Question

我正在将用C编写的斐波那契函数转换为MIPS。我的MIPS代码目前无法正常工作，我无法确定问题。我是汇编的新手，我希望你能帮助我找出MIPS代码中的主要问题。在我的MIPS代码下查看我的函数fibonacci。当我编译我的MIPS代码时，我收到以下错误：“无法将堆栈段扩展24个字节到5242888个字节。

我有一个C代码如下：

int fib(int n) {
    if (n == 0) {
        return 0;
    } else if (n == 1) 
    {
        return 1;
    }
    return fib(n-1) + fib(n-2);}

我的MIPS如下：

        .text
            .globl main
    main:


 subu $sp,$sp,32         # Stack frame is 32 bytes long
        sw $ra,20($sp)          # Save return address
        sw $fp,16($sp)          # Save old frame pointer
        addiu $fp,$sp,28        # Set up frame pointer

        li $a0,10               # Put argument (10) in $a0
        jal fibonacci                # Call fibonacci function
        move $t0,$v0            # Move fact result to $t0 (temporary)
        la $a0,$LC              # Put format string in $a0
        li $v0, 4               # System call code for print_str
        syscall                 # Make system call
        move $a0, $t0           # Move $t0 fibonacci result to $a0 (argument)
        li $v0, 1               # System call code for print_int
        syscall                 # Make system call
        #jal printf              # Call the print function

        lw $ra,20($sp)          # Restore return address
        lw $fp,16($sp)          # Restore frame pointer
        addiu $sp,$sp,32        # Pop stack frame
        jr $ra                  # Return to caller

        .rdata
$LC:
        .ascii "The fibonacci of 10 is "

    .text
fibonacci:
        subu $sp,$sp,32         # Stack framee is 32 bytes long
        sw $ra,20($sp)          # Save return address
        sw $fp,16($sp)          # Save frame pointer
        addiu $fp,$sp,28        # Set up frame pointer
        sw $a0,0($fp)           # Save argument (n)
        sw $a1,4($fp)

        lw $v0,0($fp)           # Load n
        li $v0,1                # Return 1

        # a0 = n
        # v0 = return_value 

        move $s0, $a0           #put n in $s0
        bne $s0, $0, not_zero   # if n doesn't equal to zero go to else if
        add $v0, $0, 0          # set return value to zero 
        j exit                  #go to exit

not_zero:
        li    $t0, 1                # assigning t0 to 1
        bne   $s0, $t0, test_two    # if no equal to one go to the else
        add   $v0, $0, 1            # set return value to one
        j exit                      # go to exit

test_two:

        addi $a0, $s0, -1   # assign $a0 = n -1
        jal fibonacci
        move $s1, $v0

        addi  $a0, $s0, -1  # assign $a0 = n -1
        jal fibonacci
        add   $v0, $s1, $v0 # Add f_(n-1) + f_(n-2)
        j exit

exit:                           # Result is in $v0
        lw $ra, 20($sp)         # Restore $ra
        lw $fp, 16($sp)         # Restore $fp
        addiu $sp, $sp, 32      # Pop stack
        jr $ra                  # Return to caller

MIPS Fibonacci递归有什么问题？

0 个答案: