search for: machineschedulers

I think those should be considered internal options for (llvm codegen) developers, a normal compiler user should not need to use any of them. Of course you can look around the llvm sourcecode (esp. in lib/CodeGen/MachineScheduler.cpp) and see what cl::opt options are available and how they affect the scheduler operation. In case of the MachineScheduler all settings are the same regardless of the

...this is moving from llvm-commits to llvm-dev. On Feb 10, 2012, at 12:14 PM, Sergei Larin <slarin at codeaurora.org> wrote: > 1) Can a BB presented to the MI scheduler be _not_ terminated (end on a non > terminator MI) under any circumstances? Below you are speaking about "Empty > blocks, or blocks with only a single instruction that not a terminator..." - > What

Hi, I'm trying to understand why MachineScheduler does a poor job in straight line code in cases like the one in the attached debug dump. This is on AMDGPU, an in-order target, and the problem is that the IMAGE_SAMPLE instructions have very high (80 cycle) latency, but in the resulting schedule they are often placed right next to their uses like this: 1784B %140:vgpr_32 =

Dear Dev-Team, I am currently in the process of writing my bachelor thesis. The topic is about the implementation and evaluation of trace scheduling in the llvm framework for VLIW architecture. Simplifying the problem, only loop free code will be processed. Further, preparations and studies of llvm framework have shown, that, in my humble opinion, the machineScheduler::runOnMachineFunction()

...me time. In the TableGen definitions, should I do: def HWVMEM : ProcResource<15>; or let BufferSize = 15 in { def HWVMEM : ProcResource<1>; } 2. Southern Islands has 256 registers, but there is a significant performance penalty if you use more than a certain amount. Do any of the MachineSchedulers support switching into an 'optimize for register pressure mode' once it detects register pressure above a certain limit? Thanks, Tom

I was handed a makefile which is used to compile a library and was told to figure out why the compilation is failing. There is a lot of output and at this point I'm not sure what is important and what is not. I'm trying to solve this problem in small steps, so if asked I can certainly provide more information. The first error that I see during compilation is

Hello Andy, Thank you for your offer to work together on implementing the your new scheduler on X86. I can start working on this right away. In case you were unaware, the new Silvermont micro-architecture is only out of order on the integer side. The SSE instructions are still in order, so the current postRA scheduler is very beneficial for code with lots of SSE instructions, such as the ISPC

Hi Andy, Thanks for the explanations. Yes AMDGPU is in-order and has MicroOpBufferSize = 1. Re "issue limited" and instruction groups: could it make sense to disable the generic scheduler's detection of issue limitation on in-order CPUs, or on CPUs that don't define instruction groups, or some similar condition? Something like: --- a/lib/CodeGen/MachineScheduler.cpp +++

...if you have def HW1 : ProcResource<15>; def HW2 : ProcResource<3>; LatencyFactor=15 ResourceFactor(HW1)=1 ResourceFactor(HW2)=5 > 2. Southern Islands has 256 registers, but there is a significant > performance penalty if you use more than a certain amount. Do any of > the MachineSchedulers support switching into an 'optimize for register > pressure mode' once it detects register pressure above a certain limit? The code in ConvergingScheduler (I’ll rename it to GenericScheduler soon) is meant to demonstrate most of the features so developers can copy what they need into t...

I'm briefly enabling the MachineScheduler pass for x86 tonight to collect information on any failures that may show up. To properly enable the new scheduler, this hook is implemented in X86Subtarget: bool enableMachineScheduler() const LLVM_OVERRIDE { return true; } The MachineScheduler pass itself can be enabled/disabled with -enable-misched=true/false. But most of the codegen changes

Thanks that clears things up. So if I want to mess around with how schedules are generated, looking at the MachineScheduler pass is the best place now? -Dilan On Mon, Jul 31, 2017 at 3:24 PM Matthias Braun <mbraun at apple.com> wrote: > > > On Jul 31, 2017, at 2:51 PM, Dilan Manatunga via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > > > Hi, > >

I see that there are several options to influence instruction scheduling, but there doesn't seem to be a lot of information about what they do, for example: -misched-topdown -misched-bottomup The description in MachineScheduler.cpp says: "Force top-down list scheduling" and "Force bottom-up list scheduling" Which isn't too helpful - where might I want to use these?

Hi Andy, >> Right now it seems that BeginGroup/EndGroup is only used by SystemZ, >> or? I see they are used in checkHazard(), which I actually don't see >> as helpful during pre-RA scheduling for SystemZ. Could this be made >> optional, or perhaps only done post-RA if target does post-RA >> scheduling? SystemZ does post-RA scheduling to manage decoder

On 4/28/2016 2:11 PM, Rail Shafigulin wrote: > > On Thu, Apr 28, 2016 at 6:13 AM, Krzysztof Parzyszek > <kparzysz at codeaurora.org <mailto:kparzysz at codeaurora.org>> wrote: > > > IIRC, > > What is IIRC? If I remember correctly... -Krzysztof -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Hi, >From what I can understand from analyzing several *.td files, there are two ways of specifying scheduling information for a specific target, either using SchedWriteRes and InstrItinClass/Data. Specifically looking at ARMScheduleA9.td, I can find both representations and a comment (in the beggining of the file): // This section contains legacy support for itineraries. This is // required

Hi to everyone, while working with the machine scheduler for a personal project, I came up with the necessity of inserting a backup boundary in the MachineSchedulerStrategy -- specifically, the PostGenericScheduler -- to hold a copy the scheduler's state, in order to implement a really trivial (and really inefficient) backtracking mechanism. This approach leads to a subtle "segmentation fault", when the pass ends and invokes the deleter. The rea...

On Mon, Jun 24, 2013 at 2:41 AM, Andrew Trick <atrick at apple.com> wrote: > I'm briefly enabling the MachineScheduler pass for x86 tonight to collect > information on any failures that may show up. > > To properly enable the new scheduler, this hook is implemented in > X86Subtarget: > > bool enableMachineScheduler() const LLVM_OVERRIDE { return true; } > >

Thanks for the suggestion. I tried your fix. It worked for my particular case, but then I got a following error: clang-3.5: /home/rail/projects/escala_llvm/trunk/llvm-or1k/lib/CodeGen/RegisterPressure.cpp:39: void decreaseSetPressure(std::vector<unsigned int>&, llvm::PSetIterator): Assertion `CurrSetPressure[*PSetI] >= Weight && "register pressure underflow"'

> On May 14, 2018, at 11:10 AM, Jonas Paulsson <paulsson at linux.vnet.ibm.com> wrote: > > Hi Andrew, > > Thank you very much for the most helpful explanations! Many things could go in as comments, if you ask me - for example: > > --- >> The LLVM machine model is an abstract machine. > >> The abstract pipeline is built around the notion of an

On Jul 31, 2012, at 8:37 AM, Ivan Llopard <ivanllopard at gmail.com> wrote: > Hi, > > I'm working on a custom top-down post RA scheduler which builds bundles > at the same time for our VLIW processor. I've borrowed most of the > implementation from the resource priority queue implemented for the > existent VLIW scheduler but applied to the context of MI