Difference between revisions of "CSC231 Homework 5 Solutions 2010"

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(Created page with '--~~~~ ---- =Program 1= <code><pre> ;;; ; File: hw5a.asm ;;; ; Author: Tiffany Q. Liu ;;; ; Acct: 231a-ac ;;; ; Date: October 28, 2010 ;;; ; ;;; ; Desc: Print the N words in ms…')
 
 
(3 intermediate revisions by the same user not shown)
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--[[User:Thiebaut|D. Thiebaut]] 14:54, 19 November 2010 (UTC)
 
--[[User:Thiebaut|D. Thiebaut]] 14:54, 19 November 2010 (UTC)
 
----
 
----
 +
<onlydft>
 
=Program 1=
 
=Program 1=
  
 
<code><pre>
 
<code><pre>
−
;;; ; File: hw5a.asm
+
;;; ; File: hw5a.asm
 
;;; ; Author: Tiffany Q. Liu
 
;;; ; Author: Tiffany Q. Liu
 
;;; ; Acct: 231a-ac
 
;;; ; Acct: 231a-ac
Line 115: Line 116:
  
 
</pre></code>
 
</pre></code>
 +
 +
=Program 2=
 +
<code><pre>
 +
;;; ; File: hw5b.asm
 +
;;; ; Author: Tiffany Q. Liu
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;;; ; Acct: 231a-ac
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;;; ; Date: October 28, 2010
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;;; ;
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;;; ; Desc: Prints the first 10 rows of Pascal's triangle using one array of
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;;; ;      10 bytes.
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;;; ;
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;;; ; to assemble and run:
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;;; ;
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;;; ;    nasm -f elf -F  stabs hw5b.asm
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;;; ;    ld -melf_i386 -o hw5b hw5b.o
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;;; ;    ./hw5b
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;;; ;
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;;; ; Output:
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;;; ; 1 0 0 0 0 0 0 0 0 0 0
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;;; ; 1 1 0 0 0 0 0 0 0 0 0
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;;; ; 1 2 1 0 0 0 0 0 0 0 0
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;;; ; 1 3 3 1 0 0 0 0 0 0 0
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;;; ; 1 4 6 4 1 0 0 0 0 0 0
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;;; ; 1 5 10 10 5 1 0 0 0 0
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;;; ; 1 6 15 20 15 6 1 0 0 0
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;;; ; 1 7 21 35 35 21 7 1 0 0
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;;; ; 1 8 28 56 70 56 28 8 1 0
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;;; ; 1 9 36 84 126 126 84 36 9 1
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;;; ; -------------------------------------------------------------------
 +
 +
%include "asm_io.inc"
 +
 +
        ;; -------------------------
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        ;; data segment
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        ;; -------------------------
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        section .data
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pas    dw      1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x00
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space db " ", 0x00
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N equ 10
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        ;; -------------------------
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        ;; code area
 +
        ;; -------------------------
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        section .text
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        global  asm_main
 +
 +
asm_main:
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mov ecx, N ; ecx <- 10, init outer loop counter
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forOut:
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push ecx ; save outer loop counter to stack
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mov ecx, N ; ecx <- 10, init 1st inner loop counter
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mov ebx, pas ; ebx <- first index of pas,
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; set up pointer
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forIn1: mov eax, 0 ; eax <- 0, clear out eax
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        mov    ax, word[ebx]  ; pass address of the int pas to ax
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        call    print_int ; call a function in asm_io library
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                              ; that will print the int
 +
 +
mov eax, space ; eax <- " ", prepare to print space
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call print_string ; call function in asm_io library that
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; will print the string
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add ebx, 1*2 ; ebx <- ebx + 2, increment ebx to point
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; to the next index in array of words
 +
 +
endIn1: loop forIn1 ; loop until all the ints in the array
 +
; are printed with a space in between
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; each int
 +
 +
        call    print_nl        ; call the function that prints
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                              ; a new blank line
 +
 +
mov ebx, pas+(N-1)*2 ; ebx <- addr of last pascal int in
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; the array
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mov ecx, N-1 ; ecx <- 1, init 2nd inner loop counter
 +
; one less than the number of int since
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; the first int never gets changed
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forIn2: mov eax, 0 ; eax <- 0, clear out eax
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mov edx, 0 ; edx <- 0, clear out edx
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mov ax, word[ebx] ; ax <- int ebx is pointing to
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mov dx, word[ebx-1*2] ; dx <- int to the left of the one
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; stored in ax
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add ax, dx ; ax <- ax+dx, obtain next pascal int in
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; ax by adding the current int to its
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; left neighbor
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mov word[ebx], ax ; move sum back to index ebx points to
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sub ebx, 1*2 ; ebx <- ebx - 2, move pointer to left
 +
; to point to the prev word
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endIn2: loop forIn2 ; loop until all ints in array are
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; updated
 +
 +
pop ecx ; retain outer loop counter from stack
 +
loop forOut ; loop until all first 10 rows of
 +
; Pascal's Triangle are printed
 +
 +
        ;; return to C program
 +
 +
        ret
 +
</pre></code>
 +
</onlydft>
 +
<br />
 +
<br />
 +
<br />
 +
[[Category:CSC231]][[Category:Homework]][[Category:Asm]]

Latest revision as of 14:07, 10 October 2012

--D. Thiebaut 14:54, 19 November 2010 (UTC)


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