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== Compiling and Running == | == Compiling and Running == | ||
| − | To compile the Postfix code directly, [[pf2asm]] can be used: | + | To compile the Postfix code directly, [[Compiladores/Projecto de Compiladores/Compiladores Exemplo|pf2asm]] can be used: |
| − | + | pf2asm click.pf | |
| − | + | yasm -felf click.asm | |
[[category:Compiladores]] | [[category:Compiladores]] | ||
[[category:Ensino]] | [[category:Ensino]] | ||
Consider the following C function:
int *click(int *x, int dim) {
int *res, i;
for (i = dim-2, res = x+dim-1; i >= 0; i--)
if (x[i] > *res) res = &x[i];
return res;
}
The Postfix code for the above function is as follows:
| Postfix code |
|---|
TEXT
ALIGN
GLOBL click, FUNC
LABEL click
ENTER 8 ;-- x@+8 dim@+12 res@-4 i@-8
;; for init
;; i = dim-2
LOCAL 12
LDINT
INT 2
SUB
DUP32
LOCAL -8
STINT
TRASH 4
;; res = x + dim - 1
LOCAL 8
LDINT
LOCAL 12
LDINT
INT 4
MUL
ADD
INT 1
INT 4
MUL
SUB
DUP32
LOCAL -4
STINT
TRASH 4
;; for test
ALIGN
LABEL for
LOCAL -8
LDINT
INT 0
GE
JZ forend
;; for block
;; if test
LOCAL 8
LDINT ; x
LOCAL -8
LDINT; i
INT 4
MUL
ADD ; x+i
LDINT ; x[i] = *(x+i)
LOCAL -4
LDINT ; res
LDINT ; *res
GT
JZ ifend
;; if block
LOCAL 8
LDINT ; x
LOCAL -8
LDINT ; i
INT 4
MUL
ADD ; x+i = &x[i]
DUP32
LOCAL -4
STINT ; res = &x[i]
TRASH 4
ALIGN
LABEL ifend
;; for increment
ALIGN
LABEL forincr
LOCAL -8
LDINT ; i
DUP32
INT 1
SUB
LOCAL -8
STINT
TRASH 4
;; for jump to cycle
JMP for
ALIGN
LABEL forend
;; return
LOCAL -4
LDINT ; res
STFVAL32
LEAVE
RET
|
To compile the Postfix code directly, pf2asm can be used:
pf2asm click.pf yasm -felf click.asm