similar to: How to traverse llvm DAG for analysis

Dear Raul, Instruction selection and instruction scheduling is, to the best of my knowledge, done at the MachineInstr (MI) IR level. The documentation you've read is on the target independent LLVM IR. You will probably need to read the documentation on LLVM's code generator. The documents on Writing an LLVM Backend, the LLVM Target Independent Code Generator, and Machine IR Format

Hi, I am trying to add Hazard scheduling nodes after buildSchedGraph(), with a scheduler derived from ScheduleDAGInstrs. I get weird errors, so I wonder what I am doing wrong? What I am doing right now is: I have a created MI with opcode HAZARD that does not have parent, and I greate a SUnit(HazardMI). I use this one HazardMI for all hazard nodes. I remove all edges using removePred. I insert

On Feb 21, 2013, at 9:11 AM, Jonas Paulsson <jonas.paulsson at ericsson.com> wrote: > Hi, > > I am trying to add Hazard scheduling nodes after buildSchedGraph(), with a scheduler derived from ScheduleDAGInstrs. I get weird errors, so I wonder what I am doing wrong? > > What I am doing right now is: > > I have a created MI with opcode HAZARD that does not have

Hi All, The description of ScheduleDAGMILive [1] says: ScheduleDAGMILive is an implementation of ScheduleDAGInstrs that schedules machine instructions while updating LiveIntervals and tracking regpressure. Does the live interval and register pressure part of ScheduleDAGMILive mean the subclass of ScheduleDAGMILive is a pre-RA scheduler? I assume the post-RA scheduler no need to take

Hi Andy, The thing is that I was trying to build a sched graph in other places than these two standard scheduling passes. For instance, in pre-emit. I would like to reschedule a basic block on my vliw target just before assembly emission. I tried to add SUnits for hazards in an experiment, but this gave very weird errors... even while allocating extra space in SUnits vector. For some function, I

On Thu, Mar 29, 2012 at 02:57:27PM -0500, Sergei Larin wrote: > Tom, > > I do not have your call stack, but packetizer calls > ScheduleDAGInstrs::buildSchedGraph to create dependency model. If this is > the first time you use the new MI sched infrastructure (like your target has > not implemented misched yet) there might be some work needed to implement > couple target

Hey Everyone, I'd like to begin a project to rework the scheduler to address some problems we've discovered on this end. The goal is to get a more configurable/flexible scheduler while simplifying maintenance by separating policy from implementation to get independent and interchangeable parts. This is going to be challenging because we are still stuck on LLVM 2.9. We will be upgrading

Hi, We are currently in the process of upgrading from LLVM 2.9 to LLVM 3.3. We are working on instruction scheduling (mainly for register pressure reduction). I have been following the llvmdev mailing list and have learned that a machine instruction (MI) scheduler has been implemented to replace (or work with?) the selection DAG (SD) scheduler. However, I could not find any document that

Thanks  Kryzstof, I will look at it. Is there any class that I should look at it ? What about Dataflow.h ? Since I am kind of new, I want to know which classes can help me quicker.    =========================================== Phone : 82-42-860-1838 Fax : 82-42-860-6790 Cell Phone: 82-10-7599-1981 =========================================== --- On Sat, 11/3/12, Krzysztof Parzyszek

On Mar 29, 2012, at 1:18 PM, Tom Stellard <thomas.stellard at amd.com> wrote: > On Thu, Mar 29, 2012 at 02:57:27PM -0500, Sergei Larin wrote: >> Tom, >> >> I do not have your call stack, but packetizer calls >> ScheduleDAGInstrs::buildSchedGraph to create dependency model. If this is >> the first time you use the new MI sched infrastructure (like your

Hi, Matthias. >From the class hierarchy, ScheduleDAGMILive is also a ScheduleDAGMI. I am wondering if there will be any problem if we use subclass of ScheduleDAGMILive as post-RA scheduler? The best case is ScheduleDAGMILive just waste time on book-keeping register pressure, but I am not sure if we can still do those book-keeping after RA. Talk about post-RA scheduler, I see there is another

On 09/05/2013 18:25, Andrew Trick wrote: > > On May 9, 2013, at 4:02 AM, Fraser Cormack <fraser at codeplay.com > <mailto:fraser at codeplay.com>> wrote: > >> I have an instruction that takes no operands, and produces two >> results, in two consecutive cycles. >> >> I tried both of the following to my Schedule.td file: >> >>

On Apr 20, 2012, at 10:31 AM, dag at cray.com wrote: > I'd like to begin a project to rework the scheduler to address some > problems we've discovered on this end. The goal is to get a more > configurable/flexible scheduler while simplifying maintenance by > separating policy from implementation to get independent and > interchangeable parts. > > This is going to be

Sent from my iPhone On Jun 28, 2013, at 2:38 PM, Ghassan Shobaki <ghassan_shobaki at yahoo.com> wrote: > Hi, > > We are currently in the process of upgrading from LLVM 2.9 to LLVM 3.3. We are working on instruction scheduling (mainly for register pressure reduction). I have been following the llvmdev mailing list and have learned that a machine instruction (MI) scheduler has been

On Jan 17, 2014, at 4:03 PM, Andrew Trick <atrick at apple.com> wrote: > > On Jan 17, 2014, at 3:54 PM, Hal Finkel <hfinkel at anl.gov> wrote: > >> Andy, et al., >> >> In ScheduleDAGInstrs::buildSchedGraph, the code for handling stores has this: >> >> if (!ExitSU.isPred(SU)) >> // Push store's up a bit to avoid them

Hi Andy, I have to resurrect an ancient question regarding scheduling boundaries. You might remember the reason for introduction of CanHandleTerminators to ScheduleDAGInstrs. In short, Hexagon is currently uses DAG construction method (buildSchedGraph) for several purposes, which includes region formation for general VLIW packetization/bundling. As such we need to handle pretty much all

On Feb 11, 2013, at 1:03 PM, Sergei Larin <slarin at codeaurora.org> wrote: > Hi Andy, > > I have to resurrect an ancient question regarding scheduling boundaries. > > You might remember the reason for introduction of CanHandleTerminators to > ScheduleDAGInstrs. In short, Hexagon is currently uses DAG construction > method (buildSchedGraph) for several purposes,

Thank you for the answers! We are currently trying to test the MI scheduler. We are using LLVM 3.3 with Dragon Egg 3.3 on an x86-64 machine. So far, we have run one SPEC CPU2006 test with the MI scheduler enabled using the option -fplugin-arg-dragonegg-llvm-option='-enable-misched:true' with -O3. This enables the machine scheduler in addition to the SD scheduler. We have verified this by

Hello again, Sorry -- I think I found the problem somewhere else. I was a bit confused and missed the fact that adjustChainDeps() is called a few lines down and does just what I wanted :-) I would like to instead ask another question: Why is I->isCtrl() used in code like // Iterate over chain dependencies only. for (SUnit::const_succ_iterator I = SUb->Succs.begin(), E =

Hi, Can anyone help me to understand the ScheduleDAGInstrs::buildSchedGraph() method? I find the handling of AliasChain is disturbing since: 1. A new alias chain add deps to all possibly aliasing SUs, and then clears those lists. 2. When AliasChain is present, the addChainDependency() method is called, but the target hook areMemAccessesTriviallyDisjoint() called inside