Check the references and:
https://www.cnblogs.com/ylhwx/p/7801058.html
https://blog.csdn.net/strliu/article/details/7906017
This week began to see in-depth understanding of computer systems, computer four major foundation also book last one I have not seen the.
Sunday in the office listening to the song writing study notes, is not a good feeling up.
Liu gave three topics
1. Information bit = + context, what is the context? What are examples of work
2. RISC instruction set CISC instruction set and what is the difference, their typical CPU What?
3. The stack-based "CPU" and register-based "CPU" What is the difference.
Come one,
All information systems are made of bits of discriminating between different meanings, it is context, context is the operating environment of the program. English called context;
And language in the context of similar, combined with text before and after a word has a different meaning now. Like js and java, there are different keywords? Also we see the wheels brother explained that the context is the method parameter? ?
--second question
RISC instruction set is a reduced instruction set computer; CISC complex instruction set computers
They are the difference between design concepts and methods different CPU.
CISC machine language instructions with minimal computational effort required to complete. This architecture increases the complexity of the requirements and process CPU CPU architecture, development beneficial to the compiler. Today Only Intel and compatible CPU still using this architecture.
RISC creation found that 80% of the most frequently used commands, only 20% of the processor instruction set, and is typical of the 82 rule ah.
From a hardware perspective CISC dealing with unequal length instruction set, it must be unequal division of command, so when performing a single instruction requires more processing. And executing RISC reduced instruction set are of equal length, CPU speed, faster in the instruction execution time and stable performance.
From a software perspective, CISC running is that we are familiar DOS, Windows operating system. And it owns more than 65% of software vendors agent-based PC CISC architecture and compatible services, such as well-known Microsoft is one of a large number of applications. The RISC in this regard was a bit weak. Though it may be running DOS, Windows on RISC, but requires a translation process, so much slower speed.
--three
Register-based virtual machine:
1, the stack is allocated to activate the recorder
2, eliminates the trouble code is register-based use of push and pop commands, reducing the total number of instructions for each function.
3, code size, and decoding efficiency is better to stack-based virtual machine, because it contains the operand, the instruction-based instruction is greater than the stack. However, based on the register to generate less code, the total number of codes is not increased.
4, the register operation instruction from the virtual machine to be decoded operand requires additional decoding operations.
Stack-based virtual machine:
1, the code must be used to move these instructions variables (i.e., push and POP)
2, a small code size decoding efficiency will be higher and
3, a stack of the virtual machine instruction has implied operands.
- sentiment
Indeed, looked at the front on a kind of feeling very excited, this is the "programmer" should be master of things right! In order to be able to say, "I have something" when forced to work overtime filling it ~