1.
Optimizing software in C++
An optimization guide for Windows, Linux, and Mac
platforms
By Agner Fog. Technical University of Denmark.
Copyright © 2004 - 2021. Last updated 2021-08-11.
Contents
1 Introduction ....................................................................................................................... 3
1.1 Why software is often slow .......................................................................................... 4
1.2 The costs of optimizing ............................................................................................... 4
2 Choosing the optimal platform ........................................................................................... 5
2.1 Choice of hardware platform ....................................................................................... 5
2.2 Choice of microprocessor ........................................................................................... 6
2.3 Choice of operating system ......................................................................................... 7
2.4 Choice of programming language ............................................................................... 8
2.5 Choice of compiler .................................................................................................... 10
2.6 Choice of function libraries ........................................................................................ 11
2.7 Choice of user interface framework ........................................................................... 13
2.8 Overcoming the drawbacks of the C++ language ...................................................... 14
3 Finding the biggest time consumers ................................................................................ 15
3.1 How much is a clock cycle? ...................................................................................... 15
3.2 Use a profiler to find hot spots .................................................................................. 16
3.3 Program installation .................................................................................................. 18
3.4 Automatic updates .................................................................................................... 18
3.5 Program loading ....................................................................................................... 19
3.6 Dynamic linking and position-independent code ....................................................... 19
3.7 File access ................................................................................................................ 19
3.8 System database ...................................................................................................... 20
3.9 Other databases ....................................................................................................... 20
3.10 Graphics ................................................................................................................. 20
3.11 Other system resources .......................................................................................... 20
3.12 Network access ...................................................................................................... 21
3.13 Memory access ....................................................................................................... 21
3.14 Context switches ..................................................................................................... 21
3.15 Dependency chains ................................................................................................ 21
3.16 Execution unit throughput ....................................................................................... 22
4 Performance and usability ............................................................................................... 22
5 Choosing the optimal algorithm ....................................................................................... 24
6 Development process ...................................................................................................... 25
7 The efficiency of different C++ constructs ........................................................................ 25
7.1 Different kinds of variable storage ............................................................................. 25
7.2 Integers variables and operators ............................................................................... 29
7.3 Floating point variables and operators ...................................................................... 31
7.4 Enums ...................................................................................................................... 33
7.5 Booleans ................................................................................................................... 33
7.6 Pointers and references ............................................................................................ 35
7.7 Function pointers ...................................................................................................... 37
7.8 Member pointers ....................................................................................................... 37
7.9 Smart pointers .......................................................................................................... 38
7.10 Arrays ..................................................................................................................... 38
剩余175页未读，继续阅读
资源评论
