8fb059ee7Misha Brukman 5692d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// Returns the offset to the next integer (mod 2**64) that is greater than 5702d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// or equal to \p Value and is a multiple of \p Align. \p Align must be 5712d9eb72178af8e79dc6432cd1b7d29bde16da1b9Dmitri Gribenko/// non-zero. 572eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbarinline uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align) { 573eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar return RoundUpToAlignment(Value, Align) - Value; 574eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar} 575eccf22528f8b4c21cdbd2f620cbe39dbb38ea6e1Daniel Dunbar 5767b9486ad4355a010d22e0737cee9cd7c7b747eceDale Johannesen/// abs64 - absolute value of a 64-bit int. Not all environments support 5777b9486ad4355a010d22e0737cee9cd7c7b747eceDale Johannesen/// "abs" on whatever their name for the 64-bit int type is. The absolute 5787b9486ad4355a010d22e0737cee9cd7c7b747eceDale Johannesen/// value of the largest negative number is undefined, as with "abs". 5797b9486ad4355a010d22e0737cee9cd7c7b747eceDale Johanneseninline int64_t abs64(int64_t x) { 5807b9486ad4355a010d22e0737cee9cd7c7b747eceDale Johannesen return (x < 0) ? -x : x; 5817b9486ad4355a010d22e0737cee9cd7c7b747eceDale Johannesen} 5827b9486ad4355a010d22e0737cee9cd7c7b747eceDale Johannesen 583b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// SignExtend32 - Sign extend B-bit number x to 32-bit int. 584b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// Usage int32_t r = SignExtend32<5>(x); 585adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesentemplate <unsigned B> inline int32_t SignExtend32(uint32_t x) { 586adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesen return int32_t(x << (32 - B)) >> (32 - B); 587b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen} 588b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen 5891144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// \brief Sign extend number in the bottom B bits of X to a 32-bit int. 5901144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// Requires 0 < B <= 32. 5911144af3c9b4da48cd581156e05b24261c8de366aRichard Smithinline int32_t SignExtend32(uint32_t X, unsigned B) { 5921144af3c9b4da48cd581156e05b24261c8de366aRichard Smith return int32_t(X << (32 - B)) >> (32 - B); 5931144af3c9b4da48cd581156e05b24261c8de366aRichard Smith} 5941144af3c9b4da48cd581156e05b24261c8de366aRichard Smith 595b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// SignExtend64 - Sign extend B-bit number x to 64-bit int. 596b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen/// Usage int64_t r = SignExtend64<5>(x); 597adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesentemplate <unsigned B> inline int64_t SignExtend64(uint64_t x) { 598adc6e06ff0c5950abda86574c2da1fc6b863b75cJakob Stoklund Olesen return int64_t(x << (64 - B)) >> (64 - B); 599b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen} 600b68a3ee82a8a34f7bae1d68d76f574e76a5535efJohnny Chen 6011144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// \brief Sign extend number in the bottom B bits of X to a 64-bit int. 6021144af3c9b4da48cd581156e05b24261c8de366aRichard Smith/// Requires 0 < B <= 64. 6031144af3c9b4da48cd581156e05b24261c8de366aRichard Smithinline int64_t SignExtend64(uint64_t X, unsigned B) { 6041144af3c9b4da48cd581156e05b24261c8de366aRichard Smith return int64_t(X << (64 - B)) >> (64 - B); 6051144af3c9b4da48cd581156e05b24261c8de366aRichard Smith} 6061144af3c9b4da48cd581156e05b24261c8de366aRichard Smith 607eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman#if defined(_MSC_VER) 608eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman // Visual Studio defines the HUGE_VAL class of macros using purposeful 609eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman // constant arithmetic overflow, which it then warns on when encountered. 610eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman const float huge_valf = std::numeric_limits<float>::infinity(); 611eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman const double huge_vald = std::numeric_limits<double>::infinity(); 612eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman const long double huge_vall = std::numeric_limits<long double>::infinity(); 613eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman#else 614eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman const float huge_valf = HUGE_VALF; 615eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman const double huge_vald = HUGE_VALD; 616eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman const long double huge_vall = HUGE_VALL; 617eb3602472026dc029beb45ccbe09bc84162ba949Aaron Ballman#endif 618d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke} // End llvm namespace 619d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 62054ea60c69e69b8e5a464a1d7688ceec5c68bacd5Chris Lattner#endif 621