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51 lines
880 B
51 lines
880 B
5 years ago
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# A demonstration of some simple MIPS instructions
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# used to test QtSPIM
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# Declare main as a global function
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.globl main
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# All program code is placed after the
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# .text assembler directive
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.text
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main:
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# Initialize param
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lw $a0, g # Reg $a0 = g
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lw $a1, h # Reg $a1 = h
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lw $a2, i # Reg $a2 = i
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lw $a3, j # Reg $a3 = j
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jal leaf_example
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move $s0, $v0 # Return value saved in $v0.
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# Print result
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li $v0, 1 # print_int syscall code = 1
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move $a0, $s0 # Load integer to print in $a0
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syscall
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# Exit
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li $v0, 10 # exit
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syscall
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leaf_example:
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addi $sp, $sp, -12
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sw $t1, 8($sp)
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sw $t0, 4($sp)
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sw $s0, 0($sp)
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add $t0,$a0,$a1
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add $t1,$a2,$a3
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sub $s0,$t0,$t1
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add $v0,$s0,$zero
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lw $s0, 0($sp)
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lw $t0, 4($sp)
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lw $t1, 8($sp)
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addi $sp,$sp, 12
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jr $ra
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# data global (and static) data
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.data
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g: .word 4
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h: .word 3
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i: .word 2
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j: .word 1
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