generate tuples from sequence

Duncan Booth duncan.booth at invalid.invalid
Thu Jan 18 14:41:32 CET 2007


Peter Otten <__peter__ at web.de> wrote:

> Let's see if I understand the above: In C a call
> 
> f(g(), g())
> 
> may result in machine code equivalent to either
> 
> x = g()
> y = g()
> f(x, y)
> 
> or
> 
> y = g()
> x = g()
> f(x, y)
> 
> Is that it?
> 

Yes, or changing one of the calls to h() and compiling with 
"cl -Fat.asm -Ox -c t.c":

------ t.c --------
extern int f(int a, int b);
extern int g();
extern int h();

int main(int argc, char **argv) {
    return f(g(), h());
}
-------------------

The output file:
------- t.asm -----
; Listing generated by Microsoft (R) Optimizing Compiler Version 13.10.3077 

	TITLE	t.c
	.386P
include listing.inc
if @Version gt 510
.model FLAT
else
_TEXT	SEGMENT PARA USE32 PUBLIC 'CODE'
_TEXT	ENDS
_DATA	SEGMENT DWORD USE32 PUBLIC 'DATA'
_DATA	ENDS
CONST	SEGMENT DWORD USE32 PUBLIC 'CONST'
CONST	ENDS
_BSS	SEGMENT DWORD USE32 PUBLIC 'BSS'
_BSS	ENDS
$$SYMBOLS	SEGMENT BYTE USE32 'DEBSYM'
$$SYMBOLS	ENDS
_TLS	SEGMENT DWORD USE32 PUBLIC 'TLS'
_TLS	ENDS
FLAT	GROUP _DATA, CONST, _BSS
	ASSUME	CS: FLAT, DS: FLAT, SS: FLAT
endif

INCLUDELIB LIBC
INCLUDELIB OLDNAMES

PUBLIC	_main
EXTRN	_f:NEAR
EXTRN	_g:NEAR
EXTRN	_h:NEAR
; Function compile flags: /Ogty
_TEXT	SEGMENT
_argc$ = 8						; size = 4
_argv$ = 12						; size = 4
_main	PROC NEAR
; File c:\temp\t.c
; Line 6
	call	_h
	push	eax
	call	_g
	push	eax
	call	_f
	add	esp, 8
; Line 7
	ret	0
_main	ENDP
_TEXT	ENDS
END
-------------------------



More information about the Python-list mailing list