> On Thu, Sep 17, 2020 at 9:39 AM Steffen Nurpmeso <stef...@sdaoden.eu> wrote: > > > Alex Richardson wrote in > > <202009171507.08hf7qns080...@repo.freebsd.org>: > > |Author: arichardson > > |Date: Thu Sep 17 15:07:25 2020 > > |New Revision: 365836 > > |URL: https://svnweb.freebsd.org/changeset/base/365836 > > | > > |Log: > > | Stop using lorder and ranlib when building libraries > > | > > | Use of ranlib or lorder is no longer necessary with current linkers > > | (probably anything newer than ~1990) and ar's ability to create an > > object > > | index and symbol table in the archive. > > | Currently the build system uses lorder+tsort to sort the .o files in > > | dependency order so that a single-pass linker can use them. However, > > | we can use the -s flag to ar to add an index to the .a file which makes > > | lorder unnecessary. > > | Running ar -s is equivalent to running ranlib afterwards, so we can > > also > > | skip the ranlib invocation. > > > > That ranlib thing yes (for long indeed), but i have vague memories > > that the tsort/lorder ordering was also meant to keep the things > > which heavily interdepend nearby each other. (Luckily Linux > > always had at least tsort available.) > > This no longer matters for all the platforms FreeBSD supports? > > > > tsort has no notion of how dependent the modules are, just an order that > allows a single pass through the .a file (otherwise you'd need to list the > .a file multiple times on the command line absent ranlib). That's the > original purpose of tsort. tsort, lsort, and ranlib all arrived in 7th > edition unix on a PDP-11, where size was more important than proximity to > locations (modulo overlays, which this doesn't affect at all). > > There were some issues of long vs short jumps on earlier architectures that > this helped (since you could only jump 16MB, for example). However, there > were workarounds for this issue on those platforms too. And if you have a > program that this does make a difference, then you can still use > tsort/lorder. They are still in the system. > > I doubt you could measure a difference here today. I doubt, honestly, that > anybody will notice at all.
The x86 archicture has relative jmps of differning lengths, even in long mode there is support for rel8 and rel32. > > Warner -- Rod Grimes rgri...@freebsd.org _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
