Revision as of 18:53, 6 May 2019

The Original Code

Consider the following S9 function:

string a = "batata";
int s9() -> 0 {
      a!
}

Postfix Code

The Postfix code for the above function is as follows:

;--- declaring the string literal
RODATA
ALIGN
LABEL _L123  ;; automatic label
STR "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
GLOBL _main, FUNC
LABEL _main
ENTER 0

ADDR a
LDINT
EXTRN prints
CALL prints
TRASH 4

INT 0
STFVAL32
LEAVE
RET

Compiling and Running

To test the first example, the S9 compilation process is as follows:

s9 batata.s9
yasm -felf batata.asm
ld -o batata batata.o -lrts

To test the second program directly, pf2asm can be used:

pf2asm batata.pf
yasm -felf batata.asm
ld -o batata batata.o -lrts