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   keithp (keithp@fosstodon.org)'s status on Wednesday, 28-Jan-2026 23:58:33 JST keithp

   You know how I always say picolibc isn't a Linux C library because it doesn't do all of the fancy Linux stuff? Well, it turns out you don't need much to get a semi-functioning system.

   $ size test-hello-picolibc test-hello-glibc
   text data bss dec hex filename
   3632 144 4656 8432 20f0 test-hello-picolibc
   645697 23704 22576 691977 a8f09 test-hello-glibc

   I blame Kees Cook for nerd-sniping me on this one.

   https://github.com/picolibc/picolibc/tree/native-linux

   • James Morris likes this.
   • Embed this notice
     Rich Felker (dalias@hachyderm.io)'s status on Wednesday, 28-Jan-2026 23:58:32 JST Rich Felker

     in reply to

     @keithp With musl, gcc -Os -static hello.c, on stock Alpine x86_64:

     text data bss dec hex filename
     3893 344 1744 5981 175d a.out

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     keithp (keithp@fosstodon.org)'s status on Thursday, 29-Jan-2026 03:22:54 JST keithp

     in reply to

     • Rich Felker
     • The Penguin of Evil

     @etchedpixels @dalias yeah, gcc converts printf("hello world\n") into puts("hello world");

     That's one of the numerous optimizations present in "hosted" mode, which is why I always tell people to get rid of -ffreestanding when building with a full C library.

     Btw, on armhf, hello world is way smaller than on x86_64:

     $ size test-hello-armhf
     text data bss dec hex filename
     1520 76 4624 6220 184c test-hello-armhf

     James Morris likes this.
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     The Penguin of Evil (etchedpixels@mastodon.social)'s status on Thursday, 29-Jan-2026 03:22:55 JST The Penguin of Evil

     in reply to

     • Rich Felker

     @dalias @keithp

     Fuzix (standard C library, 8085 CPU, not even a fancy optimizing compiler)

     base text data bss size hex filename
     100 10c5 5c 318 5177 1439 a.out

     gcc on 6809 or HC11 is way way smaller but it turns out gcc seems to know to swap the printf call magically for something else in this case.

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   • Embed this notice
     James Morris (jmorris@social.kernel.org)'s status on Thursday, 29-Jan-2026 03:24:39 JST James Morris

     in reply to
     @keithp Impressive. Reminds me about those Rust binaries...
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     keithp (keithp@fosstodon.org)'s status on Thursday, 29-Jan-2026 05:36:10 JST keithp

     in reply to

     • Paul E. McKenney

     @paulmckrcu nolibc is awesome and you know it.

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     Paul E. McKenney (paulmckrcu@social.kernel.org)'s status on Thursday, 29-Jan-2026 05:36:11 JST Paul E. McKenney

     in reply to
     @keithp Then Linux-kernel tools/include/nolibc will provide you with even more irritation!!! ;-)