similar to: Instruction Itineraries: question about operand latencies

I overrode getInstrLatency and did some printing to see what is available there. It looks like the registers are still virtual at that point when getInstrLatency is called - is that correct? (we needed to make some decisions based on actual registers that have been assigned since some registers are reserved as address space pointers and we could vary the latency based on which address space

Hi llvm-dev, I wonder why there is an extra cycle for getOperandLatency. It doesn't seem intuitive. UseCycle = DefCycle - UseCycle + 1; When I read the comments in TargetItinerary.td, it said OperandCycles are optional "cycle counts". They specify the cycle after instruction issue the values which correspond to specific operand indices are defined or read. I thought if

On Tue, Nov 17, 2015 at 11:15 AM, Krzysztof Parzyszek < kparzysz at codeaurora.org> wrote: > On 11/17/2015 12:26 PM, Rail Shafigulin wrote: > >> >> I tried setting >> let mayLoad = 1 { >> class InstrLD .... { >> } >> } >> >> But that didn't seem to work. When I looked at the debug output the >> latency for the load

Hi everyone I'm fairly new with LLVM and I've been searching around but couldn't find info on this subject. I started working on a target for a new cpu and I realizing my initial simple understanding of instruction itineraries may be completely off. I'm trying to model a CPU that has a latency of 2 cycles for multiplications fully pipelined (so it can start a new one after one

Does anybody know how to specify instruction latency in the itinerary scheduling model? For some reason no matter what I do I get a latency of 1. -- Rail -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20151111/161bd6cb/attachment.html>

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]>]>,

Jonas, At this point, the DFA packetizer models a simple VLIW architecture and does not accommodate multiple stages. That's the reason for the behavior you're seeing. -Anshu --- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation *From:*llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] *On Behalf Of *Jonas

On Mon, Aug 15, 2011 at 4:03 PM, Miguel G <miguel at esenciatech.com> wrote: > Hi everyone > I'm fairly new with LLVM and I've been searching around but couldn't find > info on this subject. > I started working on a target for a new cpu and I realizing my initial > simple understanding of instruction itineraries may be completely off. > I'm trying to model a

In the example provided: // InstrItinData<IIC_iLoad_i , [InstrStage<1, [A9_Pipe1]>, // InstrStage<1, [A9_AGU]>], // [3, 1], [A9_LdBypass]>, If there is an operand dependency, does the scheduler assume that the instruction is held in A9_Pipe1 or in A9_AGU until the operand is ready? Thanks again, Hal On Fri,

Hi Jonas, > It is interesting to find this in the ARM backend, considering your answer. The ARM backend doesn't use the DFA packetizer. It's only used by Hexagon. At this point, there is no plan to address thisin the DFA packetizer since none of the supported targets needthe functionality. Thanks -Anshu --- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,

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: InstrItinData<IIMyInstr, [InstrStage<2, [FuncU]>], [1, 2]>, InstrItinData<IIMyInstr, [InstrStage<1, [FuncU]>, InstrStage<1, [FuncU]>], [1, 2]>, From what I can see in examples, these say that the first

> 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

Hi, I looked a bit through the mail archives, and found this question answered in Oct 2011 (see below). It is interesting to find this in the ARM backend, considering your answer. Can you give more information about for example is this a temporary deficiency in the DFAPacketizer? What is the IIC_iMOVi itinerary doing below? Thanks, Jonas Thu Oct 6 15:11:25 CDT 2011: Hello Hal. > Is there

Anton, Thanks! What is the difference between Reserved and Required? -Hal On Fri, 2011-10-07 at 00:11 +0400, Anton Korobeynikov wrote: > Hello Hal. > > > Is there a way to express a multiple pipeline itinerary using the > > current scheme > Yes, surely > > > (maybe some trick with setting NextCycles = 0)? > Yep! > > > Specifically, consider a case

Hal, > What is the difference between Reserved and Required? Think about them like read/write locks. E.g. if FU is Reserved (=read lock) is can be Reserved multiple times, but never Required. If FU is Required (=write lock) it cannot be neither Reserved nor Required. -- With best regards, Anton Korobeynikov Faculty of Mathematics and Mechanics, Saint Petersburg State University

Hi Anshu, Would there be any interest in extending this algorithm to handling more extensive models, such as VLIW scheduling based on FU's and bundle space... ie handle multiple stages ? I might do it and commit, if there is acceptance and guidance... Jonas ________________________________ From: Anshuman Dasgupta [mailto:adasgupt at codeaurora.org] Sent: Tuesday, February 12, 2013 4:47 PM

On Thu, Jan 14, 2016 at 6:05 AM, Krzysztof Parzyszek < kparzysz at codeaurora.org> wrote: > On 1/13/2016 4:47 PM, Phil Tomson wrote: > >> >> First off, I got this idea from the LLVM Cookbook chapter 8: Writing an >> LLVM Backend: Lowering to multiple instructions. (now I'm having my >> doubts as to whether this is the right approach) >> > >

On May 9, 2013, at 4:02 AM, Fraser Cormack <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: > > InstrItinData<IIMyInstr, [InstrStage<2, [FuncU]>], [1, 2]>, > InstrItinData<IIMyInstr, [InstrStage<1,

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: >> >>

Akira, Thanks you for response. I understand Post-RA schedule make uses of scoreboardHazardRecognizer. But I found mips codes are good enough by default. basically, I can not easily eyeball any bubbles. I don't understand how they can do that without post-RA-sched. pre-ra-scheduler eg. (SelectionDAG/ScheduleDAGRRList.cpp) has little information and they can only schedule node in topology