There is no such thing as x32. x86 and x64 refer to the instruction set architecture of the CPU.

## Instruction set

The instruction set can be understood as the hardware’s interface to the outside world. We run programs through the operating system scheduling, and the operating system then allows the hardware to compute.

If you let the hardware compute, such as some addition and multiplication, loops and so on, you need the interface provided by the hardware, that is, the instruction set. This is what we often call machine language, which has reached the bottom of the computer.

Instruction set architecture is divided into two main categories.

• Complex Instruction Set Computing (CISC) is simply understood to provide a lot of instructions, and they are also very complex. Represented by intels x86 architecture, the main target operating systems are Microsoft’s Windows and Apple’s maxOS. Also Linux, some UNIX, etc., can run on microprocessors with complex instruction set architectures.
• Reduced Instruction Set Computing (RISC) simply means that the instructions provided are few and simple, just some basic instructions. The arm architecture of the ARM company is the representative. Currently there are UNIX, Linux, and most mobile operating systems including iOS, Android, Windows Phone, etc. running on the processor with compact instruction set.

The difference between the complex instruction set and the compact instruction set is when we program (write machine language code directly to run on the CPU), for example, to implement multiplication. Depending on the instructions provided, one command may be enough for the complex instruction set, while for the simple instruction set we may need multiple instructions such as addition, loops, etc.

Hardware and software are also complementary processes, when the hardware provides simple functions, write software is more complex. When the hardware provides more functions, write the software is simpler.

## x86 Architecture Development

The x86 architecture first appeared in the Intel 8086 CPU introduced in 1978. The 8086 was selected for the IBM PC three years later, and the x86 became the standard platform for personal computers, making it the most successful CPU architecture of all time. The 8086 was a 16-bit processor, followed by a series of processors with improvements to the 32-bit architecture, and now x86 generally refers to the 32-bit architecture.

Earlier processors in the series were named 80x86 with a number to indicate 80x86. The architecture was called x86 because it ended with 86 and included Intel 8086, 80186, 80286, 80386, and 80486.

In addition to Intel, it also licensed its patents to the now more famous Supermicro (AMD), which produced the CPU for the x86 architecture. Then in 1999 AMD made public the first 64 bit set to extend x86, an architecture called AMD64. Later Intel also introduced a compatible processor named Intel 64. Both are generally referred to as x86-64 or x64, ushering in the 64 bit era of x86.

There will be a question here, where did Intel go and why didn’t they take the lead in making 64 bit? In fact, intel did, in order to prevent other manufacturers from imitating, applied for many patents, and jointly designed with HP a new architecture IA-64, but the biggest problem is that it is not compatible with the previous x86, and the market response is relatively cold, and then cooled off.

Apple and the RPM package administrators call this 64 bit architecture by x86-64 or x86_64. Oracle and Microsoft call it x64. The BSD family and other Linux distributions use amd64, the 32 bit versions are called i386 (or i486/586/686), and Arch Linux calls this 64 bit architecture with x86_64.

Nowadays, the x86 architecture of the CPU is basically Intel and AMD.

## Arm architecture development

The arm architecture is owned by the ARM company, which does not produce chips but rather licenses them for profit. The specific development can be found here . From Nokia to Apple phones and Android phones, it established its dominant position in the smartphone market. In 16 the ARM company was acquired by Softbank of Japan.

The Qualcomm Snapdragon series is the arm architecture that you often hear about now.

## Software installation

Sometimes you need to choose your CPU architecture when downloading the installer on github. There are three architectures available for different operating systems, x86 for 32 bit architecture and 64 bit architecture, and arm architecture.

The command uname -a can be used in linux to see the architecture of the CPU.

 1  Linux DESKTOP-68NS8J3 3.4.0+ #1 PREEMPT Thu Aug 1 17:06:05 CST 2013 x86_64 x86_64 x86_64 GNU/Linux 

## Summary

CPU instruction set architectures are currently in two main categories.

Complex instruction set is x86, x64 (also called x86-64, amd64) two kinds of architecture, the patent is in the hands of Intel and AMD two companies, this architecture CPU is mainly Intel and AMD two companies, this CPU commonly used in PC machine, including Windows, macOS and Linux.

Simple instruction set is an architecture of arm, the patent of which is in the hands of ARM, the main companies of this architecture CPU are Qualcomm, Samsung, Apple, Huawei Hesi, MediaTek and so on. This CPU is commonly used in cell phones, including Android and Apple.

Just like the operating system, we can design a brand new operating system, but all kinds of software need to be redeveloped on the new system, and it is not sure if the software vendors are willing to do so.

Similarly, we can design a new instruction set architecture, but it’s still an ecological problem. Now Android and Apple’s operating systems are on the arm architecture, so your new instruction set architecture still needs to be adapted to a new operating system by Android.

If it is compatible with the previous instruction set architecture or operating system, then it may not be able to get around the various patent issues.

So now all kinds of company interests are closely linked, cooperation to win together.