All X86 Solutions on Gang of Coders

Total of 121 X86 Solutions

Why is this SSE code 6 times slower without VZEROUPPER on Skylake?

PerformanceX86IntelSseAvx

GCC's assembly output of an empty program on x86, win32

CGccX86Gnu AssemblerTdm Mingw

How do you determine 32 or 64 bit architecture of Windows using Java?

JavaWindowsX8664 Bit

How to write self-modifying code in x86 assembly

AssemblyX86JitVm ImplementationSelf Modifying

What is stack frame in assembly?

AssemblyX86

How to compile Tensorflow with SSE4.2 and AVX instructions?

TensorflowX86Compiler OptimizationSimdCompiler Options

How are cache memories shared in multicore Intel CPUs?

PerformanceX86MultiprocessingIntelCpu Cache

Divide and Get Remainder at the same time?

X86ModuloDivide

Micro fusion and addressing modes

AssemblyX86IntelCpu ArchitectureIaca

Fastest way to calculate a 128-bit integer modulo a 64-bit integer

CAlgorithmX86ModuloAssembly

What does ORG Assembly Instruction do?

AssemblyX86NasmDirective

What does the "rep stos" x86 assembly instruction sequence do?

AssemblyX86

Assembly Language - How to do Modulo?

AssemblyX86ModuloInteger Division

Does it make any sense to use the LFENCE instruction on x86/x86_64 processors?

AssemblyX86X86 64AtomicMemory Barriers

What is the correct way to obtain (-1)^n?

C++AlgorithmX86Cmath

Calling 32bit Code from 64bit Process

.NetMigrationX8664 BitFortran

What does MOV EAX, DWORD PTR DS:[ESI] mean and what does it do?

AssemblyX86

"enter" vs "push ebp; mov ebp, esp; sub esp, imm" and "leave" vs "mov esp, ebp; pop ebp"

AssemblyX86StackMicro OptimizationStack Frame

Why is linear read-shuffled write not faster than shuffled read-linear write?

PythonPerformanceNumpyX86Cpu Cache

Weird MSC 8.0 error: "The value of ESP was not properly saved across a function call..."

C++Visual C++X86StackCalling Convention

Why is gcc allowed to speculatively load from a struct?

CGccAssemblyX86Compiler Optimization

Stack allocation, padding, and alignment

CGccAssemblyX86Stack

How can I do a CPU cache flush in x86 Windows?

CWindowsX86CpuCpu Cache

NASM Vs GAS (Practical differences)

AssemblyX86NasmGnu AssemblerAtt

Do current x86 architectures support non-temporal loads (from "normal" memory)?

C++CachingX86Cpu CachePrefetch

Getting started with Intel x86 SSE SIMD instructions

CGccX86SseSimd

Is x86 RISC or CISC?

X86CpuCpu Architecture

What does `rep ret` mean?

AssemblyX86Micro OptimizationBranch Prediction

How to run a program without an operating system?

AssemblyX86Operating SystemBootloaderOsdev

What does multicore assembly language look like?

AssemblyX86CpuMulticoreSmp

What is a retpoline and how does it work?

SecurityAssemblyX86Cpu ArchitectureSpectre

What is exactly the base pointer and stack pointer? To what do they point?

CAssemblyX86Stack FrameStack Pointer

How does the ARM architecture differ from x86?

X86Arm

What Every Programmer Should Know About Memory?

OptimizationMemoryX86Cpu ArchitectureCpu Cache

Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly?

C++PerformanceAssemblyOptimizationX86

What is the difference between Trap and Interrupt?

X86Operating SystemKernelInterruptCpu Architecture

The point of test %eax %eax

AssemblyX86Att

Why does GCC generate such radically different assembly for nearly the same C code?

CGccAssemblyX86Compiler Optimization

What happens when a computer program runs?

C++MemoryOperating SystemX86Computer Architecture

What's the purpose of the LEA instruction?

AssemblyX86X86 64X86 16

An expensive jump with GCC 5.4.0

C++GccX86Conditional StatementsBranch Prediction

How do you use gcc to generate assembly code in Intel syntax?

AssemblyGccX86Intel Syntax

What is the difference between MOV and LEA?

AssemblyX86Instruction Set

What is the best way to set a register to zero in x86 assembly: xor, mov or and?

PerformanceAssemblyOptimizationX86Micro Optimization

Header files for x86 SIMD intrinsics

X86Header FilesSseSimdIntrinsics

"No such file or directory" error when executing a binary

LinuxX86ElfDynamic LinkingExecve

Why do x86-64 instructions on 32-bit registers zero the upper part of the full 64-bit register?

AssemblyX86X86 64Cpu RegistersZero Extension

What is the meaning of "non temporal" memory accesses in x86

X86SseAssembly

How does this milw0rm heap spraying exploit work?

JavascriptX86ExploitAssembly

What is the purpose of XORing a register with itself?

AssemblyX86

What does `dword ptr` mean?

AssemblyX86DwordPointers

Purpose of ESI & EDI registers?

AssemblyX86

Why does integer overflow on x86 with GCC cause an infinite loop?

C++CGccX86Undefined Behavior

What is the function of the push / pop instructions used on registers in x86 assembly?

AssemblyX86TerminologyStack MemoryStack Pointer

`testl` eax against eax?

AssemblyX86Instructions

CPU Privilege Rings: Why rings 1 and 2 aren't used?

X86CpuPrivileges

What is the "FS"/"GS" register intended for?

AssemblyX86Cpu ArchitectureCpu RegistersMemory Segmentation

Why are elementwise additions much faster in separate loops than in a combined loop?

C++PerformanceX86VectorizationCompiler Optimization

Floating point vs integer calculations on modern hardware

C++X86Floating PointX86 64

How to install ia32-libs in Ubuntu 14.04 LTS (Trusty Tahr)

UbuntuX86

System.BadImageFormatException: Could not load file or assembly (from installutil.exe)

.NetWindows ServicesX8664 BitX86 64

Why is x86 ugly? Why is it considered inferior when compared to others?

AssemblyX86MipsX86 64Cpu Architecture

Why is SSE scalar sqrt(x) slower than rsqrt(x) * x?

PerformanceAssemblyFloating PointX86Sse

What does "int 0x80" mean in assembly code?

AssemblyX86

How to write hello world in assembler under Windows?

WinapiAssemblyX86Nasm

How does x86 paging work?

X86PagingVirtual Memory

Difference between JE/JNE and JZ/JNZ

AssemblyX86

What is the purpose of the EBP frame pointer register?

PerformanceAssemblyX86

Using gdb to single-step assembly code outside specified executable causes error "cannot find bounds of current function"

LinuxAssemblyGdbX86Linux Kernel

Why does Intel hide internal RISC core in their processors?

AssemblyX86IntelCpu Architecture

How do I disassemble raw 16-bit x86 machine code?

LinuxAssemblyX86X86 16Mbr

What does "rep; nop;" mean in x86 assembly? Is it the same as the "pause" instruction?

AssemblyX86X86 64CpuMachine Code

Limitations of Intel Assembly Syntax Compared to AT&T

LinuxAssemblyX86AttIntel Syntax

memory bandwidth for many channels x86 systems

CX86OpenmpAvx512Memory Bandwidth

What are IN & OUT instructions in x86 used for?

AssemblyX86Linux Kernel

Enhanced REP MOVSB for memcpy

PerformanceAssemblyX86Cpu ArchitectureMemcpy

Double cast to unsigned int on Win32 is truncating to 2,147,483,648

CVisual C++CastingX86Floating Point

Why is the loop instruction slow? Couldn't Intel have implemented it efficiently?

PerformanceAssemblyX86IntelCpu Architecture

Which variable size to use (db, dw, dd) with x86 assembly?

VariablesAssemblyX86

Where is the lock for a std::atomic?

C++C++11X86AtomicStdatomic

What does the "lock" instruction mean in x86 assembly?

C++QtAssemblyX86

Is it possible to tell the branch predictor how likely it is to follow the branch?

CGccX86Compiler OptimizationMicro Optimization

Argument order to std::min changes compiler output for floating-point

AndroidC++AssemblyX86Floating Point

Is using double faster than float?

C++PerformanceX86IntelOsx Snow-Leopard

How to generate assembly code with clang in Intel syntax?

C++AssemblyX86ClangIntel

Why is Windows 32-bit called Windows x86 and not Windows x32?

WindowsX86Operating System32bit 64bit32 Bit

How to write a disassembler?

X86Disassembly

Can I use Intel syntax of x86 assembly with GCC?

CGccAssemblyX86Inline Assembly

What is better "int 0x80" or "syscall" in 32-bit code on Linux?

LinuxAssemblyX86System Calls32 Bit

Why is std::fill(0) slower than std::fill(1)?

C++PerformanceX86Compiler OptimizationMemset

What do the brackets mean in NASM syntax for x86 asm?

AssemblyX86Nasm

To learn assembly - should I start with 32 bit or 64 bit?

AssemblyX86X86 64Low Level

Is this "should not happen" crash an AMD Fusion CPU bug?

AssemblyCrashX86WindbgAmd Processor

What is the purpose of the "PAUSE" instruction in x86?

Parallel ProcessingX86X86 64IntelCritical Section

Why is there not a register that contains the higher bytes of EAX?

AssemblyX86Cpu Registers

Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_u64 on Intel CPUs

C++PerformanceAssemblyX86Compiler Optimization

When are x86 LFENCE, SFENCE and MFENCE instructions required?

MultithreadingAssemblyX86CpuMemory Fences

Do x86 instructions require their own encoding as well as all of their arguments to be present in memory at the same time?

AssemblyX86PagingVirtualizationKvm

x86 Assembly on a Mac

XcodeMacosX86Assembly

How can I determine if a .NET assembly was built for x86 or x64?

.NetAssembliesX8664 BitX86 64

Fast method to copy memory with translation - ARGB to BGR

CX86RgbSseMicro Optimization

What are the names of the new X86_64 processors registers?

AssemblyX86X86 64Cpu Registers

How to disassemble, modify and then reassemble a Linux executable?

LinuxX86DisassemblyObjdump

Why does leave do "mov esp,ebp" in x86 assembly?

AssemblyX86

How many CPU cycles are needed for each assembly instruction?

PerformanceAssemblyX86Cpu ArchitectureCpu Cycles

How Do You Make An Assembler?

X86Assembly

Efficient integer compare function

CAssemblyX86Inline Assembly

Deoptimizing a program for the pipeline in Intel Sandybridge-family CPUs

C++OptimizationX86IntelCpu Architecture

What does it mean to align the stack?

CAssemblyGccX86Memory Alignment

Does using xor reg, reg give advantage over mov reg, 0?

AssemblyX86Micro Optimization

Specifying multiple files with LD_PRELOAD

CLinuxDynamicX86

Assembly - JG/JNLE/JL/JNGE after CMP

AssemblyX86Eflags

Why GCC compiled C program needs .eh_frame section?

CAssemblyException HandlingX86Elf

Why is x86 little endian?

X86IntelEndiannessCpu ArchitectureMicroprocessors

What are the ESP and the EBP registers?

AssemblyX86CallstackStack Frame

What is register %eiz?

AssemblyX86Gnu AssemblerObjdump

Compile/run assembler in Linux?

LinuxUbuntuX86Assembly

LEA or ADD instruction?

AssemblyX86

Difference between x86, x32, and x64 architectures?

X8664 BitX86 64Cpu ArchitectureAbi

How are atomic operations implemented at a hardware level?

X86AtomicCpu ArchitectureLock FreeSmp

Do any languages / compilers utilize the x86 ENTER instruction with a nonzero nesting level?

AssemblyX86