我在Assembly中编写了一个程序,该程序在开头有2个数组,3个函数是:
printQArray(int size, long *array1)
invertArray(int size, long *array1)
multQuad(int size, long *array1, long *array2)
现在程序接受这些数组并为每个相应位置打印2个数组的产品并打印它们。 然后它打印Array1。 然后它打印Array1 Reversed。 然后它应该采用反转数组并再次调用乘法函数并打印第一个数组反转位置的产品和第二个不会改变的数组。(源代码中的数组值)
我在反转数组并尝试将反转的第一个数组和第二个数组相乘后出现问题。
以下是我的程序的输出
Products
200
-925
1386
-2928
9375
64350
Elements in QArray1
10
25
33
48
125
550
Elements in QArray1
550
125
48
33
25
10
Products
0
-1036
-31584
44896
0
0
所以这最后一个输出显然不是array1 reverse和array2的产品
正如你在下面的代码中看到的那样(PS我已经尝试用movq代替leaq)我的反向数组正在%rax中返回,我将它放入%rcx 这一切都很好,花花公子,因为我成功打印出
下面的反向数组#PRINT Inverted ARRAY1 void printArray(int size, long *array1);
movq $sizeQArrays, %rax
movq (%rax), %rdi #sizeQArrays to %rdi (parameter 1)
leaq (%rcx), %rsi #put reversed array into rsi
call printQArray
movq $0, %rax
然而,一旦我再次调用multQuads,我得到了奇怪的结果,我确信我的反转阵列没有被正确地移入寄存器。原始数组是一个常数,因此很简单,但我认为我将所有的值推到堆栈上并以相反的顺序将它们弹回,这已经以某种方式改变了结构。或许我有一个错字。源代码如下:
.section .rodata
.LC1: .string "Products\n"
.LC3: .string "Elements in QArray1\n"
.LC4: .string "%i\n"
.LC5: .string "\n"
.data
sizeQArrays:
.quad 6
QArray1:
.quad 10
.quad 25
.quad 33
.quad 48
.quad 125
.quad 550
QArray2:
.quad 20
.quad -37
.quad 42
.quad -61
.quad 75
.quad 117
.globl main
.type main, @function
.globl printQArray
.type printQArray, @function
.globl multQuads
.type multQuads, @function
.globl invertArray
.type invertArray, @function
.text
main:
pushq %rbp #stack housekeeping
movq %rsp, %rbp
#order of calls: quad print invert print quad
#MULTQUADS void multQuads(int size, long *array1, long *array2)
movq $sizeQArrays, %rax
movq (%rax), %rdi #1st param
movq $QArray1, %rsi #2nd Param
movq $QArray2, %rdx #3rd Param
call multQuads
movq $0, %rax
#PRINT ARRAY1 void printArray(int size, long *array1);
movq $sizeQArrays, %rax
movq (%rax), %rdi #sizeQArrays to %rdi (parameter 1)
movq $QArray1, %rsi #address of QArray1 to %rsi (parameter 2)
#purposely not pushing anything because I have not put anything in registers
#except parameters and I will be putting new values there after return
call printQArray
movq $0, %rax
#InvertArray void invertArray(long size, long *array1)
movq $sizeQArrays, %rax
movq (%rax), %rdi #1st param
movq $QArray1, %rsi #2nd Param
call invertArray
leaq (%rax), %rcx #put inverted array into %rcx
movq $0, %rax #set %rax back to 0
#PRINT Inverted ARRAY1 void printArray(int size, long *array1);
movq $sizeQArrays, %rax
movq (%rax), %rdi #sizeQArrays to %rdi (parameter 1)
movq %rcx, %rsi #put reversed array into rsi
call printQArray
movq $0, %rax
#MULTQUADS W/ REVERSED ARRAY void multQuads(int size, long *array1, long *array2);
movq $sizeQArrays, %rax
movq (%rax), %rdi #1st param
movq %rcx, %rsi #inversed array as 2nd param
movq $QArray2, %rdx #3rd Param
call multQuads
movq $0, %rax
#END of main
leave
ret
.size main, .-main
#printQArray prints an array of 8 byte values
# the size of the array is passed in %rdi,
# a pointer to the beginning of the array is passed in %rsi
printQArray:
pushq %rbp
movq %rsp, %rbp
pushq %r12
pushq %r13
pushq %rbx
movq %rdi, %r12 #copy size to %r12
movq %rsi, %r13 #copy array pointer to %r13
# print array title
movq $.LC3, %rdi
movq $0, %rax
# purposely not pushing any caller save registers.
callq printf
movq $0, %rbx #array index
printQArrayLoop:
movq (%r13, %rbx, 8), %rsi #element of array in 2nd parameter register
movq $.LC4, %rdi #format literal in 1st parameter register
movq $0, %rax
#purposely not pushing any caller save registers
callq printf
incq %rbx #increment index
decq %r12 #decrement count
jle printQArrayExit
jmp printQArrayLoop
printQArrayExit:
# print final \n
movq $.LC5, %rdi #parameter 1
movq $0, %rax
call printf
popq %rbx
popq %r13
popq %r12
leave
ret
.size printQArray, .-printQArray
multQuads:
pushq %rbp
movq %rsp, %rbp
pushq %r12
pushq %r13
pushq %r14
pushq %rbx
movq %rdi, %r12 #copy size to %r12
movq %rsi, %r13 #copy array1 pointer to %r13
movq %rdx, %r14 #copy array2 pointer to %r14
# print "Products"
movq $.LC1, %rdi
movq $0, %rax
call printf
movq $0, %rbx #array index
multQuadLoop:
movq (%r13, %rbx, 8), %rsi #element of array in 2nd parameter register
movq (%r14, %rbx, 8), %rdx #element of array in 3rd parameter register
movq $.LC4, %rdi #format literal in 1st parameter register
imulq %rdx, %rsi #insert product into second parameter
movq $0, %rax
callq printf
incq %rbx #increment index
decq %r12 #decrement count
jle multQuadExit
jmp multQuadLoop
multQuadExit:
# print final \n
movq $.LC5, %rdi #parameter 1
movq $0, %rax
call printf
popq %rbx
popq %r13
popq %r12
popq %r14
leave
ret
.size multQuad, .-multQuad
invertArray:
pushq %rbp
movq %rsp, %rbp
pushq %r12 #size
pushq %r13 #array pointer
pushq %rbx #array index
pushq %r9 #holder
pushq %r10 #holder
push %r14
movq %rdi, %r12 #copy size to %r12
movq %rdi, %r9
movq %rsi, %r13 #copy array pointer to %r13
movq $0, %rbx #array index
movq $0, %r10
invertArrayLoop:
pushq (%r13, %rbx, 8) #push elements of array onto stack
incq %rbx #increment index
decq %r12 #decrement count
jle reverseArray
jmp invertArrayLoop
reverseArray:
popq %r14
movq %r14, (%r13, %r10, 8)
incq %r10
decq %r9
subq %r12, %r9
jle invertArrayExit
jmp reverseArray
invertArrayExit:
movq %r13, %rax
popq %r14
popq %r10
popq %r9
popq %rbx
popq %r13
popq %r12
leave
ret
.size invertArray, .-invertArray
如果multQuad函数第一次工作,我可以正确打印出反向数组,那么我想在问到multQuad并设置寄存器之前问题必须正确
答案 0 :(得分:0)
我在printQArray
中丢失了数组这只是一行!!