A summary of what i learned in CS61C (fa20).

My course repo on GitHub: github/cs61c

Summary of the Course

Centered on several great ideas in computer architecture. Specifically,

1. The first half of the course teaches what’s called “the old school machine structures”.

   • High level language program - C [lec3-6]

   • Assembly language program - RISC-V [lec7-13]

   • Machine Language - still RISC-V, but without pseudo instructions [lec7-13]

   • Hardware architecture description - block diagrams, datapaths, cache, pipelining, virtual mem, etc. [lec17-27]

   • Logic circuit description [lec14-16]

Basically, that’s everything from the top – the programmer-friendly high level language C–, to the bottom arch – circuits, logic gates, and transistors–.

In terms of actual sequence, it’s like top -> middle, then bottom -> middle, and finally the two lines meet at around project3 (DIY a CPU datapath).

2. The second half teaches the new-school structures, which include more recent ideas of parallelism / high performance programming that companies hardware improvements.

   • data-level parallelism - SIMD [lec32], MapReduce, Spark, etc. [lec36]

   • thread-level parallelism - threads, cache coherency, OpenMP, etc. [lec33-35]

   • dependability [lec38]

Summary of the Labs

Not including ones I didn’t manage to set up.

• Lab1 Number Rep, C and CGDB: familiarize you with c and debugging tools
• Lab2 Advanced C: bit manipulations, memory allocation, and pointers in C
• Lab3 RISCV Assembly: ask u to figure out how simple C programs work on a lower level and write RISC-V assembly code
• Lab4 RISCV Functions, Pointers: still RISC-V practices, asking you to modify code to make the program work
• Lab5 Logisim: ~ build logic gates and practise with combinational logic
• Lab7 Caches: back to RISC-V, implement and optimize matrix-related functions to understand how cache works. This lab is valuable as it touches on one way to squeeze out performance.
• Lab8 OS, I/O, DMA, Disks, Networking & Virtual Memory: ~ play with a virtual memory simulator to understand how it works
• Lab9 SIMD Instructions: ~ work on single instruction multiple data (SIMD) – write C functions and improve their performance with x86 intrinsics. It’s like inserting assembly code into C code. (Note that ARM users unfortunately would have to use ARM NEON intrin to be able to compile the programs.)
• Lab10 Thread Level Parallelism: have you experience parallel programing with C + OpenMP. Ask you to apply parallelism to the implementation of sum vector and dot product C funcs.

Progress

Planned to complete the course within 30 study days, and achieved the goal!

• 【0611】setup, lab00
• 【0615】lec1&2
• 【0616】lec3
• 【0617】lec4
• 【0625】lec5, lab01
• 【0626】lec6
• 【0627】proj1A
• 【0702/03】proj1 Fin
• 【0704】K&Rch1-2
• 【0705】lec7+8.1, lab2
• 【0706】disc2
• 【0715】lec8-10
• 【0716】lab3
• 【0719】disc3, disc4
• 【0724】proj2 partA 50%
• 【0725】proj2 partA fin
• 【0801】lec11-13
• 【0802】disc5, lab4, lec14-15
• 【0803】lecs16+SDS State Logic handouts, lec17
• 【0804】lab5, lec 18-19
• 【0805】lec20-27 (fin CPU Pipelining Caches), disc6-8
• 【0806】disc9, lab7, lec28-2931 (fin OS VMi)
• 【0807】lec30-31(VMii I/O), disc10, lab8, disc11
• 【0808】lec32-35 (SIMD/MIMD, Parallelism), lec36-38 (MapReduce, WSC, RAID)
• 【0809】disc12, lab9, lab10, disc13-14
• 【skipped due to compatibility probs】proj4, proj3, lab6, lab11

Postscript

should’ve been preparing for the incoming semester, projects and stuff but couldn’t resist the temptation of learning how computer works :>

Last modified on 2023-08-11