x64 Architecture - x86 Architecture - x86-64 - x86_64

x64 Architecture - x86 Architecture - x86-64 - x86_64

1. uname - print system information

Print certain system information. With no OPTION, same as -s.

-a, --all
print all information, in the following order, except omit -p and -i if unknown:

yongqiang@yongqiang:~$ uname -a
Linux yongqiang 4.4.0-17763-Microsoft #864-Microsoft Thu Nov 07 15:22:00 PST 2019 x86_64 x86_64 x86_64 GNU/Linux
yongqiang@yongqiang:~$

-m, --machine
print the machine hardware name

yongqiang@yongqiang:~$ uname -m
x86_64
yongqiang@yongqiang:~$

-p, --processor
print the processor type (non-portable)

yongqiang@yongqiang:~$ uname -p
x86_64
yongqiang@yongqiang:~$

-i, --hardware-platform
print the hardware platform (non-portable)

yongqiang@yongqiang:~$ uname -i
x86_64
yongqiang@yongqiang:~$

2. x64 Architecture

The x64 architecture is a backwards-compatible extension of x86. It provides a legacy 32-bit mode, which is identical to x86, and a new 64-bit mode.
x64 體系結構是 x86 的向後兼容的擴展。它提供舊的 32 位模式 (這就相當於 x86)，以及新的 64 位模式。

The term x64 includes both AMD 64 and Intel64. The instruction sets are close to identical.
術語 x64 包括 AMD 64 和 Intel64。指令集即將於完全相同。

3. x86 Architecture

The Intel x86 processor uses complex instruction set computer (CISC) architecture, which means there is a modest number of special-purpose registers instead of large quantities of general-purpose registers. It also means that complex special-purpose instructions will predominate.
Intel x86 處理器使用複雜指令集計算機 (CISC) 體系結構，這意味着有適度數量的專用寄存器，而不是大量通用寄存器。這也意味着複雜的特殊用途指令集將主流。

The x86 processor traces its heritage at least as far back as the 8-bit Intel 8080 processor. Many peculiarities in the x86 instruction set are due to the backward compatibility with that processor (and with its Zilog Z-80 variant).
x86 處理器的歷史至少可以追溯到 8 位 Intel 8080 處理器。x86 指令集的許多特性是由於與該處理器 (及其 Zilog Z-80 變體) 的向後兼容性。

Microsoft Win32 uses the x86 processor in 32-bit flat mode.
Microsoft Win32 在 32 位平面模式下使用 x86 處理器。

peculiarity [pɪˌkjuːliˈærəti]：n. 特點，特性，怪癖，性狀

3. x86-64

x86-64 is an extension of the x86 instruction set.

x86-64 (64-bit extended，x64：64位拓展) 是 x86 架構的 64 位拓展，向後兼容於 16 位及 32 位的 x86 架構。x64 於 1999 年由 AMD 設計，AMD 首次公開 64 位指令集以擴展給 x86，稱爲 AMD64。

英特爾稱之爲 Intel 64，在之前曾使用過 Clackamas Technology (CT)、IA-32e 及 EM64T。

蘋果公司和 RPM 包管理員以 x86-64 或 x86_64 稱呼 64 位架構。甲骨文公司及 Microsoft 稱之爲 x64。Linux 發行版則使用 x64-64，32位版本則稱爲 i386 (i486/586/686)，Arch Linux 用 x86_64 稱呼 64 位架構。

References

https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/x64-architecture