64-bit (x86-64)

Architecture referenceFeex

x86-64 na di 64-bit extension of x86 instruction architecture. E dey define execution modes, registers, and addressing rules; e no dey establish complete CPU or operating-system requirements for application by imself.

Wetin you need know

How e dey work

Inside 64-bit mode, general-purpose registers fit hold 64-bit operands and di architecture dey provide additional registers and different programming environment from legacy 32-bit x86. Compatibility mode dey allow operating system make e support suitable legacy applications, but na di OS dey decide which application formats and interfaces e go provide. 64-bit CPU no mean say every instruction must use 64-bit data.

Where e dey useful

Application wey dem build for x86-64 ABI dey expect di register, calling-convention, and baseline instruction environment of dat ABI. Arm64 binary na different architecture even though di two dey call demselves 64-bit. Translation or emulation na separate software facility, no be consequence of having 64-bit registers.

How to check support and enablement

For x86 hardware, CPUID extended function 80000001H, EDX bit 29 dey enumerate long-mode capability. Supported operating system must enable di correct paging and execution environment. Check di running OS architecture as well as di processor capability.

Hardware capability, di running operating environment, and binary requirements of application na different layers. Make dem interpret architecture names and ABI levels as explicit contracts instead of general rule say newer dey always compatible.

Wetin di feature no dey guarantee

Di 64-bit label no dey establish di implemented physical or virtual address width, installed RAM limit, x86-64-v2/v3/v4 support, Windows eligibility, or compatibility with particular driver. Check each requirement separately.

Compatibility and performance inside real life

Check di complete inherited requirements and di effective environment wey di process fit see. For VM, inspect di guest instead of assuming say e expose host model without changes. Supported fallback build suppose state im own baseline clearly.

Practical verification checklist

Record di exact processor or platform model plus di application, OS and runtime version dem wey dey involve. Make you keep di exact word dem wey di error or requirement use.
Check di manufacturer reference for dat exact model, den inspect di real capability and enabled state inside di environment where di program dey run.
Compare every single requirement of di binary or backend wey you choose. Name wey resemble am, alias, or broad technology label no reach.
Confirm say di application select di implementation wey dem intend. Use di diagnostics wey dem document and supported fallback if requirement dem no complete.
Make only one supported change at a time, den run di same workload again. Keep di original configuration and recovery way ready.

If dem list di feature but software no fit use am

Start from di exact component wey dey fail. Hardware database dey describe capability wey dem record; di operating system or hypervisor fit show different real environment. If illegal-instruction error happen, you still need to check di exact instruction wey cause di fault and di binary build, because corrupt file or anoda instruction wey no dey supported fit give di same kind problem.

Install di application, driver or runtime version wey get support for dat exact platform, and use di vendor documented baseline or fallback build if e need am. Software update no fit create instruction wey di processor no get. Firmware and security-policy change dem suppose follow di system manufacturer procedure and recovery plan, no be just any common optimization advice.

Sources and scope of dis explanation

Intel 64 and IA-32 Architectures Software Developer's Manual · x86-64 psABI: processor architecture and microarchitecture level dem

Dis reference dem establish architectural behavior and software requirement dem. Dem no dey independently verify every feature value for any linked hardware model page. For model support, use dat page manufacturer evidence and check di active system configuration. Dis article no supply benchmark, certification or independent review date.

Sources and verification

Editorial ownership: Feex. No independent review date dey recorded. How we dey do research.

Intel 64 and IA-32 Architectures Software Developer's Manual · Volume 1 and 2 describe di named instruction family dem and CPUID; Volume 3 describe state, paging, VMX and protection control dem. Architecture documentation no dey prove say particular model support am.
x86-64 psABI: processor architecture and microarchitecture level dem · Machine Interface, Processor Architecture: baseline and cumulative v2/v3/v4 feature table, OS-state check dem and deployment recommendation dem.

Dis article make sense to you?

Yes or no dey enough. Choose reason if you want, or add short note.