Difference between revisions of "Code Generation/Example 2"

Revision as of 00:25, 2 May 2018

Consider the following S9 function:

<c> string a = "batata"; int s9() -> 0 {

a!

} </c>

The Postfix code for the above function is as follows:

Postfix code
<asm> --- 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 </asm>

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

@@ Line 24: / Line 24: @@
 ALIGN
 LABEL a
-ID  _L123  ;; automatic label
+SADDR  _L123  ;; automatic label
 ;--- this is the main function (note that "s9" translates to RTS's "_main")
@@ Line 34: / Line 34: @@
 ADDR a
-LOAD
+LDINT
 EXTRN prints
 CALL prints
@@ Line 40: / Line 40: @@
 INT 0
-POP
+STFVAL32
 LEAVE
 RET