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我需要編寫一個程序集程序,在-2 < = x < = 8的範圍內查找x^3 -14x^2 + 56x -64的最大值,並且最大值應在其中一個寄存器中該程序。如何將此C for循環轉換爲彙編語言?
我用C編寫了代碼,但是我不知道如何將它自己轉換成Assembly。我現在很困惑。順便說一句,我必須自己轉換它。我無法使用gcc轉換爲程序集。這是用於SPARC
#include<stdio.h>
int main()
{
int i;
int ans;
for (i = -2; i < 9; i++){
ans = (i * i * i) - (14 * i * i) + (56 * i) - 64;
}
}
我試圖編寫程序集。有人可以批評它,並告訴我,如果我在正確的方向。另外,我將如何去測試最大數量?
main:
save %sp, -96, %sp
ba test
mov -2, %a_r
loop:
mov %a_r, %o0 !a_r moved into o0
mov %a_r, %o1 !a_r moved into o1
call .mul !they are multiplied and stored in o0
call .mul !they are multiplied again and stored in o0
mov %o0, r0 !results stored in r0
mov %a_r, %o0 !a_r moved into o0 and o1
mov %a_r, %o1
call .mul !they are multiplied and stored in o0
mov 14, %o1
call .mul !o0 result is multiplied by 14 and stored in r1
mov %o0, r1
mov 56, %o0 !56 moved into o0
mov %a_r, %01 !a_r moved into o1
call .mul !they are multiplied and stored in r2
mov %o0, r2
Sub r0,r1,r0 !r0-r1 stored in r0
Add r0,r2,r0 !r0+r2 stored in r0
Sub r0,64,r0 !r0-64 stored in r0
add %a_r, 1, %a_r !a_r + 1
test:
cmp %a_r %b_r ! a_r<=8?
ble loop
[你有什麼試過?](http://mattgemmell.com/2008/12/08/what-have-you-tried/) – nrz 2013-02-17 00:13:39
'gcc -S prog.c -o prog.s'是一個開始。你可以研究生成的程序集來獲得一些想法。 – nneonneo 2013-02-17 00:14:32
是x86彙編,MIPS,ARM還是什麼? – NeXuS 2013-02-17 00:38:20