glm/glm/detail/func_integer.inl

318 lines
11 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
/// Copyright (c) 2005 - 2014 G-Truc Creation (www.g-truc.net)
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
///
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
///
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
///
/// @ref core
/// @file glm/core/func_integer.inl
/// @date 2010-03-17 / 2011-06-15
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////
#include "type_vec2.hpp"
#include "type_vec3.hpp"
#include "type_vec4.hpp"
#include "type_int.hpp"
#include "_vectorize.hpp"
#if(GLM_ARCH != GLM_ARCH_PURE)
#if(GLM_COMPILER & GLM_COMPILER_VC)
# include <intrin.h>
# pragma intrinsic(_BitScanReverse)
#endif//(GLM_COMPILER & GLM_COMPILER_VC)
#endif//(GLM_ARCH != GLM_ARCH_PURE)
#include <limits>
namespace glm{
namespace detail
{
GLM_FUNC_QUALIFIER int mask(int Bits)
{
return ~((~0) << Bits);
}
}//namespace detail
// uaddCarry
GLM_FUNC_QUALIFIER uint uaddCarry(uint const & x, uint const & y, uint & Carry)
{
uint64 Value64 = static_cast<uint64>(x) + static_cast<uint64>(y);
uint32 Result = static_cast<uint32>(Value64 % (static_cast<uint64>(1) << static_cast<uint64>(32)));
Carry = (Value64 % (static_cast<uint64>(1) << static_cast<uint64>(32))) > 1 ? static_cast<uint32>(1) : static_cast<uint32>(0);
return Result;
}
template <precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<uint, P> uaddCarry(vecType<uint, P> const & x, vecType<uint, P> const & y, vecType<uint, P> & Carry)
{
vecType<uint64, P> Value64(vecType<uint64, P>(x) + vecType<uint64, P>(y));
vecType<uint32, P> Result(Value64 % (static_cast<uint64>(1) << static_cast<uint64>(32)));
vecType<bool, P> DoCarry(greaterThan(Value64 % (static_cast<uint64>(1) << static_cast<uint64>(32)), vecType<uint64, P>(1)));
Carry = mix(vecType<uint32, P>(0), vecType<uint32, P>(1), DoCarry);
return Result;
}
// usubBorrow
GLM_FUNC_QUALIFIER uint usubBorrow(uint const & x, uint const & y, uint & Borrow)
{
GLM_STATIC_ASSERT(sizeof(uint) == sizeof(uint32), "uint and uint32 size mismatch");
Borrow = x >= y ? static_cast<uint32>(0) : static_cast<uint32>(1);
if(y >= x)
return y - x;
else
return static_cast<uint32>((static_cast<int64>(1) << static_cast<int64>(32)) + (static_cast<int64>(y) - static_cast<int64>(x)));
}
template <precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<uint, P> usubBorrow(vecType<uint, P> const & x, vecType<uint, P> const & y, vecType<uint, P> & Borrow)
{
Borrow = mix(vecType<uint, P>(1), vecType<uint, P>(0), greaterThanEqual(x, y));
vecType<uint, P> const YgeX(y - x);
vecType<uint, P> const XgeY(vecType<uint32, P>((static_cast<int64>(1) << static_cast<int64>(32)) + (vecType<int64, P>(y) - vecType<int64, P>(x))));
return mix(XgeY, YgeX, greaterThanEqual(y, x));
}
// umulExtended
GLM_FUNC_QUALIFIER void umulExtended(uint const & x, uint const & y, uint & msb, uint & lsb)
{
GLM_STATIC_ASSERT(sizeof(uint) == sizeof(uint32), "uint and uint32 size mismatch");
uint64 Value64 = static_cast<uint64>(x) * static_cast<uint64>(y);
uint32* PointerMSB = (reinterpret_cast<uint32*>(&Value64) + 1);
msb = *PointerMSB;
uint32* PointerLSB = (reinterpret_cast<uint32*>(&Value64) + 0);
lsb = *PointerLSB;
}
template <precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER void umulExtended(vecType<uint, P> const & x, vecType<uint, P> const & y, vecType<uint, P> & msb, vecType<uint, P> & lsb)
{
GLM_STATIC_ASSERT(sizeof(uint) == sizeof(uint32), "uint and uint32 size mismatch");
vecType<uint64, P> Value64(vecType<uint64, P>(x) * vecType<uint64, P>(y));
msb = vecType<uint32, P>(Value64 >> static_cast<uint64>(32));
lsb = vecType<uint32, P>(Value64);
}
// imulExtended
GLM_FUNC_QUALIFIER void imulExtended(int x, int y, int & msb, int & lsb)
{
GLM_STATIC_ASSERT(sizeof(int) == sizeof(int32), "int and int32 size mismatch");
int64 Value64 = static_cast<int64>(x) * static_cast<int64>(y);
int32* PointerMSB = (reinterpret_cast<int32*>(&Value64) + 1);
msb = *PointerMSB;
int32* PointerLSB = (reinterpret_cast<int32*>(&Value64));
lsb = *PointerLSB;
}
template <precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER void imulExtended(vecType<int, P> const & x, vecType<int, P> const & y, vecType<int, P> & msb, vecType<int, P> & lsb)
{
GLM_STATIC_ASSERT(sizeof(int) == sizeof(int32), "int and int32 size mismatch");
vecType<int64, P> Value64(vecType<int64, P>(x) * vecType<int64, P>(y));
lsb = vecType<int32, P>(Value64 & static_cast<int64>(0xFFFFFFFF));
msb = vecType<int32, P>((Value64 >> static_cast<int64>(32)) & static_cast<int64>(0xFFFFFFFF));
}
// bitfieldExtract
template <typename genIUType>
GLM_FUNC_QUALIFIER genIUType bitfieldExtract(genIUType Value, int Offset, int Bits)
{
return bitfieldExtract(tvec1<genIUType>(Value), Offset, Bits).x;
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P> bitfieldExtract(vecType<T, P> const & Value, int Offset, int Bits)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_integer, "'bitfieldExtract' only accept integer inputs");
int const Mask = detail::mask(Bits);
return (Value >> static_cast<T>(Offset)) & static_cast<T>(Mask);
}
// bitfieldInsert
template <typename genIUType>
GLM_FUNC_QUALIFIER genIUType bitfieldInsert(genIUType const & Base, genIUType const & Insert, int Offset, int Bits)
{
return bitfieldInsert(tvec1<genIUType>(Base), tvec1<genIUType>(Insert), Offset, Bits).x;
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P> bitfieldInsert(vecType<T, P> const & Base, vecType<T, P> const & Insert, int Offset, int Bits)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_integer, "'bitfieldInsert' only accept integer values");
T Mask = static_cast<T>(detail::mask(Bits) << Offset);
return (Base & ~Mask) | (Insert & Mask);
}
// bitfieldReverse
template <typename T>
GLM_FUNC_QUALIFIER T bitfieldReverse(T v)
{
return bitfieldReverse(tvec1<T>(v)).x;
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<T, P> bitfieldReverse(vecType<T, P> const & v)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_integer, "'bitfieldReverse' only accept integer values");
vecType<T, P> Result(0);
T const BitSize = static_cast<T>(sizeof(T) * 8);
for(T i = 0; i < BitSize; ++i)
{
vecType<T, P> const BitSet(v & (static_cast<T>(1) << i));
vecType<T, P> const BitFirst(BitSet >> i);
Result |= BitFirst << (BitSize - 1 - i);
}
return Result;
}
// bitCount
template <typename genIUType>
GLM_FUNC_QUALIFIER int bitCount(genIUType x)
{
return bitCount(tvec1<genIUType>(x)).x;
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<int, P> bitCount(vecType<T, P> const & v)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_integer, "'bitCount' only accept integer values");
vecType<int, P> Count(0);
for(T i = 0, n = static_cast<T>(sizeof(T) * 8); i < n; ++i)
Count += vecType<int, P>((v >> i) & static_cast<T>(1));
return Count;
}
// findLSB
template <typename genIUType>
GLM_FUNC_QUALIFIER int findLSB(genIUType Value)
{
GLM_STATIC_ASSERT(std::numeric_limits<genIUType>::is_integer, "'findLSB' only accept integer values");
if(Value == 0)
return -1;
genIUType Bit;
for(Bit = genIUType(0); !(Value & (1 << Bit)); ++Bit){}
return Bit;
}
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<int, P> findLSB(vecType<T, P> const & x)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_integer, "'findLSB' only accept integer values");
return detail::functor1<int, T, P, vecType>::call(findLSB, x);
}
// findMSB
#if (GLM_ARCH != GLM_ARCH_PURE) && (GLM_COMPILER & GLM_COMPILER_VC)
template <typename genIUType>
GLM_FUNC_QUALIFIER int findMSB(genIUType Value)
{
GLM_STATIC_ASSERT(std::numeric_limits<genIUType>::is_integer, "'findMSB' only accept integer values");
if(Value == 0)
return -1;
unsigned long Result(0);
_BitScanReverse(&Result, Value);
return int(Result);
}
/*
// __builtin_clz seems to be buggy as it crasks for some values, from 0x00200000 to 80000000
#elif((GLM_ARCH != GLM_ARCH_PURE) && (GLM_COMPILER & GLM_COMPILER_GCC) && (GLM_COMPILER >= GLM_COMPILER_GCC40))
template <typename genIUType>
GLM_FUNC_QUALIFIER int findMSB
(
genIUType const & Value
)
{
GLM_STATIC_ASSERT(std::numeric_limits<genIUType>::is_integer, "'findMSB' only accept integer values");
if(Value == 0)
return -1;
// clz returns the number or trailing 0-bits; see
// http://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Other-Builtins.html
//
// NoteBecause __builtin_clz only works for unsigned ints, this
// implementation will not work for 64-bit integers.
//
return 31 - __builtin_clzl(Value);
}
*/
#else
/* SSE implementation idea
__m128i const Zero = _mm_set_epi32( 0, 0, 0, 0);
__m128i const One = _mm_set_epi32( 1, 1, 1, 1);
__m128i Bit = _mm_set_epi32(-1, -1, -1, -1);
__m128i Tmp = _mm_set_epi32(Value, Value, Value, Value);
__m128i Mmi = Zero;
for(int i = 0; i < 32; ++i)
{
__m128i Shilt = _mm_and_si128(_mm_cmpgt_epi32(Tmp, One), One);
Tmp = _mm_srai_epi32(Tmp, One);
Bit = _mm_add_epi32(Bit, _mm_and_si128(Shilt, i));
Mmi = _mm_and_si128(Mmi, One);
}
return Bit;
*/
template <typename genIUType>
GLM_FUNC_QUALIFIER int findMSB(genIUType Value)
{
GLM_STATIC_ASSERT(std::numeric_limits<genIUType>::is_integer, "'findMSB' only accept integer values");
if(Value == genIUType(0) || Value == genIUType(-1))
return -1;
else if(Value > 0)
{
genIUType Bit = genIUType(-1);
for(genIUType tmp = Value; tmp > 0; tmp >>= 1, ++Bit){}
return Bit;
}
else //if(Value < 0)
{
int const BitCount(sizeof(genIUType) * 8);
int MostSignificantBit(-1);
for(int BitIndex(0); BitIndex < BitCount; ++BitIndex)
MostSignificantBit = (Value & (1 << BitIndex)) ? MostSignificantBit : BitIndex;
assert(MostSignificantBit >= 0);
return MostSignificantBit;
}
}
#endif//(GLM_COMPILER)
template <typename T, precision P, template <typename, precision> class vecType>
GLM_FUNC_QUALIFIER vecType<int, P> findMSB(vecType<T, P> const & x)
{
return detail::functor1<int, T, P, vecType>::call(findMSB, x);
}
}//namespace glm