[X86][MIPS][ARM] New machine instruction property 'isMoveReg'

[NikolaPrica]

Summary

This property is needed in order to follow values movement between registers.

This patch feature is prerequisite for implementing tracking values locations in LiveDebugValues -> https://reviews.llvm.org/D44016.

[NikolaPrica]

Ping.

[efriedma]

lib/Target/ARM/ARMInstrNEON.td

5065 ↗

(On Diff #140747)

An "or" is only a move if the two inputs are the same register; does that really meet the requirements of isMoveReg?

lib/Target/ARM/ARMInstrThumb.td

1158

For targets older than armv6, "movs" is a lot more common than "mov"; you probably want to handle that too?

lib/Target/ARM/ARMInstrVFP.td

1027

We usually use VMOVRRD (which moves two 32-bit integers into one 64-bit register) rather than VMOVRS; is there some way you can treat that as a "copy"?

[NikolaPrica]

lib/Target/ARM/ARMInstrVFP.td

1027

There is similar instruction for MIPS that I've covered. On MIPS architecture similar instruction is used to transfer function arguments that were previously held in 32-bit register but for purpouse of call are transfered into 64-bit. I think that it should be treated as copy?

[NikolaPrica]

[ARM] Consider VORRq as copy instruction when two inputs are the same register

Treat tMOVsr as isMoveReg
Treat VMOVRRD as isMoveReg

[craig.topper]

lib/Target/X86/X86InstrAVX512.td

2770

Why is it disabled for this class and KMOVB above?

3242

This should be tagged I think.

3323

Why was this line deleted?

3344

This should be tagged I think.

lib/Target/X86/X86InstrInfo.td

1616

What about these?

lib/Target/X86/X86InstrMMX.td

294

Why isn't MMX_MOVQ64rr_REV tagged?

lib/Target/X86/X86InstrSSE.td

650

Shouldn't this be move reg?

743

Why is this only on VMOVAPSrr_REV and not the 3 following instructions?

[efriedma]

ARM changes look fine.

lib/Target/ARM/ARMInstrVFP.td

1027

Not sure how the target-independent code will understand the semantics for a "move" with multiple inputs, but I'll let you figure that out, I guess.

[NikolaPrica]

Thank you for your reviews and expertise @efriedma and @craig.topper !

@craig.topper I wasnt sure wich instructions could be considered as "move register to register" so I've just tagged some of the instructions from copyPhysReg method.

In this new diff I've changed the following:
-Added isMoveReg for table definiton class avx512_mask_mov_gpr ???
-Remove disabling flags for KMOVB and KMOVD
-Added isMoveReg for table definiton class avx512_load and avx512_store for "def rr" and "def rr_REV"
-Tagged MOV*rr_REV instructions as isMoveReg
-Tagged MMX_MOVQ64rr_REV as isMoveReg
-Added isMoveReg for table definition class sse12_mov_packed for "def rr"
-Tagged VMOVAP[S|D][Y]rr_REV, VMOVUP[S|D][Y]rr_REV, MOVAP[S|D]rr_REV and MOVUP[S|D]rr_REV as isMoveREg ???

[NikolaPrica]

lib/Target/ARM/ARMInstrVFP.td

1027

In following patch new destination register is recognized as one that is marked as <def> and the source register is recognized only if it is marked as <killed>. Do you think that this will be enough?

lib/Target/X86/X86InstrAVX512.td

3323

Oh, this got here by mistake. I've overlooked it.

[craig.topper]

lib/Target/X86/X86InstrAVX512.td

2749

The widths of the registers don't always match here. Is that a problem? Bits are either truncated or zero extended.

[NikolaPrica]

lib/Target/X86/X86InstrAVX512.td

2749

If bits are truncated then it can be a problem. I will remove this then.

[NikolaPrica]

Removed isMoveReg from avx512_move_gpr

[efriedma]

lib/Target/ARM/ARMInstrVFP.td

1027

The issue with vmovrrd in particular is that there are multiple source registers; the current patch in D44016 only looks for one of them.

[kparzysz]

Wouldn't it be better to have this as a TII hook? There are instructions like "or reg, 0" or "add reg, 0" that are effectively copies, but only with specific operands.

[NikolaPrica]

In D45204#1066331, @kparzysz wrote:

Wouldn't it be better to have this as a TII hook? There are instructions like "or reg, 0" or "add reg, 0" that are effectively copies, but only with specific operands.

There is already such hook for some mips and arm instructions like that.

lib/Target/ARM/ARMInstrVFP.td

1027

Oh. I've looked closer now. That could be a problem. Currently I'm not sure how to handle this in proper general way. It might be best to leave this as FIXME in ARMBaseInfo::isCopyInstr and untagg VMOVRRD since this is sort of a corner case?

[NikolaPrica]

Added FIXME in ARMBaseInstrInfo::isCopyInstr
Untagged isMoveReg from VMOVRRD

[kparzysz]

In D45204#1066982, @NikolaPrica wrote:

There is already such hook for some mips and arm instructions like that.

Why can't you use that hook then? Make it available for all targets in TargetInstrInfo. I think that adding such bits to the instruction descriptor is a bad idea in general.

Edit: I just saw that you actually added a hook, so I take the comment back. My apologies.

[NikolaPrica]

Why can't you use that hook then? Make it available for all targets in TargetInstrInfo. I think that adding such bits to the instruction descriptor is a bad idea in general.

I've firstly implemented like that but I've got comment that it might be better to implement it through table description instead of using multiple switch-case constructions for every register move instruction.

[kparzysz]

In D45204#1067117, @NikolaPrica wrote:

I've firstly implemented like that but I've got comment that it might be better to implement it through table description instead of using multiple switch-case constructions for every register move instruction.

Yeah, I just saw that you have added a hook to TII.

The problem with bits in MCInstrDesc is that they apply to an opcode, not an instruction as a whole. If a given instruction has a certain property regardless of what operands it has, then the descriptor solution is good. In cases like "is-copy" (and a few others that are already there), it tells you a little, but not enough to be useful. Specifically, in some cases, there is no way to tell whether an instruction is a copy without looking at its operands. Moreover, in cases like "or reg, reg-always-zero", a target-independent pass will see two registers as inputs without knowing which is the one being copied. Excluding instructions that aren't always copies would reduce the accuracy of your analysis without making it easy to improve it later on. Following the logic of isCompare/isBranch, there could be a flag "could-be-copy" with the corresponding "analyzeCopy" or something like that that would tell the caller exactly what gets copied where.

I'm not going to oppose committing of this patch in the current form, I don't want it to bounce between two opposing ideas. At the same time I want to emphasize that common interfaces should have enough generality to be useful outside of the current objectives.

[NikolaPrica]

@kparzysz There are already instructions that have different bits set for different opcodes. But you have a point. In purpose of creating useful interface for TII the best way may be to use such bit isPossilbe[copy/move] to exclude non-copy-instructions and after exclusion return source and destination registers depending on opcode? Or just do it without MCInstDesc exclusion?
@sdardis What do you think about this?

[NikolaPrica]

Ping.

[qcolombet]

A while back, with Hal, we talked about having something like:
bool TargetInstrInfo::isEquivalentTo(GenericOpcode, ExpectedOperand)

Like, TII->isEquivalentTo(TargetOpcode::COPY, InputMI, [out]MODef, [out]MOSrc), would return true if InputMI is equivalent to a copy and would populate MODef and MOSrc with the related equivalent input and output.
The nice thing about such a thing is, thanks to GISel, we now have a way to express common structure like G_ADD.

(Credit to Hal for suggesting that.)

[NikolaPrica]

@qcolombet Yes. It would be nice to have such interface but it would require a lot of additional work ( which would need to address all needed generic opcodes). This patch could be part of such work.

I've extended isCopyInstr to return source and destination operands. The most usual case is, if it is move instruction, destination operand is 0 and source operand is 1 -> I didn't want to hoist it to the TII::isCopyInstr so it would cause any problems for future architectures that would support isMoveReg machine property.

Also for X86 instructions that have suffix _REV is saw in 'evex-to-vex-compress.mir' that they are used as for example "$ymm0 = VMOVAPDYrr_REV $ymm0" so I've let that destination operand is 0 and source is 1.

[qcolombet]

Hi,

The general direction makes sense and I agree you probably don't want to implement the full isEquivalentTo stuff I was talking about.
A general pointer you might have missed. We already track copy like instructions through isRegSequenceLike, isExtractSubRegLike and so on. These are more complicated than just plain copies though (e.g., VMOVRRD should already be supported).

Random thoughts:

• you may want to teach the peephole optimizer how to use that information to eliminate more copies.
• why can't you do your analysis before the instructions are lowered (i.e., when all that stuff are still copies).

Cheers,
-Quentin

lib/Target/ARM/ARMBaseInstrInfo.cpp

941

VMOVRRD should already fall into the "extract sub reg" category. So there shouldn't be anything to do here.

[NikolaPrica]

A general pointer you might have missed. We already track copy like instructions through isRegSequenceLike, isExtractSubRegLike and so on. These are more complicated than just plain copies though (e.g., VMOVRRD should already be supported).

Yes. I've missed that. Thanks for that! As you can see I left VMOVRRD ARM instruction as FIXME since it is more complicated copy. I'm not quite sure whether I should consolidate getRegSequenceInputs and getExtractSubregInputs into isCopyInstr or just use them as they are? Or maybe just rename isCopyInstr into isSimpleCopyInstr?

• you may want to teach the peephole optimizer how to use that information to eliminate more copies.

I could check that. But I suppose that it would be better to upgrade it with separate patch since I've already have one patch on the stack that depends on this functionality?

• why can't you do your analysis before the instructions are lowered (i.e., when all that stuff are still copies).

I've considered such approach but this information is needed to perform data flow analysis inside of each basic block in order to conclude in which registers is a variable kept. Such analysis could be performed only during or after the LiveDebugValues which is one of the latest passes. In this pass we propagate certain DBG_VALUE pseudo instructions (whose range in which it is valid is its basic block) in successors blocks that should also contain proper DBG_VALUE instruction. It is the place where we should know which register from each basic block might hold which variable in order to propagate valid variable DBG_VALUE. All DBG_VALUE analysis are performed on basic block level but only at this pass existing DBG_VALUEs are propagated to other blocks.

[qcolombet]

As you can see I left VMOVRRD ARM instruction as FIXME since it is more complicated copy.

Yes, I saw that :).

I'm not quite sure whether I should consolidate getRegSequenceInputs and getExtractSubregInputs into isCopyInstr or just use them as they are?

I would just leave them as they are. I was just pointing them out in case you wanted to see how we've done that so far.

Or maybe just rename isCopyInstr into isSimpleCopyInstr?

Up to you.

I could check that. But I suppose that it would be better to upgrade it with separate patch since I've already have one patch on the stack that depends on this functionality?

Definitely a different patch. I wanted to give other pointer on the kind of usages we may want to do with this callback.

why can't you do your analysis before the instructions are lowered (i.e., when all that stuff are still copies).

[...] only at this pass existing DBG_VALUEs are propagated to other blocks.

I see, that's unfortunate but I understand.

[NikolaPrica]

Updated just comment in ARMBaseInstrInfo.cpp

If there is no more comments and everything looks fine, can someone approve this?

[NikolaPrica]

Updating patch to match latest trunk version.

[aivchenk]

In a lot of cases, we would like to treat MoveReg-type instructions and generic COPY instruction in the same way.
E.g. in this code:

// Analyze copies (which don't overlap themselves).
if (MI->isCopy() && !TRI->regsOverlap(MI->getOperand(0).getReg(),
                                      MI->getOperand(1).getReg())) {
  unsigned Def = MI->getOperand(0).getReg();
  unsigned Src = MI->getOperand(1).getReg();

>

const MachineOperand *DefOp = nullptr;
const MachineOperand *SrcOp = nullptr;	 
// Analyze copies (which don't overlap themselves).	 
if (TII->isCopyInstr(*MI, SrcOp, DefOp) &&	 
    !TRI->regsOverlap(DefOp->getReg(), SrcOp->getReg())) {	 
  unsigned DefReg = DefOp->getReg();
  unsigned SrcReg = SrcOp->getReg();

But in order for this to work, we need to modify isCopyInstr to include isCopy check:

+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -3114,7 +3114,7 @@ void X86InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
bool X86InstrInfo::isCopyInstr(const MachineInstr &MI,

const MachineOperand *&Src,
const MachineOperand *&Dest) const {

• if (MI.isMoveReg()) {

+ if (MI.isCopy() || MI.isMoveReg()) {

Dest = &MI.getOperand(0);
Src = &MI.getOperand(1);
return true;

Do you think it makes sense?

[NikolaPrica]

Yes. I think that it make sense. IsCopyInstr() currently supports check target specific instructions, but with that extension it could be used to check more general instructions. The only thing that this extension needs to worry about is proper setting of source and destination operands, but I suppose that all of this instructions that are considered as IsCopy() have source as operand 1 and destination as operand 0.

[aivchenk]

Thanks, I submitted this idea for a review here: https://reviews.llvm.org/D49913

include/llvm/CodeGen/MachineInstr.h

public:
   }
 
   /// Return true if this instruction is a move immediate
   /// (including conditional moves) instruction.
   bool isMoveImmediate(QueryType Type = IgnoreBundle) const {
     return hasProperty(MCID::MoveImm, Type);
   }
 
+  /// Return true if this instruction is a register move.
+  /// (including moving values from subreg to reg)
+  bool isMoveReg(QueryType Type = IgnoreBundle) const {
+    return hasProperty(MCID::MoveReg, Type);
+  }
+
   /// Return true if this instruction is a bitcast instruction.
   bool isBitcast(QueryType Type = IgnoreBundle) const {
     return hasProperty(MCID::Bitcast, Type);
   }
 
   /// Return true if this instruction is a select instruction.
   bool isSelect(QueryType Type = IgnoreBundle) const {
     return hasProperty(MCID::Select, Type);

include/llvm/CodeGen/TargetInstrInfo.h

public:
   /// large registers. See for example the ARM target.
   virtual void copyPhysReg(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MI, const DebugLoc &DL,
                            unsigned DestReg, unsigned SrcReg,
                            bool KillSrc) const {
     llvm_unreachable("Target didn't implement TargetInstrInfo::copyPhysReg!");
   }
 
+  /// If the specific machine instruction is a instruction that moves/copies
+  /// value from one register to another register return true.
+  virtual bool isCopyInstr(MachineInstr &MI) const {
+    return MI.isMoveReg();
+  }
+
   /// Store the specified register of the given register class to the specified
   /// stack frame index. The store instruction is to be added to the given
   /// machine basic block before the specified machine instruction. If isKill
   /// is true, the register operand is the last use and must be marked kill.
   virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MI,
                                    unsigned SrcReg, bool isKill, int FrameIndex,
                                    const TargetRegisterClass *RC,

include/llvm/MC/MCInstrDesc.h

enum Flag {
   Return,
   Call,
   Barrier,
   Terminator,
   Branch,
   IndirectBranch,
   Compare,
   MoveImm,
+  MoveReg,
   Bitcast,
   Select,
   DelaySlot,
   FoldableAsLoad,
   MayLoad,
   MayStore,
   Predicable,
   NotDuplicable,
public:
   bool isPseudo() const { return Flags & (1ULL << MCID::Pseudo); }
 
   /// \brief Return true if the instruction is a return.
   bool isReturn() const { return Flags & (1ULL << MCID::Return); }
 
   /// \brief Return true if the instruction is an add instruction.
   bool isAdd() const { return Flags & (1ULL << MCID::Add); }
 
+  /// \brief Return true if the instruction is a register to register move.
+  bool isMoveReg() const { return Flags & (1ULL << MCID::MoveReg); }
+
   /// \brief  Return true if the instruction is a call.
   bool isCall() const { return Flags & (1ULL << MCID::Call); }
 
   /// \brief Returns true if the specified instruction stops control flow
   /// from executing the instruction immediately following it.  Examples include
   /// unconditional branches and return instructions.
   bool isBarrier() const { return Flags & (1ULL << MCID::Barrier); }
 

include/llvm/Target/Target.td

class Instruction {
 
   // These bits capture information about the high-level semantics of the
   // instruction.
   bit isReturn     = 0;     // Is this instruction a return instruction?
   bit isBranch     = 0;     // Is this instruction a branch instruction?
   bit isIndirectBranch = 0; // Is this instruction an indirect branch?
   bit isCompare    = 0;     // Is this instruction a comparison instruction?
   bit isMoveImm    = 0;     // Is this instruction a move immediate instruction?
+  bit isMoveReg    = 0;     // Is this instruction a move register instruction?
   bit isBitcast    = 0;     // Is this instruction a bitcast instruction?
   bit isSelect     = 0;     // Is this instruction a select instruction?
   bit isBarrier    = 0;     // Can control flow fall through this instruction?
   bit isCall       = 0;     // Is this instruction a call instruction?
   bit isAdd        = 0;     // Is this instruction an add instruction?
   bit canFoldAsLoad = 0;    // Can this be folded as a simple memory operand?
   bit mayLoad      = ?;     // Is it possible for this inst to read memory?
   bit mayStore     = ?;     // Is it possible for this inst to write memory?

lib/Target/ARM/ARMBaseInstrInfo.h

public:
   void copyFromCPSR(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                     unsigned DestReg, bool KillSrc,
                     const ARMSubtarget &Subtarget) const;
 
   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                    const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
                    bool KillSrc) const override;
 
+  bool isCopyInstr(MachineInstr &MI) const override;
+
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
                            unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC,
                            const TargetRegisterInfo *TRI) const override;
 
   void loadRegFromStackSlot(MachineBasicBlock &MBB,
                             MachineBasicBlock::iterator MBBI,

lib/Target/ARM/ARMBaseInstrInfo.cpp

if (Opc == ARM::MOVr)
       Mov = Mov.add(condCodeOp());
   }
   // Add implicit super-register defs and kills to the last instruction.
   Mov->addRegisterDefined(DestReg, TRI);
   if (KillSrc)
     Mov->addRegisterKilled(SrcReg, TRI);
 }
 
+bool ARMBaseInstrInfo::isCopyInstr(MachineInstr &MI) const {
+  // VORRq is considered as a move only if two inputs are
+  // the same register.
+  if (MI.getOpcode() == ARM::VORRq &&
+      MI.getOperand(1).getReg() == MI.getOperand(2).getReg())
+    return true;
+  else
+    return TargetInstrInfo::isCopyInstr(MI);
+}
+
 const MachineInstrBuilder &
 ARMBaseInstrInfo::AddDReg(MachineInstrBuilder &MIB, unsigned Reg,
                           unsigned SubIdx, unsigned State,
                           const TargetRegisterInfo *TRI) const {
   if (!SubIdx)
     return MIB.addReg(Reg, State);
 
   if (TargetRegisterInfo::isPhysicalRegister(Reg))

lib/Target/ARM/ARMInstrInfo.td

defm sysSTM : arm_ldst_mult<"stm", " ^", 0, 1, LdStMulFrm, IIC_iStore_m,
                                IIC_iStore_mu>;
 
 
 
 //===----------------------------------------------------------------------===//
 //  Move Instructions.
 //
 
-let hasSideEffects = 0 in
+let hasSideEffects = 0, isMoveReg = 1 in
 def MOVr : AsI1<0b1101, (outs GPR:$Rd), (ins GPR:$Rm), DPFrm, IIC_iMOVr,
                 "mov", "\t$Rd, $Rm", []>, UnaryDP, Sched<[WriteALU]> {
   bits<4> Rd;
   bits<4> Rm;
 
   let Inst{19-16} = 0b0000;
   let Inst{11-4} = 0b00000000;
   let Inst{25} = 0;

lib/Target/ARM/ARMInstrThumb.td

 }
 // Because we have an explicit tMOVSr below, we need an alias to handle
 // the immediate "movs" form here. Blech.
 def : tInstAlias <"movs $Rdn, $imm",
                  (tMOVi8 tGPR:$Rdn, CPSR, imm0_255:$imm, 14, 0)>;
 
 // A7-73: MOV(2) - mov setting flag.
 
-let hasSideEffects = 0 in {
+let hasSideEffects = 0, isMoveReg = 1 in {
 def tMOVr : Thumb1pI<(outs GPR:$Rd), (ins GPR:$Rm), AddrModeNone,
                       2, IIC_iMOVr,
                       "mov", "\t$Rd, $Rm", "", []>,
                   T1Special<{1,0,?,?}>, Sched<[WriteALU]> {
   // A8.6.97
   bits<4> Rd;
   bits<4> Rm;
   let Inst{7}   = Rd{3};
   let Inst{6-3} = Rm;

lib/Target/ARM/ARMInstrVFP.td

def VSQRTS : ASuI<0b11101, 0b11, 0b0001, 0b11, 0,
              Sched<[WriteFPSQRT32]>;
 
 def VSQRTH : AHuI<0b11101, 0b11, 0b0001, 0b11, 0,
                   (outs SPR:$Sd), (ins SPR:$Sm),
                   IIC_fpSQRT16, "vsqrt", ".f16\t$Sd, $Sm",
                   []>;
 
 let hasSideEffects = 0 in {
+let isMoveReg = 1 in {
 def VMOVD  : ADuI<0b11101, 0b11, 0b0000, 0b01, 0,
                   (outs DPR:$Dd), (ins DPR:$Dm),
                   IIC_fpUNA64, "vmov", ".f64\t$Dd, $Dm", []>;
 
 def VMOVS  : ASuI<0b11101, 0b11, 0b0000, 0b01, 0,
                   (outs SPR:$Sd), (ins SPR:$Sm),
                   IIC_fpUNA32, "vmov", ".f32\t$Sd, $Sm", []>;
+} // isMoveReg
 
 let PostEncoderMethod = "", DecoderNamespace = "VFPV8" in {
 def VMOVH  : ASuInp<0b11101, 0b11, 0b0000, 0b01, 0,
                   (outs SPR:$Sd), (ins SPR:$Sm),
                   IIC_fpUNA16, "vmovx.f16\t$Sd, $Sm", []>,
              Requires<[HasFullFP16]>;
 
 def VINSH  : ASuInp<0b11101, 0b11, 0b0000, 0b11, 0,
                   (outs SPR:$Sd), (ins SPR:$Sm),
                   IIC_fpUNA16, "vins.f16\t$Sd, $Sm", []>,
              Requires<[HasFullFP16]>;
 } // PostEncoderMethod
 } // hasSideEffects
 
 //===----------------------------------------------------------------------===//
 // FP <-> GPR Copies.  Int <-> FP Conversions.
 //
 
+let isMoveReg = 1 in {
 def VMOVRS : AVConv2I<0b11100001, 0b1010,
                       (outs GPR:$Rt), (ins SPR:$Sn),
                       IIC_fpMOVSI, "vmov", "\t$Rt, $Sn",
                       [(set GPR:$Rt, (bitconvert SPR:$Sn))]>,
              Sched<[WriteFPMOV]> {
   // Instruction operands.
   bits<4> Rt;
   bits<5> Sn;
 
def VMOVSR : AVConv4I<0b11100000, 0b1010,
 
   let Inst{6-5}   = 0b00;
   let Inst{3-0}   = 0b0000;
 
   // Some single precision VFP instructions may be executed on both NEON and VFP
   // pipelines.
   let D = VFPNeonDomain;
 }
+} // isMoveReg
 
-let hasSideEffects = 0 in {
+let hasSideEffects = 0, isMoveReg = 1 in {
 def VMOVRRD  : AVConv3I<0b11000101, 0b1011,
                         (outs GPR:$Rt, GPR:$Rt2), (ins DPR:$Dm),
                         IIC_fpMOVDI, "vmov", "\t$Rt, $Rt2, $Dm",
                  [(set GPR:$Rt, GPR:$Rt2, (arm_fmrrd DPR:$Dm))]>,
                Sched<[WriteFPMOV]> {
   // Instruction operands.
   bits<5> Dm;
   bits<4> Rt;

lib/Target/Mips/MicroMipsDSPInstrInfo.td

class REPLV_QB_MM_DESC : ABSQ_S_PH_MM_R2_DESC_BASE<"replv.qb", int_mips_repl_qb,
                                                    GPR32Opnd>;
 
 class WRDSP_MM_DESC {
   dag OutOperandList = (outs);
   dag InOperandList = (ins GPR32Opnd:$rt, uimm7:$mask);
   string AsmString = !strconcat("wrdsp", "\t$rt, $mask");
   list<dag> Pattern = [(int_mips_wrdsp GPR32Opnd:$rt, immZExt7:$mask)];
   InstrItinClass Itinerary = NoItinerary;
+  bit isMoveReg = 1;
 }
 
 class BPOSGE32C_MMR3_DESC {
   dag OutOperandList = (outs);
   dag InOperandList = (ins brtarget1SImm16:$offset);
   string AsmString = !strconcat("bposge32c", "\t$offset");
   InstrItinClass Itinerary = NoItinerary;
   bit isBranch = 1;

lib/Target/Mips/MicroMipsInstrFPU.td

 defm FABS : ABSS_MMM<"abs.d", II_SQRT_D, fabs>, ABS_FM_MM<1, 0xd>;
 
 let DecoderNamespace = "MicroMips" in {
   def FABS_S_MM : MMRel, ABSS_FT<"abs.s", FGR32Opnd, FGR32Opnd, II_ABS, fabs>,
                   ABS_FM_MM<0, 0xd>, ISA_MICROMIPS;
 }
 
 def FMOV_S_MM : MMRel, ABSS_FT<"mov.s", FGR32Opnd, FGR32Opnd, II_MOV_S>,
-                ABS_FM_MM<0, 0x1>, ISA_MICROMIPS;
+                ABS_FM_MM<0, 0x1>, ISA_MICROMIPS {
+  let isMoveReg = 1;
+}
 def FNEG_S_MM : MMRel, ABSS_FT<"neg.s", FGR32Opnd, FGR32Opnd, II_NEG, fneg>,
                 ABS_FM_MM<0, 0x2d>, ISA_MICROMIPS;
 
 let DecoderNamespace = "MicroMips" in {
   def CVT_D32_S_MM : MMRel, ABSS_FT<"cvt.d.s", AFGR64Opnd, FGR32Opnd, II_CVT>,
                      ABS_FM_MM<0, 0x4d>, ISA_MICROMIPS, FGR_32;
   def CVT_D32_W_MM : MMRel, ABSS_FT<"cvt.d.w", AFGR64Opnd, FGR32Opnd, II_CVT>,
                      ABS_FM_MM<1, 0x4d>, ISA_MICROMIPS, FGR_32;

lib/Target/Mips/MicroMipsInstrInfo.td

def movep_regpair : Operand<i32> {
   let MIOperandInfo = (ops ptr_rc, ptr_rc);
 }
 
 class MovePMM16<string opstr, RegisterOperand RO> :
 MicroMipsInst16<(outs movep_regpair:$dst_regs), (ins RO:$rs, RO:$rt),
                  !strconcat(opstr, "\t$dst_regs, $rs, $rt"), [],
                  NoItinerary, FrmR> {
   let isReMaterializable = 1;
+  let isMoveReg = 1;
 }
 
 /// A register pair used by load/store pair instructions.
 def RegPairAsmOperand : AsmOperandClass {
   let Name = "RegPair";
   let ParserMethod = "parseRegisterPair";
   let PredicateMethod = "isRegPair";
 }
class AddImmUSP<string opstr> :
   MicroMipsInst16<(outs), (ins simm9_addiusp:$imm),
                   !strconcat(opstr, "\t$imm"), [], II_ADDIU, FrmI>;
 
 class MoveFromHILOMM<string opstr, RegisterOperand RO, Register UseReg> :
       MicroMipsInst16<(outs RO:$rd), (ins), !strconcat(opstr, "\t$rd"),
   [], II_MFHI_MFLO, FrmR> {
   let Uses = [UseReg];
   let hasSideEffects = 0;
+  let isMoveReg = 1;
 }
 
 class MoveMM16<string opstr, RegisterOperand RO>
     :  MicroMipsInst16<(outs RO:$rd), (ins RO:$rs),
                        !strconcat(opstr, "\t$rd, $rs"), [], II_MOVE, FrmR> {
   let isReMaterializable = 1;
+  let isMoveReg = 1;
 }
 
 class LoadImmMM16<string opstr, Operand Od, RegisterOperand RO> :
   MicroMipsInst16<(outs RO:$rd), (ins Od:$imm),
                   !strconcat(opstr, "\t$rd, $imm"), [], II_LI, FrmI> {
   let isReMaterializable = 1;
 }
 

lib/Target/Mips/Mips16InstrInfo.td

 //
 def Move32R16: FI8_MOV32R16_ins<"move", IIM16Alu>;
 
 //
 // Format: MOVE ry, r32 MIPS16e
 //Purpose: Move
 // To move the contents of a GPR to a GPR.
 //
-def MoveR3216: FI8_MOVR3216_ins<"move", IIM16Alu>;
+def MoveR3216: FI8_MOVR3216_ins<"move", IIM16Alu> {
+  let isMoveReg = 1;
+}
 
 //
 // Format: MFHI rx MIPS16e
 // Purpose: Move From HI Register
 // To copy the special purpose HI register to a GPR.
 //
 def Mfhi16: FRR16_M_ins<0b10000, "mfhi", IIM16Alu> {
   let Uses = [HI0];
   let hasSideEffects = 0;
+  let isMoveReg = 1;
 }
 
 //
 // Format: MFLO rx MIPS16e
 // Purpose: Move From LO Register
 // To copy the special purpose LO register to a GPR.
 //
 def Mflo16: FRR16_M_ins<0b10010, "mflo", IIM16Alu> {
   let Uses = [LO0];
   let hasSideEffects = 0;
+  let isMoveReg = 0;
 }
 
 //
 // Pseudo Instruction for mult
 //
 def MultRxRy16:  FMULT16_ins<"mult",  IIM16Alu> {
   let isCommutable = 1;
   let hasSideEffects = 0;

lib/Target/Mips/Mips64InstrInfo.td

def DEXT64_32 : InstSE<(outs GPR64Opnd:$rt),
                               uimm5_plus1:$size),
                          "dext $rt, $rs, $pos, $size", [], II_EXT, FrmR, "dext">,
                   EXT_FM<3>, ISA_MIPS64R2;
 }
 
 let isCodeGenOnly = 1, rs = 0, shamt = 0 in {
   def DSLL64_32 : FR<0x00, 0x3c, (outs GPR64:$rd), (ins GPR32:$rt),
                      "dsll\t$rd, $rt, 32", [], II_DSLL>;
+  let isMoveReg = 1 in {
     def SLL64_32 : FR<0x0, 0x00, (outs GPR64:$rd), (ins GPR32:$rt),
                       "sll\t$rd, $rt, 0", [], II_SLL>;
     def SLL64_64 : FR<0x0, 0x00, (outs GPR64:$rd), (ins GPR64:$rt),
                       "sll\t$rd, $rt, 0", [], II_SLL>;
   }
+}
 
 // We need the following pseudo instruction to avoid offset calculation for
 // long branches.  See the comment in file MipsLongBranch.cpp for detailed
 // explanation.
 
 // Expands to: daddiu $dst, $src, %PART($tgt - $baltgt)
 // where %PART may be %hi or %lo, depending on the relocation kind
 // that $tgt is annotated with.

lib/Target/Mips/MipsDSPInstrInfo.td

 class RDDSP_DESC_BASE<string instr_asm, SDPatternOperator OpNode,
                       InstrItinClass itin> {
   dag OutOperandList = (outs GPR32Opnd:$rd);
   dag InOperandList = (ins uimm10:$mask);
   string AsmString = !strconcat(instr_asm, "\t$rd, $mask");
   list<dag> Pattern = [(set GPR32Opnd:$rd, (OpNode immZExt10:$mask))];
   InstrItinClass Itinerary = itin;
   string BaseOpcode = instr_asm;
+  bit isMoveReg = 1;
 }
 
 class WRDSP_DESC_BASE<string instr_asm, SDPatternOperator OpNode,
                       InstrItinClass itin> {
   dag OutOperandList = (outs);
   dag InOperandList = (ins GPR32Opnd:$rs, uimm10:$mask);
   string AsmString = !strconcat(instr_asm, "\t$rs, $mask");
   list<dag> Pattern = [(OpNode GPR32Opnd:$rs, immZExt10:$mask)];
   InstrItinClass Itinerary = itin;
   string BaseOpcode = instr_asm;
+  bit isMoveReg = 1;
 }
 
 class DPA_W_PH_DESC_BASE<string instr_asm, SDPatternOperator OpNode> {
   dag OutOperandList = (outs ACC64DSPOpnd:$ac);
   dag InOperandList = (ins GPR32Opnd:$rs, GPR32Opnd:$rt, ACC64DSPOpnd:$acin);
   string AsmString = !strconcat(instr_asm, "\t$ac, $rs, $rt");
   list<dag> Pattern = [(set ACC64DSPOpnd:$ac,
                         (OpNode GPR32Opnd:$rs, GPR32Opnd:$rt, ACC64DSPOpnd:$acin))];

 class MFHI_DESC_BASE<string instr_asm, RegisterOperand RO, SDNode OpNode,
                      InstrItinClass itin> {
   dag OutOperandList = (outs GPR32Opnd:$rd);
   dag InOperandList = (ins RO:$ac);
   string AsmString = !strconcat(instr_asm, "\t$rd, $ac");
   list<dag> Pattern = [(set GPR32Opnd:$rd, (OpNode RO:$ac))];
   InstrItinClass Itinerary = itin;
   string BaseOpcode = instr_asm;
+  bit isMoveReg = 1;
 }
 
 class MTHI_DESC_BASE<string instr_asm, RegisterOperand RO, InstrItinClass itin> {
   dag OutOperandList = (outs RO:$ac);
   dag InOperandList = (ins GPR32Opnd:$rs);
   string AsmString = !strconcat(instr_asm, "\t$rs, $ac");
   InstrItinClass Itinerary = itin;
   string BaseOpcode = instr_asm;
+  bit isMoveReg = 1;
 }
 
 class BPOSGE32_PSEUDO_DESC_BASE<SDPatternOperator OpNode, InstrItinClass itin> :
   MipsPseudo<(outs GPR32Opnd:$dst), (ins), [(set GPR32Opnd:$dst, (OpNode))]> {
   bit usesCustomInserter = 1;
 }
 
 class BPOSGE32_DESC_BASE<string instr_asm, DAGOperand opnd,

lib/Target/Mips/MipsInstrFPU.td

multiclass ROUND_M<string opstr, InstrItinClass Itin> {
   def _D64 : StdMMR6Rel, ABSS_FT<opstr, FGR32Opnd, FGR64Opnd, Itin>, FGR_64 {
     let DecoderNamespace = "MipsFP64";
   }
 }
 
 class MFC1_FT<string opstr, RegisterOperand DstRC, RegisterOperand SrcRC,
               InstrItinClass Itin, SDPatternOperator OpNode= null_frag> :
   InstSE<(outs DstRC:$rt), (ins SrcRC:$fs), !strconcat(opstr, "\t$rt, $fs"),
-         [(set DstRC:$rt, (OpNode SrcRC:$fs))], Itin, FrmFR, opstr>, HARDFLOAT;
+         [(set DstRC:$rt, (OpNode SrcRC:$fs))], Itin, FrmFR, opstr>, HARDFLOAT {
+  let isMoveReg = 1;
+}
 
 class MTC1_FT<string opstr, RegisterOperand DstRC, RegisterOperand SrcRC,
               InstrItinClass Itin, SDPatternOperator OpNode= null_frag> :
   InstSE<(outs DstRC:$fs), (ins SrcRC:$rt), !strconcat(opstr, "\t$rt, $fs"),
-         [(set DstRC:$fs, (OpNode SrcRC:$rt))], Itin, FrmFR, opstr>, HARDFLOAT;
+         [(set DstRC:$fs, (OpNode SrcRC:$rt))], Itin, FrmFR, opstr>, HARDFLOAT {
+  let isMoveReg = 1;
+}
 
 class MTC1_64_FT<string opstr, RegisterOperand DstRC, RegisterOperand SrcRC,
                  InstrItinClass Itin> :
   InstSE<(outs DstRC:$fs), (ins DstRC:$fs_in, SrcRC:$rt),
          !strconcat(opstr, "\t$rt, $fs"), [], Itin, FrmFR, opstr>, HARDFLOAT {
   // $fs_in is part of a white lie to work around a widespread bug in the FPU
   // implementation. See expandBuildPairF64 for details.
   let Constraints = "$fs = $fs_in";
def MTHC1_D64 : MTC1_64_FT<"mthc1", FGR64Opnd, GPR32Opnd, II_MTHC1>,
     let DecoderNamespace = "MipsFP64";
   }
 }
 let AdditionalPredicates = [NotInMicroMips] in {
   def DMTC1 : MTC1_FT<"dmtc1", FGR64Opnd, GPR64Opnd, II_DMTC1,
               bitconvert>, MFC1_FM<5>, ISA_MIPS3;
   def DMFC1 : MFC1_FT<"dmfc1", GPR64Opnd, FGR64Opnd, II_DMFC1,
                       bitconvert>, MFC1_FM<1>, ISA_MIPS3;
+  let isMoveReg = 1 in {
     def FMOV_S   : MMRel, ABSS_FT<"mov.s", FGR32Opnd, FGR32Opnd, II_MOV_S>,
                    ABSS_FM<0x6, 16>;
     def FMOV_D32 : MMRel, ABSS_FT<"mov.d", AFGR64Opnd, AFGR64Opnd, II_MOV_D>,
                    ABSS_FM<0x6, 17>, FGR_32;
     def FMOV_D64 : ABSS_FT<"mov.d", FGR64Opnd, FGR64Opnd, II_MOV_D>,
                    ABSS_FM<0x6, 17>, FGR_64 {
                      let DecoderNamespace = "MipsFP64";
     }
+  } // isMoveReg
 }
 
 /// Floating Point Memory Instructions
 let AdditionalPredicates = [NotInMicroMips] in {
   def LWC1 : MMRel, LW_FT<"lwc1", FGR32Opnd, mem_simm16, II_LWC1, load>,
              LW_FM<0x31>;
   def SWC1 : MMRel, SW_FT<"swc1", FGR32Opnd, mem_simm16, II_SWC1, store>,
              LW_FM<0x39>;

lib/Target/Mips/MipsInstrInfo.td

class PseudoMFLOHI<RegisterClass DstRC, RegisterClass SrcRC, SDNode OpNode>
   : PseudoSE<(outs DstRC:$rd), (ins SrcRC:$hilo),
              [(set DstRC:$rd, (OpNode SrcRC:$hilo))], II_MFHI_MFLO>;
 
 class MoveFromLOHI<string opstr, RegisterOperand RO, Register UseReg>:
   InstSE<(outs RO:$rd), (ins), !strconcat(opstr, "\t$rd"), [], II_MFHI_MFLO,
          FrmR, opstr> {
   let Uses = [UseReg];
   let hasSideEffects = 0;
+  let isMoveReg = 1;
 }
 
 class PseudoMTLOHI<RegisterClass DstRC, RegisterClass SrcRC>
   : PseudoSE<(outs DstRC:$lohi), (ins SrcRC:$lo, SrcRC:$hi),
              [(set DstRC:$lohi, (MipsMTLOHI SrcRC:$lo, SrcRC:$hi))],
              II_MTHI_MTLO>;
 
 class MoveToLOHI<string opstr, RegisterOperand RO, list<Register> DefRegs>:
   InstSE<(outs), (ins RO:$rs), !strconcat(opstr, "\t$rs"), [], II_MTHI_MTLO,
   FrmR, opstr> {
   let Defs = DefRegs;
   let hasSideEffects = 0;
+  let isMoveReg = 1;
 }
 
 class EffectiveAddress<string opstr, RegisterOperand RO> :
   InstSE<(outs RO:$rt), (ins mem_ea:$addr), !strconcat(opstr, "\t$rt, $addr"),
          [(set RO:$rt, addr:$addr)], II_ADDIU, FrmI,
          !strconcat(opstr, "_lea")> {
   let isCodeGenOnly = 1;
   let hasNoSchedulingInfo = 1;

lib/Target/Mips/MipsMSAInstrInfo.td

class CEQI_D_DESC : MSA_I5_DESC_BASE<"ceqi.d", vseteq_v2i64, vsplati64_simm5,
                                      MSA128DOpnd>;
 
 class CFCMSA_DESC {
   dag OutOperandList = (outs GPR32Opnd:$rd);
   dag InOperandList = (ins MSA128CROpnd:$cs);
   string AsmString = "cfcmsa\t$rd, $cs";
   InstrItinClass Itinerary = NoItinerary;
   bit hasSideEffects = 1;
+  bit isMoveReg = 1;
 }
 
 class CLE_S_B_DESC : MSA_3R_DESC_BASE<"cle_s.b", vsetle_v16i8, MSA128BOpnd>;
 class CLE_S_H_DESC : MSA_3R_DESC_BASE<"cle_s.h", vsetle_v8i16, MSA128HOpnd>;
 class CLE_S_W_DESC : MSA_3R_DESC_BASE<"cle_s.w", vsetle_v4i32, MSA128WOpnd>;
 class CLE_S_D_DESC : MSA_3R_DESC_BASE<"cle_s.d", vsetle_v2i64, MSA128DOpnd>;
 
 class CLE_U_B_DESC : MSA_3R_DESC_BASE<"cle_u.b", vsetule_v16i8, MSA128BOpnd>;
class COPY_FD_PSEUDO_DESC : MSA_COPY_PSEUDO_BASE<vector_extract, v2f64,
                                                  MSA128D>;
 
 class CTCMSA_DESC {
   dag OutOperandList = (outs);
   dag InOperandList = (ins MSA128CROpnd:$cd, GPR32Opnd:$rs);
   string AsmString = "ctcmsa\t$cd, $rs";
   InstrItinClass Itinerary = NoItinerary;
   bit hasSideEffects = 1;
+  bit isMoveReg = 1;
 }
 
 class DIV_S_B_DESC : MSA_3R_DESC_BASE<"div_s.b", sdiv, MSA128BOpnd>;
 class DIV_S_H_DESC : MSA_3R_DESC_BASE<"div_s.h", sdiv, MSA128HOpnd>;
 class DIV_S_W_DESC : MSA_3R_DESC_BASE<"div_s.w", sdiv, MSA128WOpnd>;
 class DIV_S_D_DESC : MSA_3R_DESC_BASE<"div_s.d", sdiv, MSA128DOpnd>;
 
 class DIV_U_B_DESC : MSA_3R_DESC_BASE<"div_u.b", udiv, MSA128BOpnd>;

 class MOD_U_D_DESC : MSA_3R_DESC_BASE<"mod_u.d", urem, MSA128DOpnd>;
 
 class MOVE_V_DESC {
   dag OutOperandList = (outs MSA128BOpnd:$wd);
   dag InOperandList = (ins MSA128BOpnd:$ws);
   string AsmString = "move.v\t$wd, $ws";
   list<dag> Pattern = [];
   InstrItinClass Itinerary = NoItinerary;
+  bit isMoveReg = 1;
 }
 
 class MSUB_Q_H_DESC : MSA_3RF_4RF_DESC_BASE<"msub_q.h", int_mips_msub_q_h,
                                             MSA128HOpnd>;
 class MSUB_Q_W_DESC : MSA_3RF_4RF_DESC_BASE<"msub_q.w", int_mips_msub_q_w,
                                             MSA128WOpnd>;
 
 class MSUBR_Q_H_DESC : MSA_3RF_4RF_DESC_BASE<"msubr_q.h", int_mips_msubr_q_h,

lib/Target/Mips/MipsSEInstrInfo.h

public:
   /// any side effects other than storing to the stack slot.
   unsigned isStoreToStackSlot(const MachineInstr &MI,
                               int &FrameIndex) const override;
 
   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
                    const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
                    bool KillSrc) const override;
 
+  bool isCopyInstr(MachineInstr &MI) const override;
+
   void storeRegToStack(MachineBasicBlock &MBB,
                        MachineBasicBlock::iterator MI,
                        unsigned SrcReg, bool isKill, int FrameIndex,
                        const TargetRegisterClass *RC,
                        const TargetRegisterInfo *TRI,
                        int64_t Offset) const override;
 
   void loadRegFromStack(MachineBasicBlock &MBB,

lib/Target/Mips/MipsSEInstrInfo.cpp

void MipsSEInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
 
   if (SrcReg)
     MIB.addReg(SrcReg, getKillRegState(KillSrc));
 
   if (ZeroReg)
     MIB.addReg(ZeroReg);
 }
 
+/// We check for the common case of 'or', as it's MIPS' preferred instruction
+/// for GPRs but we have to check the operands to ensure that is the case.
+/// Other move instructions for MIPS are directly identifiable.
+bool MipsSEInstrInfo::isCopyInstr(MachineInstr &MI) const {
+  switch (MI.getOpcode()) {
+  case Mips::OR_MM:
+  case Mips::OR:
+    if (MI.getOperand(2).getReg() == Mips::ZERO)
+      return true;
+  case Mips::OR64:
+    if (MI.getOperand(2).getReg() == Mips::ZERO_64)
+      return true;
+  default:
+    return TargetInstrInfo::isCopyInstr(MI);
+  }
+}
+
 void MipsSEInstrInfo::
 storeRegToStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                 unsigned SrcReg, bool isKill, int FI,
                 const TargetRegisterClass *RC, const TargetRegisterInfo *TRI,
                 int64_t Offset) const {
   DebugLoc DL;
   MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOStore);
 

lib/Target/X86/X86InstrAVX512.td

 // Mask register copy, including
 // - copy between mask registers
 // - load/store mask registers
 // - copy from GPR to mask register and vice versa
 //
 multiclass avx512_mask_mov<bits<8> opc_kk, bits<8> opc_km, bits<8> opc_mk,
                          string OpcodeStr, RegisterClass KRC,
                          ValueType vvt, X86MemOperand x86memop> {
-  let hasSideEffects = 0, SchedRW = [WriteMove] in
+  let isMoveReg = 1, hasSideEffects = 0, SchedRW = [WriteMove] in
   def kk : I<opc_kk, MRMSrcReg, (outs KRC:$dst), (ins KRC:$src),
              !strconcat(OpcodeStr, "\t{$src, $dst|$dst, $src}"), [],
              IIC_SSE_MOVDQ>, Sched<[WriteMove]>;
   def km : I<opc_km, MRMSrcMem, (outs KRC:$dst), (ins x86memop:$src),
              !strconcat(OpcodeStr, "\t{$src, $dst|$dst, $src}"),
              [(set KRC:$dst, (vvt (load addr:$src)))], IIC_SSE_MOVDQ>,
              Sched<[WriteLoad]>;
   def mk : I<opc_mk, MRMDestMem, (outs), (ins x86memop:$dst, KRC:$src),
              !strconcat(OpcodeStr, "\t{$src, $dst|$dst, $src}"),
              [(store KRC:$src, addr:$dst)], IIC_SSE_MOVDQ>,
              Sched<[WriteStore]>;
 }
 
 multiclass avx512_mask_mov_gpr<bits<8> opc_kr, bits<8> opc_rk,
                              string OpcodeStr,
                              RegisterClass KRC, RegisterClass GRC> {
-  let hasSideEffects = 0 in {
+  let hasSideEffects = 0, isMoveReg = 1 in {
     def kr : I<opc_kr, MRMSrcReg, (outs KRC:$dst), (ins GRC:$src),
                !strconcat(OpcodeStr, "\t{$src, $dst|$dst, $src}"), [],
                IIC_SSE_MOVD_ToGP>, Sched<[WriteMove]>;
     def rk : I<opc_rk, MRMSrcReg, (outs GRC:$dst), (ins KRC:$src),
                !strconcat(OpcodeStr, "\t{$src, $dst|$dst, $src}"), [],
                IIC_SSE_MOVD_ToGP>, Sched<[WriteMove]>;
   }
 }
 
 let Predicates = [HasDQI] in
   defm KMOVB : avx512_mask_mov<0x90, 0x90, 0x91, "kmovb", VK8, v8i1, i8mem>,
                avx512_mask_mov_gpr<0x92, 0x93, "kmovb", VK8, GR32>,
                VEX, PD;
 
 let Predicates = [HasAVX512] in
   defm KMOVW : avx512_mask_mov<0x90, 0x90, 0x91, "kmovw", VK16, v16i1, i16mem>,
                avx512_mask_mov_gpr<0x92, 0x93, "kmovw", VK16, GR32>,
                VEX, PS;
 
 let Predicates = [HasBWI] in {
   defm KMOVD : avx512_mask_mov<0x90, 0x90, 0x91, "kmovd", VK32, v32i1,i32mem>,
                VEX, PD, VEX_W;
   defm KMOVD : avx512_mask_mov_gpr<0x92, 0x93, "kmovd", VK32, GR32>,
                VEX, XD;
   defm KMOVQ : avx512_mask_mov<0x90, 0x90, 0x91, "kmovq", VK64, v64i1, i64mem>,
                VEX, PS, VEX_W;
   defm KMOVQ : avx512_mask_mov_gpr<0x92, 0x93, "kmovq", VK64, GR64>,
                VEX, XD, VEX_W;
 }

 //
 
 
 multiclass avx512_load<bits<8> opc, string OpcodeStr, MoveLoadStoreItins itins,
                        X86VectorVTInfo _, PatFrag ld_frag, PatFrag mload,
                        bit NoRMPattern = 0,
                        SDPatternOperator SelectOprr = vselect> {
   let hasSideEffects = 0 in {
+  let isMoveReg = 1 in
   def rr : AVX512PI<opc, MRMSrcReg, (outs _.RC:$dst), (ins _.RC:$src),
                     !strconcat(OpcodeStr, "\t{$src, $dst|$dst, $src}"), [],
                     _.ExeDomain, itins.rr>, EVEX, Sched<[WriteMove]>;
   def rrkz : AVX512PI<opc, MRMSrcReg, (outs _.RC:$dst),
                       (ins _.KRCWM:$mask,  _.RC:$src),
                       !strconcat(OpcodeStr, "\t{$src, ${dst} {${mask}} {z}|",
                        "${dst} {${mask}} {z}, $src}"),
                        [(set _.RC:$dst, (_.VT (SelectOprr _.KRCWM:$mask,
                                            (_.VT _.RC:$src),
multiclass avx512_alignedload_vl<bits<8> opc, string OpcodeStr,
   }
 }
 
 multiclass avx512_load_vl<bits<8> opc, string OpcodeStr,
                                   AVX512VLVectorVTInfo _,
                                   Predicate prd,
                                   bit NoRMPattern = 0,
                                   SDPatternOperator SelectOprr = vselect> {
   let Predicates = [prd] in
   defm Z : avx512_load<opc, OpcodeStr, SSE_MOVU, _.info512, _.info512.LdFrag,
                        masked_load_unaligned, NoRMPattern,
                        SelectOprr>, EVEX_V512;
 
   let Predicates = [prd, HasVLX] in {
   defm Z256 : avx512_load<opc, OpcodeStr, SSE_MOVU, _.info256, _.info256.LdFrag,
                          masked_load_unaligned, NoRMPattern,
                          SelectOprr>, EVEX_V256;
   defm Z128 : avx512_load<opc, OpcodeStr, SSE_MOVU, _.info128, _.info128.LdFrag,
                          masked_load_unaligned, NoRMPattern,
                          SelectOprr>, EVEX_V128;
   }
 }
 
 multiclass avx512_store<bits<8> opc, string OpcodeStr, MoveLoadStoreItins itins,
                         X86VectorVTInfo _, PatFrag st_frag, PatFrag mstore,
                         string Name, bit NoMRPattern = 0> {
   let hasSideEffects = 0 in {
+  let isMoveReg = 1 in
   def rr_REV  : AVX512PI<opc, MRMDestReg, (outs _.RC:$dst), (ins _.RC:$src),
                          OpcodeStr # ".s\t{$src, $dst|$dst, $src}",
                          [], _.ExeDomain, itins.rr>, EVEX, FoldGenData<Name#rr>,
                          Sched<[WriteMove]>;
   def rrk_REV : AVX512PI<opc, MRMDestReg, (outs  _.RC:$dst),
                          (ins _.KRCWM:$mask, _.RC:$src),
                          OpcodeStr # ".s\t{$src, ${dst} {${mask}}|"#
                          "${dst} {${mask}}, $src}",
                          [], _.ExeDomain, itins.rr>,  EVEX, EVEX_K,

lib/Target/X86/X86InstrInfo.td

def CMPSQ : RI<0xA7, RawFrmDstSrc, (outs), (ins dstidx64:$dst, srcidx64:$src),
                Requires<[In64BitMode]>;
 }
 } // SchedRW
 
 //===----------------------------------------------------------------------===//
 //  Move Instructions.
 //
 let SchedRW = [WriteMove] in {
-let hasSideEffects = 0 in {
+let hasSideEffects = 0, isMoveReg = 1 in {
 def MOV8rr  : I<0x88, MRMDestReg, (outs GR8 :$dst), (ins GR8 :$src),
                 "mov{b}\t{$src, $dst|$dst, $src}", [], IIC_MOV>;
 def MOV16rr : I<0x89, MRMDestReg, (outs GR16:$dst), (ins GR16:$src),
                 "mov{w}\t{$src, $dst|$dst, $src}", [], IIC_MOV>, OpSize16;
 def MOV32rr : I<0x89, MRMDestReg, (outs GR32:$dst), (ins GR32:$src),
                 "mov{l}\t{$src, $dst|$dst, $src}", [], IIC_MOV>, OpSize32;
 def MOV64rr : RI<0x89, MRMDestReg, (outs GR64:$dst), (ins GR64:$src),
                  "mov{q}\t{$src, $dst|$dst, $src}", [], IIC_MOV>;

 def MOV64o64a : RIi64<0xA3, RawFrmMemOffs, (outs), (ins offset64_64:$dst),
                      "movabs{q}\t{%rax, $dst|$dst, rax}", [], IIC_MOV_MEM>,
                      AdSize64;
 } // mayStore
 } // SchedRW
 } // hasSideEffects = 0
 
 let isCodeGenOnly = 1, ForceDisassemble = 1, hasSideEffects = 0,
-    SchedRW = [WriteMove] in {
+    SchedRW = [WriteMove], isMoveReg = 1 in {
 def MOV8rr_REV : I<0x8A, MRMSrcReg, (outs GR8:$dst), (ins GR8:$src),
                    "mov{b}\t{$src, $dst|$dst, $src}", [], IIC_MOV>,
                    FoldGenData<"MOV8rr">;
 def MOV16rr_REV : I<0x8B, MRMSrcReg, (outs GR16:$dst), (ins GR16:$src),
                     "mov{w}\t{$src, $dst|$dst, $src}", [], IIC_MOV>, OpSize16,
                     FoldGenData<"MOV16rr">;
 def MOV32rr_REV : I<0x8B, MRMSrcReg, (outs GR32:$dst), (ins GR32:$src),
                     "mov{l}\t{$src, $dst|$dst, $src}", [], IIC_MOV>, OpSize32,
                     FoldGenData<"MOV32rr">;
def MOV64mr : RI<0x89, MRMDestMem, (outs), (ins i64mem:$dst, GR64:$src),
                  "mov{q}\t{$src, $dst|$dst, $src}",
                  [(store GR64:$src, addr:$dst)], IIC_MOV_MEM>;
 } // SchedRW
 
 // Versions of MOV8rr, MOV8mr, and MOV8rm that use i8mem_NOREX and GR8_NOREX so
 // that they can be used for copying and storing h registers, which can't be
 // encoded when a REX prefix is present.
 let isCodeGenOnly = 1 in {
-let hasSideEffects = 0 in
+let hasSideEffects = 0, isMoveReg = 1 in
 def MOV8rr_NOREX : I<0x88, MRMDestReg,
                      (outs GR8_NOREX:$dst), (ins GR8_NOREX:$src),
                      "mov{b}\t{$src, $dst|$dst, $src}", [], IIC_MOV>,
                    Sched<[WriteMove]>;
 let mayStore = 1, hasSideEffects = 0 in
 def MOV8mr_NOREX : I<0x88, MRMDestMem,
                      (outs), (ins i8mem_NOREX:$dst, GR8_NOREX:$src),
                      "mov{b}\t{$src, $dst|$dst, $src}", [],

lib/Target/X86/X86InstrMMX.td

 // recognize a register-register movq, we write them as
 // movd.
 let SchedRW = [WriteMove], isBitcast = 1 in {
 def MMX_MOVD64from64rr : MMXRI<0x7E, MRMDestReg,
                                (outs GR64:$dst), (ins VR64:$src),
                                "movq\t{$src, $dst|$dst, $src}",
                              [(set GR64:$dst,
                               (bitconvert VR64:$src))], IIC_MMX_MOV_REG_MM>;
-let hasSideEffects = 0 in
+let isMoveReg = 1, hasSideEffects = 0 in {
 def MMX_MOVQ64rr : MMXI<0x6F, MRMSrcReg, (outs VR64:$dst), (ins VR64:$src),
                         "movq\t{$src, $dst|$dst, $src}", [],
                         IIC_MMX_MOVQ_RR>;
-let isCodeGenOnly = 1, ForceDisassemble = 1, hasSideEffects = 0 in {
+let isCodeGenOnly = 1, ForceDisassemble = 1 in {
 def MMX_MOVQ64rr_REV : MMXI<0x7F, MRMDestReg, (outs VR64:$dst), (ins VR64:$src),
                         "movq\t{$src, $dst|$dst, $src}", [],
                         IIC_MMX_MOVQ_RR>, FoldGenData<"MMX_MOVQ64rr">;
 }
+} // isMoveReg, hasSideEffects
 } // SchedRW
 
 let isCodeGenOnly = 1, ForceDisassemble = 1, hasSideEffects = 0, mayStore = 1 in
 def MMX_MOVD64from64rm : MMXRI<0x7E, MRMDestMem,
                                (outs), (ins i64mem:$dst, VR64:$src),
                                "movq\t{$src, $dst|$dst, $src}",
                                [], IIC_MMX_MOV_REG_MM>, Sched<[WriteStore]>;
 

lib/Target/X86/X86InstrSSE.td

 //===----------------------------------------------------------------------===//
 // SSE 1 & 2 - Move Aligned/Unaligned FP Instructions
 //===----------------------------------------------------------------------===//
 
 multiclass sse12_mov_packed<bits<8> opc, RegisterClass RC,
                             X86MemOperand x86memop, PatFrag ld_frag,
                             string asm, Domain d,
                             OpndItins itins> {
-let hasSideEffects = 0 in
+let hasSideEffects = 0, isMoveReg = 1 in
   def rr : PI<opc, MRMSrcReg, (outs RC:$dst), (ins RC:$src),
               !strconcat(asm, "\t{$src, $dst|$dst, $src}"), [], itins.rr, d>,
            Sched<[WriteFShuffle]>;
 let canFoldAsLoad = 1, isReMaterializable = 1 in
   def rm : PI<opc, MRMSrcMem, (outs RC:$dst), (ins x86memop:$src),
               !strconcat(asm, "\t{$src, $dst|$dst, $src}"),
                    [(set RC:$dst, (ld_frag addr:$src))], itins.rm, d>,
            Sched<[WriteLoad]>;
 }

 def VMOVUPDYmr : VPDI<0x11, MRMDestMem, (outs), (ins f256mem:$dst, VR256:$src),
                    "movupd\t{$src, $dst|$dst, $src}",
                    [(store (v4f64 VR256:$src), addr:$dst)],
                    IIC_SSE_MOVU_P_MR>, VEX, VEX_L, VEX_WIG;
 } // SchedRW
 
 // For disassembler
 let isCodeGenOnly = 1, ForceDisassemble = 1, hasSideEffects = 0,
-    SchedRW = [WriteFShuffle] in {
+    SchedRW = [WriteFShuffle], isMoveReg = 1 in {
   def VMOVAPSrr_REV : VPSI<0x29, MRMDestReg, (outs VR128:$dst),
                           (ins VR128:$src),
                           "movaps\t{$src, $dst|$dst, $src}", [],
                           IIC_SSE_MOVA_P_RR>, VEX, VEX_WIG,
                           FoldGenData<"VMOVAPSrr">;
   def VMOVAPDrr_REV : VPDI<0x29, MRMDestReg, (outs VR128:$dst),
                            (ins VR128:$src),
                            "movapd\t{$src, $dst|$dst, $src}", [],
                            IIC_SSE_MOVA_P_RR>, VEX, VEX_WIG,

 def MOVUPDmr : PDI<0x11, MRMDestMem, (outs), (ins f128mem:$dst, VR128:$src),
                    "movupd\t{$src, $dst|$dst, $src}",
                    [(store (v2f64 VR128:$src), addr:$dst)],
                    IIC_SSE_MOVU_P_MR>;
 } // SchedRW
 
 // For disassembler
 let isCodeGenOnly = 1, ForceDisassemble = 1, hasSideEffects = 0,
-    SchedRW = [WriteFShuffle] in {
+    SchedRW = [WriteFShuffle], isMoveReg = 1 in {
   def MOVAPSrr_REV : PSI<0x29, MRMDestReg, (outs VR128:$dst), (ins VR128:$src),
                          "movaps\t{$src, $dst|$dst, $src}", [],
                          IIC_SSE_MOVA_P_RR>, FoldGenData<"MOVAPSrr">;
   def MOVAPDrr_REV : PDI<0x29, MRMDestReg, (outs VR128:$dst), (ins VR128:$src),
                          "movapd\t{$src, $dst|$dst, $src}", [],
                          IIC_SSE_MOVA_P_RR>, FoldGenData<"MOVAPDrr">;
   def MOVUPSrr_REV : PSI<0x11, MRMDestReg, (outs VR128:$dst), (ins VR128:$src),
                          "movups\t{$src, $dst|$dst, $src}", [],

utils/TableGen/CodeGenInstruction.h

public:
     std::vector<Record*> ImplicitDefs, ImplicitUses;
 
     // Various boolean values we track for the instruction.
     bool isReturn : 1;
     bool isBranch : 1;
     bool isIndirectBranch : 1;
     bool isCompare : 1;
     bool isMoveImm : 1;
+    bool isMoveReg : 1;
     bool isBitcast : 1;
     bool isSelect : 1;
     bool isBarrier : 1;
     bool isCall : 1;
     bool isAdd : 1;
     bool canFoldAsLoad : 1;
     bool mayLoad : 1;
     bool mayLoad_Unset : 1;

utils/TableGen/CodeGenInstruction.cpp

CodeGenInstruction::CodeGenInstruction(Record *R)
   Namespace = R->getValueAsString("Namespace");
   AsmString = R->getValueAsString("AsmString");
 
   isReturn     = R->getValueAsBit("isReturn");
   isBranch     = R->getValueAsBit("isBranch");
   isIndirectBranch = R->getValueAsBit("isIndirectBranch");
   isCompare    = R->getValueAsBit("isCompare");
   isMoveImm    = R->getValueAsBit("isMoveImm");
+  isMoveReg    = R->getValueAsBit("isMoveReg");
   isBitcast    = R->getValueAsBit("isBitcast");
   isSelect     = R->getValueAsBit("isSelect");
   isBarrier    = R->getValueAsBit("isBarrier");
   isCall       = R->getValueAsBit("isCall");
   isAdd        = R->getValueAsBit("isAdd");
   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
   isPredicable = Operands.isPredicable || R->getValueAsBit("isPredicable");
   isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");

utils/TableGen/InstrInfoEmitter.cpp

void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
 
   // Emit all of the target independent flags...
   if (Inst.isPseudo)           OS << "|(1ULL<<MCID::Pseudo)";
   if (Inst.isReturn)           OS << "|(1ULL<<MCID::Return)";
   if (Inst.isBranch)           OS << "|(1ULL<<MCID::Branch)";
   if (Inst.isIndirectBranch)   OS << "|(1ULL<<MCID::IndirectBranch)";
   if (Inst.isCompare)          OS << "|(1ULL<<MCID::Compare)";
   if (Inst.isMoveImm)          OS << "|(1ULL<<MCID::MoveImm)";
+  if (Inst.isMoveReg)          OS << "|(1ULL<<MCID::MoveReg)";
   if (Inst.isBitcast)          OS << "|(1ULL<<MCID::Bitcast)";
   if (Inst.isAdd)              OS << "|(1ULL<<MCID::Add)";
   if (Inst.isSelect)           OS << "|(1ULL<<MCID::Select)";
   if (Inst.isBarrier)          OS << "|(1ULL<<MCID::Barrier)";
   if (Inst.hasDelaySlot)       OS << "|(1ULL<<MCID::DelaySlot)";
   if (Inst.isCall)             OS << "|(1ULL<<MCID::Call)";
   if (Inst.canFoldAsLoad)      OS << "|(1ULL<<MCID::FoldableAsLoad)";
   if (Inst.mayLoad)            OS << "|(1ULL<<MCID::MayLoad)";