Assembly is a family of very low-level programming languages, just above machine code. Use this tag for assembly language programming questions, on any processor. You should also use a tag for your processor or instruction set architecture (ISA), e.g. arm, avr, mips, x86, x86-64, etc. Consider a tag ...
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Performing a Backspace in YASM or NASM assembly
I have a program reading characters in raw mode. That is, any characters input are read immediately instead of being buffered.
I would like to know how to perform a backspace. That is, when I press ...
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0answers
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MIPS register content
We run code from adress 8002000 to 80020028 and the question is what is inside register $18 at when we are at the end. I think there might be 0x0E but I am really not sure how i got to this answer ...
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vote
1answer
18 views
MIPS, assembly - a few questions
I am trying to study for a test where I have to know something about MIPS and assembly code. Can u help me plz? I will try to write what I think is a correct answer for given question but Im not sure ...
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0answers
20 views
Can assembled ASM code result in more than a single possible way (except for offset values)?
I don't know x86 ASM very well, but I'm rather comfortable with SHARP-z80, and I know by experience that each instruction (mnemonic) has a corresponding byte/word value, and by looking at the hex dump ...
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votes
1answer
43 views
How do I compile JVM assembly code into bytecode?
If I ran javap -c ASM.class > ASM.java to get the assembly code, how would I recompile this back into JVM bytecode?
2
votes
1answer
43 views
“Hello world” in ARM Assembly
This is my simpe "Hello world" program in ASM:
.global _start
_start:
adr r1, hello
b test
loop: ldr r12, =0x16000000
str r0, [r12]
test: ldrb r0, ...
2
votes
2answers
76 views
Math.h library functions in assembly x86?
I tried to convert C code that is written under Linux (fedora 9) to assembly x86 code, however, I have problem in a Math.h functions. The functions in this library such as ceil, floor, log, log10, ...
5
votes
1answer
42 views
Force GCC to use repeat prefix in memset() call
I'm developing an application where performance is critical. I want GCC to translate some specific calls to memset() as an instruction with a repeat prefix like "rep stos QWORD PTR es:[rdi],rax". GCC ...
1
vote
1answer
53 views
How to preserve argument/parameter registers under x86-64?
The System V AMD64 ABI call convention is mandated thus:
Registers %rbp, %rbx and %r12 through %r15 “belong” to the calling
function and the called function is required to preserve their values.
...
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votes
2answers
33 views
Is possible to include an assembly code to php script?
I mean something like this:
asm(
//assembly code here
mov dx, 4 // etc...
)
asm() - php function
is possible?
5
votes
1answer
52 views
Select unique/deduplication in SSE/AVX
Problem
Are there any computationally feasible approaches to intra-register deduplication of a set of integers using x86 SIMD instructions?
Example
We have a 4-tuple register R1 = {3, 9, 2, 9}, and ...
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1answer
36 views
Block copy in assembler
My project - RAM speed testing utilite.
So I used MOVSD (as MOV with the biggest size block DW) to read some memory from one source and write to another. But the results that I got display that RAM ...
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0answers
20 views
lseek in nasm assembly
I would like an example of how to use lseek in nasm assembly
have the following code structure
mov eax, 3
mov ebx, [fdin]
mov ecx, buffer
mov edx, bsize
int 80h
need to read the data from a buffer ...
4
votes
1answer
43 views
Why would gcc movl to the same register?
For this piece of C code:
uint64_t roundUp(uint64_t value, uint32_t blockSize)
{
return (value + blockSize - 1) & ~(blockSize - 1);
}
gcc 4.6 -O3 generated the following assembly:
...
1
vote
1answer
40 views
Difference between LEA and MOVE.L?
Are there any differences between
LEA $1000,A0
and
MOVE #$1000,A0
to put an address in the address registry
?
