Are x86 assembly instructions REPE/REPZ and REPNE/REPNZ equal?
Just a quick question: Are REPE equal to REPZ and REPNE equal to REPNZ? Thanks. ...
x86
Intel x86 coprocessor assembly question
I am having some trouble understanding how to retrieve the result of a calculation done using the Intel's x86 coprocessor. Please consider the following data segment. .data res real4 ? x real4 5.0 k real4 3.4 and the following code segments, version 1: .code main: fld x ; 5.0 fadd k1 ; 5.0 + 3.4 fistp res ; store as inte...
Assembler task - min and max values of the array..
Hi. I've encountered problems with assembler code. I'm a newbie to assembler, so it seems difficult for me to solve it myself. The task is: "To find minimal and maximal elements of the array." All I've already done is searching for maximal element. I can't find out, how to make check for the minimal element and where I should put suc...
Dummy operations handling of Intel processor
Hello, Admittedly, I have a bit silly question. Basically, I am wondering if there are some special mechanisms provided by Intel processors to efficiently execute a series of dummy, i.e., NOP instructions? For instance,I could imagine there could be some kind of pre-fetch mechanism that identifies NOPS, discards them and tries to fetch ...
x86 assembly on x64 operating systems
Hello Recently i decided that it was worth getting a try on basic x86 assembly so that it would be easier to debug programs, etc, etc. So I started (about a week ago) learning x86 assembly, in that time, I upgraded my computer to 8GB ram, so obviusly my x86 Windows XP installation was wasting up all that memory, now, I'm running a x64 W...
Overwhelmed while learning assembly. Orientation please
Recently I decided that learning assembly would be a good idea, but right now, I'm really overwhelmed by all the material I have read about assembly in forums, here, tutos etc (Some of it is really old) so I would love to have some orientation about the assembly language, how to "compile" etc, I would also like it to be able to run on my...
Assembly: Jump from one section to another
In x86 assembly, how can I perform an unconditional jump from one section another? Eg: .section .text main: ... jmp here ... .section .another here: ... I guess this is a far jump. I get a segfault when trying to run this. Any workaround? ...
ASM .com won't run
Hello I found this sample tutorial The clueless guide to Hello World in nasm about basic ASM, when I compile it, everyting goes just fine!!! Great, but when I run it I get this message: This version of hi.com is not compatible with the version of Windows you are running This happens on Windows 7 x64 (Which i was told would run fine...
What Assembly Instructions Live In the Master Boot Record?
Curious about what explicit assembly instructions actually make up the Master Boot Record on an X86 architecture. Thanks for any insights. Other architectures welcome, but this is primarily for X86. ...
Where can I find an assembler for the x86?
I study ASM-86 language at high school and I want to program a little at home. Do you know any "compiler" for this language that I can program and view the state of the memory? ...
Visual Studio: Different DLLs for configurations
I'd like to make a x86 and x64 version of my application because some of the libraries I'm using have differences for x86 and x64 (e.g. SQLite). I made a new configuration for release builds that has as target operating system "x64". Is there a way to define different DLLs for the configuration e.g. use SQLite.dll for x86 release and ...
a Simple "Hello World" Inline Assembly language Program in C/C++....
i use devcpp and borland c compiler.... asm { mov ax,4 // (I/O Func.) mov bx,1 // (Output func) mov cx,&name // (address of the string) mov dx,6 // (lenght of the string) int 0x21 // system call } in the above code snippets i want to print a string with the help of assembly language... ...
GCC Extended ASM syntax: load 128-bit memory location as source
Hi all, GCC generates this code for the shuffle() below: movaps xmm0,XMMWORD PTR [rip+0x125] pshufb xmm4,xmm0 Ideally this should be: pshufb xmm4,XMMWORD PTR [rip+0x125] What is the extended ASM syntax to generate this single instruction? Many thanks, Adam PS: The commented out intrinsic generates the optimal code for this examp...
What am I doing wrong? (Simple Assembly Loop)
It won't let me post the picture. Btw, Someone from Reddit.programming sent me over here. So thanks! TITLE MASM Template ; Description ; ; Revision date: INCLUDE Irvine32.inc .data myArray BYTE 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 .code main PROC call Clrscr mov esi, OFFSET myArray mov ecx, LENGTHOF myArray mov e...
Odd optimization problem under MSVC
I've seen this blog: http://igoro.com/archive/gallery-of-processor-cache-effects/ The "weirdness" in part 7 is what caught my interest. My first thought was "Thats just C# being weird". Its not I wrote the following C++ code. volatile int* p = (volatile int*)_aligned_malloc( sizeof( int ) * 8, 64 ); memset( (void*)p, 0, sizeof( int ...
What AOP tools exist for doing aspect-oriented programming at the assembly language level against x86 application files for native OS X and MS-Windows native executables?
Looking for a tool I can use to do aspect-oriented programming at the assembly language level. For experimentation purposes, I would like the code weaver to operate native application level executable and dynamic link libraries. I have already done object-oriented AOP. I know assembly language for x86 and so forth. I would like to be...
Storing two x86 32 bit registers into 128 bit xmm register
Is there any faster method to store two x86 32 bit registers in one 128 bit xmm register? movd xmm0, edx movd xmm1, eax pshufd xmm0, xmm0, $1 por xmm0, xmm1 So if EAX is 0x12345678 and EDX is 0x87654321 the result in xmm0 must be 0x8765432112345678. Thanks ...
masm division overflow
I'm trying divide two numbers in assembly. I'm working out of the Irvine assembly for intel computers book and I can't make division work for the life of me. Here's my code .code main PROC call division exit main ENDP division PROC mov eax, 4 mov ebx, 2 div ebx call WriteDec ret divison ENDP END main Whe...
Include syntax on MASM32
When including files into MASM32, it cannot find it's own files. After including masm32rt.inc, the assembler cannot find \masm32\include\windows.inc Apparently most MASM system include files begin with \ instead of specyfing a relative or absolute path. I tried specifying the directory in %PATH%, setting the /I compile switch, and sett...
What is at memory location 1 on an Intel x86 machine running Windows XP?
I am running Windows XP on an Intel x86 machine and I got an error in the instruction at memory location 0x00000001. I am not worried about debugging the error, but I was interested to know what instructions would generally be located at the very begging of memory. The only processors I have written low-level code for are PIC microc...