以下程序
1。打印出阵列
2。给定用户输入的下限和上限，确定范围内的最小和最小指数
它运行打印数组功能。
然而，我尝试跟踪QTSPIM中的寄存器，它没有正确地将下界和上界分别分配给$a0和$a1。事实上，$v0似乎甚至不会扫描任何内容。要将扫描的输入从$v0移动到$t0，请尝试使用"移动$t0、$v0"。问题仍然存在。
# Ask the user for two indices
li $v0, 5 # System call code for read_int
syscall
add $t0, $v0, $zero # store input in $t0
sll $t0, $t0, 2 # relative address position (lower bound)
add $a0, $t9, $t0 # array pointer (lower bound)
li $v0, 5 # System call code for read_int
syscall
add $t0, $v0, $zero # store input in $t0
sll $t0, $t0, 2 # relative address position (upper bound)
add $a1, $t9, $t0 # array pointer (upper bound)
完整的代码如下。如果有什么不对的地方，有人能告诉我吗？
# arrayFunction.asm
.data
array: .word 8, 2, 1, 6, 9, 7, 3, 5, 0, 4
newl: .asciiz "n"
.text
main:
# Print the original content of array
# setup the parameter(s)
la $a0, array # base address of array
add $t9, $a0, $zero # store base address
la $a1, 10 # number of elements in array
# call the printArray function
jal printArray # call function
# Ask the user for two indices
li $v0, 5 # System call code for read_int
syscall
add $t0, $v0, $zero # store input in $t0
sll $t0, $t0, 2 # relative address position (lower bound)
add $a0, $t9, $t0 # array pointer (lower bound)
li $v0, 5 # System call code for read_int
syscall
add $t0, $v0, $zero # store input in $t0
sll $t0, $t0, 2 # relative address position (upper bound)
add $a1, $t9, $t0 # array pointer (upper bound)
# Call the findMin function
# setup the parameter(s)
# call the function
jal findMin # call function
# Print the min item
# place the min item in $t3 for printing
addi $t3, $t1, 0
# Print an integer followed by a newline
li $v0, 1 # system call code for print_int
addi $a0, $t3, 0 # print $t3
syscall # make system call
li $v0, 4 # system call code for print_string
la $a0, newl
syscall # print newline
#Calculate and print the index of min item
la $a0, array
add $t3, $v0, $a0
srl $t3, $t3, 2
# Place the min index in $t3 for printing
# Print the min index
# Print an integer followed by a newline
li $v0, 1 # system call code for print_int
addi $a0, $t3, 0 # print $t3
syscall # make system call
li $v0, 4 # system call code for print_string
la $a0, newl #
syscall # print newline
# End of main, make a syscall to "exit"
li $v0, 10 # system call code for exit
syscall # terminate program
#######################################################################
### Function printArray ###
#Input: Array Address in $a0, Number of elements in $a1
#Output: None
#Purpose: Print array elements
#Registers used: $t0, $t1, $t2, $t3
#Assumption: Array element is word size (4-byte)
printArray:
addi $t1, $a0, 0 #$t1 is the pointer to the item
sll $t2, $a1, 2 #$t2 is the offset beyond the last item
add $t2, $a0, $t2 #$t2 is pointing beyond the last item
l1:
beq $t1, $t2, e1
lw $t3, 0($t1) #$t3 is the current item
li $v0, 1 # system call code for print_int
addi $a0, $t3, 0 # integer to print
syscall # print it
addi $t1, $t1, 4
j l1 # Another iteration
e1:
li $v0, 4 # system call code for print_string
la $a0, newl #
syscall # print newline
jr $ra # return from this function
#######################################################################
### Student Function findMin ###
#Input: Lower Array Pointer in $a0, Higher Array Pointer in $a1
#Output: $v0 contains the address of min item
#Purpose: Find and return the minimum item
# between $a0 and $a1 (inclusive)
#Registers used: $t0 (counter), $t1 (max add), $t2 (min), $v0 (min pos), $t3 (current item)
#Assumption: Array element is word size (4-byte), $a0 <= $a1
findMin:
lw, $t2, 0($a0) # initialise min (value) to the lower bound
addi $t0, $a0, 0 # initialise $t0 (current pointer) to lower bound
addi $t1, $a1, 0 # initialise $t1 (add of end of array) to upper bound
Loop: slt $t4, $t1, $t0
bne $t4, $zero, End # branch to end if upper < lower
lw, $t3, 0($a0) # store the content of the lower array pointer
slt $t4, $t3, $t2 # if current ($t3) < min ($t2), store 1 in $t4
beq $t4, $zero, LoopEnd # if it is 0, go to LoopEnd
addi $t2, $t3, 0 # store content ($t3) as minimum ($t2)
addi $v0, $t0, 0 # store the address of min
LoopEnd: addi, $t0, 4 # increments current pointer lower bound
j Loop # Jump to loop
End:
jr $ra # return from this function
您可以正确读取整数。的问题在其他地方
- 在
findMin函数中，您使用lw, $t3, 0($a0)，但应该将其与$t0一起使用，而不是与$a0一起使用 - 从该函数返回后，意外地将
$t1保存为最小值，而不是实际保存它的$t2 - 此外，您也没有保存
$v0，它保存最小值的指针，因此您稍后会使用一些垃圾数据，而不是预期的垃圾数据 - 当您根据指针计算最小值的索引时，您使用
add，但它应该是sub - 正如
LoopEnd的评论中所提到的，add在语法上是错误的。应该是addi $t0, $t0, 4。但这可能只是一些复制粘贴错误
这是固定的代码。已更改，并标有ERROR。
# arrayFunction.asm
.data
array: .word 8, 2, 1, 6, 9, 7, 3, 5, 0, 4
newl: .asciiz "n"
.text
main:
# Print the original content of array
# setup the parameter(s)
la $a0, array # base address of array
add $t9, $a0, $zero # store base address
la $a1, 10 # number of elements in array
# call the printArray function
jal printArray # call function
# Ask the user for two indices
li $v0, 5 # System call code for read_int
syscall
add $t0, $v0, $zero # store input in $t0
sll $t0, $t0, 2 # relative address position (lower bound)
add $a0, $t9, $t0 # array pointer (lower bound)
li $v0, 5 # System call code for read_int
syscall
add $t0, $v0, $zero # store input in $t0
sll $t0, $t0, 2 # relative address position (upper bound)
add $a1, $t9, $t0 # array pointer (upper bound)
# Call the findMin function
# setup the parameter(s)
# call the function
jal findMin # call function
# Print the min item
# place the min item in $t3 for printing
addi $t3, $t2, 0 # ERROR: min is in $t2 not $t1
addi $t4, $v0, 0 # ERROR: not saving the pointer to the min element
# Print an integer followed by a newline
li $v0, 1 # system call code for print_int
addi $a0, $t3, 0 # print $t3
syscall # make system call
li $v0, 4 # system call code for print_string
la $a0, newl
syscall # print newline
#Calculate and print the index of min item
la $a0, array
sub $t3, $t4, $a0 # ERROR: sub should used not add
srl $t3, $t3, 2
# Place the min index in $t3 for printing
# Print the min index
# Print an integer followed by a newline
li $v0, 1 # system call code for print_int
addi $a0, $t3, 0 # print $t3
syscall # make system call
li $v0, 4 # system call code for print_string
la $a0, newl #
syscall # print newline
# End of main, make a syscall to "exit"
li $v0, 10 # system call code for exit
syscall # terminate program
#######################################################################
### Function printArray ###
#Input: Array Address in $a0, Number of elements in $a1
#Output: None
#Purpose: Print array elements
#Registers used: $t0, $t1, $t2, $t3
#Assumption: Array element is word size (4-byte)
printArray:
addi $t1, $a0, 0 #$t1 is the pointer to the item
sll $t2, $a1, 2 #$t2 is the offset beyond the last item
add $t2, $a0, $t2 #$t2 is pointing beyond the last item
l1:
beq $t1, $t2, e1
lw $t3, 0($t1) #$t3 is the current item
li $v0, 1 # system call code for print_int
addi $a0, $t3, 0 # integer to print
syscall # print it
addi $t1, $t1, 4
j l1 # Another iteration
e1:
li $v0, 4 # system call code for print_string
la $a0, newl #
syscall # print newline
jr $ra # return from this function
#######################################################################
### Student Function findMin ###
#Input: Lower Array Pointer in $a0, Higher Array Pointer in $a1
#Output: $v0 contains the address of min item
#Purpose: Find and return the minimum item
# between $a0 and $a1 (inclusive)
#Registers used: $t0 (counter), $t1 (max add), $t2 (min), $v0 (min pos), $t3 (current item)
#Assumption: Array element is word size (4-byte), $a0 <= $a1
findMin:
lw, $t2, 0($a0) # initialise min (value) to the lower bound
addi $t0, $a0, 0 # initialise $t0 (current pointer) to lower bound
addi $t1, $a1, 0 # initialise $t1 (add of end of array) to upper bound
Loop:
slt $t4, $t1, $t0
bne $t4, $zero, End # branch to end if upper < lower
lw, $t3, 0($t0) # store the content of the lower array pointer, ERROR: t0 should be used not a0
slt $t4, $t3, $t2 # if current ($t3) < min ($t2), store 1 in $t4
beq $t4, $zero, LoopEnd # if it is 0, go to LoopEnd
addi $t2, $t3, 0 # store content ($t3) as minimum ($t2)
addi $v0, $t0, 0 # store the address of min
LoopEnd:
addi $t0, $t0, 4 # increments current pointer lower bound
j Loop # Jump to loop
End:
jr $ra # return from this function