How long to compile

Improve this answer. Thanks for documenting this. It's very useful to have a reference! You can accept your own answer as the solution to your question to pass the message that your query was answered : — goncalotomas. Mine takes 4 hours and 20 minutes, single thread with 16 concurrent compiling tasks Ryzen 7 X. Hi, do you remember how long it took to download the prerequisites?

I ran. It just seems to be stuck. How do I know if things are even getting downloaded? I'm working behind a proxy so I'm not sure.

Helpful to see this while waiting for libgcc7 to compile on an old PowerPC Mac mini, which took about 13 hours! Add a comment. The Overflow Blog. Does ES6 make JavaScript frameworks obsolete? Yes, there are mitigations, like forward declaration, which has perceived downsides , or the pimpl idiom , which is a nonzero cost abstraction.

The worst part: If you think about it, the need to declare private functions in their public header is not even necessary: The moral equivalent of member functions can be, and commonly is, mimicked in C, which does not recreate this problem. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more.

Ask Question. Asked 12 years, 11 months ago. Active 1 year, 2 months ago. Viewed k times. Improve this question. Martin Broadhurst 8, 2 2 gold badges 26 26 silver badges 34 34 bronze badges.

Dan Goldstein Dan Goldstein Using them will help. A lot. Yes in my case mostly C with a few classes - no templates precompiled headers speed up about 10x — Lothar. Certainly that is twice as long, but hardly significant. Or do you mean 10 minutes compared to 5 seconds?

Please quantify. OT: use ccache to speed up :- — pevik. I hope to see a good package manager with artifactory integration after the modules — Abdurrahim.

Show 9 more comments. Active Oldest Votes. Several reasons Header files Every single compilation unit requires hundreds or even thousands of headers to be 1 loaded and 2 compiled. Linking Once compiled, all the object files have to be linked together. Parsing The syntax is extremely complicated to parse, depends heavily on context, and is very hard to disambiguate.

Conclusion Most of these factors are shared by C code, which actually compiles fairly efficiently. Improve this answer. It's definitely the frontend that causes the slowdown, and not the code generation. Redundant definitions are eliminated by the linker. Inline functions or anything else defined in headers will be recompiled everywhere it's included. But yeah, that's especially painful with templates. Not sure if optimization is the problem, since our DEBUG builds are actually slower than the release mode builds.

The pdb generation is also a culprit. Show 22 more comments. Peter Mortensen 29k 21 21 gold badges 97 97 silver badges bronze badges. James Curran James Curran Well, file access sure has a hand in this but as jalf said, the main reason for this will be something else, namely the repeated parsing of many, many, many nested!

It is at that point that your friend needs to set up precompiled headers, break dependancies between different header files try to avoid one header including another, instead forward declare and get a faster HDD.

That aside, a pretty amazing metric. If the whole header file except possible comments and empty lines is within the header guards, gcc is able to remember the file and skip it if the correct symbol is defined. Parsing is a big deal. Putting all text into a single file is cutting down that duplicate parsing. Small side note: The include guards guard against multiple parsings per compilation unit.

Not against multiple parsings overall. Show 3 more comments. The slowdown is not necessarily the same with any compiler. It's interesting to compare Pascal, since Niklaus Wirth used the time it took the compiler to compile itself as a benchmark when designing his languages and compilers. There is a story that after carefully writing a module for fast symbol lookup, he replaced it with a simple linear search because the reduced code size made the compiler compile itself faster.

DietrichEpp Empiricism pays off. Add a comment. Dave Ray Dave Ray CesarB: It still has to process it in full once per compilation unit. Python is an interpreted language that is also compiled into byte-code. Alan Alan The cost added by pre-processing is trivial. The major "other reason" for a slowdown is that compilation is split into separate tasks one per object file , so common headers get processed over and over again.

You could tell from the same argumentation that C, Pascal etc. C is slow. It suffers from the same header parsing problem as is the accepted solution. The steps are roughly as follows: Configuration Build tool startup Dependency checking Compilation Linking We will now look at each step in more detail focusing on how they can be made faster.

Configuration This is the first step when starting to build. Build tool startup This is what happens when you run make or click on the build icon on an IDE which is usually an alias for make. Dependency checking Once the build tool has read its configuration, it has to determine what files have changed and which ones need to be recompiled.

Compilation At this point we finally invoke the compiler. Ravindra Acharya Ravindra Acharya 3 3 silver badges 3 3 bronze badges. The biggest issues are: 1 The infinite header reparsing. Marco van de Voort Marco van de Voort Nemanja Trifunovic Nemanja Trifunovic For example: include "BigClass.

Andy Brice Andy Brice 2, 1 1 gold badge 21 21 silver badges 27 27 bronze badges. Especially true if BigClass happens to include 5 more files that it uses, eventually including all the code in your program. This is perhaps one reason. This is not because gcc:s optimization take longer but rather that Pascal is easier to parse and don't have to deal with a preprocessor. Also see Digital Mars D compiler. If you are using the pdftex engine, you can measure the time that each package takes to be loaded by adding the following near the start of your document.

This is the cumulative for all the runs needed to resolve references, etc. For more detailed usage, there is a timing module, which gives a graphical output of the resources used per page. TeX , LaTeX and all its distributives offer at least since version 3 a compilation command -time-statistics.

You can find a list of compilation options and commands, by opening a command line and execute latex --help. Not sure though, wether and how one may invoke this compilation command directly from. Besides, here's what its execution looks like:. You need to download timeit from Windows Resource Kit. Then run in Windows command line:. It will output the time of each pass of the TeX-engine as well as the accumulated total time to generate all the documents.

For example, the command. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Is there a way to find out how long it took for my document to compile? Ask Question. Asked 10 years, 2 months ago. Active 1 year, 9 months ago. Viewed 3k times. Improve this question. Zev Chonoles Zev Chonoles 5, 5 5 gold badges 27 27 silver badges 52 52 bronze badges.

Related question: how to determine the run time of a loop — Peter Grill. Add a comment. Active Oldest Votes. Improve this answer. Alan Munn Alan Munn k 38 38 gold badges silver badges bronze badges. Thanks for your answer! But I suppose this is good motivation to figure that out : When you say "modify the latex command", how would I do that in something like TeXnicCenter?