Last century 70 years , Memory is slow and expensive , Programmers have to do everything they can to save memory .
Compilers in those days were also poor
therefore ,70 Almost all programmers in the '80s were good at assembly .
In order to help programmers write assembly , At this time CPU The instruction set has also been intentionally enhanced .
80 The beginning of the decade ,Intel Of x86 CPU And Microsoft DOS cover IBM Select , Become IBM PC Compatible processor and operating system .
Under the control of Moore's law , x86 CPU It's getting more and more complicated .
last , Even the compiler can't stand it .
IBM Research Institute John Cocke find , A large number of instruction sets and addressing methods provided by the processor are not used by the code generated by the compiler .
since it is so , Why not design a new instruction set , Keep the most commonly used 20% What about your instructions ?
such CPU Isn't it simpler to design and implement ?
This is the famous reduced instruction set （RISC） The way of thinking .
at that time ,IBM, University of California, Berkeley David Patterson, Stanford University John Hennessy yes RISC A pioneer in research .
RISC It's not just about streamlining the instructions , There are other very important improvements .
The birth of new theories has never been smooth sailing , at that time CICS Some of our design masters hold different opinions .
David Patterson Hold your breath , Lead your students , Designed a RISC processor , 1982 year , RISC-I Processor released .
notice RISC There is such a performance , A large number of companies began to adopt it RISC To design the processor based on the idea of ,RISC It's like a prairie fire , Quickly captured the server-side market .
Although firmly in the hands of the ruler PC market , but RISC The development of science and technology makes us happy Intel I feel a lot of pressure ,Intel Decided to walk on two legs .
however PC yes x86 framework , All operating systems and software are built around it .
i860 Not even a compatible operating system or software , It can't develop at all .
since RISC It can't develop ,Intel Make up your mind , abandon RISC, One way to black .
here we are 1995 year ,Intel At last we found a way , That's to put it x86 Instruction set for , Decode into something similar to RISC Micromanipulation of (uops), When executing, use RISC kernel .
Intel Use from PC Huge profits made by the market , Continuous investment , With the development of architecture and microelectronics technology ,CICS The structural disadvantage gradually disappeared .
stay Intel Under the attack of , RISC On the server CPU The market is declining , Today , cover Intel Occupied 95% Our market .
Plus the desktop market , x86 Almost completed the monopoly .
RISC Did it fail ?
stay 90 Years and 21 The beginning of the century ,PC It's in a dominant position , But a new star is dormant , Waiting for the outbreak .
But I'm sorry ,Newton Technology is too advanced , Poor user experience , Not accepted by the market , It ended in failure .
but ARM Accumulated experience , Continue to improve technology . It wasn't long , It was successful on Nokia and other function computers .
2007 year , ARM Finally ushered in their own golden age .
The following story is quite clear , ARM Stepping on the wave of mobile era , Dominated the mobile phone market .
More Than This , Mobile market dominated by ARM, It's time to counterattack servers and desktops !
2007 year ,David Patterson and John Hennessy Because in RISC Turing Award for outstanding contributions in this field
actually , review CPU past times 40 The development of the year ,Intel Once to RISC study , Got it RISC kernel .
and ARM New instruction sets with higher code density are also introduced , towards CISC Learning from the classics .
CISC And RISC Differences at the instruction set architecture level have been bridged .
More wonderful technical cartoons , Turn over in the yard