[Mingw-users] [mingw - C/C++] i got tipped by some asm expert

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https://sourceforge.net/forum/message.php?msg_id=3139217
By: brokenblade

here is the log:
Actually there's one instruction that can be omitted,and the next one to be
changed to
inc  dword ptr [ebp-10h]
‎The Darkone ‎(04:50 PM)‎ : 
and that will optimize the compiler further more?
‎The Darkone ‎(04:50 PM)‎ : 
why actually?
‎Ultrano ‎(04:52 PM)‎ : 
saving an instruction + optimizing the pipeline, removing a stall - the cpu
can then fetch that memory much much earlier

it was about this function:
int f(vector <int> a, int num)
{
	int c = 0;
	
	vector<int>::iterator viter = a.begin();
	
	int r = 0;
	if ( c != 20 )
	{
		for ( int i = c; i < 0; i-- )
			if ( a[i] < num )
				r++;
	}
	else
		for ( viter  = a.begin(); viter != a.end(); ++viter )
			if ( *viter < num )
				r++;
				
	return r;
		
}
and the commented asm code is:
0040147C   mov         eax,dword ptr [eax]
0040147E   cmp         eax,dword ptr [ebp+0Ch]
00401481   jge         00401488
00401483   lea         eax,[ebp-10h]
00401486   inc         dword ptr [eax]
00401488   lea         eax,[ebp-8]
0040148B   mov         dword ptr [esp],eax

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