c++ - Fastest way to split a word into two bytes -


so fastest way split word 2 bytes ?

short s = 0x3210; char c1 = s >> 8; char c2 = s & 0x00ff;

versus

short s = 0x3210; char c1 = s >> 8; char c2 = (s << 8) >> 8;

edit

how about

short s = 0x3210; char* c = (char*)&s; // c1 = c[0] , c2 = c[1]

let compiler work you. use union, bytes split without hand made bit-shifts. @ pseudo code:

union u {   short s;  // or use int16_t more specific   //   vs.   struct byte {     char c1, c2;  // or use int8_t more specific   }   byte; };

usage simple:

u u; u.s = 0x3210; std::cout << u.byte.c1 << " , " << u.byte.c2;

the concept simple, afterwards can overload operators make more fancy if want.

important note depending on compiler order of c1 , c2 may differ, known before compilation. can set conditinal macros make sure order according needs in compiler.


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