Code Generation/Example 2: Difference between revisions
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| Line 20: | Line 20: | ||
ALIGN | ALIGN | ||
LABEL _L123 ;; automatic label | LABEL _L123 ;; automatic label | ||
SSTRING "batata" | |||
;--- declaring the global variable "a" | ;--- declaring the global variable "a" | ||
DATA | DATA | ||
| Line 30: | Line 30: | ||
TEXT | TEXT | ||
ALIGN | ALIGN | ||
GLOBAL _main, FUNC | |||
LABEL _main | LABEL _main | ||
ENTER 0 | ENTER 0 | ||
| Line 36: | Line 36: | ||
ADDR a | ADDR a | ||
LDINT | LDINT | ||
EXTERN prints | |||
CALL prints | CALL prints | ||
TRASH 4 | TRASH 4 | ||
Revision as of 12:29, 29 April 2020
The Original Code
Consider the following C function:
const char *a = "batata";
int main() {
prints(a);
return 0;
}
Postfix Code
The Postfix code for the above function is as follows:
| Postfix code |
|---|
;--- declaring the string literal
RODATA
ALIGN
LABEL _L123 ;; automatic label
SSTRING "batata"
;--- declaring the global variable "a"
DATA
ALIGN
LABEL a
SADDR _L123 ;; automatic label
;--- this is the main function (note that "s9" translates to RTS's "_main")
TEXT
ALIGN
GLOBAL _main, FUNC
LABEL _main
ENTER 0
ADDR a
LDINT
EXTERN prints
CALL prints
TRASH 4
INT 0
STFVAL32
LEAVE
RET
|
Compiling and Running
To test the second program directly, pf2asm can be used:
pf2asm batata.pf yasm -felf batata.asm ld -o batata batata.o -lrts