This is what I see by disassemble for the statement function(1,2,3);: movl $0x3,0x8(%esp) movl $0x2,0x4(%esp) movl $0x1,(%esp) call 0x4012d0 <_Z8functioniii> It seems the ret address is not pushed into stack at all,then how does ret work? ...
Google doesn't show the result, Anyone knows? ...
I encounter a problem when reading information dumped out from an executable file in linux. The information is as follows: 804a0ea: 04 08 add $0x8, %al ... 804a0f4: a6 cmpsb %es:(%edi),%ds:(%esi) I have two questions: what does the address 804a0ea and 804a0f4 mean? the virtual address in the process's...
0x004012d0 <main+0>: push %ebp 0x004012d1 <main+1>: mov %esp,%ebp 0x004012d3 <main+3>: sub $0x28,%esp If the address is not available,can we calculate it ourselves? I mean we only have this: push %ebp mov %esp,%ebp sub $0x28,%esp ...
I'm a bit ashamed about asking this, but how do i output the value of a byte in assembler? Suppose I have the number 62 in the AL register. I'm targeting an 8086. There seem to be available only interrupts that output it's ascii value. Edit: Thank you Nick D, that was what i was looking for. To answer a couple of questions, i'm actually...
What is the shortest way to fetch a value from memory in X86 Assembler? ...
How to generate random numbers using assembly code in the range 1--4 ? ...
I have some C++ code #include <cstdio> #include <boost/bind.hpp> #include <boost/function.hpp> class A { public: void do_it() { std::printf("aaa"); } }; void call_it(const boost::function<void()> &f) { f(); } void func() { A *a = new A; call_it(boost::bind(&A::do_it, a)); } which gcc 4 compiles into the following as...
I'm using SDL with FASM, and have code that's minimally like the following: format ELF extrn _SDL_Init extrn _SDL_SetVideoMode extrn _SDL_Quit extrn _exit SDL_INIT_VIDEO equ 0x00000020 section '.text' public _SDL_main _SDL_main: ccall _SDL_Init, SDL_INIT_VIDEO ccall _SDL_SetVideoMode, 640, 480, 32, 0 ccall _SDL_Quit...
In the following assembly code that I dumped out using objdump: lea 0x0(%esi,%eiz,1),%esi What is register %eiz? What does the preceding code mean? ...
Hi, there: Here I have a question. What is the priority of the operator * in assembly language? For example: *0x804983c(,%eax,4) Does it mean ( %eax * 4 ) + *0x804983c or *( %eax * 4 + 0x804983c )? Thanks! ...
popl %ebp It seems the %ebp is unnecessary because the pop operation of stack doesn't need a parameter. Why does it make sense? ...
I've done some inline ASM coding for SSE before and it was not too hard even for someone who doesn't know ASM. But I note MS also provide intrinsics wrapping many such special instructions. Is there a particular performance difference, or any other strong reason why one should be used above the other? To repeat from the title, this is ...
I'd like to write a function that would have some optional code to be executed or not depending on user settings. The function is cpu-intensive and having ifs in it would be slow since the branch predictor is not that good. My idea is making a copy in memory of the function and replace NOPs with a jump when I don't want to execute some ...
hi I write a program to delete a file from somewhere of my harddisk in 8086 but when i use int 21h (ah=41h) an error happens and carry set to 1.and I cannot delete that. does anyone know what can I do? I think it should be from protected mode which does not allow my program to delete another file.I want the answer and language is not mat...
I have a 128-bit unsigned integer A and a 64-bit unsigned integer B. What's the fastest way to calculate A % B - that is the (64-bit) remainder from dividing A by B? I'm looking to do this in either C or assembly language, but I need to target the 32-bit x86 platform. This unfortunately means that I cannot take advantage of compiler sup...
I have a strange question concerning subroutines: As I'm creating a minimal language and I don't want to add high-level loops like while or for I was planning on just adding gotos to keep it Turing-Complete. Now I thought, eww - gotos - I wouldn't want to program in that language if I had to use gotos so often. So I thought about adding...
Hi, everyone: As the title described, how to use c library function fgets in assembly language? Indeed, I want to know how to get the file pointer to stdin. Thanks for your reply. ...
I was reading over this question and wondered if the accepted answer might also be a way to determine the architecture. For instance, in asm could I push a WORD onto the stack and then check SP. Compare the new SP to the old SP: Diff of 4 means 32 bit Diff of 8 means 64 bit Am I correct in this thinking? ...
When deploying my application to GoogleAppEngine I'm getting the following message after the upload Exception in thread "Thread-0" You have selected to use ClassEnhancer "ASM" yet the JAR for that enhancer does not seem to be in the CLASSPATH! org.datanucleus.enhancer.NucleusEnhanceException: You have selected to use ClassEnhancer "ASM"...