2014-05-09 13:24 GMT-04:00 Rik Cabanier <caban...@gmail.com>: > > > > On Fri, May 9, 2014 at 10:14 AM, Benoit Jacob <jacob.benoi...@gmail.com>wrote: > >> Totally agree that 1% is probably still too much to drop, but the 4x drop >> over the past two years makes me hopeful that we'll be able to drop >> non-SSE2, eventually. >> >> SSE2 is not just about SIMD. The most important thing it buys us IMHO is >> to >> be able to not use x87 instructions anymore and instead use SSE2 (scalar) >> instructions. That removes entire classes of bugs caused by x87 being >> non-IEEE754-compliant with its crazy 80-bit registers. >> > > Out of interest, do you have links to bugs for this issue? >
No: there are the bugs we probably have but don't know about; and there are the things that we caught in time and caused us to give up on approaches before they would become patches... I don't have an example of a bug we found after the fact. > > Also, can't you ask the compiler to produce both sse and non-sse code and > make a decision at runtime? > Not that I know of. At least GCC documentation does no list anything about that here, http://gcc.gnu.org/onlinedocs/gcc/i386-and-x86-64-Options.html -mfpmath=both or -mfpmath=sse+387 does not seem to be doing that; instead it seems to be about using both in the same code path. Benoit > > >> 2014-05-09 13:01 GMT-04:00 Chris Peterson <cpeter...@mozilla.com>: >> >> > What does requiring SSE2 buy us? 1% of hundreds of millions of Firefox >> > users is still millions of people. >> > >> > chris >> > >> > >> > >> > On 5/8/14, 5:42 PM, matthew.br...@gmail.com wrote: >> > >> >> On Tuesday, January 3, 2012 4:37:53 PM UTC-8, Benoit Jacob wrote: >> >> >> >>> 2012/1/3 Jeff Muizelaar <jmuizel...@mozilla.com>: >> >>> >> >>> >> >>>> >> >>> On 2012-01-03, at 2:01 PM, Benoit Jacob wrote: >> >>>> >> >>> >> >>> >> >>>> >> >>> 2012/1/2 Robert Kaiser <ka...@kairo.at>: >> >>>> >> >>> >> >>> >> >>>> >> >>> Jean-Marc Desperrier schrieb: >> >>>> >> >>> >> >>> >> >>>> >> >>> >> >>>> >> >>> According to https://bugzilla.mozilla.org/show_bug.cgi?id=594160#c6, >> >>>> >> >>> >> >>> >> >>>> >> >>> the Raw Dump tab on crash-stats.mozilla.com shows the needed >> >>>> >> >>> >> >>> >> >>>> >> >>> information, you need to sort out from the info on the second line >> CPU >> >>>> >> >>> >> >>> >> >>>> >> >>> maker, family, model, and stepping information whether SSE2 is there >> or >> >>>> >> >>> >> >>> >> >>>> >> >>> not (With a little search, I can find that info again, bug 593117 >> gives >> >>>> >> >>> >> >>> >> >>>> >> >>> a formula that's correct for most of the cases). >> >>>> >> >>> >> >>> >> >>>> >> >>> >> >>>> >> >>> >> >>>> >> >>> https://crash-analysis.mozilla.com/crash_analysis/ holds >> >>>> >> >>> >> >>> >> >>>> >> >>> *-pub-crashdata.csv.gz files that have that info from all Firefox >> >>>> >> >>> >> >>> >> >>>> >> >>> desktop/mobile crashes on a given day, you should be able to analyze >> >>>> that >> >>>> >> >>> >> >>> >> >>>> >> >>> for this info - with a bias, of course, as it's only people having >> >>>> crashes >> >>>> >> >>> >> >>> >> >>>> >> >>> that you see there. No idea if the less biased telemetry samples have >> >>>> that >> >>>> >> >>> >> >>> >> >>>> >> >>> info as well. >> >>>> >> >>> >> >>> >> >>>> >> >>> >> >>>> >> >>> On yesterday's crash data, assuming that AuthenticAMD\ family\ >> >>>> >> >>> >> >>> [1-6][^0-9] is the proper way to identify these old AMD CPUs (I >> >>>> >> >>> >> >>> didn't check that very well), I get these results: >> >>>> >> >>> >> >>> >> >>>> >> >>> >> >>>> >> >>> The measurement I have used in the past was: >> >>>> >> >>> >> >>> >> >>>> >> >>> CPUs have sse2 if: >> >>>> >> >>> >> >>> >> >>>> >> >>> if vendor == AuthenticAMD and family >= 15 >> >>>> >> >>> >> >>> if vendor == GenuineIntel and family >= 15 or (family == 6 and (model >> >>>> == 9 >> >>>> >> >>> >> >>> or model > 11)) >> >>>> >> >>> >> >>> if vendor == CentaurHauls and family >= 6 and model >= 10 >> >>>> >> >>> >> >>> >> >>>> >> >>> >> >>> >> >>> Thanks. >> >>> >> >>> >> >>> >> >>> AMD and Intel CPUs amount to 296362 crashes: >> >>> >> >>> >> >>> >> >>> bjacob@cahouette:~$ egrep AuthenticAMD\|GenuineIntel >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 296362 >> >>> >> >>> >> >>> >> >>> Counting SSE2-capable CPUs: >> >>> >> >>> >> >>> >> >>> bjacob@cahouette:~$ egrep GenuineIntel\ family\ 1[5-9] >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 58490 >> >>> >> >>> bjacob@cahouette:~$ egrep GenuineIntel\ family\ [2-9][0-9] >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 0 >> >>> >> >>> bjacob@cahouette:~$ egrep GenuineIntel\ family\ 6\ model\ 9 >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 792 >> >>> >> >>> bjacob@cahouette:~$ egrep GenuineIntel\ family\ 6\ model\ 1[2-9] >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 52473 >> >>> >> >>> bjacob@cahouette:~$ egrep GenuineIntel\ family\ 6\ model\ [2-9][0-9] >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 103655 >> >>> >> >>> bjacob@cahouette:~$ egrep AuthenticAMD\ family\ 1[5-9] >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 59463 >> >>> >> >>> bjacob@cahouette:~$ egrep AuthenticAMD\ family\ [2-9][0-9] >> >>> >> >>> 20120102-pub-crashdata.csv | wc -l >> >>> >> >>> 8120 >> >>> >> >>> >> >>> >> >>> Total SSE2 capable CPUs: >> >>> >> >>> >> >>> >> >>> 58490 + 792 + 52473 + 103655 + 59463 + 8120 = 282993 >> >>> >> >>> >> >>> >> >>> 1 - 282993 / 296362 = 0.045 >> >>> >> >>> >> >>> >> >>> So the proportion of non-SSE2-capable CPUs among crash reports is 4.5 >> %. >> >>> >> >> >> >> Just for the record, I coded this analysis up here: >> >> https://gist.github.com/matthew-brett/9cb5274f7451a3eb8fc0 >> >> >> >> SSE2 apparently now at about one percent: >> >> >> >> 20120102-pub-crashdata.csv.gz: 4.53 >> >> 20120401-pub-crashdata.csv.gz: 4.24 >> >> 20120701-pub-crashdata.csv.gz: 2.77 >> >> 20121001-pub-crashdata.csv.gz: 2.83 >> >> 20130101-pub-crashdata.csv.gz: 2.66 >> >> 20130401-pub-crashdata.csv.gz: 2.59 >> >> 20130701-pub-crashdata.csv.gz: 2.20 >> >> 20131001-pub-crashdata.csv.gz: 1.92 >> >> 20140101-pub-crashdata.csv.gz: 1.86 >> >> 20140401-pub-crashdata.csv.gz: 1.12 >> >> >> >> Cheers, >> >> >> >> Matthew >> >> >> >> >> > _______________________________________________ >> > dev-platform mailing list >> > dev-platform@lists.mozilla.org >> > https://lists.mozilla.org/listinfo/dev-platform >> > >> _______________________________________________ >> dev-platform mailing list >> dev-platform@lists.mozilla.org >> https://lists.mozilla.org/listinfo/dev-platform >> > > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
