search for: schedmodels

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 +++

I'm unclear how does DFAPacketizer and the scheduler know a given instruction is a load. Here is what I'm talking about Let's assume my VLIW target is described as follows: def MyTargetItineraries : ProcessorItineraries<[Slot0, Slot1], [], [ .............................. InstrItinData<RI, [InstrStage<1, [Slot0, Slot1]>]>,

Hi, I would like to ask what IssueWidth and NumMicroOps refer to in MachineScheduler, just to be 100% sure what the intent is. Are we modeling the decoder phase or the execution stage? Background: First of all, there seems to be different meanings of "issue" depending on which platform you're on:

(on the correct mailing list) 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 the tool part. - The core part simulates the execution of a basic block of machine instructions as modeled by the llvm SchedModel.

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 =

Hi Andy and all, I have a question about per-operand machine model. I am finding some relations between 'MCWriteLatencyEntry' and 'MCWriteProcResEntry'. For example, class InstTEST<..., InstrItinClass itin> : Instruction { let Itinerary = Itin; } // I assume this MI writes 2 registers. def TESTINST : InstTEST<..., II_TEST> // schedule info II_TEST:

> In particular, the LoadLatency is used in defaultDefLatency: > > /// Return the default expected latency for a def based on it's opcode. > unsigned TargetInstrInfo::defaultDefLatency( > const MCSchedModel &SchedModel, const MachineInstr *DefMI) const { > if (DefMI->isTransient()) > return 0; > if (DefMI->mayLoad()) > return

...================================================================== --- utils/TableGen/SubtargetEmitter.cpp (revision 201607) +++ utils/TableGen/SubtargetEmitter.cpp (working copy) @@ -932,12 +932,7 @@ WLEntry.Cycles = 0; unsigned WriteID = WriteSeq.back(); WriterNames.push_back(SchedModels.getSchedWrite(WriteID).Name); - // If this Write is not referenced by a ReadAdvance, don't distinguish it - // from other WriteLatency entries. - if (!SchedModels.hasReadOfWrite( - SchedModels.getSchedWrite(WriteID).TheDef)) { - WriteID = 0; - } + WL...

> On May 9, 2018, at 9:43 AM, Jonas Paulsson <paulsson at linux.vnet.ibm.com> wrote: > > Hi, > > I would like to ask what IssueWidth and NumMicroOps refer to in MachineScheduler, just to be 100% sure what the intent is. > Are we modeling the decoder phase or the execution stage? > > Background: > > First of all, there seems to be different meanings of

Dear All, Attached files is related to the changes made to add the Schedmodel for a AMD bulldozer target, Please note that , the model is incomplete but has some of the valuables features implemented. Request to the group or someone from AMD for the comments on the implementation. Thanks ~umesh On Wed, Nov 13, 2013 at 8:14 PM, Umesh Kalappa <umesh.kalappa0 at gmail.com>wrote: >

Hi Andy, Dave, I've been doing a bit of experimentation trying to understand the schedmodel a bit better and improving modelling of FDIV (on Cortex-A57). FDIV is not pipelined, and blocks other FDIV operations (FDIVDrr and FDIVSrr). This seems to be already semi-modelled, with a "ResourceCycles=[18]" line in the SchedWriteRes for this instruction. This doesn't seem to work (a

Dear Andrew and the Group, I’m trying come up with a SchedMachineModel for the AMD bulldozer http://en.wikipedia.org/wiki/Bulldozer_(microarchitecture). The model is not exist for the same .Please correct me if am i wrong here. I was going through your reference @ https://llvm.org/svn/llvm-project/llvm/trunk/include/llvm/Target/TargetSchedule.td . But I couldn’t model some of the

Hello everybody, I'm reading the .td files defining the Cortex-A57 processor, which is a subtarget of AArch64 target, and there is something confusing me in the `AArch64SchedA57.td` file. In the top of `AArch64SchedA57.td`, various processor resource are defined, as follows ``` def A57UnitB : ProcResource<1>; // Type B micro-ops def A57UnitI : ProcResource<2>; // Type

Dear all, Some benchmarking experimentation I`ve done recently -- all on AArch64 -- has shown that it might be beneficial for all AArch64 targets to have a positive LoopMicroOpBufferSize, whereas the default that applies to all ISAs seems to be zero. Although I`ve tried going as far down the rabbit hole as I can, I haven`t found a way to set DefaultLoopMicroOpBufferSize on a per-ISA basis or

On Apr 26, 2013, at 3:53 AM, Martin J. O'Riordan <Martin.ORiordan at movidius.com> wrote: > I am migrating the llvm/clang derived compiler for our processor from the > v3.1 to v3.2 codebase. This has mostly gone well except that instruction > latency scheduling is no longer happening. > > The people who implemented this previously sub-classed 'ScheduleDAGInstrs'

...he apply method to output <idx, pat> pairs and <idx, name> pairs and then joined them togather using a script. However, I couldn't easily determine from within that method what specific subtarget the patterns came from. Is there a better place to do this check? It seems that CodeGenSchedModels::checkCompleteness would be the logical place. Joel Jones

Tom , Thank you for correcting me here , All , Please review the changes made and is it ok to commit ?? Thanks ~Umesh On Thu, Nov 21, 2013 at 11:47 PM, Tom Stellard <tom at stellard.net> wrote: > Hi Umesh, > > You should send patches to llvm-commits at cs.uiuc.edu, also each patch > should be its own plain-text attachment. > > -Tom > > On Thu, Nov 21, 2013 at

Hi Phil. You more or less answered your own question, but let me give you some more info. Maybe it is of use. >From what I understand the SchedMachineModel is the future, although it is not as powerful as itineraries at present. The mi-scheduler is mostly developed around out-of-orders cores, I believe (I love to hear arguments on the contrary). Some of the constraints that can be found in

So if I use the SchedMachineModel method, can I just skip itineraries? Phil On Wed, Apr 20, 2016 at 12:29 PM, Sergei Larin <slarin at codeaurora.org> wrote: > Target does make a difference. VLIW needs more hand-holding. For what you > are describing it should be fairly simple. > > > > Best strategy – see what other targets do. ARM might be a good start for > generic

I'm trying to create a simplified 2 slot VLIW from an OR1K. The codebase I'm working with is here <https://github.com/openrisc/llvm-or1k>. I've created an initial MyTargetSchedule.td def MyTargetModel : SchedMachineModel { // HW can decode 2 instructions per cycle. let IssueWidth = 2; let LoadLatency = 4; let MispredictPenalty = 16; // This flag is set to allow the