On Tue, Aug 8, 2017 at 4:47 AM, Adam Borowski <kilob...@angband.pl> wrote: > On Sat, Aug 05, 2017 at 10:28:36PM +0200, Adam Borowski wrote: >> It's easy to quite reliably detect the presence of such instructions >> (probably no one JITs such code). There's no real way to check if it's >> executed unconditionally, though -- a lot of software has optimized code >> paths that are chosen at runtime. >> >> I guess we could apply such check to the archive: for example, if any of >> these instructions are present in a code section: [snip] >> then the program may need sse2. But there's no good way to weed out false >> positives automatically, so all we'd get is a list of candidates to check. > > I went through the whole archive and disassembled all binaries in unstable > in amd64 and i386 (not sure where to get a good list of neon instructions > for armhf) -- results attached, and so is the script for analyzing a > package[1]. > > Alas, there's way too many false positives to turn this into a lintian > check. There's 254 amd64 and 409 i386 sources which produce executables > that include those instructions (I ignored other ISA extensions for now), > most of them use proper runtime detection. So unless someone can propose > a better check, they'd need to be tested by hand.
I will prefer to implement it on lintian. Even if false positive. BTW could you print path ? Bastien > > And no, presence of cpuid is not enough -- for example chromium:i386 checks > it, yet requires sse2 (it even has proper runtime optimizations for sse4.2). > > > Meow! > > [1]. pkgext needs to have the path to ext edited; I didn't bother adding > fragile $0 logic. > -- > ⢀⣴⠾⠻⢶⣦⠀ > ⣾⠁⢰⠒⠀⣿⡁ James Damore is a hero. Even mild criticism of bigots these days > ⢿⡄⠘⠷⠚⠋⠀ comes at great personal risk. > ⠈⠳⣄⠀⠀⠀⠀
