1 //===-- PPCISelDAGToDAG.cpp - PPC --pattern matching inst selector --------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Chris Lattner and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a pattern matching instruction selector for PowerPC,
11 // converting from a legalized dag to a PPC dag.
13 //===----------------------------------------------------------------------===//
16 #include "PPCTargetMachine.h"
17 #include "PPCISelLowering.h"
18 #include "llvm/CodeGen/MachineInstrBuilder.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/SSARegMap.h"
21 #include "llvm/CodeGen/SelectionDAG.h"
22 #include "llvm/CodeGen/SelectionDAGISel.h"
23 #include "llvm/Target/TargetOptions.h"
24 #include "llvm/ADT/Statistic.h"
25 #include "llvm/Constants.h"
26 #include "llvm/GlobalValue.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Support/MathExtras.h"
32 Statistic<> FusedFP ("ppc-codegen", "Number of fused fp operations");
33 Statistic<> FrameOff("ppc-codegen", "Number of frame idx offsets collapsed");
35 //===--------------------------------------------------------------------===//
36 /// PPCDAGToDAGISel - PPC specific code to select PPC machine
37 /// instructions for SelectionDAG operations.
39 class PPCDAGToDAGISel : public SelectionDAGISel {
40 PPCTargetLowering PPCLowering;
41 unsigned GlobalBaseReg;
43 PPCDAGToDAGISel(TargetMachine &TM)
44 : SelectionDAGISel(PPCLowering), PPCLowering(TM) {}
46 virtual bool runOnFunction(Function &Fn) {
47 // Make sure we re-emit a set of the global base reg if necessary
49 return SelectionDAGISel::runOnFunction(Fn);
52 /// getI32Imm - Return a target constant with the specified value, of type
54 inline SDOperand getI32Imm(unsigned Imm) {
55 return CurDAG->getTargetConstant(Imm, MVT::i32);
58 /// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
59 /// base register. Return the virtual register that holds this value.
60 SDOperand getGlobalBaseReg();
62 // Select - Convert the specified operand from a target-independent to a
63 // target-specific node if it hasn't already been changed.
64 SDOperand Select(SDOperand Op);
66 SDNode *SelectBitfieldInsert(SDNode *N);
68 /// SelectCC - Select a comparison of the specified values with the
69 /// specified condition code, returning the CR# of the expression.
70 SDOperand SelectCC(SDOperand LHS, SDOperand RHS, ISD::CondCode CC);
72 /// SelectAddr - Given the specified address, return the two operands for a
73 /// load/store instruction, and return true if it should be an indexed [r+r]
75 bool SelectAddr(SDOperand Addr, SDOperand &Op1, SDOperand &Op2);
77 /// SelectAddrIndexed - Given the specified addressed, force it to be
78 /// represented as an indexed [r+r] operation, rather than possibly
79 /// returning [r+imm] as SelectAddr may.
80 void SelectAddrIndexed(SDOperand Addr, SDOperand &Op1, SDOperand &Op2);
82 SDOperand BuildSDIVSequence(SDNode *N);
83 SDOperand BuildUDIVSequence(SDNode *N);
85 /// InstructionSelectBasicBlock - This callback is invoked by
86 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
87 virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
89 virtual const char *getPassName() const {
90 return "PowerPC DAG->DAG Pattern Instruction Selection";
93 // Include the pieces autogenerated from the target description.
94 #include "PPCGenDAGISel.inc"
97 SDOperand SelectDYNAMIC_STACKALLOC(SDOperand Op);
98 SDOperand SelectADD_PARTS(SDOperand Op);
99 SDOperand SelectSUB_PARTS(SDOperand Op);
100 SDOperand SelectSETCC(SDOperand Op);
101 SDOperand SelectCALL(SDOperand Op);
105 /// InstructionSelectBasicBlock - This callback is invoked by
106 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
107 void PPCDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
110 // The selection process is inherently a bottom-up recursive process (users
111 // select their uses before themselves). Given infinite stack space, we
112 // could just start selecting on the root and traverse the whole graph. In
113 // practice however, this causes us to run out of stack space on large basic
114 // blocks. To avoid this problem, select the entry node, then all its uses,
115 // iteratively instead of recursively.
116 std::vector<SDOperand> Worklist;
117 Worklist.push_back(DAG.getEntryNode());
119 // Note that we can do this in the PPC target (scanning forward across token
120 // chain edges) because no nodes ever get folded across these edges. On a
121 // target like X86 which supports load/modify/store operations, this would
122 // have to be more careful.
123 while (!Worklist.empty()) {
124 SDOperand Node = Worklist.back();
127 // Chose from the least deep of the top two nodes.
128 if (!Worklist.empty() &&
129 Worklist.back().Val->getNodeDepth() < Node.Val->getNodeDepth())
130 std::swap(Worklist.back(), Node);
132 if ((Node.Val->getOpcode() >= ISD::BUILTIN_OP_END &&
133 Node.Val->getOpcode() < PPCISD::FIRST_NUMBER) ||
134 CodeGenMap.count(Node)) continue;
136 for (SDNode::use_iterator UI = Node.Val->use_begin(),
137 E = Node.Val->use_end(); UI != E; ++UI) {
138 // Scan the values. If this use has a value that is a token chain, add it
141 for (unsigned i = 0, e = User->getNumValues(); i != e; ++i)
142 if (User->getValueType(i) == MVT::Other) {
143 Worklist.push_back(SDOperand(User, i));
148 // Finally, legalize this node.
152 // Select target instructions for the DAG.
153 DAG.setRoot(Select(DAG.getRoot()));
155 DAG.RemoveDeadNodes();
157 // Emit machine code to BB.
158 ScheduleAndEmitDAG(DAG);
161 /// getGlobalBaseReg - Output the instructions required to put the
162 /// base address to use for accessing globals into a register.
164 SDOperand PPCDAGToDAGISel::getGlobalBaseReg() {
165 if (!GlobalBaseReg) {
166 // Insert the set of GlobalBaseReg into the first MBB of the function
167 MachineBasicBlock &FirstMBB = BB->getParent()->front();
168 MachineBasicBlock::iterator MBBI = FirstMBB.begin();
169 SSARegMap *RegMap = BB->getParent()->getSSARegMap();
170 // FIXME: when we get to LP64, we will need to create the appropriate
171 // type of register here.
172 GlobalBaseReg = RegMap->createVirtualRegister(PPC::GPRCRegisterClass);
173 BuildMI(FirstMBB, MBBI, PPC::MovePCtoLR, 0, PPC::LR);
174 BuildMI(FirstMBB, MBBI, PPC::MFLR, 1, GlobalBaseReg);
176 return CurDAG->getRegister(GlobalBaseReg, MVT::i32);
180 // isIntImmediate - This method tests to see if a constant operand.
181 // If so Imm will receive the 32 bit value.
182 static bool isIntImmediate(SDNode *N, unsigned& Imm) {
183 if (N->getOpcode() == ISD::Constant) {
184 Imm = cast<ConstantSDNode>(N)->getValue();
190 // isOprShiftImm - Returns true if the specified operand is a shift opcode with
191 // a immediate shift count less than 32.
192 static bool isOprShiftImm(SDNode *N, unsigned& Opc, unsigned& SH) {
193 Opc = N->getOpcode();
194 return (Opc == ISD::SHL || Opc == ISD::SRL || Opc == ISD::SRA) &&
195 isIntImmediate(N->getOperand(1).Val, SH) && SH < 32;
198 // isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s with
199 // any number of 0s on either side. The 1s are allowed to wrap from LSB to
200 // MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
201 // not, since all 1s are not contiguous.
202 static bool isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
203 if (isShiftedMask_32(Val)) {
204 // look for the first non-zero bit
205 MB = CountLeadingZeros_32(Val);
206 // look for the first zero bit after the run of ones
207 ME = CountLeadingZeros_32((Val - 1) ^ Val);
210 Val = ~Val; // invert mask
211 if (isShiftedMask_32(Val)) {
212 // effectively look for the first zero bit
213 ME = CountLeadingZeros_32(Val) - 1;
214 // effectively look for the first one bit after the run of zeros
215 MB = CountLeadingZeros_32((Val - 1) ^ Val) + 1;
223 // isRotateAndMask - Returns true if Mask and Shift can be folded into a rotate
224 // and mask opcode and mask operation.
225 static bool isRotateAndMask(SDNode *N, unsigned Mask, bool IsShiftMask,
226 unsigned &SH, unsigned &MB, unsigned &ME) {
227 // Don't even go down this path for i64, since different logic will be
228 // necessary for rldicl/rldicr/rldimi.
229 if (N->getValueType(0) != MVT::i32)
233 unsigned Indeterminant = ~0; // bit mask marking indeterminant results
234 unsigned Opcode = N->getOpcode();
235 if (N->getNumOperands() != 2 ||
236 !isIntImmediate(N->getOperand(1).Val, Shift) || (Shift > 31))
239 if (Opcode == ISD::SHL) {
240 // apply shift left to mask if it comes first
241 if (IsShiftMask) Mask = Mask << Shift;
242 // determine which bits are made indeterminant by shift
243 Indeterminant = ~(0xFFFFFFFFu << Shift);
244 } else if (Opcode == ISD::SRL) {
245 // apply shift right to mask if it comes first
246 if (IsShiftMask) Mask = Mask >> Shift;
247 // determine which bits are made indeterminant by shift
248 Indeterminant = ~(0xFFFFFFFFu >> Shift);
249 // adjust for the left rotate
255 // if the mask doesn't intersect any Indeterminant bits
256 if (Mask && !(Mask & Indeterminant)) {
258 // make sure the mask is still a mask (wrap arounds may not be)
259 return isRunOfOnes(Mask, MB, ME);
264 // isOpcWithIntImmediate - This method tests to see if the node is a specific
265 // opcode and that it has a immediate integer right operand.
266 // If so Imm will receive the 32 bit value.
267 static bool isOpcWithIntImmediate(SDNode *N, unsigned Opc, unsigned& Imm) {
268 return N->getOpcode() == Opc && isIntImmediate(N->getOperand(1).Val, Imm);
271 // isOprNot - Returns true if the specified operand is an xor with immediate -1.
272 static bool isOprNot(SDNode *N) {
274 return isOpcWithIntImmediate(N, ISD::XOR, Imm) && (signed)Imm == -1;
277 // Immediate constant composers.
278 // Lo16 - grabs the lo 16 bits from a 32 bit constant.
279 // Hi16 - grabs the hi 16 bits from a 32 bit constant.
280 // HA16 - computes the hi bits required if the lo bits are add/subtracted in
282 static unsigned Lo16(unsigned x) { return x & 0x0000FFFF; }
283 static unsigned Hi16(unsigned x) { return Lo16(x >> 16); }
284 static unsigned HA16(unsigned x) { return Hi16((signed)x - (signed short)x); }
286 // isIntImmediate - This method tests to see if a constant operand.
287 // If so Imm will receive the 32 bit value.
288 static bool isIntImmediate(SDOperand N, unsigned& Imm) {
289 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N)) {
290 Imm = (unsigned)CN->getSignExtended();
296 /// SelectBitfieldInsert - turn an or of two masked values into
297 /// the rotate left word immediate then mask insert (rlwimi) instruction.
298 /// Returns true on success, false if the caller still needs to select OR.
300 /// Patterns matched:
301 /// 1. or shl, and 5. or and, and
302 /// 2. or and, shl 6. or shl, shr
303 /// 3. or shr, and 7. or shr, shl
305 SDNode *PPCDAGToDAGISel::SelectBitfieldInsert(SDNode *N) {
306 bool IsRotate = false;
307 unsigned TgtMask = 0xFFFFFFFF, InsMask = 0xFFFFFFFF, SH = 0;
310 SDOperand Op0 = N->getOperand(0);
311 SDOperand Op1 = N->getOperand(1);
313 unsigned Op0Opc = Op0.getOpcode();
314 unsigned Op1Opc = Op1.getOpcode();
316 // Verify that we have the correct opcodes
317 if (ISD::SHL != Op0Opc && ISD::SRL != Op0Opc && ISD::AND != Op0Opc)
319 if (ISD::SHL != Op1Opc && ISD::SRL != Op1Opc && ISD::AND != Op1Opc)
322 // Generate Mask value for Target
323 if (isIntImmediate(Op0.getOperand(1), Value)) {
325 case ISD::SHL: TgtMask <<= Value; break;
326 case ISD::SRL: TgtMask >>= Value; break;
327 case ISD::AND: TgtMask &= Value; break;
333 // Generate Mask value for Insert
334 if (!isIntImmediate(Op1.getOperand(1), Value))
341 if (Op0Opc == ISD::SRL) IsRotate = true;
347 if (Op0Opc == ISD::SHL) IsRotate = true;
354 // If both of the inputs are ANDs and one of them has a logical shift by
355 // constant as its input, make that AND the inserted value so that we can
356 // combine the shift into the rotate part of the rlwimi instruction
357 bool IsAndWithShiftOp = false;
358 if (Op0Opc == ISD::AND && Op1Opc == ISD::AND) {
359 if (Op1.getOperand(0).getOpcode() == ISD::SHL ||
360 Op1.getOperand(0).getOpcode() == ISD::SRL) {
361 if (isIntImmediate(Op1.getOperand(0).getOperand(1), Value)) {
362 SH = Op1.getOperand(0).getOpcode() == ISD::SHL ? Value : 32 - Value;
363 IsAndWithShiftOp = true;
365 } else if (Op0.getOperand(0).getOpcode() == ISD::SHL ||
366 Op0.getOperand(0).getOpcode() == ISD::SRL) {
367 if (isIntImmediate(Op0.getOperand(0).getOperand(1), Value)) {
369 std::swap(TgtMask, InsMask);
370 SH = Op1.getOperand(0).getOpcode() == ISD::SHL ? Value : 32 - Value;
371 IsAndWithShiftOp = true;
376 // Verify that the Target mask and Insert mask together form a full word mask
377 // and that the Insert mask is a run of set bits (which implies both are runs
378 // of set bits). Given that, Select the arguments and generate the rlwimi
381 if (((TgtMask & InsMask) == 0) && isRunOfOnes(InsMask, MB, ME)) {
382 bool fullMask = (TgtMask ^ InsMask) == 0xFFFFFFFF;
383 bool Op0IsAND = Op0Opc == ISD::AND;
384 // Check for rotlwi / rotrwi here, a special case of bitfield insert
385 // where both bitfield halves are sourced from the same value.
386 if (IsRotate && fullMask &&
387 N->getOperand(0).getOperand(0) == N->getOperand(1).getOperand(0)) {
388 Op0 = CurDAG->getTargetNode(PPC::RLWINM, MVT::i32,
389 Select(N->getOperand(0).getOperand(0)),
390 getI32Imm(SH), getI32Imm(0), getI32Imm(31));
393 SDOperand Tmp1 = (Op0IsAND && fullMask) ? Select(Op0.getOperand(0))
395 SDOperand Tmp2 = IsAndWithShiftOp ? Select(Op1.getOperand(0).getOperand(0))
396 : Select(Op1.getOperand(0));
397 Op0 = CurDAG->getTargetNode(PPC::RLWIMI, MVT::i32, Tmp1, Tmp2,
398 getI32Imm(SH), getI32Imm(MB), getI32Imm(ME));
404 /// SelectAddr - Given the specified address, return the two operands for a
405 /// load/store instruction, and return true if it should be an indexed [r+r]
407 bool PPCDAGToDAGISel::SelectAddr(SDOperand Addr, SDOperand &Op1,
410 if (Addr.getOpcode() == ISD::ADD) {
411 if (isIntImmediate(Addr.getOperand(1), imm) && isInt16(imm)) {
412 Op1 = getI32Imm(Lo16(imm));
413 if (FrameIndexSDNode *FI =
414 dyn_cast<FrameIndexSDNode>(Addr.getOperand(0))) {
416 Op2 = CurDAG->getTargetFrameIndex(FI->getIndex(), MVT::i32);
418 Op2 = Select(Addr.getOperand(0));
421 } else if (Addr.getOperand(1).getOpcode() == PPCISD::Lo) {
422 // Match LOAD (ADD (X, Lo(G))).
423 assert(!cast<ConstantSDNode>(Addr.getOperand(1).getOperand(1))->getValue()
424 && "Cannot handle constant offsets yet!");
425 Op1 = Addr.getOperand(1).getOperand(0); // The global address.
426 assert(Op1.getOpcode() == ISD::TargetGlobalAddress ||
427 Op1.getOpcode() == ISD::TargetConstantPool);
428 Op2 = Select(Addr.getOperand(0));
429 return false; // [&g+r]
431 Op1 = Select(Addr.getOperand(0));
432 Op2 = Select(Addr.getOperand(1));
433 return true; // [r+r]
437 if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Addr))
438 Op2 = CurDAG->getTargetFrameIndex(FI->getIndex(), MVT::i32);
445 /// SelectAddrIndexed - Given the specified addressed, force it to be
446 /// represented as an indexed [r+r] operation, rather than possibly
447 /// returning [r+imm] as SelectAddr may.
448 void PPCDAGToDAGISel::SelectAddrIndexed(SDOperand Addr, SDOperand &Op1,
450 if (Addr.getOpcode() == ISD::ADD) {
451 Op1 = Select(Addr.getOperand(0));
452 Op2 = Select(Addr.getOperand(1));
456 if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Addr)) {
457 Op1 = CurDAG->getTargetNode(PPC::LI, MVT::i32, getI32Imm(0));
458 Op2 = CurDAG->getTargetFrameIndex(FI->getIndex(), MVT::i32);
461 Op1 = CurDAG->getTargetNode(PPC::LI, MVT::i32, getI32Imm(0));
465 /// SelectCC - Select a comparison of the specified values with the specified
466 /// condition code, returning the CR# of the expression.
467 SDOperand PPCDAGToDAGISel::SelectCC(SDOperand LHS, SDOperand RHS,
469 // Always select the LHS.
472 // Use U to determine whether the SETCC immediate range is signed or not.
473 if (MVT::isInteger(LHS.getValueType())) {
474 bool U = ISD::isUnsignedIntSetCC(CC);
476 if (isIntImmediate(RHS, Imm) &&
477 ((U && isUInt16(Imm)) || (!U && isInt16(Imm))))
478 return CurDAG->getTargetNode(U ? PPC::CMPLWI : PPC::CMPWI, MVT::i32,
479 LHS, getI32Imm(Lo16(Imm)));
480 return CurDAG->getTargetNode(U ? PPC::CMPLW : PPC::CMPW, MVT::i32,
482 } else if (LHS.getValueType() == MVT::f32) {
483 return CurDAG->getTargetNode(PPC::FCMPUS, MVT::i32, LHS, Select(RHS));
485 return CurDAG->getTargetNode(PPC::FCMPUD, MVT::i32, LHS, Select(RHS));
489 /// getBCCForSetCC - Returns the PowerPC condition branch mnemonic corresponding
491 static unsigned getBCCForSetCC(ISD::CondCode CC) {
493 default: assert(0 && "Unknown condition!"); abort();
494 case ISD::SETOEQ: // FIXME: This is incorrect see PR642.
495 case ISD::SETEQ: return PPC::BEQ;
496 case ISD::SETONE: // FIXME: This is incorrect see PR642.
497 case ISD::SETNE: return PPC::BNE;
498 case ISD::SETOLT: // FIXME: This is incorrect see PR642.
500 case ISD::SETLT: return PPC::BLT;
501 case ISD::SETOLE: // FIXME: This is incorrect see PR642.
503 case ISD::SETLE: return PPC::BLE;
504 case ISD::SETOGT: // FIXME: This is incorrect see PR642.
506 case ISD::SETGT: return PPC::BGT;
507 case ISD::SETOGE: // FIXME: This is incorrect see PR642.
509 case ISD::SETGE: return PPC::BGE;
511 case ISD::SETO: return PPC::BUN;
512 case ISD::SETUO: return PPC::BNU;
517 /// getCRIdxForSetCC - Return the index of the condition register field
518 /// associated with the SetCC condition, and whether or not the field is
519 /// treated as inverted. That is, lt = 0; ge = 0 inverted.
520 static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool& Inv) {
522 default: assert(0 && "Unknown condition!"); abort();
523 case ISD::SETOLT: // FIXME: This is incorrect see PR642.
525 case ISD::SETLT: Inv = false; return 0;
526 case ISD::SETOGE: // FIXME: This is incorrect see PR642.
528 case ISD::SETGE: Inv = true; return 0;
529 case ISD::SETOGT: // FIXME: This is incorrect see PR642.
531 case ISD::SETGT: Inv = false; return 1;
532 case ISD::SETOLE: // FIXME: This is incorrect see PR642.
534 case ISD::SETLE: Inv = true; return 1;
535 case ISD::SETOEQ: // FIXME: This is incorrect see PR642.
536 case ISD::SETEQ: Inv = false; return 2;
537 case ISD::SETONE: // FIXME: This is incorrect see PR642.
538 case ISD::SETNE: Inv = true; return 2;
539 case ISD::SETO: Inv = true; return 3;
540 case ISD::SETUO: Inv = false; return 3;
545 SDOperand PPCDAGToDAGISel::SelectDYNAMIC_STACKALLOC(SDOperand Op) {
548 // FIXME: We are currently ignoring the requested alignment for handling
549 // greater than the stack alignment. This will need to be revisited at some
550 // point. Align = N.getOperand(2);
551 if (!isa<ConstantSDNode>(N->getOperand(2)) ||
552 cast<ConstantSDNode>(N->getOperand(2))->getValue() != 0) {
553 std::cerr << "Cannot allocate stack object with greater alignment than"
554 << " the stack alignment yet!";
557 SDOperand Chain = Select(N->getOperand(0));
558 SDOperand Amt = Select(N->getOperand(1));
560 SDOperand R1Reg = CurDAG->getRegister(PPC::R1, MVT::i32);
562 SDOperand R1Val = CurDAG->getCopyFromReg(Chain, PPC::R1, MVT::i32);
563 Chain = R1Val.getValue(1);
565 // Subtract the amount (guaranteed to be a multiple of the stack alignment)
566 // from the stack pointer, giving us the result pointer.
567 SDOperand Result = CurDAG->getTargetNode(PPC::SUBF, MVT::i32, Amt, R1Val);
569 // Copy this result back into R1.
570 Chain = CurDAG->getNode(ISD::CopyToReg, MVT::Other, Chain, R1Reg, Result);
572 // Copy this result back out of R1 to make sure we're not using the stack
573 // space without decrementing the stack pointer.
574 Result = CurDAG->getCopyFromReg(Chain, PPC::R1, MVT::i32);
576 // Finally, replace the DYNAMIC_STACKALLOC with the copyfromreg.
577 CodeGenMap[Op.getValue(0)] = Result;
578 CodeGenMap[Op.getValue(1)] = Result.getValue(1);
579 return SDOperand(Result.Val, Op.ResNo);
582 SDOperand PPCDAGToDAGISel::SelectADD_PARTS(SDOperand Op) {
584 SDOperand LHSL = Select(N->getOperand(0));
585 SDOperand LHSH = Select(N->getOperand(1));
588 bool ME = false, ZE = false;
589 if (isIntImmediate(N->getOperand(3), Imm)) {
590 ME = (signed)Imm == -1;
594 std::vector<SDOperand> Result;
595 SDOperand CarryFromLo;
596 if (isIntImmediate(N->getOperand(2), Imm) &&
597 ((signed)Imm >= -32768 || (signed)Imm < 32768)) {
598 // Codegen the low 32 bits of the add. Interestingly, there is no
599 // shifted form of add immediate carrying.
600 CarryFromLo = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
601 LHSL, getI32Imm(Imm));
603 CarryFromLo = CurDAG->getTargetNode(PPC::ADDC, MVT::i32, MVT::Flag,
604 LHSL, Select(N->getOperand(2)));
606 CarryFromLo = CarryFromLo.getValue(1);
608 // Codegen the high 32 bits, adding zero, minus one, or the full value
609 // along with the carry flag produced by addc/addic.
612 ResultHi = CurDAG->getTargetNode(PPC::ADDZE, MVT::i32, LHSH, CarryFromLo);
614 ResultHi = CurDAG->getTargetNode(PPC::ADDME, MVT::i32, LHSH, CarryFromLo);
616 ResultHi = CurDAG->getTargetNode(PPC::ADDE, MVT::i32, LHSH,
617 Select(N->getOperand(3)), CarryFromLo);
618 Result.push_back(CarryFromLo.getValue(0));
619 Result.push_back(ResultHi);
621 CodeGenMap[Op.getValue(0)] = Result[0];
622 CodeGenMap[Op.getValue(1)] = Result[1];
623 return Result[Op.ResNo];
625 SDOperand PPCDAGToDAGISel::SelectSUB_PARTS(SDOperand Op) {
627 SDOperand LHSL = Select(N->getOperand(0));
628 SDOperand LHSH = Select(N->getOperand(1));
629 SDOperand RHSL = Select(N->getOperand(2));
630 SDOperand RHSH = Select(N->getOperand(3));
632 std::vector<SDOperand> Result;
633 Result.push_back(CurDAG->getTargetNode(PPC::SUBFC, MVT::i32, MVT::Flag,
635 Result.push_back(CurDAG->getTargetNode(PPC::SUBFE, MVT::i32, RHSH, LHSH,
636 Result[0].getValue(1)));
637 CodeGenMap[Op.getValue(0)] = Result[0];
638 CodeGenMap[Op.getValue(1)] = Result[1];
639 return Result[Op.ResNo];
642 SDOperand PPCDAGToDAGISel::SelectSETCC(SDOperand Op) {
645 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
646 if (isIntImmediate(N->getOperand(1), Imm)) {
647 // We can codegen setcc op, imm very efficiently compared to a brcond.
648 // Check for those cases here.
651 SDOperand Op = Select(N->getOperand(0));
655 Op = CurDAG->getTargetNode(PPC::CNTLZW, MVT::i32, Op);
656 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Op, getI32Imm(27),
657 getI32Imm(5), getI32Imm(31));
659 SDOperand AD = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
661 return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op,
665 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Op, getI32Imm(1),
666 getI32Imm(31), getI32Imm(31));
668 SDOperand T = CurDAG->getTargetNode(PPC::NEG, MVT::i32, Op);
669 T = CurDAG->getTargetNode(PPC::ANDC, MVT::i32, T, Op);;
670 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, T, getI32Imm(1),
671 getI32Imm(31), getI32Imm(31));
674 } else if (Imm == ~0U) { // setcc op, -1
675 SDOperand Op = Select(N->getOperand(0));
679 Op = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
681 return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
682 CurDAG->getTargetNode(PPC::LI, MVT::i32,
686 Op = CurDAG->getTargetNode(PPC::NOR, MVT::i32, Op, Op);
687 SDOperand AD = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
689 return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op,
693 SDOperand AD = CurDAG->getTargetNode(PPC::ADDI, MVT::i32, Op,
695 SDOperand AN = CurDAG->getTargetNode(PPC::AND, MVT::i32, AD, Op);
696 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, AN, getI32Imm(1),
697 getI32Imm(31), getI32Imm(31));
700 Op = CurDAG->getTargetNode(PPC::RLWINM, MVT::i32, Op, getI32Imm(1),
701 getI32Imm(31), getI32Imm(31));
702 return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Op, getI32Imm(1));
708 unsigned Idx = getCRIdxForSetCC(CC, Inv);
709 SDOperand CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC);
712 // Force the ccreg into CR7.
713 SDOperand CR7Reg = CurDAG->getRegister(PPC::CR7, MVT::i32);
715 SDOperand InFlag(0, 0); // Null incoming flag value.
716 CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), CR7Reg, CCReg,
719 if (TLI.getTargetMachine().getSubtarget<PPCSubtarget>().isGigaProcessor())
720 IntCR = CurDAG->getTargetNode(PPC::MFOCRF, MVT::i32, CR7Reg, CCReg);
722 IntCR = CurDAG->getTargetNode(PPC::MFCR, MVT::i32, CCReg);
725 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, IntCR,
726 getI32Imm((32-(3-Idx)) & 31),
727 getI32Imm(31), getI32Imm(31));
730 CurDAG->getTargetNode(PPC::RLWINM, MVT::i32, IntCR,
731 getI32Imm((32-(3-Idx)) & 31),
732 getI32Imm(31),getI32Imm(31));
733 return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1));
737 /// isCallCompatibleAddress - Return true if the specified 32-bit value is
738 /// representable in the immediate field of a Bx instruction.
739 static bool isCallCompatibleAddress(ConstantSDNode *C) {
740 int Addr = C->getValue();
741 if (Addr & 3) return false; // Low 2 bits are implicitly zero.
742 return (Addr << 6 >> 6) == Addr; // Top 6 bits have to be sext of immediate.
745 SDOperand PPCDAGToDAGISel::SelectCALL(SDOperand Op) {
747 SDOperand Chain = Select(N->getOperand(0));
750 std::vector<SDOperand> CallOperands;
752 if (GlobalAddressSDNode *GASD =
753 dyn_cast<GlobalAddressSDNode>(N->getOperand(1))) {
754 CallOpcode = PPC::BL;
755 CallOperands.push_back(N->getOperand(1));
756 } else if (ExternalSymbolSDNode *ESSDN =
757 dyn_cast<ExternalSymbolSDNode>(N->getOperand(1))) {
758 CallOpcode = PPC::BL;
759 CallOperands.push_back(N->getOperand(1));
760 } else if (isa<ConstantSDNode>(N->getOperand(1)) &&
761 isCallCompatibleAddress(cast<ConstantSDNode>(N->getOperand(1)))) {
762 ConstantSDNode *C = cast<ConstantSDNode>(N->getOperand(1));
763 CallOpcode = PPC::BLA;
764 CallOperands.push_back(getI32Imm((int)C->getValue() >> 2));
766 // Copy the callee address into the CTR register.
767 SDOperand Callee = Select(N->getOperand(1));
768 Chain = CurDAG->getTargetNode(PPC::MTCTR, MVT::Other, Callee, Chain);
770 // Copy the callee address into R12 on darwin.
771 SDOperand R12 = CurDAG->getRegister(PPC::R12, MVT::i32);
772 Chain = CurDAG->getNode(ISD::CopyToReg, MVT::Other, Chain, R12, Callee);
774 CallOperands.push_back(R12);
775 CallOpcode = PPC::BCTRL;
778 unsigned GPR_idx = 0, FPR_idx = 0;
779 static const unsigned GPR[] = {
780 PPC::R3, PPC::R4, PPC::R5, PPC::R6,
781 PPC::R7, PPC::R8, PPC::R9, PPC::R10,
783 static const unsigned FPR[] = {
784 PPC::F1, PPC::F2, PPC::F3, PPC::F4, PPC::F5, PPC::F6, PPC::F7,
785 PPC::F8, PPC::F9, PPC::F10, PPC::F11, PPC::F12, PPC::F13
788 SDOperand InFlag; // Null incoming flag value.
790 for (unsigned i = 2, e = N->getNumOperands(); i != e; ++i) {
791 unsigned DestReg = 0;
792 MVT::ValueType RegTy = N->getOperand(i).getValueType();
793 if (RegTy == MVT::i32) {
794 assert(GPR_idx < 8 && "Too many int args");
795 DestReg = GPR[GPR_idx++];
797 assert(MVT::isFloatingPoint(N->getOperand(i).getValueType()) &&
798 "Unpromoted integer arg?");
799 assert(FPR_idx < 13 && "Too many fp args");
800 DestReg = FPR[FPR_idx++];
803 if (N->getOperand(i).getOpcode() != ISD::UNDEF) {
804 SDOperand Val = Select(N->getOperand(i));
805 Chain = CurDAG->getCopyToReg(Chain, DestReg, Val, InFlag);
806 InFlag = Chain.getValue(1);
807 CallOperands.push_back(CurDAG->getRegister(DestReg, RegTy));
811 // Finally, once everything is in registers to pass to the call, emit the
814 CallOperands.push_back(InFlag); // Strong dep on register copies.
816 CallOperands.push_back(Chain); // Weak dep on whatever occurs before
817 Chain = CurDAG->getTargetNode(CallOpcode, MVT::Other, MVT::Flag,
820 std::vector<SDOperand> CallResults;
822 // If the call has results, copy the values out of the ret val registers.
823 switch (N->getValueType(0)) {
824 default: assert(0 && "Unexpected ret value!");
825 case MVT::Other: break;
827 if (N->getValueType(1) == MVT::i32) {
828 Chain = CurDAG->getCopyFromReg(Chain, PPC::R4, MVT::i32,
829 Chain.getValue(1)).getValue(1);
830 CallResults.push_back(Chain.getValue(0));
831 Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32,
832 Chain.getValue(2)).getValue(1);
833 CallResults.push_back(Chain.getValue(0));
835 Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32,
836 Chain.getValue(1)).getValue(1);
837 CallResults.push_back(Chain.getValue(0));
842 Chain = CurDAG->getCopyFromReg(Chain, PPC::F1, N->getValueType(0),
843 Chain.getValue(1)).getValue(1);
844 CallResults.push_back(Chain.getValue(0));
848 CallResults.push_back(Chain);
849 for (unsigned i = 0, e = CallResults.size(); i != e; ++i)
850 CodeGenMap[Op.getValue(i)] = CallResults[i];
851 return CallResults[Op.ResNo];
854 // Select - Convert the specified operand from a target-independent to a
855 // target-specific node if it hasn't already been changed.
856 SDOperand PPCDAGToDAGISel::Select(SDOperand Op) {
858 if (N->getOpcode() >= ISD::BUILTIN_OP_END &&
859 N->getOpcode() < PPCISD::FIRST_NUMBER)
860 return Op; // Already selected.
862 // If this has already been converted, use it.
863 std::map<SDOperand, SDOperand>::iterator CGMI = CodeGenMap.find(Op);
864 if (CGMI != CodeGenMap.end()) return CGMI->second;
866 switch (N->getOpcode()) {
868 case ISD::BasicBlock: return CodeGenMap[Op] = Op;
869 case ISD::DYNAMIC_STACKALLOC: return SelectDYNAMIC_STACKALLOC(Op);
870 case ISD::ADD_PARTS: return SelectADD_PARTS(Op);
871 case ISD::SUB_PARTS: return SelectSUB_PARTS(Op);
872 case ISD::SETCC: return SelectSETCC(Op);
873 case ISD::CALL: return SelectCALL(Op);
874 case ISD::TAILCALL: return SelectCALL(Op);
875 case PPCISD::GlobalBaseReg: return getGlobalBaseReg();
877 case ISD::FrameIndex: {
878 int FI = cast<FrameIndexSDNode>(N)->getIndex();
880 return CurDAG->SelectNodeTo(N, PPC::ADDI, MVT::i32,
881 CurDAG->getTargetFrameIndex(FI, MVT::i32),
883 return CodeGenMap[Op] =
884 CurDAG->getTargetNode(PPC::ADDI, MVT::i32,
885 CurDAG->getTargetFrameIndex(FI, MVT::i32),
889 // FIXME: since this depends on the setting of the carry flag from the srawi
890 // we should really be making notes about that for the scheduler.
891 // FIXME: It sure would be nice if we could cheaply recognize the
892 // srl/add/sra pattern the dag combiner will generate for this as
893 // sra/addze rather than having to handle sdiv ourselves. oh well.
895 if (isIntImmediate(N->getOperand(1), Imm)) {
896 if ((signed)Imm > 0 && isPowerOf2_32(Imm)) {
898 CurDAG->getTargetNode(PPC::SRAWI, MVT::i32, MVT::Flag,
899 Select(N->getOperand(0)),
900 getI32Imm(Log2_32(Imm)));
901 return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
902 Op.getValue(0), Op.getValue(1));
903 } else if ((signed)Imm < 0 && isPowerOf2_32(-Imm)) {
905 CurDAG->getTargetNode(PPC::SRAWI, MVT::i32, MVT::Flag,
906 Select(N->getOperand(0)),
907 getI32Imm(Log2_32(-Imm)));
909 CurDAG->getTargetNode(PPC::ADDZE, MVT::i32, Op.getValue(0),
911 return CurDAG->SelectNodeTo(N, PPC::NEG, MVT::i32, PT);
915 // Other cases are autogenerated.
920 // If this is an and of a value rotated between 0 and 31 bits and then and'd
921 // with a mask, emit rlwinm
922 if (isIntImmediate(N->getOperand(1), Imm) && (isShiftedMask_32(Imm) ||
923 isShiftedMask_32(~Imm))) {
926 if (isRotateAndMask(N->getOperand(0).Val, Imm, false, SH, MB, ME)) {
927 Val = Select(N->getOperand(0).getOperand(0));
928 } else if (Imm == 0) {
929 // AND X, 0 -> 0, not "rlwinm 32".
930 return Select(N->getOperand(1));
932 Val = Select(N->getOperand(0));
933 isRunOfOnes(Imm, MB, ME);
936 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Val, getI32Imm(SH),
937 getI32Imm(MB), getI32Imm(ME));
940 // Other cases are autogenerated.
944 if (SDNode *I = SelectBitfieldInsert(N))
945 return CodeGenMap[Op] = SDOperand(I, 0);
947 // Other cases are autogenerated.
950 unsigned Imm, SH, MB, ME;
951 if (isOpcWithIntImmediate(N->getOperand(0).Val, ISD::AND, Imm) &&
952 isRotateAndMask(N, Imm, true, SH, MB, ME)) {
953 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32,
954 Select(N->getOperand(0).getOperand(0)),
955 getI32Imm(SH), getI32Imm(MB), getI32Imm(ME));
958 // Other cases are autogenerated.
962 unsigned Imm, SH, MB, ME;
963 if (isOpcWithIntImmediate(N->getOperand(0).Val, ISD::AND, Imm) &&
964 isRotateAndMask(N, Imm, true, SH, MB, ME)) {
965 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32,
966 Select(N->getOperand(0).getOperand(0)),
967 getI32Imm(SH & 0x1F), getI32Imm(MB),
971 // Other cases are autogenerated.
975 SDOperand Val = Select(N->getOperand(0));
976 MVT::ValueType Ty = N->getValueType(0);
977 if (N->getOperand(0).Val->hasOneUse()) {
979 switch (Val.isTargetOpcode() ? Val.getTargetOpcode() : 0) {
980 default: Opc = 0; break;
981 case PPC::FABSS: Opc = PPC::FNABSS; break;
982 case PPC::FABSD: Opc = PPC::FNABSD; break;
983 case PPC::FMADD: Opc = PPC::FNMADD; break;
984 case PPC::FMADDS: Opc = PPC::FNMADDS; break;
985 case PPC::FMSUB: Opc = PPC::FNMSUB; break;
986 case PPC::FMSUBS: Opc = PPC::FNMSUBS; break;
988 // If we inverted the opcode, then emit the new instruction with the
989 // inverted opcode and the original instruction's operands. Otherwise,
990 // fall through and generate a fneg instruction.
992 if (Opc == PPC::FNABSS || Opc == PPC::FNABSD)
993 return CurDAG->SelectNodeTo(N, Opc, Ty, Val.getOperand(0));
995 return CurDAG->SelectNodeTo(N, Opc, Ty, Val.getOperand(0),
996 Val.getOperand(1), Val.getOperand(2));
999 // Other cases are autogenerated.
1005 case ISD::SEXTLOAD: {
1007 // If this is a vector load, then force this to be indexed addressing, since
1008 // altivec does not have immediate offsets for loads.
1010 if (N->getOpcode() == ISD::LOAD && MVT::isVector(N->getValueType(0))) {
1011 SelectAddrIndexed(N->getOperand(1), Op1, Op2);
1013 isIdx = SelectAddr(N->getOperand(1), Op1, Op2);
1015 MVT::ValueType TypeBeingLoaded = (N->getOpcode() == ISD::LOAD) ?
1016 N->getValueType(0) : cast<VTSDNode>(N->getOperand(3))->getVT();
1019 switch (TypeBeingLoaded) {
1020 default: N->dump(); assert(0 && "Cannot load this type!");
1022 case MVT::i8: Opc = isIdx ? PPC::LBZX : PPC::LBZ; break;
1024 if (N->getOpcode() == ISD::SEXTLOAD) { // SEXT load?
1025 Opc = isIdx ? PPC::LHAX : PPC::LHA;
1027 Opc = isIdx ? PPC::LHZX : PPC::LHZ;
1030 case MVT::i32: Opc = isIdx ? PPC::LWZX : PPC::LWZ; break;
1031 case MVT::f32: Opc = isIdx ? PPC::LFSX : PPC::LFS; break;
1032 case MVT::f64: Opc = isIdx ? PPC::LFDX : PPC::LFD; break;
1033 case MVT::v4f32: Opc = PPC::LVX; break;
1036 // If this is an f32 -> f64 load, emit the f32 load, then use an 'extending
1038 if (TypeBeingLoaded != MVT::f32 || N->getOpcode() == ISD::LOAD) {
1039 return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), MVT::Other,
1040 Op1, Op2, Select(N->getOperand(0))).
1043 std::vector<SDOperand> Ops;
1046 Ops.push_back(Select(N->getOperand(0)));
1047 SDOperand Res = CurDAG->getTargetNode(Opc, MVT::f32, MVT::Other, Ops);
1048 SDOperand Ext = CurDAG->getTargetNode(PPC::FMRSD, MVT::f64, Res);
1049 CodeGenMap[Op.getValue(0)] = Ext;
1050 CodeGenMap[Op.getValue(1)] = Res.getValue(1);
1052 return Res.getValue(1);
1057 case ISD::TRUNCSTORE:
1059 SDOperand AddrOp1, AddrOp2;
1060 // If this is a vector store, then force this to be indexed addressing,
1061 // since altivec does not have immediate offsets for stores.
1063 if (N->getOpcode() == ISD::STORE &&
1064 MVT::isVector(N->getOperand(1).getValueType())) {
1065 SelectAddrIndexed(N->getOperand(2), AddrOp1, AddrOp2);
1067 isIdx = SelectAddr(N->getOperand(2), AddrOp1, AddrOp2);
1071 if (N->getOpcode() == ISD::STORE) {
1072 switch (N->getOperand(1).getValueType()) {
1073 default: assert(0 && "unknown Type in store");
1074 case MVT::i32: Opc = isIdx ? PPC::STWX : PPC::STW; break;
1075 case MVT::f64: Opc = isIdx ? PPC::STFDX : PPC::STFD; break;
1076 case MVT::f32: Opc = isIdx ? PPC::STFSX : PPC::STFS; break;
1077 case MVT::v4f32: Opc = PPC::STVX;
1079 } else { //ISD::TRUNCSTORE
1080 switch(cast<VTSDNode>(N->getOperand(4))->getVT()) {
1081 default: assert(0 && "unknown Type in store");
1082 case MVT::i8: Opc = isIdx ? PPC::STBX : PPC::STB; break;
1083 case MVT::i16: Opc = isIdx ? PPC::STHX : PPC::STH; break;
1087 return CurDAG->SelectNodeTo(N, Opc, MVT::Other, Select(N->getOperand(1)),
1088 AddrOp1, AddrOp2, Select(N->getOperand(0)));
1091 case ISD::SELECT_CC: {
1092 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
1094 // handle the setcc cases here. select_cc lhs, 0, 1, 0, cc
1095 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
1096 if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N->getOperand(2)))
1097 if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N->getOperand(3)))
1098 if (N1C->isNullValue() && N3C->isNullValue() &&
1099 N2C->getValue() == 1ULL && CC == ISD::SETNE) {
1100 SDOperand LHS = Select(N->getOperand(0));
1102 CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
1103 LHS, getI32Imm(~0U));
1104 return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, Tmp, LHS,
1108 SDOperand CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC);
1109 unsigned BROpc = getBCCForSetCC(CC);
1111 bool isFP = MVT::isFloatingPoint(N->getValueType(0));
1112 unsigned SelectCCOp;
1113 if (MVT::isInteger(N->getValueType(0)))
1114 SelectCCOp = PPC::SELECT_CC_Int;
1115 else if (N->getValueType(0) == MVT::f32)
1116 SelectCCOp = PPC::SELECT_CC_F4;
1118 SelectCCOp = PPC::SELECT_CC_F8;
1119 return CurDAG->SelectNodeTo(N, SelectCCOp, N->getValueType(0), CCReg,
1120 Select(N->getOperand(2)),
1121 Select(N->getOperand(3)),
1126 SDOperand Chain = Select(N->getOperand(0)); // Token chain.
1128 if (N->getNumOperands() == 2) {
1129 SDOperand Val = Select(N->getOperand(1));
1130 if (N->getOperand(1).getValueType() == MVT::i32) {
1131 Chain = CurDAG->getCopyToReg(Chain, PPC::R3, Val);
1133 assert(MVT::isFloatingPoint(N->getOperand(1).getValueType()));
1134 Chain = CurDAG->getCopyToReg(Chain, PPC::F1, Val);
1136 } else if (N->getNumOperands() > 1) {
1137 assert(N->getOperand(1).getValueType() == MVT::i32 &&
1138 N->getOperand(2).getValueType() == MVT::i32 &&
1139 N->getNumOperands() == 3 && "Unknown two-register ret value!");
1140 Chain = CurDAG->getCopyToReg(Chain, PPC::R4, Select(N->getOperand(1)));
1141 Chain = CurDAG->getCopyToReg(Chain, PPC::R3, Select(N->getOperand(2)));
1144 // Finally, select this to a blr (return) instruction.
1145 return CurDAG->SelectNodeTo(N, PPC::BLR, MVT::Other, Chain);
1148 case ISD::BRTWOWAY_CC: {
1149 SDOperand Chain = Select(N->getOperand(0));
1150 MachineBasicBlock *Dest =
1151 cast<BasicBlockSDNode>(N->getOperand(4))->getBasicBlock();
1152 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
1153 SDOperand CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC);
1155 // If this is a two way branch, then grab the fallthrough basic block
1156 // argument and build a PowerPC branch pseudo-op, suitable for long branch
1157 // conversion if necessary by the branch selection pass. Otherwise, emit a
1158 // standard conditional branch.
1159 if (N->getOpcode() == ISD::BRTWOWAY_CC) {
1160 SDOperand CondTrueBlock = N->getOperand(4);
1161 SDOperand CondFalseBlock = N->getOperand(5);
1163 // If the false case is the current basic block, then this is a self loop.
1164 // We do not want to emit "Loop: ... brcond Out; br Loop", as it adds an
1165 // extra dispatch group to the loop. Instead, invert the condition and
1166 // emit "Loop: ... br!cond Loop; br Out
1167 if (cast<BasicBlockSDNode>(CondFalseBlock)->getBasicBlock() == BB) {
1168 std::swap(CondTrueBlock, CondFalseBlock);
1169 CC = getSetCCInverse(CC,
1170 MVT::isInteger(N->getOperand(2).getValueType()));
1173 unsigned Opc = getBCCForSetCC(CC);
1174 SDOperand CB = CurDAG->getTargetNode(PPC::COND_BRANCH, MVT::Other,
1175 CondCode, getI32Imm(Opc),
1176 CondTrueBlock, CondFalseBlock,
1178 return CurDAG->SelectNodeTo(N, PPC::B, MVT::Other, CondFalseBlock, CB);
1180 // Iterate to the next basic block
1181 ilist<MachineBasicBlock>::iterator It = BB;
1184 // If the fallthrough path is off the end of the function, which would be
1185 // undefined behavior, set it to be the same as the current block because
1186 // we have nothing better to set it to, and leaving it alone will cause
1187 // the PowerPC Branch Selection pass to crash.
1188 if (It == BB->getParent()->end()) It = Dest;
1189 return CurDAG->SelectNodeTo(N, PPC::COND_BRANCH, MVT::Other, CondCode,
1190 getI32Imm(getBCCForSetCC(CC)),
1191 N->getOperand(4), CurDAG->getBasicBlock(It),
1197 return SelectCode(Op);
1201 /// createPPCISelDag - This pass converts a legalized DAG into a
1202 /// PowerPC-specific DAG, ready for instruction scheduling.
1204 FunctionPass *llvm::createPPCISelDag(TargetMachine &TM) {
1205 return new PPCDAGToDAGISel(TM);