Calling functions on x86

patriciak784-gccmainling@yahoo.de patriciak784-gccmainling@yahoo.de
Tue Sep 20 11:14:00 GMT 2005


On x86 and GCC 3.4.2, the resulting asm code when
leaving a stackframe is (in intel_syntax)
mov esp,ebp
pop ebp
.(results in 0x89EC5D or 0x8BE55D)
The AMD optimisation guide for AMD64 tells you not to
use mov esp, ebp - pop ebp but to use "leave"(just
0xC9)!
Perhaps using "enter x(16bit), imm8" is better than
"push ebp - mov ebp, esp - sub esp, x"

I hope you can improve performance with these optimisations.


	

	
		
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