MIPS汇编程序数组求和功能异常排查及代码优化咨询

First, let's pinpoint the core issue: your code never actually calculates the sum of the input numbers! You're storing all 10 integers into the array correctly, but you never add them to $t1—the register you're using to hold the total. Since $t1 starts at 0 (and stays that way), your output will always be 0, no matter what numbers you input.

A secondary (but important) detail: you should explicitly initialize registers like $t0 (your array index counter) and $t1 (your sum accumulator) to 0. While some MIPS simulators default registers to 0, relying on that isn't good practice—explicit initialization makes your code predictable across environments.

Corrected Code #

Here's a fixed version that calculates the sum as you input each number (more efficient than storing first then summing):

.data
array: .space 40          # 10 integers * 4 bytes each
input: .asciiz "Enter the 10 Elements: \n"
output: .asciiz "\nThe sum is: "

.text
main:
    li $t0, 0             # Initialize array index counter to 0
    li $t1, 0             # Initialize sum accumulator to 0
    
    la $a0, input         # Load prompt string address
    li $v0, 4             # Syscall code for print string
    syscall
    
    jal loop              # Jump to input loop
    
    la $a0, output        # Load result prompt address
    li $v0, 4
    syscall
    
    move $a0, $t1         # Move sum to $a0 for printing
    li $v0, 1             # Syscall code for print integer
    syscall
    
    li $v0, 10            # Exit program
    syscall

loop:
    beq $t0, 40, end_loop # Exit loop when we've processed 10 elements (40 bytes)
    
    li $v0, 5             # Read integer syscall
    syscall
    
    sw $v0, array($t0)    # Store input in array (optional if you don't need the array later)
    add $t1, $t1, $v0     # Add input value to sum accumulator
    
    add $t0, $t0, 4       # Increment index by 4 bytes (1 integer)
    j loop

end_loop:
    jr $ra                # Return to main

If you want to store all numbers first and then calculate the sum (maybe for later use), here's an alternative version of the loop termination section:

end_loop:
    li $t0, 0             # Reset index to 0 for summing
sum_loop:
    beq $t0, 40, print_sum
    lw $t2, array($t0)    # Load element from array
    add $t1, $t1, $t2     # Add to sum
    add $t0, $t0, 4
    j sum_loop

print_sum:
    jr $ra

Optimization Tips for MIPS Beginners #

• Follow register conventions: Use temporary registers ($t0-$t9) for variables you don't need to preserve across function calls, and saved registers ($s0-$s7) if you need to keep values when calling other functions. Remember to save/restore saved registers to the stack if you use them!
• Explicitly initialize all registers: Never assume a register starts at 0—this avoids bugs in simulators or hardware that don't default to zero.
• Avoid redundant operations: If you don't need to keep the input array (just need the sum), you can skip storing the values entirely to save memory and cycles.
• Add clear comments: Comment every section of your code (e.g., "Initialize sum accumulator", "Read integer input")—this makes debugging and revisiting code much easier.
• Test incrementally: Build and test small parts of your program first (e.g., test printing a string, then reading one integer, then summing two integers) before putting it all together.

内容的提问来源于stack exchange，提问作者Liyanna