Code Generation/Example 3: Difference between revisions
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The Postfix code for the above function is as follows: | The Postfix code for the above function is as follows: | ||
{{CollapsedCode|Postfix code| | |||
<asm> | <asm> | ||
TEXT | TEXT | ||
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;; i = dim-2 | ;; i = dim-2 | ||
LOCAL 12 | |||
LOAD | |||
INT 2 | INT 2 | ||
SUB | SUB | ||
DUP | DUP | ||
LOCAL -8 | |||
STORE | |||
TRASH 4 | TRASH 4 | ||
;; res = x + dim - 1 | ;; res = x + dim - 1 | ||
LOCAL 8 | |||
LOAD | |||
LOCAL 12 | |||
LOAD | |||
INT 4 | INT 4 | ||
MUL | MUL | ||
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SUB | SUB | ||
DUP | DUP | ||
LOCAL -4 | |||
STORE | |||
TRASH 4 | TRASH 4 | ||
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ALIGN | ALIGN | ||
LABEL for | LABEL for | ||
LOCAL -8 | |||
LOAD | |||
INT 0 | INT 0 | ||
GE | GE | ||
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;; if test | ;; if test | ||
LOCAL 8 | |||
LOAD ; x | |||
LOCAL -8 | |||
LOAD ; i | |||
INT 4 | INT 4 | ||
MUL | MUL | ||
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LOAD ; x[i] = *(x+i) | LOAD ; x[i] = *(x+i) | ||
LOCAL -4 | |||
LOAD ; res | |||
LOAD ; *res | LOAD ; *res | ||
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;; if block | ;; if block | ||
LOCAL 8 | |||
LOAD ; x | |||
LOCAL -8 | |||
LOAD ; i | |||
INT 4 | INT 4 | ||
MUL | MUL | ||
ADD ; x+i = &x[i] | ADD ; x+i = &x[i] | ||
DUP | DUP | ||
LOCAL -4 | |||
STORE ; res = &x[i] | |||
TRASH 4 | TRASH 4 | ||
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ALIGN | ALIGN | ||
LABEL forincr | LABEL forincr | ||
LOCAL -8 | |||
LOAD ; i | |||
DUP | DUP | ||
INT 1 | INT 1 | ||
SUB | SUB | ||
LOCAL -8 | |||
STORE | |||
TRASH 4 | TRASH 4 | ||
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;; return | ;; return | ||
LOCAL -4 | |||
LOAD ; res | |||
POP | POP | ||
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RET | RET | ||
</asm> | </asm> | ||
}} | |||
== Compiling and Running == | == Compiling and Running == | ||
Revision as of 07:29, 9 May 2017
The Original Code
Consider the following C function:
<c> 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;
} </c>
Postfix Code
The Postfix code for the above function is as follows:
| Postfix code |
|---|
| {{{2}}} |
Compiling and Running
To compile the Postfix code directly, pf2asm can be used:
- pf2asm click.pf
- yasm -felf click.asm