similar to: [LLVMdev] Branch transformation with branch-weight metadata

On Fri, Apr 22, 2016 at 10:39 AM, Philip Reames <listmail at philipreames.com> wrote: > > > On 04/22/2016 09:20 AM, Sanjay Patel via llvm-dev wrote: > > I've proposed removing the llvm.expect intrinsic: > http://reviews.llvm.org/D19300 > > The motivation for this change is in: > http://reviews.llvm.org/D19299 > > For reference: > 1. We created an

I've proposed removing the llvm.expect intrinsic: http://reviews.llvm.org/D19300 The motivation for this change is in: http://reviews.llvm.org/D19299 For reference: 1. We created an intrinsic that's only reason for existing is to improve perf, but the intrinsic can harm optimization by interfering with transforms in other passes. 2. To solve that, we created a pass to always transform

I, of course, thought the ~100 lines added by D19299 was a reasonable trade for the ~800 lines removed in D19300. David Li (and anyone else following along), do you still like those patches after hearing this objection or should I abandon? On Fri, Apr 22, 2016 at 11:55 AM, Reid Kleckner <rnk at google.com> wrote: > Sorry, I didn't realize that was the clang side. > > I think

Hi Reid - The intent of D19299 is to remove all Clang refs to llvm.expect. Do you see any holes after applying that patch? On Fri, Apr 22, 2016 at 11:36 AM, Reid Kleckner <rnk at google.com> wrote: > Clang still appears to use llvm.expect. I think if you can show that it's > trivial to update clang with a patch, then yeah, moving back down to one > representation for this

Sorry for jumping in so late into this discussion, but I genuinely believe that removing this is a bad idea. My reason for saying this is going to sound very strange, but I think that we need to understand a bit more about how this is being handled. A while back one of my customers asked me if there was a method for advising the compiler how an if-statement was likely to resolve, and I

Hi everyone, I am looking at a way to mark part of a source code for an optimisation pass (or how to transfert information from source code to IR). I want to work on C / C++ / Objective-c and Swift. Something like: ... //Begin Optimisation if(i % 2){ printf(“Something”); } //End Optimisation for(int i = 0; i < 10; ++i){ printf("%d, “, i); } printf("\n”); … I have found

If I read the llvm language correctly, it doesn't have a way to specify the preferred branch, correct ? I see nothing in the specs for "branch" or "switch". And __buildin_expect does nothing, that I am sure of. Unfortunately llvm has this knack for ordering my one most crucial part of code exactly the opposite I want to, it does: (x86_64) cmpq %r15, (%rax,%rdx) jne

Doesn't llvm-gcc support GCC's builtin_expect? Or does it transform it into nothing? On Wed, Oct 22, 2008 at 6:28 PM, Paul Biggar <paul.biggar at gmail.com> wrote: > Hi, > > I'm interested in whether or not there is a way of providing > source-level annotations to help LLVM with optimizations, similar to > VisualC++'s __assume facility >

On Sun, Jul 15, 2012 at 8:32 AM, Alastair Murray <alastairmurray42 at gmail.com > wrote: > Hi Chandler, > > I'm a GSoC student working on profiling support (mentor CC'ed). I'm no > stranger to the issues with the current system: my original proposal was > written without knowledge of the limitations. This is why this list > hasn't heard much from me yet.

Hi all, In light of the expected removal of ProfileInfo this is a request for comments on the next few items that I now plan to work on for GSoC. Planned tasks: #0 Add support for determining branch weight metadata by profiling At the absolute minimum this will require writing a new profile loader which will set branch weight metadata based on profiling data. #1 Optionally use profiling

Hi Chandler, I'm a GSoC student working on profiling support (mentor CC'ed). I'm no stranger to the issues with the current system: my original proposal was written without knowledge of the limitations. This is why this list hasn't heard much from me yet. I would like to continue working on profiling support but I'm not attached to ProfileInfo and wouldn't be

Hi, I'm interested in whether or not there is a way of providing source-level annotations to help LLVM with optimizations, similar to VisualC++'s __assume facility (http://msdn.microsoft.com/en-us/library/1b3fsfxw.aspx). As part of our PHP compiler (phpcompiler.org), it would be great to be able to annotate our generated C code with, for example, (var != NULL), or (var->type ==

Hi, extractRangeChecksFromBranch uses BranchProbabilityInfo to decide whether its worth trying the InductiveRangeCheckElimination transformation. For the following example: void split() { for (int i = 0; i < 100; ++i) { if (i < 99) do_something() else do_something_else() } } But the reported BPI is reported as 50/50 to whether do_something will be called, but we

Greetings - I don't think this is a bug; just something I don't understand. I'm using RedHat Linux v7.0 with an i686 processor. I've been using openssl v0.9.5a with openssh v2.2.1 I've upgraded to openssl v0.9.6b and openssh v2.9.p2 I've built both packages with the '--prefix=/usr' option. During the openssh 'make install' at 'host-key' I get

Hi, I've actually run R quite a bit in Windows. I've had a release 8.04 of Ubuntu running a laptop for 3 days now. After struggling for much of that time to install R, I finally figured out that Dell shipped with the sources.list obsolete or just plain wrong. So I finally got it installed last night (for some reason v2.6.2, not v2.9.x). This morning I was able to download and install

Hello folks, I'd like to remove all of the old and defunct profile info passes from LLVM. These have been almost entirely supplanted by the BranchProbability and BlockFrequency systems, which are actually on by default, and in use in optimization passes. The old system is not on, and hasn't been touched in years except to do minor build fixes and updates. As far as I'm aware, the

What would you recommend: ansible is in EPEL8 and ConfigSIG. For the latter I do not see any sources in git.centos.org. Where they come from? I wonder with which repository I should use (long term)? dnf not checking gpg signature sounds scary: https://github.com/ansible/ansible/blob/v2.9.13/changelogs/CHANGELOG-v2.9.rst#security-fixes -- Leon

I am stuck trying to adapt my out-of-target implementation to build on SVN head (actually the v3.8 branch, rev #257626). This is currently working on the v3.7.1 sources, but the changes to 'llvm::ScheduleDAGInstrs' have me stumped as to how to revise my implementation to track the changes to this class. Our 'SHAVEAsmScheduler' derives from 'ScheduleDAGInstrs' and uses

Does anyone know if there is any document from SAMBA team states that the SAMBA software is Y2k ready ? If yes, where is it I can download it or what is the version requirement ? Thanks ! Stephen Wu Output Management Services Tel: (248)696-1413 [8-366] Fax: (248)696-1804 [8-366] Mailto:Stephen.Wu-eds@eds.com

Adding Maxim On Apr 9, 2018, at 10:06 AM, Sam Parker via llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote: Hi, extractRangeChecksFromBranch uses BranchProbabilityInfo to decide whether its worth trying the InductiveRangeCheckElimination transformation. For the following example: void split() { for (int i = 0; i < 100; ++i) { if (i < 99)