while-loop-code-gen.cpp

// loop-code-gen.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"


int _tmain(int argc, _TCHAR* argv[])
{
    int i = 0, n = 1;

    while (i++ < n) if (i == 1) break;
    while (i++ < n && i != 1);

    return 0;
}

// code gen of MS 2005 in debug mode

int i = 0, n = 1;
0041137E  mov         dword ptr [i],0 
00411385  mov         dword ptr [n],1 

    while (i++ < n) if (i == 1) break;
0041138C  mov         eax,dword ptr [i] 
0041138F  mov         ecx,dword ptr [n] 
00411392  mov         edx,dword ptr [i] 
00411395  add         edx,1 
00411398  mov         dword ptr [i],edx 
0041139B  cmp         eax,ecx 
0041139D  jge         wmain+4Bh (4113ABh) 
0041139F  mov         dword ptr [ebp-0DCh],1 
004113A9  jmp         wmain+55h (4113B5h) 
004113AB  mov         dword ptr [ebp-0DCh],0 
004113B5  cmp         dword ptr [ebp-0DCh],0 
004113BC  je          wmain+68h (4113C8h) 
004113BE  cmp         dword ptr [i],1 
004113C2  jne         wmain+66h (4113C6h) 
004113C4  jmp         wmain+68h (4113C8h) 
    while (i++ < n && i != 1);
004113C6  jmp         wmain+2Ch (41138Ch) 
004113C8  mov         eax,dword ptr [i] 
004113CB  mov         ecx,dword ptr [n] 
004113CE  mov         edx,dword ptr [i] 
004113D1  add         edx,1 
004113D4  mov         dword ptr [i],edx 
004113D7  cmp         eax,ecx 
004113D9  jge         wmain+87h (4113E7h) 
004113DB  mov         dword ptr [ebp-0DCh],1 
004113E5  jmp         wmain+91h (4113F1h) 
004113E7  mov         dword ptr [ebp-0DCh],0 
004113F1  cmp         dword ptr [ebp-0DCh],0 
004113F8  je          wmain+0A2h (411402h) 
004113FA  cmp         dword ptr [i],1 
004113FE  je          wmain+0A2h (411402h) 
00411400  jmp         wmain+68h (4113C8h) 

    return 0;
00411402  xor         eax,eax