C addition disassembly

gistfile1.txt

int i = 1;
i += ++i + ++i;

.. disassembly of above (compiled with gcc 4.2 with no optimizations):

>> x = 1
0000000100000f14	movl	$0x00000001,0xf8(%rbp)

>> ++x
0000000100000f1b	movl	0xf8(%rbp),%eax
0000000100000f1e	addl	$0x01,%eax
0000000100000f21	movl	%eax,0xf8(%rbp)

>> ++x
0000000100000f24	movl	0xf8(%rbp),%eax
0000000100000f27	addl	$0x01,%eax
0000000100000f2a	movl	%eax,0xf8(%rbp)

>> now adds the value of the newly incremented x (now 3) to itself twice
0000000100000f2d	movl	0xf8(%rbp),%eax
0000000100000f30	movl	0xf8(%rbp),%ecx
0000000100000f33	addl	%ecx,%eax
0000000100000f35	movl	0xf8(%rbp),%ecx
0000000100000f38	addl	%ecx,%eax

>> puts 9 back into x
0000000100000f3a	movl	%eax,0xf8(%rbp)

..

WITH optimizations at -O4, it just turns into 9 right away ;-)