1 //==--- InstrEmitter.cpp - Emit MachineInstrs for the SelectionDAG class ---==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements the Emit routines for the SelectionDAG class, which creates
11 // MachineInstrs based on the decisions of the SelectionDAG instruction
14 //===----------------------------------------------------------------------===//
16 #define DEBUG_TYPE "instr-emitter"
17 #include "InstrEmitter.h"
18 #include "SDNodeDbgValue.h"
19 #include "llvm/CodeGen/MachineConstantPool.h"
20 #include "llvm/CodeGen/MachineFunction.h"
21 #include "llvm/CodeGen/MachineInstrBuilder.h"
22 #include "llvm/CodeGen/MachineRegisterInfo.h"
23 #include "llvm/Target/TargetData.h"
24 #include "llvm/Target/TargetMachine.h"
25 #include "llvm/Target/TargetInstrInfo.h"
26 #include "llvm/Target/TargetLowering.h"
27 #include "llvm/ADT/Statistic.h"
28 #include "llvm/Support/Debug.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include "llvm/Support/MathExtras.h"
33 /// CountResults - The results of target nodes have register or immediate
34 /// operands first, then an optional chain, and optional glue operands (which do
35 /// not go into the resulting MachineInstr).
36 unsigned InstrEmitter::CountResults(SDNode *Node) {
37 unsigned N = Node->getNumValues();
38 while (N && Node->getValueType(N - 1) == MVT::Glue)
40 if (N && Node->getValueType(N - 1) == MVT::Other)
41 --N; // Skip over chain result.
45 /// CountOperands - The inputs to target nodes have any actual inputs first,
46 /// followed by an optional chain operand, then an optional glue operand.
47 /// Compute the number of actual operands that will go into the resulting
49 unsigned InstrEmitter::CountOperands(SDNode *Node) {
50 unsigned N = Node->getNumOperands();
51 while (N && Node->getOperand(N - 1).getValueType() == MVT::Glue)
53 if (N && Node->getOperand(N - 1).getValueType() == MVT::Other)
54 --N; // Ignore chain if it exists.
58 /// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an
59 /// implicit physical register output.
61 EmitCopyFromReg(SDNode *Node, unsigned ResNo, bool IsClone, bool IsCloned,
62 unsigned SrcReg, DenseMap<SDValue, unsigned> &VRBaseMap) {
64 if (TargetRegisterInfo::isVirtualRegister(SrcReg)) {
65 // Just use the input register directly!
66 SDValue Op(Node, ResNo);
69 bool isNew = VRBaseMap.insert(std::make_pair(Op, SrcReg)).second;
70 (void)isNew; // Silence compiler warning.
71 assert(isNew && "Node emitted out of order - early");
75 // If the node is only used by a CopyToReg and the dest reg is a vreg, use
76 // the CopyToReg'd destination register instead of creating a new vreg.
78 const TargetRegisterClass *UseRC = NULL;
79 EVT VT = Node->getValueType(ResNo);
81 // Stick to the preferred register classes for legal types.
82 if (TLI->isTypeLegal(VT))
83 UseRC = TLI->getRegClassFor(VT);
85 if (!IsClone && !IsCloned)
86 for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
90 if (User->getOpcode() == ISD::CopyToReg &&
91 User->getOperand(2).getNode() == Node &&
92 User->getOperand(2).getResNo() == ResNo) {
93 unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
94 if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
97 } else if (DestReg != SrcReg)
100 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
101 SDValue Op = User->getOperand(i);
102 if (Op.getNode() != Node || Op.getResNo() != ResNo)
104 EVT VT = Node->getValueType(Op.getResNo());
105 if (VT == MVT::Other || VT == MVT::Glue)
108 if (User->isMachineOpcode()) {
109 const MCInstrDesc &II = TII->get(User->getMachineOpcode());
110 const TargetRegisterClass *RC = 0;
111 if (i+II.getNumDefs() < II.getNumOperands())
112 RC = TII->getRegClass(II, i+II.getNumDefs(), TRI);
116 const TargetRegisterClass *ComRC =
117 TRI->getCommonSubClass(UseRC, RC);
118 // If multiple uses expect disjoint register classes, we emit
119 // copies in AddRegisterOperand.
131 const TargetRegisterClass *SrcRC = 0, *DstRC = 0;
132 SrcRC = TRI->getMinimalPhysRegClass(SrcReg, VT);
134 // Figure out the register class to create for the destreg.
136 DstRC = MRI->getRegClass(VRBase);
138 assert(UseRC->hasType(VT) && "Incompatible phys register def and uses!");
141 DstRC = TLI->getRegClassFor(VT);
144 // If all uses are reading from the src physical register and copying the
145 // register is either impossible or very expensive, then don't create a copy.
146 if (MatchReg && SrcRC->getCopyCost() < 0) {
149 // Create the reg, emit the copy.
150 VRBase = MRI->createVirtualRegister(DstRC);
151 BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
152 VRBase).addReg(SrcReg);
155 SDValue Op(Node, ResNo);
158 bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
159 (void)isNew; // Silence compiler warning.
160 assert(isNew && "Node emitted out of order - early");
163 /// getDstOfCopyToRegUse - If the only use of the specified result number of
164 /// node is a CopyToReg, return its destination register. Return 0 otherwise.
165 unsigned InstrEmitter::getDstOfOnlyCopyToRegUse(SDNode *Node,
166 unsigned ResNo) const {
167 if (!Node->hasOneUse())
170 SDNode *User = *Node->use_begin();
171 if (User->getOpcode() == ISD::CopyToReg &&
172 User->getOperand(2).getNode() == Node &&
173 User->getOperand(2).getResNo() == ResNo) {
174 unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
175 if (TargetRegisterInfo::isVirtualRegister(Reg))
181 void InstrEmitter::CreateVirtualRegisters(SDNode *Node, MachineInstr *MI,
182 const MCInstrDesc &II,
183 bool IsClone, bool IsCloned,
184 DenseMap<SDValue, unsigned> &VRBaseMap) {
185 assert(Node->getMachineOpcode() != TargetOpcode::IMPLICIT_DEF &&
186 "IMPLICIT_DEF should have been handled as a special case elsewhere!");
188 for (unsigned i = 0; i < II.getNumDefs(); ++i) {
189 // If the specific node value is only used by a CopyToReg and the dest reg
190 // is a vreg in the same register class, use the CopyToReg'd destination
191 // register instead of creating a new vreg.
193 const TargetRegisterClass *RC = TII->getRegClass(II, i, TRI);
194 if (II.OpInfo[i].isOptionalDef()) {
195 // Optional def must be a physical register.
196 unsigned NumResults = CountResults(Node);
197 VRBase = cast<RegisterSDNode>(Node->getOperand(i-NumResults))->getReg();
198 assert(TargetRegisterInfo::isPhysicalRegister(VRBase));
199 MI->addOperand(MachineOperand::CreateReg(VRBase, true));
202 if (!VRBase && !IsClone && !IsCloned)
203 for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
206 if (User->getOpcode() == ISD::CopyToReg &&
207 User->getOperand(2).getNode() == Node &&
208 User->getOperand(2).getResNo() == i) {
209 unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
210 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
211 const TargetRegisterClass *RegRC = MRI->getRegClass(Reg);
214 MI->addOperand(MachineOperand::CreateReg(Reg, true));
221 // Create the result registers for this node and add the result regs to
222 // the machine instruction.
224 assert(RC && "Isn't a register operand!");
225 VRBase = MRI->createVirtualRegister(RC);
226 MI->addOperand(MachineOperand::CreateReg(VRBase, true));
232 bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
233 (void)isNew; // Silence compiler warning.
234 assert(isNew && "Node emitted out of order - early");
238 /// getVR - Return the virtual register corresponding to the specified result
239 /// of the specified node.
240 unsigned InstrEmitter::getVR(SDValue Op,
241 DenseMap<SDValue, unsigned> &VRBaseMap) {
242 if (Op.isMachineOpcode() &&
243 Op.getMachineOpcode() == TargetOpcode::IMPLICIT_DEF) {
244 // Add an IMPLICIT_DEF instruction before every use.
245 unsigned VReg = getDstOfOnlyCopyToRegUse(Op.getNode(), Op.getResNo());
246 // IMPLICIT_DEF can produce any type of result so its MCInstrDesc
247 // does not include operand register class info.
249 const TargetRegisterClass *RC = TLI->getRegClassFor(Op.getValueType());
250 VReg = MRI->createVirtualRegister(RC);
252 BuildMI(*MBB, InsertPos, Op.getDebugLoc(),
253 TII->get(TargetOpcode::IMPLICIT_DEF), VReg);
257 DenseMap<SDValue, unsigned>::iterator I = VRBaseMap.find(Op);
258 assert(I != VRBaseMap.end() && "Node emitted out of order - late");
263 /// AddRegisterOperand - Add the specified register as an operand to the
264 /// specified machine instr. Insert register copies if the register is
265 /// not in the required register class.
267 InstrEmitter::AddRegisterOperand(MachineInstr *MI, SDValue Op,
269 const MCInstrDesc *II,
270 DenseMap<SDValue, unsigned> &VRBaseMap,
271 bool IsDebug, bool IsClone, bool IsCloned) {
272 assert(Op.getValueType() != MVT::Other &&
273 Op.getValueType() != MVT::Glue &&
274 "Chain and glue operands should occur at end of operand list!");
275 // Get/emit the operand.
276 unsigned VReg = getVR(Op, VRBaseMap);
277 assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
279 const MCInstrDesc &MCID = MI->getDesc();
280 bool isOptDef = IIOpNum < MCID.getNumOperands() &&
281 MCID.OpInfo[IIOpNum].isOptionalDef();
283 // If the instruction requires a register in a different class, create
284 // a new virtual register and copy the value into it, but first attempt to
285 // shrink VReg's register class within reason. For example, if VReg == GR32
286 // and II requires a GR32_NOSP, just constrain VReg to GR32_NOSP.
287 const unsigned MinRCSize = 4;
289 const TargetRegisterClass *DstRC = 0;
290 if (IIOpNum < II->getNumOperands())
291 DstRC = TII->getRegClass(*II, IIOpNum, TRI);
292 assert((DstRC || (MCID.isVariadic() && IIOpNum >= MCID.getNumOperands())) &&
293 "Don't have operand info for this instruction!");
294 if (DstRC && !MRI->constrainRegClass(VReg, DstRC, MinRCSize)) {
295 unsigned NewVReg = MRI->createVirtualRegister(DstRC);
296 BuildMI(*MBB, InsertPos, Op.getNode()->getDebugLoc(),
297 TII->get(TargetOpcode::COPY), NewVReg).addReg(VReg);
302 // If this value has only one use, that use is a kill. This is a
303 // conservative approximation. InstrEmitter does trivial coalescing
304 // with CopyFromReg nodes, so don't emit kill flags for them.
305 // Avoid kill flags on Schedule cloned nodes, since there will be
307 // Tied operands are never killed, so we need to check that. And that
308 // means we need to determine the index of the operand.
309 bool isKill = Op.hasOneUse() &&
310 Op.getNode()->getOpcode() != ISD::CopyFromReg &&
312 !(IsClone || IsCloned);
314 unsigned Idx = MI->getNumOperands();
316 MI->getOperand(Idx-1).isReg() && MI->getOperand(Idx-1).isImplicit())
318 bool isTied = MI->getDesc().getOperandConstraint(Idx, MCOI::TIED_TO) != -1;
323 MI->addOperand(MachineOperand::CreateReg(VReg, isOptDef,
324 false/*isImp*/, isKill,
325 false/*isDead*/, false/*isUndef*/,
326 false/*isEarlyClobber*/,
327 0/*SubReg*/, IsDebug));
330 /// AddOperand - Add the specified operand to the specified machine instr. II
331 /// specifies the instruction information for the node, and IIOpNum is the
332 /// operand number (in the II) that we are adding. IIOpNum and II are used for
334 void InstrEmitter::AddOperand(MachineInstr *MI, SDValue Op,
336 const MCInstrDesc *II,
337 DenseMap<SDValue, unsigned> &VRBaseMap,
338 bool IsDebug, bool IsClone, bool IsCloned) {
339 if (Op.isMachineOpcode()) {
340 AddRegisterOperand(MI, Op, IIOpNum, II, VRBaseMap,
341 IsDebug, IsClone, IsCloned);
342 } else if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
343 MI->addOperand(MachineOperand::CreateImm(C->getSExtValue()));
344 } else if (ConstantFPSDNode *F = dyn_cast<ConstantFPSDNode>(Op)) {
345 const ConstantFP *CFP = F->getConstantFPValue();
346 MI->addOperand(MachineOperand::CreateFPImm(CFP));
347 } else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
348 MI->addOperand(MachineOperand::CreateReg(R->getReg(), false));
349 } else if (GlobalAddressSDNode *TGA = dyn_cast<GlobalAddressSDNode>(Op)) {
350 MI->addOperand(MachineOperand::CreateGA(TGA->getGlobal(), TGA->getOffset(),
351 TGA->getTargetFlags()));
352 } else if (BasicBlockSDNode *BBNode = dyn_cast<BasicBlockSDNode>(Op)) {
353 MI->addOperand(MachineOperand::CreateMBB(BBNode->getBasicBlock()));
354 } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Op)) {
355 MI->addOperand(MachineOperand::CreateFI(FI->getIndex()));
356 } else if (JumpTableSDNode *JT = dyn_cast<JumpTableSDNode>(Op)) {
357 MI->addOperand(MachineOperand::CreateJTI(JT->getIndex(),
358 JT->getTargetFlags()));
359 } else if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(Op)) {
360 int Offset = CP->getOffset();
361 unsigned Align = CP->getAlignment();
362 Type *Type = CP->getType();
363 // MachineConstantPool wants an explicit alignment.
365 Align = TM->getTargetData()->getPrefTypeAlignment(Type);
367 // Alignment of vector types. FIXME!
368 Align = TM->getTargetData()->getTypeAllocSize(Type);
373 MachineConstantPool *MCP = MF->getConstantPool();
374 if (CP->isMachineConstantPoolEntry())
375 Idx = MCP->getConstantPoolIndex(CP->getMachineCPVal(), Align);
377 Idx = MCP->getConstantPoolIndex(CP->getConstVal(), Align);
378 MI->addOperand(MachineOperand::CreateCPI(Idx, Offset,
379 CP->getTargetFlags()));
380 } else if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Op)) {
381 MI->addOperand(MachineOperand::CreateES(ES->getSymbol(),
382 ES->getTargetFlags()));
383 } else if (BlockAddressSDNode *BA = dyn_cast<BlockAddressSDNode>(Op)) {
384 MI->addOperand(MachineOperand::CreateBA(BA->getBlockAddress(),
385 BA->getTargetFlags()));
387 assert(Op.getValueType() != MVT::Other &&
388 Op.getValueType() != MVT::Glue &&
389 "Chain and glue operands should occur at end of operand list!");
390 AddRegisterOperand(MI, Op, IIOpNum, II, VRBaseMap,
391 IsDebug, IsClone, IsCloned);
395 /// getSuperRegisterRegClass - Returns the register class of a superreg A whose
396 /// "SubIdx"'th sub-register class is the specified register class and whose
397 /// type matches the specified type.
398 static const TargetRegisterClass*
399 getSuperRegisterRegClass(const TargetRegisterClass *TRC,
400 unsigned SubIdx, EVT VT) {
401 // Pick the register class of the superegister for this type
402 for (TargetRegisterInfo::regclass_iterator I = TRC->superregclasses_begin(),
403 E = TRC->superregclasses_end(); I != E; ++I)
404 if ((*I)->hasType(VT) && (*I)->getSubRegisterRegClass(SubIdx) == TRC)
406 assert(false && "Couldn't find the register class");
410 /// EmitSubregNode - Generate machine code for subreg nodes.
412 void InstrEmitter::EmitSubregNode(SDNode *Node,
413 DenseMap<SDValue, unsigned> &VRBaseMap,
414 bool IsClone, bool IsCloned) {
416 unsigned Opc = Node->getMachineOpcode();
418 // If the node is only used by a CopyToReg and the dest reg is a vreg, use
419 // the CopyToReg'd destination register instead of creating a new vreg.
420 for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
423 if (User->getOpcode() == ISD::CopyToReg &&
424 User->getOperand(2).getNode() == Node) {
425 unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
426 if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
433 if (Opc == TargetOpcode::EXTRACT_SUBREG) {
434 // EXTRACT_SUBREG is lowered as %dst = COPY %src:sub
435 unsigned SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
437 // Figure out the register class to create for the destreg.
438 unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
439 MachineInstr *DefMI = MRI->getVRegDef(VReg);
440 unsigned SrcReg, DstReg, DefSubIdx;
442 TII->isCoalescableExtInstr(*DefMI, SrcReg, DstReg, DefSubIdx) &&
443 SubIdx == DefSubIdx) {
445 // r1025 = s/zext r1024, 4
446 // r1026 = extract_subreg r1025, 4
448 // r1026 = copy r1024
449 const TargetRegisterClass *TRC = MRI->getRegClass(SrcReg);
450 VRBase = MRI->createVirtualRegister(TRC);
451 BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
452 TII->get(TargetOpcode::COPY), VRBase).addReg(SrcReg);
454 const TargetRegisterClass *TRC = MRI->getRegClass(VReg);
455 const TargetRegisterClass *SRC = TRC->getSubRegisterRegClass(SubIdx);
456 assert(SRC && "Invalid subregister index in EXTRACT_SUBREG");
458 // Figure out the register class to create for the destreg.
459 // Note that if we're going to directly use an existing register,
460 // it must be precisely the required class, and not a subclass
462 if (VRBase == 0 || SRC != MRI->getRegClass(VRBase)) {
464 assert(SRC && "Couldn't find source register class");
465 VRBase = MRI->createVirtualRegister(SRC);
468 // Create the extract_subreg machine instruction.
469 MachineInstr *MI = BuildMI(*MF, Node->getDebugLoc(),
470 TII->get(TargetOpcode::COPY), VRBase);
472 // Add source, and subreg index
473 AddOperand(MI, Node->getOperand(0), 0, 0, VRBaseMap, /*IsDebug=*/false,
475 assert(TargetRegisterInfo::isVirtualRegister(MI->getOperand(1).getReg())&&
476 "Cannot yet extract from physregs");
477 MI->getOperand(1).setSubReg(SubIdx);
478 MBB->insert(InsertPos, MI);
480 } else if (Opc == TargetOpcode::INSERT_SUBREG ||
481 Opc == TargetOpcode::SUBREG_TO_REG) {
482 SDValue N0 = Node->getOperand(0);
483 SDValue N1 = Node->getOperand(1);
484 SDValue N2 = Node->getOperand(2);
485 unsigned SubReg = getVR(N1, VRBaseMap);
486 unsigned SubIdx = cast<ConstantSDNode>(N2)->getZExtValue();
487 const TargetRegisterClass *TRC = MRI->getRegClass(SubReg);
488 const TargetRegisterClass *SRC =
489 getSuperRegisterRegClass(TRC, SubIdx, Node->getValueType(0));
491 // Figure out the register class to create for the destreg.
492 // Note that if we're going to directly use an existing register,
493 // it must be precisely the required class, and not a subclass
495 if (VRBase == 0 || SRC != MRI->getRegClass(VRBase)) {
497 assert(SRC && "Couldn't find source register class");
498 VRBase = MRI->createVirtualRegister(SRC);
501 // Create the insert_subreg or subreg_to_reg machine instruction.
502 MachineInstr *MI = BuildMI(*MF, Node->getDebugLoc(), TII->get(Opc));
503 MI->addOperand(MachineOperand::CreateReg(VRBase, true));
505 // If creating a subreg_to_reg, then the first input operand
506 // is an implicit value immediate, otherwise it's a register
507 if (Opc == TargetOpcode::SUBREG_TO_REG) {
508 const ConstantSDNode *SD = cast<ConstantSDNode>(N0);
509 MI->addOperand(MachineOperand::CreateImm(SD->getZExtValue()));
511 AddOperand(MI, N0, 0, 0, VRBaseMap, /*IsDebug=*/false,
513 // Add the subregster being inserted
514 AddOperand(MI, N1, 0, 0, VRBaseMap, /*IsDebug=*/false,
516 MI->addOperand(MachineOperand::CreateImm(SubIdx));
517 MBB->insert(InsertPos, MI);
519 llvm_unreachable("Node is not insert_subreg, extract_subreg, or subreg_to_reg");
522 bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
523 (void)isNew; // Silence compiler warning.
524 assert(isNew && "Node emitted out of order - early");
527 /// EmitCopyToRegClassNode - Generate machine code for COPY_TO_REGCLASS nodes.
528 /// COPY_TO_REGCLASS is just a normal copy, except that the destination
529 /// register is constrained to be in a particular register class.
532 InstrEmitter::EmitCopyToRegClassNode(SDNode *Node,
533 DenseMap<SDValue, unsigned> &VRBaseMap) {
534 unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
536 // Create the new VReg in the destination class and emit a copy.
537 unsigned DstRCIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
538 const TargetRegisterClass *DstRC = TRI->getRegClass(DstRCIdx);
539 unsigned NewVReg = MRI->createVirtualRegister(DstRC);
540 BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
541 NewVReg).addReg(VReg);
544 bool isNew = VRBaseMap.insert(std::make_pair(Op, NewVReg)).second;
545 (void)isNew; // Silence compiler warning.
546 assert(isNew && "Node emitted out of order - early");
549 /// EmitRegSequence - Generate machine code for REG_SEQUENCE nodes.
551 void InstrEmitter::EmitRegSequence(SDNode *Node,
552 DenseMap<SDValue, unsigned> &VRBaseMap,
553 bool IsClone, bool IsCloned) {
554 unsigned DstRCIdx = cast<ConstantSDNode>(Node->getOperand(0))->getZExtValue();
555 const TargetRegisterClass *RC = TRI->getRegClass(DstRCIdx);
556 unsigned NewVReg = MRI->createVirtualRegister(RC);
557 MachineInstr *MI = BuildMI(*MF, Node->getDebugLoc(),
558 TII->get(TargetOpcode::REG_SEQUENCE), NewVReg);
559 unsigned NumOps = Node->getNumOperands();
560 assert((NumOps & 1) == 1 &&
561 "REG_SEQUENCE must have an odd number of operands!");
562 const MCInstrDesc &II = TII->get(TargetOpcode::REG_SEQUENCE);
563 for (unsigned i = 1; i != NumOps; ++i) {
564 SDValue Op = Node->getOperand(i);
566 unsigned SubIdx = cast<ConstantSDNode>(Op)->getZExtValue();
567 unsigned SubReg = getVR(Node->getOperand(i-1), VRBaseMap);
568 const TargetRegisterClass *TRC = MRI->getRegClass(SubReg);
569 const TargetRegisterClass *SRC =
570 TRI->getMatchingSuperRegClass(RC, TRC, SubIdx);
571 if (SRC && SRC != RC) {
572 MRI->setRegClass(NewVReg, SRC);
576 AddOperand(MI, Op, i+1, &II, VRBaseMap, /*IsDebug=*/false,
580 MBB->insert(InsertPos, MI);
582 bool isNew = VRBaseMap.insert(std::make_pair(Op, NewVReg)).second;
583 (void)isNew; // Silence compiler warning.
584 assert(isNew && "Node emitted out of order - early");
587 /// EmitDbgValue - Generate machine instruction for a dbg_value node.
590 InstrEmitter::EmitDbgValue(SDDbgValue *SD,
591 DenseMap<SDValue, unsigned> &VRBaseMap) {
592 uint64_t Offset = SD->getOffset();
593 MDNode* MDPtr = SD->getMDPtr();
594 DebugLoc DL = SD->getDebugLoc();
596 if (SD->getKind() == SDDbgValue::FRAMEIX) {
597 // Stack address; this needs to be lowered in target-dependent fashion.
598 // EmitTargetCodeForFrameDebugValue is responsible for allocation.
599 unsigned FrameIx = SD->getFrameIx();
600 return TII->emitFrameIndexDebugValue(*MF, FrameIx, Offset, MDPtr, DL);
602 // Otherwise, we're going to create an instruction here.
603 const MCInstrDesc &II = TII->get(TargetOpcode::DBG_VALUE);
604 MachineInstrBuilder MIB = BuildMI(*MF, DL, II);
605 if (SD->getKind() == SDDbgValue::SDNODE) {
606 SDNode *Node = SD->getSDNode();
607 SDValue Op = SDValue(Node, SD->getResNo());
608 // It's possible we replaced this SDNode with other(s) and therefore
609 // didn't generate code for it. It's better to catch these cases where
610 // they happen and transfer the debug info, but trying to guarantee that
611 // in all cases would be very fragile; this is a safeguard for any
613 DenseMap<SDValue, unsigned>::iterator I = VRBaseMap.find(Op);
614 if (I==VRBaseMap.end())
615 MIB.addReg(0U); // undef
617 AddOperand(&*MIB, Op, (*MIB).getNumOperands(), &II, VRBaseMap,
618 /*IsDebug=*/true, /*IsClone=*/false, /*IsCloned=*/false);
619 } else if (SD->getKind() == SDDbgValue::CONST) {
620 const Value *V = SD->getConst();
621 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
622 if (CI->getBitWidth() > 64)
625 MIB.addImm(CI->getSExtValue());
626 } else if (const ConstantFP *CF = dyn_cast<ConstantFP>(V)) {
629 // Could be an Undef. In any case insert an Undef so we can see what we
634 // Insert an Undef so we can see what we dropped.
638 MIB.addImm(Offset).addMetadata(MDPtr);
642 /// EmitMachineNode - Generate machine code for a target-specific node and
643 /// needed dependencies.
646 EmitMachineNode(SDNode *Node, bool IsClone, bool IsCloned,
647 DenseMap<SDValue, unsigned> &VRBaseMap) {
648 unsigned Opc = Node->getMachineOpcode();
650 // Handle subreg insert/extract specially
651 if (Opc == TargetOpcode::EXTRACT_SUBREG ||
652 Opc == TargetOpcode::INSERT_SUBREG ||
653 Opc == TargetOpcode::SUBREG_TO_REG) {
654 EmitSubregNode(Node, VRBaseMap, IsClone, IsCloned);
658 // Handle COPY_TO_REGCLASS specially.
659 if (Opc == TargetOpcode::COPY_TO_REGCLASS) {
660 EmitCopyToRegClassNode(Node, VRBaseMap);
664 // Handle REG_SEQUENCE specially.
665 if (Opc == TargetOpcode::REG_SEQUENCE) {
666 EmitRegSequence(Node, VRBaseMap, IsClone, IsCloned);
670 if (Opc == TargetOpcode::IMPLICIT_DEF)
671 // We want a unique VR for each IMPLICIT_DEF use.
674 const MCInstrDesc &II = TII->get(Opc);
675 unsigned NumResults = CountResults(Node);
676 unsigned NodeOperands = CountOperands(Node);
677 bool HasPhysRegOuts = NumResults > II.getNumDefs() && II.getImplicitDefs()!=0;
679 unsigned NumMIOperands = NodeOperands + NumResults;
681 assert(NumMIOperands >= II.getNumOperands() &&
682 "Too few operands for a variadic node!");
684 assert(NumMIOperands >= II.getNumOperands() &&
685 NumMIOperands <= II.getNumOperands()+II.getNumImplicitDefs() &&
686 "#operands for dag node doesn't match .td file!");
689 // Create the new machine instruction.
690 MachineInstr *MI = BuildMI(*MF, Node->getDebugLoc(), II);
692 // The MachineInstr constructor adds implicit-def operands. Scan through
693 // these to determine which are dead.
694 if (MI->getNumOperands() != 0 &&
695 Node->getValueType(Node->getNumValues()-1) == MVT::Glue) {
696 // First, collect all used registers.
697 SmallVector<unsigned, 8> UsedRegs;
698 for (SDNode *F = Node->getGluedUser(); F; F = F->getGluedUser())
699 if (F->getOpcode() == ISD::CopyFromReg)
700 UsedRegs.push_back(cast<RegisterSDNode>(F->getOperand(1))->getReg());
702 // Collect declared implicit uses.
703 const MCInstrDesc &MCID = TII->get(F->getMachineOpcode());
704 UsedRegs.append(MCID.getImplicitUses(),
705 MCID.getImplicitUses() + MCID.getNumImplicitUses());
706 // In addition to declared implicit uses, we must also check for
707 // direct RegisterSDNode operands.
708 for (unsigned i = 0, e = F->getNumOperands(); i != e; ++i)
709 if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(F->getOperand(i))) {
710 unsigned Reg = R->getReg();
711 if (TargetRegisterInfo::isPhysicalRegister(Reg))
712 UsedRegs.push_back(Reg);
715 // Then mark unused registers as dead.
716 MI->setPhysRegsDeadExcept(UsedRegs, *TRI);
719 // Add result register values for things that are defined by this
722 CreateVirtualRegisters(Node, MI, II, IsClone, IsCloned, VRBaseMap);
724 // Emit all of the actual operands of this instruction, adding them to the
725 // instruction as appropriate.
726 bool HasOptPRefs = II.getNumDefs() > NumResults;
727 assert((!HasOptPRefs || !HasPhysRegOuts) &&
728 "Unable to cope with optional defs and phys regs defs!");
729 unsigned NumSkip = HasOptPRefs ? II.getNumDefs() - NumResults : 0;
730 for (unsigned i = NumSkip; i != NodeOperands; ++i)
731 AddOperand(MI, Node->getOperand(i), i-NumSkip+II.getNumDefs(), &II,
732 VRBaseMap, /*IsDebug=*/false, IsClone, IsCloned);
734 // Transfer all of the memory reference descriptions of this instruction.
735 MI->setMemRefs(cast<MachineSDNode>(Node)->memoperands_begin(),
736 cast<MachineSDNode>(Node)->memoperands_end());
738 // Insert the instruction into position in the block. This needs to
739 // happen before any custom inserter hook is called so that the
740 // hook knows where in the block to insert the replacement code.
741 MBB->insert(InsertPos, MI);
743 // Additional results must be physical register defs.
744 if (HasPhysRegOuts) {
745 for (unsigned i = II.getNumDefs(); i < NumResults; ++i) {
746 unsigned Reg = II.getImplicitDefs()[i - II.getNumDefs()];
747 if (Node->hasAnyUseOfValue(i))
748 EmitCopyFromReg(Node, i, IsClone, IsCloned, Reg, VRBaseMap);
749 // If there are no uses, mark the register as dead now, so that
750 // MachineLICM/Sink can see that it's dead. Don't do this if the
751 // node has a Glue value, for the benefit of targets still using
752 // Glue for values in physregs.
753 else if (Node->getValueType(Node->getNumValues()-1) != MVT::Glue)
754 MI->addRegisterDead(Reg, TRI);
758 // If the instruction has implicit defs and the node doesn't, mark the
759 // implicit def as dead. If the node has any glue outputs, we don't do this
760 // because we don't know what implicit defs are being used by glued nodes.
761 if (Node->getValueType(Node->getNumValues()-1) != MVT::Glue)
762 if (const unsigned *IDList = II.getImplicitDefs()) {
763 for (unsigned i = NumResults, e = II.getNumDefs()+II.getNumImplicitDefs();
765 MI->addRegisterDead(IDList[i-II.getNumDefs()], TRI);
768 // Run post-isel target hook to adjust this instruction if needed.
770 if (II.hasPostISelHook())
772 TLI->AdjustInstrPostInstrSelection(MI, Node);
775 /// EmitSpecialNode - Generate machine code for a target-independent node and
776 /// needed dependencies.
778 EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
779 DenseMap<SDValue, unsigned> &VRBaseMap) {
780 switch (Node->getOpcode()) {
785 llvm_unreachable("This target-independent node should have been selected!");
787 case ISD::EntryToken:
788 llvm_unreachable("EntryToken should have been excluded from the schedule!");
790 case ISD::MERGE_VALUES:
791 case ISD::TokenFactor: // fall thru
793 case ISD::CopyToReg: {
795 SDValue SrcVal = Node->getOperand(2);
796 if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(SrcVal))
797 SrcReg = R->getReg();
799 SrcReg = getVR(SrcVal, VRBaseMap);
801 unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
802 if (SrcReg == DestReg) // Coalesced away the copy? Ignore.
805 BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
806 DestReg).addReg(SrcReg);
809 case ISD::CopyFromReg: {
810 unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
811 EmitCopyFromReg(Node, 0, IsClone, IsCloned, SrcReg, VRBaseMap);
814 case ISD::EH_LABEL: {
815 MCSymbol *S = cast<EHLabelSDNode>(Node)->getLabel();
816 BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
817 TII->get(TargetOpcode::EH_LABEL)).addSym(S);
821 case ISD::INLINEASM: {
822 unsigned NumOps = Node->getNumOperands();
823 if (Node->getOperand(NumOps-1).getValueType() == MVT::Glue)
824 --NumOps; // Ignore the glue operand.
826 // Create the inline asm machine instruction.
827 MachineInstr *MI = BuildMI(*MF, Node->getDebugLoc(),
828 TII->get(TargetOpcode::INLINEASM));
830 // Add the asm string as an external symbol operand.
831 SDValue AsmStrV = Node->getOperand(InlineAsm::Op_AsmString);
832 const char *AsmStr = cast<ExternalSymbolSDNode>(AsmStrV)->getSymbol();
833 MI->addOperand(MachineOperand::CreateES(AsmStr));
835 // Add the HasSideEffect and isAlignStack bits.
837 cast<ConstantSDNode>(Node->getOperand(InlineAsm::Op_ExtraInfo))->
839 MI->addOperand(MachineOperand::CreateImm(ExtraInfo));
841 // Add all of the operand registers to the instruction.
842 for (unsigned i = InlineAsm::Op_FirstOperand; i != NumOps;) {
844 cast<ConstantSDNode>(Node->getOperand(i))->getZExtValue();
845 unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
847 MI->addOperand(MachineOperand::CreateImm(Flags));
848 ++i; // Skip the ID value.
850 switch (InlineAsm::getKind(Flags)) {
851 default: llvm_unreachable("Bad flags!");
852 case InlineAsm::Kind_RegDef:
853 for (; NumVals; --NumVals, ++i) {
854 unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
855 // FIXME: Add dead flags for physical and virtual registers defined.
856 // For now, mark physical register defs as implicit to help fast
857 // regalloc. This makes inline asm look a lot like calls.
858 MI->addOperand(MachineOperand::CreateReg(Reg, true,
859 /*isImp=*/ TargetRegisterInfo::isPhysicalRegister(Reg)));
862 case InlineAsm::Kind_RegDefEarlyClobber:
863 case InlineAsm::Kind_Clobber:
864 for (; NumVals; --NumVals, ++i) {
865 unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
866 MI->addOperand(MachineOperand::CreateReg(Reg, /*isDef=*/ true,
867 /*isImp=*/ TargetRegisterInfo::isPhysicalRegister(Reg),
871 /*isEarlyClobber=*/ true));
874 case InlineAsm::Kind_RegUse: // Use of register.
875 case InlineAsm::Kind_Imm: // Immediate.
876 case InlineAsm::Kind_Mem: // Addressing mode.
877 // The addressing mode has been selected, just add all of the
878 // operands to the machine instruction.
879 for (; NumVals; --NumVals, ++i)
880 AddOperand(MI, Node->getOperand(i), 0, 0, VRBaseMap,
881 /*IsDebug=*/false, IsClone, IsCloned);
886 // Get the mdnode from the asm if it exists and add it to the instruction.
887 SDValue MDV = Node->getOperand(InlineAsm::Op_MDNode);
888 const MDNode *MD = cast<MDNodeSDNode>(MDV)->getMD();
890 MI->addOperand(MachineOperand::CreateMetadata(MD));
892 MBB->insert(InsertPos, MI);
898 /// InstrEmitter - Construct an InstrEmitter and set it to start inserting
899 /// at the given position in the given block.
900 InstrEmitter::InstrEmitter(MachineBasicBlock *mbb,
901 MachineBasicBlock::iterator insertpos)
902 : MF(mbb->getParent()),
903 MRI(&MF->getRegInfo()),
904 TM(&MF->getTarget()),
905 TII(TM->getInstrInfo()),
906 TRI(TM->getRegisterInfo()),
907 TLI(TM->getTargetLowering()),
908 MBB(mbb), InsertPos(insertpos) {