Rethinking Fedora's compiler policy [LWN.net]

Rethinking Fedora's compiler policy

Posted Apr 28, 2021 18:35 UTC (Wed) by mss (subscriber, #138799)
Parent article: Rethinking Fedora's compiler policy

Clang used to produce a binary that's slightly slower at run time than when the same code was built by GCC.
Is it sill true in 2021?

On the other hand, I can still see a significant advantage that Clang has over GCC in terms of build speed and compiler memory usage when compiling larger C++ codebases like Firefox/Thunderbird or Chromium.

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Rethinking Fedora's compiler policy

Posted Apr 28, 2021 20:24 UTC (Wed) by eru (subscriber, #2753) [Link] (1 responses)

You can probably get either result, depending on what you are compiling, and whether you have picked the best flags for that particular source and compiler. Comparing compilers fairly is hard.

Rethinking Fedora's compiler policy

Posted Apr 30, 2021 18:20 UTC (Fri) by JoeBuck (subscriber, #2330) [Link]

We are fortunate to have two strong compilers; the competition between them has made them both better.

As for what distros should do, I think library packages need to be built with one compiler, but for non-libraries it's less critical. However, it's always helped GCC that, before a new major version is released, someone or someones try building entire distros with the new compiler, to shake out bugs in both and to help produce the porting notes (sometimes additional strictness flags problems with code that built with the previous compiler release but perhaps shouldn't have).