32 bit division in assembly language -

-

i'm learning assembly language programming in college course (80386 programming). currently, i'm learning ins , outs of 32 bit division using edx , eax registers store remainder , quotient respectively. want know, why not correct output when don't include

mov edx, 00000000h

in program. program either doesn't run or gives wrong output.

relevant source code:

mov edx, 00000000h mov eax, 1234567ah div 11111111h ; edx=remainder, eax=quotient

i post full code if needed.

when using div 32-bit operand, divide 64-bit value in edx:eax (high dword in edx, low dword in eax) operand , put quotient in eax , remainder in edx.

therefore should clear edx prior division if value want divide 32 bits (fits in eax alone). failure result in incorrect results, or division overflow if quotient doesn't fit in eax.


Comments

Post a Comment

Popular posts from this blog

how to insert data php javascript mysql with multiple array session 2 -

-
i have method method discussed , successful data entered 1 when more 1 can not database this programs my php form : <form class="form-horizontal" id="form-produk"> <div class="control-group" > <label class="control-label" for="kelas">kategori</label> <div class="controls"> <select class='form-control' name='id_kategori'> <?php $tampil=mysql_query("select * kategori order nama_kategori"); if ($id_kat==0){ echo "<option value=0 selected>- pilih kategori -</option>"; } while($w=mysql_fetch_array($tampil)){ if ($id_kat==$w[id_kategori]){ echo "<option value=$w[id_kategori] selected>$w[nama_kategori]</option>"; } else{ echo "<option value=$w[id_kategori]>$...
Read more

multithreading - Exception in Application constructor -

-
i wanna write snake game javafx , there exception don't know , want know how fix it. ( know it's not complete yet ) and want know , class extends application ( start override ) main in other programs? see , here not static void main bc didn't need, if want add main shoud do? it's exeption... exception in application constructor exception in thread "main" java.lang.nosuchmethodexception: main_snake.main([ljava.lang.string;) @ java.lang.class.getmethod(class.java:1819) @ com.intellij.rt.execution.application.appmain.main(appmain.java:125) and code : import javafx.animation.animationtimer; import javafx.application.application; import javafx.event.eventhandler; import javafx.scene.scene; import javafx.scene.canvas.canvas; import javafx.scene.canvas.graphicscontext; import javafx.scene.input.keyevent; import javafx.scene.layout.borderpane; import javafx.scene.paint.color; import javafx.stage.stage; import java.util.arraylist; /** * creat...
Read more

windows - CertCreateCertificateContext returns CRYPT_E_ASN1_BADTAG / 8009310b -

-
i realize similar post others (e.g. this one ), there details missing posts might significant case. to start with, here's simplified program: #include "stdafx.h" #include <windows.h> #include <wincrypt.h> int _tmain(int argc, _tchar* argv[]) { // usage: certextract certpath char keyfile[] = "c:\\certificates\\public.crt"; byte lp[65536]; security_attributes sa; handle hkeyfile; dword bytes; pccert_context certcontext; sa.nlength = sizeof(sa); sa.lpsecuritydescriptor = null; sa.binherithandle = false; hkeyfile = createfile(keyfile, generic_read, file_share_read, &sa, open_existing, file_attribute_normal, null); if (hkeyfile) { if (readfile(hkeyfile, lp, getfilesize(hkeyfile, null), &bytes, null) && bytes > 0) { certcontext = certcreatecertificatecontext(x509_asn_encoding, lp, bytes); if (certcontext) { printf("yay...
Read more