Simple C code as compiled by different compilers

main()

{

int a = 7;

int b = 15;

int c;

c = b + a;

}

SPIM assembly

##################################################################

# addasm.s

# addition of two integers

#that are automatic variables.

# the result is stored on stack.

#

#################################################################.verstamp 3 19

.text

.align 2

.globl main

# 1 main()

# 2 {

main:

# 3 int a = 7;

li $14, 7

sw $14, 12($sp)

# 4 int b = 15;

li $15, 15

sw $15, 8($sp)

# 5 int c;

# 6 c = b + a;

li $24, 22 # the compiler is smart:

# performs addtion of two constants

# at compile time!

sw $24, 4($sp)

# 7 }

.end main

MIPS assembly

Pentium Assembly

TITLE F:\Cs342fall99\Sep27\testadd\addasm.c

.386P

include listing.inc

if @Version gt 510

.model FLAT

else

_TEXT SEGMENT PARA USE32 PUBLIC 'CODE'

_TEXT ENDS

_DATA SEGMENT DWORD USE32 PUBLIC 'DATA'

_DATA ENDS

CONST SEGMENT DWORD USE32 PUBLIC 'CONST'

CONST ENDS

_BSS SEGMENT DWORD USE32 PUBLIC 'BSS'

_BSS ENDS

$$SYMBOLS SEGMENT BYTE USE32 'DEBSYM'

$$SYMBOLS ENDS

$$TYPES SEGMENT BYTE USE32 'DEBTYP'

$$TYPES ENDS

_TLS SEGMENT DWORD USE32 PUBLIC 'TLS'

_TLS ENDS

; COMDAT _main