В Чт, 27/09/2018 в 15:45 +0200, Hanno Böck пишет: > On Fri, 21 Sep 2018 00:16:48 +0100 > Luis Ressel <ara...@aixah.de> wrote: > > > On Wed, 19 Sep 2018 09:24:27 +0200 > > Hanno Böck <ha...@hboeck.de> wrote: > > > > > If the flag just disables assembly optimizations then I wonder if > > > it > > > should be renamed (or if we need it at all - in case these > > > assembly > > > optimizations have no downsides). > > > > Many (all?) of the ebuilds with this flag do indeed only disable > > assembly snippets, and most of them only do this on 32-bit x86 > > (gzip > > being the prominent exception). > > And ffmpeg and mesa. > > In ffmpeg the flag description says: > "Force shared libraries to be built as PIC (this is slower)" > > Which confuses me - I thought shared libraries are always PIC. > > It looks to me these are all historic leftovers, but I'd like to > understand it better before I open bugs asking for removal of these > flags.
IIRC the main issue was a limited general purpose register set on x86 architecture. https://wiki.gentoo.org/wiki/Hardened/Toolchain#Issues_with_PIEs "Occasionally application code will fail to compile with -fPIE. If this happens it is usually down to non-position-independent assembler code, and is most prevelant on X86 which has a limited general purpose register set." I guess a lot of programs was fixed since then. For example currently I don't see any problems when building mesa with USE=-pic on x86_32.
