similar to: [LLVMdev] extra one cycle of getOperandLatency

In our architecture loads from certain memory locations take a long time to complete (on the order of 150 clock cycles). Since we don't have a way to tell at compile time if the address being loaded from lies in slow or fast memory, I've gone ahead and made all of the load numbers high, such as: InstrItinData< II_LOAD1, [InstrStage<150, [AGU]>]>, However, I see that

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 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

Hi everyone, The MachineLICM pass has a heuristic such that, even in low-register-pressure situations, it will refuse to hoist "cheap" instructions out of loops. By default, when an itinerary is available, this means that all of the defined operands are available in at most 1 cycle. ARM overrides this, and provides this more-customized definition: bool ARMBaseInstrInfo::

We'd like to be able to vary the latency of our load instructions based on what address space is being loaded from. I was thinking I could do this by overriding getOperandLatency in our target, but I'm wondering if the addrspace info is available when instructions are scheduled? For example, I have this in our llvm IR: %0 = load i32 addrspace(4)* @answer, align 4 store i32 %0, i32*

I keep getting this error upon building: > Linking CXX executable ../../bin/opt > ../../lib/libLLVMTarget.so: error: undefined reference to > 'llvm::TargetInstrInfo::getNumMicroOps(llvm::InstrItineraryData > const*, llvm::MachineInstr const*) const' > ../../lib/libLLVMTarget.so: error: undefined reference to >

It it possible to specify an instruction latency in the itinerary through a command line option? We have several options for a hardware divider which have different latencies and it would be nice if I could specify it through a compiler option rather than changing the value in the code and recompiling llvm every time? Any help is appreciated. -- Rail Shafigulin Software Engineer Esencia

On Jun 8, 2012, at 12:52 PM, Marc J. Driftmeyer <mjd at reanimality.com> wrote: > I keep getting this error upon building: > >> Linking CXX executable ../../bin/opt >> ../../lib/libLLVMTarget.so: error: undefined reference to 'llvm::TargetInstrInfo::getNumMicroOps(llvm::InstrItineraryData const*, llvm::MachineInstr const*) const' >>

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'