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...ly moves the files and updates all references. We'd like to hear if there are any things comments/objections to this change. Thanks ! *note: We did this before llvm-mca was released and were using a different simulator, but the idea remains the same. On Wed, Dec 12, 2018 at 11:44 AM Clement Courbet <courbet at google.com> wrote: > Hi all, > > tl;dr: We'd like to propose moving tools/llvm-mca/lib into lib/MCA and > create a new MCA library in LLVM. > > llvm-mca has recently been split > <https://bugs.llvm.org/show_bug.cgi?id=37696> into its core part and t...

On Thu, Jan 10, 2019 at 4:47 PM Clement Courbet <courbet at google.com> wrote: > > > On Wed, Jan 9, 2019 at 6:16 PM James Y Knight <jyknight at google.com> wrote: > >> >> >> On Tue, Jan 8, 2019 at 9:24 AM Clement Courbet <courbet at google.com> >> wrote: >> >>> >>> &g...

...ils. I don't think the function attribute works here because we want this to be globally enabled instead of per-function (but maybe I misunderstood what you were suggesting). On Thu, Jan 3, 2019 at 6:40 PM Finkel, Hal J. <hfinkel at anl.gov> wrote: > > On 1/3/19 3:29 AM, Clement Courbet via llvm-dev wrote: > > Hi all, > > We'd like to suggest *adding a -memeq-lib-function* flag to allow the > user to specify a `*memeq()*` function to improve string equality check > performance. > > Hi, Clement, > > We really shouldn't be adding backend flags f...

On Tue, Jan 8, 2019 at 9:24 AM Clement Courbet <courbet at google.com> wrote: > > > On Mon, Jan 7, 2019 at 10:26 PM James Y Knight <jyknight at google.com> > wrote: > I'm afraid about the "almost" and "generally": what about users who don't ? > Even so, it should be fine to enable it f...

...l deps. Right now if the tool is enabled and libpfm is not on the system, we die with an error message. The other options would be to disable the tool in that case (I'm not sure how to do that). Opinions ? > > -Hal > > -- > Guillaume Chatelet (gchatelet at google.com), Clement Courbet ( > courbet at google.com) for the Google Compiler Research Team > > > > _______________________________________________ > LLVM Developers mailing listllvm-dev at lists.llvm.orghttp://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev > > > -- > Hal Finkel > Lead, Com...

On Mon, Jan 7, 2019 at 5:50 AM Clement Courbet <courbet at google.com> wrote: > On Fri, Jan 4, 2019 at 12:34 PM James Y Knight via llvm-dev < >> llvm-dev at lists.llvm.org> wrote: >> >>> This seems a somewhat odd and overcomplicated way to go about this. >>> >>> Given that bcmp was required...

...ions. - [??] Make the tool work for other CPUs. This mainly depends on the presence of performance counters. Open QuestionsWe depend on libpfm <http://perfmon2.sourceforge.net/docs_v4.html>. How do we handle the dependency ? -- Guillaume Chatelet (gchatelet at google.com), Clement Courbet ( courbet at google.com) for the Google Compiler Research Team -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180315/cdc319d2/attachment.html>

Hi everyone, Can someone help me with running llvm-exegesis tool on x86_64? I saw that I need libpfm library, but I'm still getting segmentation fault when I try to run the tool. Is there anything else I need to do (build llvm on some specific way) ? This is how I tried to run this tool: llvm-exegesis -mode=latency -opcode-name=ADD64rr Thanks, Luka -------------- next part -------------- An

...f it exists? > > Of course, it would then also be a good idea to go back to POSIX and > present the performance numbers to make a case for why it was actually a > quite valuable function and should be reinstated into the standard as well. > > On Thu, Jan 3, 2019 at 4:30 AM Clement Courbet via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> Hi all, >> >> We'd like to suggest *adding a -memeq-lib-function* flag to allow the >> user to specify a `*memeq()*` function to improve string equality check >> performance. >> >> Rig...

...How do we handle the dependency ? Are there options that you have in mind? It's an external MIT-licensed dependency. Wouldn't CMake just detect it when it's available?  -Hal > -- > Guillaume Chatelet (gchatelet at google.com > <mailto:gchatelet at google.com>), Clement Courbet (courbet at google.com > <mailto:courbet at google.com>) for the Google Compiler Research Team > > > > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev...

On 03/15/2018 10:49 AM, Clement Courbet wrote: > > > On Thu, Mar 15, 2018 at 4:41 PM, Hal Finkel via llvm-dev > <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > > > On 03/15/2018 10:04 AM, Guillaume Chatelet via llvm-dev wrote: >> [You can find an easier to read and...

...esence of performance counters. > > > Open Questions > > We depend on libpfm <http://perfmon2.sourceforge.net/docs_v4.html>. > How do we handle the dependency ? > -- > Guillaume Chatelet (gchatelet at google.com > <mailto:gchatelet at google.com>), Clement Courbet (courbet at google.com > <mailto:courbet at google.com>) for the Google Compiler Research Team > > > > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev...

Since the option of running -mode=inverse_throughput was added to llvm-exegesis the names of classes like UopsSnippetGenerator and UopsBenchmarkRunner, that this mode shares with uops, started to be less descriptive. Inverse_throughput doesn't use the uops counters, so for example, the instruction layout shared between these two modes is really connected to parallelism, not uops. It's

Hi all, We'd like to suggest *adding a -memeq-lib-function* flag to allow the user to specify a `*memeq()*` function to improve string equality check performance. Right now, when llvm encounters a *string equality check*, e.g. `if (memcmp(a, b, s) == 0)`, it tries to expand to an equality comparison if `s` is a small compile-time constant, and falls back on calling `memcmp()` else. This is

Hi all, I'm working on a new pass to optimize comparison chains. Motivation Clang currently generates inefficient code when dealing with contiguous member-by-member structural equality. Consider: struct A { bool operator==(const A& o) const { return i == o.i && j == o.j; } uint32 i; uint32 j; }; This generates: mov eax, dword ptr [rdi] cmp eax,

Hi all, In a recent IISWC paper <http://groups.csail.mit.edu/commit/papers/19/ithemal-measurement.pdf>, we've proposed BHive - a new methodology for benchmarking arbitrary basic blocks that has several advantages over the one currently used in llvm-exegesis. In particular, the new methodology: - automatically handles memory accesses in the basic block, without the need to manually

...itry Andric has [collected data](http://lists.llvm.org/pipermail/llvm-dev/2018-March/121871.html) on the size of Clang executables and the time taken to compile Clang since October 2015. Since then, total executable size grew by 43% and build time increased by 60%. * Guillaume Chatelet and Clement Courbet have posted an [RFC on llvm-exegesis](http://lists.llvm.org/pipermail/llvm-dev/2018-March/121814.html), a tool to automatically determine instruction scheduling properties (such as latency and the number of micro-ops). Feedback has been very positive so far, and Clement [explained](http://lists.llv...

...aid. I believe the intrinsics are a better design to support many architectures. IACA users are probably decorating their code with IACA_START / IACA_END macros. One possibility is to provide a header that define these macros in terms of the new intrinsics. On Mon, Dec 10, 2018 at 3:59 PM Clement Courbet <courbet at google.com> wrote: > Hi Matt/Andrea, > > I see pros and cons for IACA-style markers vs intrinsics. > On the one hand, IACA-style markers are very magical, and not very visible > in both the source and object code. Using IACA-style markers has the > advantage tha...

...support many architectures. >> >> IACA users are probably decorating their code with IACA_START / IACA_END >> macros. One possibility is to provide a header that define these macros in >> terms of the new intrinsics. >> >> On Mon, Dec 10, 2018 at 3:59 PM Clement Courbet <courbet at google.com> wrote: >> >>> Hi Matt/Andrea, >>> >>> I see pros and cons for IACA-style markers vs intrinsics. >>> On the one hand, IACA-style markers are very magical, and not very visible >>> in both the source and object code. Usi...

Hi Andrea, Thanks for this great RFC ! I've put some high-level comments here, and I'll give more focused comments in the review on Phabricator. On Thu, Mar 1, 2018 at 6:22 PM, Andrea Di Biagio <andrea.dibiagio at gmail.com> wrote: > Hi all, > > At Sony we developed an LLVM based performance analysis tool named > llvm-mca. We > currently use it internally to