Allan McRae <allan@archlinux.org> on Mon, 2016/09/19 19:34:
On 19/09/16 19:05, Christian Hesse wrote:
Bartłomiej Piotrowski <bpiotrowski@archlinux.org> on Fri, 2016/09/16 21:44:
Actually, why don't raise the bar higher? SSE2 has been introduced in 2001 – that's 15 years to upgrade one's hardware and given my sad experiences with computers, I find it hard to believe anyone has that old PC that happens to run Arch.
I do. Running Arch Linux on a bunch of informational room displays... These are based on Geode CPUs and I am pretty sure no SSE2 is available. (Taking a look at /proc/cpuinfo these devices do not even feature SSE... The CPU identifies itself as i586.)
This is buggy hardware... SSE is available ('gcc -O3 -msse -mno-sse2' produces functional output), SSE2 is not ('gcc -O3 -msse2' breaks with illegal instruction).
That said I will be able to handle that myself. ;) Possibly I will have to do local rebuilds of webkitgtk2 to make surf run on these devices from time to time.
If we adopt SSE2 in any form, you will need to rebuild your entire system to use it. It will be used in optimizations everywhere.
Well, that could cause some headache for me... :-p In the end it depends on what code is optimized by gcc. Would SSE2 code be used by that much packages? We could just keep i686 as-is for maximum compatibility. Let's take a realistic look at the things: Most users run i686, so why bother and optimize i686 - just to save some CPU cycles for a minority? (I would even wast CPU cycle rebuilding a bunch of packages... pacman tells me the effected boxes have 399 packages installed.) So better raise requirements for x86_64. All x86_64 (and most overall) users will benefit. Older AMD CPUs (or really old Intel ones?) without SSE4 could still run i686 then - so nobody is forced to run anything else than Arch Linux. ;) -- main(a){char*c=/* Schoene Gruesse */"B?IJj;MEH" "CX:;",b;for(a/* Best regards my address: */=0;b=c[a++];) putchar(b-1/(/* Chris cc -ox -xc - && ./x */b/42*2-3)*42);}