{"id":567,"date":"2016-05-22T04:50:02","date_gmt":"2016-05-22T04:50:02","guid":{"rendered":"http:\/\/darthjedi.logiodice.com\/?p=567"},"modified":"2016-05-29T02:17:08","modified_gmt":"2016-05-29T02:17:08","slug":"bubble-sort-in-x86-asm","status":"publish","type":"post","link":"https:\/\/darthjedi.logiodice.com\/?p=567","title":{"rendered":"Bubble sort in x86 ASM"},"content":{"rendered":"

[[NOTE: For a more efficient way to implement the bubble sort, see my later post<\/a>]]<\/p>\n

Why? \u00a0I have no idea. \u00a0It’s funny how many times I set off my AV scanner trying to compile and run my PE. \u00a0That brings back some great memories with the VCL<\/a>.<\/p>\n

I’m sure there are cleaner ways to do it – but right now, I’m just worried about making it work. \u00a0\ud83d\ude09<\/p>\n

NOTE: Written in FASM<\/a>, and the training.inc can be found over at xorpd on git<\/a>.<\/p>\n

; Author J. Logiodice
\n; Date: 05\/22\/2016
\n; Purpose: Bubble SOrt
\n; This method will read in a series of TOTAL_NUMS numbers
\n; And bubble sort them, then print them out in sorted order to the screen
\nformat PE console
\nentry start<\/p>\n

include ‘win32a.inc’<\/p>\n

TOTAL_NUMS = 10 ;10<\/p>\n

section ‘.bss’ data readable writeable<\/p>\n

array_numbers dd TOTAL_NUMS dup (?)
\nnMinus1Mem dd ?
\nboolSwapped dd ?<\/p>\n

section ‘.text’ code readable executable<\/p>\n

start:<\/p>\n

; Set up the loop variables
\nmov ecx, TOTAL_NUMS
\nmov esi, ecx
\n; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
\n; Read in one number at a time, for TOTAL_NUMS numbers, store them in the bytes that
\n; start with array_numbers
\n; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
\nloopRead:<\/p>\n

dec esi<\/p>\n

; read input into eax but first clear out eax
\nxor eax, eax
\ncall read_hex<\/p>\n

; move value into memory offset (reverse order)
\nmov dword [array_numbers + esi * 4], eax<\/p>\n

loop loopRead<\/p>\n

; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
\n; I am sure there is a more effecient way of doing this
\n; I will probably try and clean it up later, but for now it works.
\n; loop iteratively over the array until no more swapping occurs,
\n; and the highest number ends up in the lowest part of the array (lowest to highest)
\n; start with array_numbers
\n; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
\n; Set back up the loop variables
\nrestartLoop:<\/p>\n

mov ecx, TOTAL_NUMS
\nmov esi, ecx<\/p>\n

; set the swapped variable to false
\nmov [boolSwapped], dword 0<\/p>\n

loopSort:<\/p>\n

dec esi
\nmov eax, esi
\nsub eax,1d<\/p>\n

test esi, esi
\njbe loopExit
\nmov edx, dword [array_numbers + eax * 4]
\ncmp edx, dword [array_numbers + esi * 4]
\njbe noSwap
\n; if we get into this section, then swapping needs to occur
\n; set the boolSwapped to true
\nmov [boolSwapped], dword 1<\/p>\n

; need to swap the two numbers
\nmov [nMinus1Mem], dword edx
\nmov edx, dword [array_numbers + esi * 4]
\nmov [array_numbers + eax * 4], dword edx
\nmov edx, dword [nMinus1Mem]
\nmov [array_numbers + esi * 4], dword edx
\nnoSwap:
\n; jump here if no swapping needs to occur, but we’re still in the loop
\nloop loopSort<\/p>\n

loopExit:<\/p>\n

; if boolSwapped isn’t false, then we’ve swapped at least one
\n; during the iteration, let’s go through it one more time to make sure
\n; that we don’t have any more to swap
\ncmp [boolSwapped], 1b
\njae restartLoop
\n; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
\n; Print each number back out to the screen for unmodified numbers
\n; we will loop from the lowest to highest part of the array – which is the largest to smallest number
\n; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++<\/p>\n

;mov edi, array_numbers
\nmov ecx, TOTAL_NUMS
\nmov esi, ecx<\/p>\n

loopPrint:<\/p>\n

dec esi
\nmov eax, [array_numbers + esi * 4]
\ncall print_eax<\/p>\n

loop loopPrint<\/p>\n

exit_prog:
\npush 0
\ncall [ExitProcess]
\ninclude ‘training.inc’<\/p>\n","protected":false},"excerpt":{"rendered":"

[[NOTE: For a more efficient way to implement the bubble sort, see my later post]] Why? \u00a0I have no idea. \u00a0It’s funny how many times I set off my AV scanner trying to compile and run my PE. \u00a0That brings back some great memories with the VCL. I’m sure there are cleaner ways to do … Continue reading “Bubble sort in x86 ASM”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":568,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[6,28],"tags":[],"class_list":["post-567","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-diary","category-technology"],"jetpack_featured_media_url":"https:\/\/darthjedi.logiodice.com\/wp-content\/uploads\/2016\/05\/bubblesort.jpg","jetpack_sharing_enabled":true,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=\/wp\/v2\/posts\/567","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=567"}],"version-history":[{"count":8,"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=\/wp\/v2\/posts\/567\/revisions"}],"predecessor-version":[{"id":578,"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=\/wp\/v2\/posts\/567\/revisions\/578"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=\/wp\/v2\/media\/568"}],"wp:attachment":[{"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=567"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=567"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/darthjedi.logiodice.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}