similar to: [LLVMdev] Live Intervals and Register Classes

David Greene wrote: > If I take the first LiveRange LR from LI, look up its > instruction/operand at "start" and then look at its > TargetOperandInfo and send TOI::RegClass to > MRegisterInfo:getRegClass, is that sufficient. > > It seems way overly complicated. Umm...yeah. That way be dragons. :-/ Fortunately, I found

Dear llvmers, I am trying to insert a move instruction where both source and destination registers are physical registers. How is the code for this? I tried this one here: void PhiDeconstruction_Fer::add_move ( MachineFunction & mf, MachineBasicBlock & mbb, unsigned

On Sun, 2 Jul 2006, Fernando Magno Quintao Pereira wrote: > MachineBasicBlock::iterator iter = mbb.getFirstTerminator(); > const TargetRegisterClass *rc = mf.getSSARegMap()->getRegClass(dst); > const MRegisterInfo * reg_info = mf.getTarget().getRegisterInfo(); > reg_info->copyRegToReg(mbb, iter, dst, src, rc); > } > > But the getRegClass method seems to

> > Thank you Chris. I will try to implement the TwoAddress pass to run on > > machine code. Why it has not been originally implemented to run on > > machine code? > > I'm not sure what you mean. It definitely does run on machine code. I was thinking that it only transformed instructions with virtual registers because of this code in the TwoAddressInstructionPass.cpp:

On Mon, 26 Jun 2006, Fernando Magno Quintao Pereira wrote: >>> Thank you Chris. I will try to implement the TwoAddress pass to run on >>> machine code. Why it has not been originally implemented to run on >>> machine code? >> >> I'm not sure what you mean. It definitely does run on machine code. > > I was thinking that it only transformed

Can someone explain the theory behind the spillers in VirtRegMap.cpp? It seems as though the spillers do triple duty: - Insert load/store operations and/or fold instructions as necessary to carry out spills - Rewrite the spilled virtual registers to use machine registers (mapping given by the caller in the VRM). - Rewrite machine code to change virtual registers to physical registers

> On Sun, 2 Jul 2006, Fernando Magno Quintao Pereira wrote: > > > MachineBasicBlock::iterator iter = mbb.getFirstTerminator(); > > const TargetRegisterClass *rc = mf.getSSARegMap()->getRegClass(dst); > > const MRegisterInfo * reg_info = mf.getTarget().getRegisterInfo(); > > reg_info->copyRegToReg(mbb, iter, dst, src, rc); > > } > > >

On Tue, 20 Sep 2005, Tzu-Chien Chiu wrote: > One of my pass requires LiveIntervals to build the interference graph, Ok. > because LiveVariables do not provide an interface to iterate through > all viritual registers. Ok, you could add a method to LiveVariables that returns VirtRegInfo.size(). The virtual registers are defined by the range: [MRegisterInfo::FirstVirtualRegister,

On 20/09/05, Chris Lattner <sabre at nondot.org> wrote: > > because LiveVariables do not provide an interface to iterate through > > all viritual registers. > > Ok, you could add a method to LiveVariables that returns > VirtRegInfo.size(). The virtual registers are defined by the range: > [MRegisterInfo::FirstVirtualRegister, >

Hello. I am making a backend for a virtual machine. But it does assume infinite number of virtual registers unlike those of usual machines. In this case, how can I implement this? Would you mind telling me some tips? Thank you so much. Seung Jae Lee

On Fri, 11 May 2007, David Greene wrote: > Umm...yeah. That way be dragons. :-/ > > Fortunately, I found > MachineFunction::getSSARegMap()->getRegClass(LI.reg) which > works swimmingly. Yep, that's exactly the right way to go for vregs. It won't work for physregs, primarily because they can be in multiple reg classes :) -Chris -- http://nondot.org/sabre/

This code or subtle variations of it appears in multiple targets. It tries to convert from a register to a register class using getRegClass, but getRegClass is really supposed to take a register class enum value and get the register class object for it. It doesn't convert a register to a class. In fact there's not always a single or canonical class for a given register. What is the right

Hi, Sorry for the delay. I was trying to wrap my head around some live interval analysis code and have forgotten about emails. :-) On Aug 6, 2007, at 9:20 AM, David Greene wrote: > Can someone explain the theory behind the spillers in VirtRegMap.cpp? > > It seems as though the spillers do triple duty: > > - Insert load/store operations and/or fold instructions as >

> On Aug 24, 2015, at 4:46 PM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > Here is the snippet that matters: > > void > InstrEmitter::AddRegisterOperand(MachineInstrBuilder &MIB, > SDValue Op, > unsigned IIOpNum, > const MCInstrDesc *II, >

Quentin, This is the issue. Somewhere prior to the constrainRegClass, it's assigning the GPRBase sub class of GPR to the MOV instruction, so it can't constrain it to Base and hence has to add the COPY. Now I just need to find out why it is ignoring the TableGen defined GPRBase for the MOV MI in favor of it's sub class GPR. Thanks. On Mon, Aug 24, 2015 at 8:34 PM, Ryan Taylor

How do I get the TargetRegisterClass for a physical register? SSARegMap::getRegClass only works for virtual registers. -Dave

One of my pass requires LiveIntervals to build the interference graph, because LiveVariables do not provide an interface to iterate through all viritual registers. But LiveIntervalAnalysis.h is not in "include/llvm/CodeGen", so I have to either include it by: #include "../../llvm/lib/CodeGen/LiveIntervalAnalysis.h" or point my project include path to

Hi Ryan, > On Aug 24, 2015, at 6:49 PM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > Quentin, > > I apologize for the spamming here but in getVR (where VReg is assigned an RC), it calls: > > const TargetRegisterClass *RC = TLI->getRegClassFor(Op.getSimpleValueType()); > VReg = MRI->createVirtualRegister(RC); > > My question is why is it using the

Take a look at getPhysicalRegisterRegClass( const MRegisterInfo *MRI, MVT::ValueType VT, unsigned reg) in ScheduleDAG.cpp. -- Christopher Lamb On Jun 18, 2007, at 4:52 PM, David A. Greene wrote: > How do I get the TargetRegisterClass for a physical register? > SSARegMap::getRegClass only works for virtual registers. > >

I have not tried 3.5, it's a significant amount of work to port from one version to the next though, I did not personally do the 3.4 to 3.6 porting. I agree though, it was very strange that it suddenly just changed behavior. It looks like to me that InstrEmitter.cpp:getVR is the one assigning the virtual register no? Though this code in CreateVirtualRegisters: const TargetRegisterClass *RC