//+--------------------------------------------------------------------------- // // Copyright (C) Microsoft Corporation, 1997-1998. // // File: unaligned.hpp // // Contents: Templatized data types for access to unaligned scalar values. // //---------------------------------------------------------------------------- // Implementation of UNALIGNED data values. This works for simple scalar values. // This file is heavily macro-based. The intent is to do this work with arithmetic. // The functionality may be expressed much more consisely with memcpy, but I need an // implementation faster than that. // To create an UNALIGNED type, use the MAKE_UNALIGNED_TYPE macro. For example, if // you need an int_UNALIGNED, say // // MAKE_UNALIGNED_TYPE( int, 4 ); // // Note that you need to specifiy the size of the base type. This is because the // amount of work to be done needs to be known by the preprocessor, where sizeof() // doesn't work. // To use: The intent is that replace occurances of "type UNALIGNED" in your code // with "type_UNALIGNED". It's simply a lexical change. You could automate this // change in order to easily convert code. More importantly, the reverse // transformation may also be easily automated, making it easier to merge with code // that doesn't use these types. // UNALIGNED64: The unaligned 64 types are an optimization. They should only be used // for values over four bytes in size (e.g. __int64, double). They assume that the // pointers are aligned to 4-bytes, so that access may be done with two 32-bit // references, instead of 8 8-bit references. #ifndef __unaligned_h__ #define __unaligned_h__ #if defined (_MSC_VER) || defined(__APOGEE__) #define MAKE_UNALIGNED_TYPE(base,size) typedef base UNALIGNED base##_UNALIGNED // // Use MAKE_UNALIGNED64_TYPE for QWORD data that may only be DWORD aligned on 64-bit // machines. Only 64-bit architectures pay the penalty for accessing such data. // #ifdef SPARC #define MAKE_UNALIGNED64_TYPE(base,size) typedef base base##_UNALIGNED64 #else #define MAKE_UNALIGNED64_TYPE(base,size) typedef base UNALIGNED base##_UNALIGNED64 #endif // SPARC #define MAKE_UNALIGNEDPTR_TYPE(base) typedef base UNALIGNED *base##_UNALIGNEDPTR #else // defined (_MSC_VER) || defined(__APOGEE__) #ifdef BIG_ENDIAN #define SET2(val,data) \ data[0] = (val) >> 8, \ data[1] = (val) #define GET2(data) \ ( ( data[0] << 8 ) | \ ( data[1] ) ) #define SET4(val,data) \ data[0] = (val) >> 24, \ data[1] = (val) >> 16, \ data[2] = (val) >> 8, \ data[3] = (val) #define GET4(data) \ ( ( data[0] << 24 ) | \ ( data[1] << 16 ) | \ ( data[2] << 8 ) | \ ( data[3] ) ) #define SET8(val,data) \ data[0] = (val) >> 56, \ data[1] = (val) >> 48, \ data[2] = (val) >> 40, \ data[3] = (val) >> 32 \ data[4] = (val) >> 24, \ data[5] = (val) >> 16, \ data[6] = (val) >> 8, \ data[7] = (val) #define GET8(data) \ ( ( data[0] << 56 ) | \ ( data[1] << 48 ) | \ ( data[2] << 40 ) | \ ( data[3] << 32 ) | \ ( data[4] << 24 ) | \ ( data[5] << 16 ) | \ ( data[6] << 8 ) | \ ( data[7] ) ) #define SET648(val,data) \ data[0] = (val) >> 32, \ data[1] = (val) #define GET648(data) \ ( ( data[0] << 32 ) | \ ( data[1] ) ) #else #define SET2(val,data) \ data[1] = (val) >> 8, \ data[0] = (val) #define GET2(data) \ ( ( data[1] << 8 ) | \ ( data[0] ) ) #define SET4(val,data) \ data[3] = (val) >> 24, \ data[2] = (val) >> 16, \ data[1] = (val) >> 8, \ data[0] = (val) #define GET4(data) \ ( ( data[3] << 24 ) | \ ( data[2] << 16 ) | \ ( data[1] << 8 ) | \ ( data[0] ) ) #define SET8(val,data) \ data[7] = (val) >> 56, \ data[6] = (val) >> 48, \ data[5] = (val) >> 40, \ data[4] = (val) >> 32, \ data[3] = (val) >> 24, \ data[2] = (val) >> 16, \ data[1] = (val) >> 8, \ data[0] = (val) #define GET8(data) \ ( ( data[7] << 56 ) | \ ( data[6] << 48 ) | \ ( data[5] << 40 ) | \ ( data[4] << 32 ) | \ ( data[3] << 24 ) | \ ( data[2] << 16 ) | \ ( data[1] << 8 ) | \ ( data[0] ) ) #define SET648(val,data) \ data[1] = (val) >> 32, \ data[0] = (val) #define GET648(data) \ ( ( data[1] << 32 ) | \ ( data[0] ) ) #endif #define GROUP(type,size,get,set,sfx) \ Unaligned##sfx##size( type v ) { set##size( v, data ); } \ type operator = ( type v ) { set##size( v, data ); return v; } \ operator type() { return get##size( data ); } \ type operator += (const type v) { set##size( get##size(data) + v, data); return *this; } \ type operator -= (const type v) { set##size( get##size(data) - v, data); return *this; } \ type operator <<= (const type v) { set##size( get##size(data) << v, data); return *this; } \ type operator *= (const type v) { set##size( get##size(data) * v, data); return *this; } \ type operator /= (const type v) { set##size( get##size(data) / v, data); return *this; } \ type operator %= (const type v) { set##size( get##size(data) % v, data); return *this; } \ type operator >>= (const type v) { set##size( get##size(data) >> v, data); return *this; } \ type operator ^= (const type v) { set##size( get##size(data) ^ v, data); return *this; } \ type operator &= (const type v) { set##size( get##size(data) & v, data); return *this; } \ type operator |= (const type v) { set##size( get##size(data) | v, data); return *this; } \ #define MAKE_TEMPLATE(size,type,sfx) \ template \ class Unaligned##sfx##size \ { \ protected: \ type data[ size / sizeof(type) ]; \ \ public: \ \ GROUP( signed char, size, GET##sfx, SET##sfx, sfx ) \ GROUP( short, size, GET##sfx, SET##sfx, sfx ) \ GROUP( int, size, GET##sfx, SET##sfx, sfx ) \ GROUP( wchar_t, size, GET##sfx, SET##sfx, sfx ) \ GROUP( long, size, GET##sfx, SET##sfx, sfx ) \ GROUP( __int64, size, GET##sfx, SET##sfx, sfx ) \ GROUP( unsigned char, size, GET##sfx, SET##sfx, sfx ) \ GROUP( unsigned short, size, GET##sfx, SET##sfx, sfx ) \ GROUP( unsigned int, size, GET##sfx, SET##sfx, sfx ) \ GROUP( unsigned long, size, GET##sfx, SET##sfx, sfx ) \ GROUP( unsigned __int64, size, GET##sfx, SET##sfx, sfx ) \ } MAKE_TEMPLATE( 2, unsigned char, ); MAKE_TEMPLATE( 4, unsigned char, ); MAKE_TEMPLATE( 8, unsigned char, ); MAKE_TEMPLATE( 8, unsigned int, 64 ); template class UnalignedPtr : Unaligned4 { public: UnalignedPtr(const void * v) : Unaligned4((int)v) { } void *operator = (void * v) { SET4((int)v,data); return v; } const void *operator = (const void * v) { SET4((int)v,data); return v; } operator BASE() { return (BASE)GET4(data); } }; #undef SET2 #undef SET4 #undef SET8 #undef SET648 #undef GROUP #undef MAKE_TEMPLATE #define MAKE_UNALIGNED_TYPE(base,size) typedef Unaligned##size base##_UNALIGNED #define MAKE_UNALIGNED64_TYPE(base,size) typedef Unaligned64##size base##_UNALIGNED64 #define MAKE_UNALIGNEDPTR_TYPE(base) typedef UnalignedPtr * base##_UNALIGNEDPTR #endif // _MSC_VER // Predefine some of the basic types. MAKE_UNALIGNED_TYPE( short, 2 ); MAKE_UNALIGNED_TYPE( int, 4 ); MAKE_UNALIGNED_TYPE( long, 4 ); MAKE_UNALIGNED_TYPE( WORD, 2 ); MAKE_UNALIGNED_TYPE( DWORD, 4 ); MAKE_UNALIGNED_TYPE( USHORT, 4 ); MAKE_UNALIGNED_TYPE( SHORT, 4 ); MAKE_UNALIGNED_TYPE( __int64, 8 ); MAKE_UNALIGNED64_TYPE( __int64, 8 ); #endif __unaligned_h__