GCC/Make Build Time Optimizations

Question

We have project which uses gcc and make files. Project also contains of one big subproject (SDK) and a lot of relatively small subprojects which use that SDK and some shared fra

Answer 1

The best I can think of with make is the -j option. This tells make to run as many jobs as possible in parallel:

make -j

If you want to limit the number of concurrent jobs to n you can use:

make -j n

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Make sure the dependencies are correct so make doesn't run jobs it doesn't have to.

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Another thing to take into account is optimizations that gcc does with the -O switch. You can specify various levels of optimization. The higher the optimization, the longer the compile and link times. A project I work with runs takes 2 minutes to link with -O3, and half a minute with -O1. You should make sure you're not optimizing more than you need to. You could build without optimization for development builds and with optimization for deployment builds.

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Compiling with debug info (gcc -g) will probably increase the size of your executable and may impact your build time. If you don't need it, try removing it to see if it affects you.

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The type of linking (static vs. dynamic) should make a difference. As far as I understand static linking takes longer (though I may be wrong here). You should see if this affects your build.