Target Code Generation - Crafting a Compiler - page 500

subi $sp,$sp,20 # Push frame on stack

sw $ra,0($sp) # Save return address

sw $fp,4($sp) # Save old frame pointer

move $fp,$sp # Set $fp to access new frame

sw $a0,8($fp) # Store limit in frame

sw $0,12($fp) # Store 0 ($0) into sum

li $t0,1 # Load 1 into $t0

sw $t0,16($fp) # Store 1 into i

j L2 # Go to end of loop test

L1: lw $t1,12($fp) # Load sum into $t1

lw $t2,16($fp) # Load i into $t2

add $t3,$t1,$t2 # Add sum + i into $t3

sw $t3,12($fp) # Store sum + i into sum

lw $t4,16($fp) # Load i into $t2

addi $t4,$t4,1 # Increment $t4 by 1

sw $t4,16($fp) # Store $t4 into i

L2: lw $t5,16($fp) # Load i into $t5

lw $t6,8($fp) # Load limit into $t6

sle $t7,$t5,$t6 # set $t7 = i <= limit

bnez $t7,L1 # Goto L1 if i <= limit

lw $t8,12($fp) # Load sum into $t8

move $a0,$t8 # Copy $t8 to parm register

jal String_toString_int_ # Call toString

# String ref now is in $v0

lw $ra,0($fp) # Reload return address

lw $fp,4($fp) # Reload old frame pointer

addi $sp,$sp,20 # Pop frame from stack

jr $ra # Jump to return address

Figure 13.8: MIPS code for method stringSum