These determine the assumed/default size of instruction operands, and restricts which opcodes are available, and how they are used.
Modern operating systems, booted inside Real
mode,
// Just before switching jobs: | |
// Add one of these. | |
// Preferably into the same commit where you do a large merge. | |
// | |
// This started as a tweet with a joke of "C++ pro-tip: #define private public", | |
// and then it quickly escalated into more and more evil suggestions. | |
// I've tried to capture interesting suggestions here. | |
// | |
// Contributors: @r2d2rigo, @joeldevahl, @msinilo, @_Humus_, | |
// @YuriyODonnell, @rygorous, @cmuratori, @mike_acton, @grumpygiant, |
Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.
$ python -m SimpleHTTPServer 8000
L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns
Compress 1K bytes with Zippy ............. 3,000 ns = 3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns = 20 µs
SSD random read ........................ 150,000 ns = 150 µs
Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs