struct structure increases program overhead

struct structure can strengthen the management of variables, increase the readability of the program, but on the other hand, the structure will increase the cost of the program.

Look at the following section of code:

struct Test_s{int a;int b;float c;}; int _tmain (int argc, _tchar* argv[]) {test_s ts;int a;int b;int c;ts.a = 100;ts.b = 200;TS.C = 300.f;a = 100;b = 200;c = 30 0.f;return 0;}

using the Disassembly tool,

<strong><span style= "FONT-SIZE:18PX;" ></span></strong><pre name= "code" class= "cpp" >TS.A = 100;ts.b = 200;TS.C = 300.F;

Assigning 3 variables to a struct, in fact the assembly code under debug is:

mov         dword ptr [TS],64H mov         dword ptr [ebp-0ch],0c8h  movss       xmm0,dword ptr ds:[0ba5858h]  movss       DWORD ptr [EBP-8],XMM0  

As you can see from the assembly code, in addition to the first variable in the struct, the next variable needs to be offset on the basis of the struct's header address, rather than the struct:

A = 100;b = 200;c = 300.F;

The assembly code is as follows:

mov         dword ptr [a],64h  mov         dword ptr [b],0c8h  mov         

significantly less one-step address subtraction.
However, in the case of release, the compiler optimizes the program by default, because the assembly code under optimization cannot be viewed, so the actual overhead is not ascertained.

struct structure increases program overhead