Assembly
Assembly language (asm) programming questions. BE SURE TO ALSO TAG with the processor and/or instruction set you're using, as well as the assembler. WARNING: For .NET assemblies, use the tag [.net-assembly] instead. For Java ASM, use the tag [java-bytecode-asm] instead.
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What is the difference between native code, machine code and assembly code?
I'm confused about machine code and native code in the context of .NET languages. What is the difference
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Why does Windows64 use a different calling convention from all other OSes on x86-64?
AMD has an ABI specification that describes the calling convention to use on x86-64. All OSes follow it, excep
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What is the function of the push / pop instructions used on registers in x86 assembly?
When reading about assembler I often come across people writing that they push a certain register of the proce
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`testl` eax against eax?
I am trying to understand some assembly. The assembly as follows, I am interested in the testl line: 000319d
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What are CFI directives in Gnu Assembler (GAS) used for?
There seem to be a .CFI directive after every line and also there are wide varities of these ex.,.cfi_startpro
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How to view the assembly behind the code using Visual C++?
I was reading another question pertaining the efficiency of two lines of code, and the OP said that he looked
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Purpose of ESI & EDI registers?
What is the actual purpose and use of the EDI & ESI registers in assembler? I know they are used for stri
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What is the purpose of XORing a register with itself?
xor eax, eax will always set eax to zero, right? So, why does MSVC++ sometimes put it in my executable
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What is the meaning of "non temporal" memory accesses in x86
This is a somewhat low-level question. In x86 assembly there are two SSE instructions: MOVDQA xmmi, m128
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What does `dword ptr` mean?
Could someone explain what this means? (Intel Syntax, x86, Windows) and dword ptr [ebp-4], 0
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What is the best way to set a register to zero in x86 assembly: xor, mov or and?
All the following instructions do the same thing: set %eax to zero. Which way is optimal (requiring fewest mac
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Why do x86-64 instructions on 32-bit registers zero the upper part of the full 64-bit register?
In the x86-64 Tour of Intel Manuals, I read Perhaps the most surprising fact is that an instruction such a
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What is the difference between MOV and LEA?
I would like to know what the difference between these instructions is: MOV AX, [TABLE-ADDR] and LEA AX,
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How do you use gcc to generate assembly code in Intel syntax?
The gcc -S option will generate assembly code in AT&T syntax, is there a way to generate files in Intel sy
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Show current assembly instruction in GDB
I'm doing some assembly-level debugging in GDB. Is there a way to get GDB to show me the current assembly
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Why would introducing useless MOV instructions speed up a tight loop in x86_64 assembly?
Background: While optimizing some Pascal code with embedded assembly language, I noticed an unnecessary MOV i
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Assembly code vs Machine code vs Object code?
What is the difference between object code, machine code and assembly code? Can you give a visual example of
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What is a retpoline and how does it work?
In order to mitigate against kernel or cross-process memory disclosure (the Spectre attack), the Linux kernel1
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What does multicore assembly language look like?
Once upon a time, to write x86 assembler, for example, you would have instructions stating "load the EDX regis
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How to run a program without an operating system?
How do you run a program all by itself without an operating system running? Can you create assembly programs t
