similar to: [LLVMdev] TableGen Register Class not matching for MI in 3.6

Quentin, It's in the instruction selection, sorry I forgot to mention that. The Vreg class is GPR and an extra COPY is generated to copy from the GPR to the Base Reg, even though my 'mov' instruction has Base in the Register class list. On Fri, Jul 31, 2015 at 12:50 PM, Quentin Colombet <qcolombet at apple.com> wrote: > Hi Ryan, > > Could you check where those moves

Hi Ryan, Could you check where those moves come from? In particular, is this the product of the instruction selection process? You use -print-machineinstrs to see when it is inserted. Thanks, -Quentin > On Jul 30, 2015, at 2:02 PM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > In LLVM 3.6, > > We have an instruction that uses a register class that is defined of

Essentially it doesn't appear that the reg class assignment is based on uses and is instead inserting an extra COPY for this. Is this accurate? If so, why? In this above example, I'm getting an extra "mov %r0, $b1" (this is an MI::COPY) even though "mov @a, %b1" (this is an MI::MOV) is entirely acceptable since both GPRRegs and BaseRegs are in the reg class list.. If

It seems the problem arises from using multiple reg classes for one MI in the td file, I guess. I'm not sure it takes first available, if I swap the reg classes in the list it does not change and if I replace the GPR reg class with something different than it picks the base reg class fine, potentially it is using the reg class with most available? idk. I just need to create MIs for every

Yes, you're probably right about the ID. The odd part is that I have other simpler instructions that use the same type of superset and it always, so far, matches correctly (it doesn't just pick GPRRegs all the time). Like I said, we can just 'fill in the gaps' with new MIs but that sure seems like a brush off solution. The td files would be so much cleaner if you could have a

BB#0: derived from LLVM BB %entry %vreg0<def> = MOV16Copy_IMM_REG <ga:@a+1>[TF=1]; GPRRegs:%vreg0 %vreg1<def> = COPY %vreg0; PTRRegs:%vreg1 GPRRegs:%vreg0 Send_iii %NULLR0, %vreg1<kill>, 1, 1, 1, 1, 0; PTRRegs:%vreg1 RetRA This is what I get. This is what I'd like to get: BB#0: derived from LLVM BB %entry %vreg0<def> = MOV16Copy_IMM_REG

> On Aug 22, 2015, at 9:10 AM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > One last question regarding this please. > > Why aren't we simply changing the register class in AddRegisterOperand instead of building a new COPY? I admit I haven't thought this out but for my test cases so far this works just fine and reduces the number of ASM mov instructions that are

AddRegisterOperand calls getVR and yes, I think an IMPLICIT_DEF is being generated. On Tue, Aug 25, 2015 at 2:40 PM, Quentin Colombet <qcolombet at apple.com> wrote: > > On Aug 25, 2015, at 11:05 AM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > 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

Here is the instruction in question: multiclass AD<string asmstr, SDPatternOperator OpNode, RegisterClass srcAReg, RegisterClass dstReg, ValueType srcAType, ValueType dstType, Operand ImmOd, ImmLeaf imm_type> { def REG_REG : SetADInOut<asmstr, srcAReg, dstReg, [(set dstReg:$dstD, (OpNode srcAReg:$srcA))]>; def IMM_REG :

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

1. MOV16Copy_IMM_REG is the instruction matched, sorry. AD is the multiclass. The IMM in my case is a global. So you can see that GPRBaseRegs, GPRBaseRegs sets the registerclass for both the src and dst operands, in this case (MOV16Copy_IMM_REG) it's the dst. 2. Yes I agree, it most likely would. Honestly, this comes across like a bug, or unintended feature. It's adding an extra COPY to

> On Aug 24, 2015, at 1:30 PM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > I'm trying to do something like this: > > // Dst = NewVReg's reg class > // *II = MCInstrDesc > // IIOpNum = II Operand Num > > if (TRI->getCommonSubClass(DstRC, TRI->getRegClass(II->OpInfo[IIOpNum].RegClass)) == DstRC) > MRI->setRegClass(VReg, DstRC); >

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

> 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

Dear all, I'm working on an exploratory backend on llvm. In the instruction set I'm using I have an instruction (called DECJNZ) that decrements a register and, if the decremented value is not zero, jumps (with a relative jump) to a given offset. I've described in tablegen this instruction as follow: def DECJNZ : Instruction { let Namespace = "MyTarget"; let

On Wed, Jul 25, 2012 at 12:48 AM, Michele Scandale <michele.scandale at gmail.com> wrote: > Dear all, > > I'm working on an exploratory backend on llvm. In the instruction set I'm using > I have an instruction (called DECJNZ) that decrements a register and, if the > decremented value is not zero, jumps (with a relative jump) to a given offset. > > I've

Where does the unsignedSub come from? On 2017-02-15 20:38, Ryan Taylor wrote: > Sorry, it should be: > > defm SUB16u_ : ABD_NonCommutative<"sub16u", unsignedSub, LOADRegs, > GPRRegs, DSTRegs, i16, i16, i16, uimm16, immZExt16x>; > > On Wed, Feb 15, 2017 at 2:37 PM, Ryan Taylor <ryta1203 at gmail.com> > wrote: > >> I see. If I put simm16 and

Hi, I define a customized node with customized type. The job of this customized node is to move a value from one register class to another class. I find that if there is no use of the destination register, this node will be deleted from SDAG. For some reasons, I want to keep this node. So I attach mayStore attribute to this node and I hope it will not be deleted. However, it does not work like I

I see. If I put simm16 and immSExt16x in place of uimm16 and immZExt16x respectively, the imm matches but it prints out -32768 (which is invalid for sub16u). We are using uimm16 not match unsigned but for PrintMethod, effectively uimm16 and simm16 are both Operand<i16>. I'm still unclear why simm16 matches and uimm16 does not. Here is the pattern if that helps at all. So just as a