search for: schedules

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

Hi, I am currently writing a paper documenting a research project that we have done on pre-allocation instruction scheduling to balance ILP and register pressure. In the paper we compare the pre-allocation scheduler that we have developed to LLVM's default schedulers for two targets: x86-64 and x86-32. We would like to include in our paper some brief descriptions of the two LLVM

Hi Andrew, What we have is not a patch to any of LLVM's schedulers. We have implemented our own scheduler and integrated it into LLVM 2.9 as yet-another scheduler. Our scheduler uses a combinatorial optimization approach to balance ILP and register pressure. In one experiment, we added more precise latency information for most common x86 instructions to our scheduler and noticed a 10%

...ive a thourough update of the MI scheduler. Hopefully that will answer many of your questions. Some important things changed between the time I introduced the MI scheduler a year ago, and the release of 3.3. The biggest change was loop vectorization, which reduces register pressure and somewhat preschedules loops. Since 3.3 was released, the generic MI scheduler's heuristics were reevaluated in preparation for making it the default for targets without a custom scheduling strategy--more on that later. The source order scheduler was also fixed so that it actually preserves IR order, which is at leas...

On Thu, 10 May 2012 20:33:53 -0700 Andrew Trick <atrick at apple.com> wrote: > On May 9, 2012, at 8:34 AM, dag at cray.com wrote: > > > Andrew Trick <atrick at apple.com> writes: > > > >>> When I asked about enhancing scheduler heuristics a month or so > >>> ago, I got a response about a MachineInstr scheduler and that > >>> that

On Sep 17, 2011, at 10:07 AM, Ghassan Shobaki wrote: > Hi, > > I am currently writing a paper documenting a research project that we have done on pre-allocation instruction scheduling to balance ILP and register pressure. In the paper we compare the pre-allocation scheduler that we have developed to LLVM's default schedulers for two targets: x86-64 and x86-32. We would like to

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

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

...o make your exhaustive search as efficient as possible. However, a bottom-up analysis that examines particular test cases (like what we are currently trying to do with gromacs) may give some interesting insights. BTW, there are two other test cases for which our scheduler found significantly better schedules than LLVM's scheduler using LLVM's latencies (lbm on x86-64 (21%) and milc on x86-32 (13%)).  I will keep you updated with any findings that we may come up with.    What may be more interesting for you though is finding out whether adding more precise latency information improves the perf...

On Sep 23, 2011, at 6:16 AM, Ghassan Shobaki wrote: > Hi Andrew, > > What we have is not a patch to any of LLVM's schedulers. We have implemented our own scheduler and integrated it into LLVM 2.9 as yet-another scheduler. Our scheduler uses a combinatorial optimization approach to balance ILP and register pressure. In one experiment, we added more precise latency information for

On May 10, 2012, at 9:06 PM, Hal Finkel <hfinkel at anl.gov> wrote: >> - Target pass configuration: DONE >> - MachineScheduler pass framework: DONE >> - MI Scheduling DAG: DONE >> - AliasAnalysis aware DAG option: In review (Sergei) >> - Bidirectional list scheduling: DONE >> - LiveInterval Update: WIP (simple instruction reordering is >> supported)

If a sched job depends on a dma-fence from a job from the same GPU scheduler instance, but a different scheduler entity, the GPU scheduler does only wait for the particular job to be scheduled, rather than for the job to fully complete. This is due to the GPU scheduler assuming that there is a scheduler instance per ring. However, the current implementation, in order to avoid arbitrary amounts of

...I can''t figure out. Guidance would be very much appreciated. I''m using the Ryan Bates technique from Advanced Rails recipes to dynamically add and remove elements on a multi-model form. http://media.pragprog.com/titles/fr_arr/multiple_models_one_form.pdf I have 3 models: users, schedules and markets. Users has_many :schedules has_many :markets, :through => :schedules Markets has_many :schedules has_many :users, :through => :schedules Schedules belongs_to :users belongs_to :markets Schedules has columns user_id and market_id, but also has additional columns: monday, tuesday...

Hi Andy, We have done some experimental evaluation of the different schedulers in LLVM 3.3 (source, BURR, ILP, fast, MI). The evaluation was done on x86-64 using SPEC CPU2006. We have measured both the amount of spill code as well as the execution time as detailed below. Here are our main findings: 1. The SD schedulers significantly impact the spill counts and the execution times for many

...om adding precise latencies was on the gromacs benchmark, which has a high degree of ILP. I am attaching the benchmarking results on x86-64 using both LLVM's rough latencies and Agner's precise latencies: This work makes two points: -A B&B algorithm can discover significantly better schedules than a heuristic can do for some larger hard-to-schedule blocks, and if such blocks happen to occur in hot code, their scheduling will have a substantial impact on performance. - A B&B algorithm is generally slower than a heuristic, but it is not a slow as most people think. By applying su...

...latencies was on the gromacs benchmark, which has a high degree of ILP. I am attaching the benchmarking results on x86-64 using both LLVM's rough latencies and Agner's precise latencies: > > This work makes two points: > > -A B&B algorithm can discover significantly better schedules than a heuristic can do for some larger hard-to-schedule blocks, and if such blocks happen to occur in hot code, their scheduling will have a substantial impact on performance. > - A B&B algorithm is generally slower than a heuristic, but it is not a slow as most people think. By applying su...

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: > > &...

My 2c... Even though I understand it might be way off in the future, but we are talking about long term plans here anyway. Also as a VLIW backend maintainer, I just have to say it :) - We do need to have a way to assign bundles much earlier than we do now. And it needs to be intertwined with scheduling (Bundler currently reuses a good chunk of scheduler infrastructure). It is also obvious

On Jul 2, 2013, at 2:35 PM, Ghassan Shobaki <ghassan_shobaki at yahoo.com> wrote: > 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.

Hello, In a previous email, Matthias mentioned that register pressure estimates in the machine scheduler are not absolute; they only account for the registers that are used in the block.I assume that he meant that registers that are live-through (both live-in and live-out) are not accounted for in register pressure calculations. If a register is either live-in or live-out but not both, it must be