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<> FrameOff("ppc-codegen", "Number of frame idx offsets collapsed");
34 //===--------------------------------------------------------------------===//
35 /// PPCDAGToDAGISel - PPC specific code to select PPC machine
36 /// instructions for SelectionDAG operations.
38 class PPCDAGToDAGISel : public SelectionDAGISel {
39 PPCTargetLowering PPCLowering;
40 unsigned GlobalBaseReg;
42 PPCDAGToDAGISel(TargetMachine &TM)
43 : SelectionDAGISel(PPCLowering), PPCLowering(TM) {}
45 virtual bool runOnFunction(Function &Fn) {
46 // Make sure we re-emit a set of the global base reg if necessary
48 return SelectionDAGISel::runOnFunction(Fn);
51 /// getI32Imm - Return a target constant with the specified value, of type
53 inline SDOperand getI32Imm(unsigned Imm) {
54 return CurDAG->getTargetConstant(Imm, MVT::i32);
57 /// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
58 /// base register. Return the virtual register that holds this value.
59 SDOperand getGlobalBaseReg();
61 // Select - Convert the specified operand from a target-independent to a
62 // target-specific node if it hasn't already been changed.
63 SDOperand Select(SDOperand Op);
65 SDNode *SelectBitfieldInsert(SDNode *N);
67 /// SelectCC - Select a comparison of the specified values with the
68 /// specified condition code, returning the CR# of the expression.
69 SDOperand SelectCC(SDOperand LHS, SDOperand RHS, ISD::CondCode CC);
71 /// SelectAddr - Given the specified address, return the two operands for a
72 /// load/store instruction, and return true if it should be an indexed [r+r]
74 bool SelectAddr(SDOperand Addr, SDOperand &Op1, SDOperand &Op2);
76 /// SelectAddrIndexed - Given the specified addressed, force it to be
77 /// represented as an indexed [r+r] operation, rather than possibly
78 /// returning [r+imm] as SelectAddr may.
79 void SelectAddrIndexed(SDOperand Addr, SDOperand &Op1, SDOperand &Op2);
81 SDOperand BuildSDIVSequence(SDNode *N);
82 SDOperand BuildUDIVSequence(SDNode *N);
84 /// InstructionSelectBasicBlock - This callback is invoked by
85 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
86 virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
88 virtual const char *getPassName() const {
89 return "PowerPC DAG->DAG Pattern Instruction Selection";
92 // Include the pieces autogenerated from the target description.
93 #include "PPCGenDAGISel.inc"
96 SDOperand SelectDYNAMIC_STACKALLOC(SDOperand Op);
97 SDOperand SelectADD_PARTS(SDOperand Op);
98 SDOperand SelectSUB_PARTS(SDOperand Op);
99 SDOperand SelectSETCC(SDOperand Op);
100 SDOperand SelectCALL(SDOperand Op);
104 /// InstructionSelectBasicBlock - This callback is invoked by
105 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
106 void PPCDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
109 // The selection process is inherently a bottom-up recursive process (users
110 // select their uses before themselves). Given infinite stack space, we
111 // could just start selecting on the root and traverse the whole graph. In
112 // practice however, this causes us to run out of stack space on large basic
113 // blocks. To avoid this problem, select the entry node, then all its uses,
114 // iteratively instead of recursively.
115 std::vector<SDOperand> Worklist;
116 Worklist.push_back(DAG.getEntryNode());
118 // Note that we can do this in the PPC target (scanning forward across token
119 // chain edges) because no nodes ever get folded across these edges. On a
120 // target like X86 which supports load/modify/store operations, this would
121 // have to be more careful.
122 while (!Worklist.empty()) {
123 SDOperand Node = Worklist.back();
126 // Chose from the least deep of the top two nodes.
127 if (!Worklist.empty() &&
128 Worklist.back().Val->getNodeDepth() < Node.Val->getNodeDepth())
129 std::swap(Worklist.back(), Node);
131 if ((Node.Val->getOpcode() >= ISD::BUILTIN_OP_END &&
132 Node.Val->getOpcode() < PPCISD::FIRST_NUMBER) ||
133 CodeGenMap.count(Node)) continue;
135 for (SDNode::use_iterator UI = Node.Val->use_begin(),
136 E = Node.Val->use_end(); UI != E; ++UI) {
137 // Scan the values. If this use has a value that is a token chain, add it
140 for (unsigned i = 0, e = User->getNumValues(); i != e; ++i)
141 if (User->getValueType(i) == MVT::Other) {
142 Worklist.push_back(SDOperand(User, i));
147 // Finally, legalize this node.
151 // Select target instructions for the DAG.
152 DAG.setRoot(Select(DAG.getRoot()));
154 DAG.RemoveDeadNodes();
156 // Emit machine code to BB.
157 ScheduleAndEmitDAG(DAG);
160 /// getGlobalBaseReg - Output the instructions required to put the
161 /// base address to use for accessing globals into a register.
163 SDOperand PPCDAGToDAGISel::getGlobalBaseReg() {
164 if (!GlobalBaseReg) {
165 // Insert the set of GlobalBaseReg into the first MBB of the function
166 MachineBasicBlock &FirstMBB = BB->getParent()->front();
167 MachineBasicBlock::iterator MBBI = FirstMBB.begin();
168 SSARegMap *RegMap = BB->getParent()->getSSARegMap();
169 // FIXME: when we get to LP64, we will need to create the appropriate
170 // type of register here.
171 GlobalBaseReg = RegMap->createVirtualRegister(PPC::GPRCRegisterClass);
172 BuildMI(FirstMBB, MBBI, PPC::MovePCtoLR, 0, PPC::LR);
173 BuildMI(FirstMBB, MBBI, PPC::MFLR, 1, GlobalBaseReg);
175 return CurDAG->getRegister(GlobalBaseReg, MVT::i32);
179 // isIntImmediate - This method tests to see if a constant operand.
180 // If so Imm will receive the 32 bit value.
181 static bool isIntImmediate(SDNode *N, unsigned& Imm) {
182 if (N->getOpcode() == ISD::Constant) {
183 Imm = cast<ConstantSDNode>(N)->getValue();
189 // isOprShiftImm - Returns true if the specified operand is a shift opcode with
190 // a immediate shift count less than 32.
191 static bool isOprShiftImm(SDNode *N, unsigned& Opc, unsigned& SH) {
192 Opc = N->getOpcode();
193 return (Opc == ISD::SHL || Opc == ISD::SRL || Opc == ISD::SRA) &&
194 isIntImmediate(N->getOperand(1).Val, SH) && SH < 32;
197 // isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s with
198 // any number of 0s on either side. The 1s are allowed to wrap from LSB to
199 // MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
200 // not, since all 1s are not contiguous.
201 static bool isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
202 if (isShiftedMask_32(Val)) {
203 // look for the first non-zero bit
204 MB = CountLeadingZeros_32(Val);
205 // look for the first zero bit after the run of ones
206 ME = CountLeadingZeros_32((Val - 1) ^ Val);
209 Val = ~Val; // invert mask
210 if (isShiftedMask_32(Val)) {
211 // effectively look for the first zero bit
212 ME = CountLeadingZeros_32(Val) - 1;
213 // effectively look for the first one bit after the run of zeros
214 MB = CountLeadingZeros_32((Val - 1) ^ Val) + 1;
222 // isRotateAndMask - Returns true if Mask and Shift can be folded into a rotate
223 // and mask opcode and mask operation.
224 static bool isRotateAndMask(SDNode *N, unsigned Mask, bool IsShiftMask,
225 unsigned &SH, unsigned &MB, unsigned &ME) {
226 // Don't even go down this path for i64, since different logic will be
227 // necessary for rldicl/rldicr/rldimi.
228 if (N->getValueType(0) != MVT::i32)
232 unsigned Indeterminant = ~0; // bit mask marking indeterminant results
233 unsigned Opcode = N->getOpcode();
234 if (N->getNumOperands() != 2 ||
235 !isIntImmediate(N->getOperand(1).Val, Shift) || (Shift > 31))
238 if (Opcode == ISD::SHL) {
239 // apply shift left to mask if it comes first
240 if (IsShiftMask) Mask = Mask << Shift;
241 // determine which bits are made indeterminant by shift
242 Indeterminant = ~(0xFFFFFFFFu << Shift);
243 } else if (Opcode == ISD::SRL) {
244 // apply shift right to mask if it comes first
245 if (IsShiftMask) Mask = Mask >> Shift;
246 // determine which bits are made indeterminant by shift
247 Indeterminant = ~(0xFFFFFFFFu >> Shift);
248 // adjust for the left rotate
254 // if the mask doesn't intersect any Indeterminant bits
255 if (Mask && !(Mask & Indeterminant)) {
257 // make sure the mask is still a mask (wrap arounds may not be)
258 return isRunOfOnes(Mask, MB, ME);
263 // isOpcWithIntImmediate - This method tests to see if the node is a specific
264 // opcode and that it has a immediate integer right operand.
265 // If so Imm will receive the 32 bit value.
266 static bool isOpcWithIntImmediate(SDNode *N, unsigned Opc, unsigned& Imm) {
267 return N->getOpcode() == Opc && isIntImmediate(N->getOperand(1).Val, Imm);
270 // isOprNot - Returns true if the specified operand is an xor with immediate -1.
271 static bool isOprNot(SDNode *N) {
273 return isOpcWithIntImmediate(N, ISD::XOR, Imm) && (signed)Imm == -1;
276 // Immediate constant composers.
277 // Lo16 - grabs the lo 16 bits from a 32 bit constant.
278 // Hi16 - grabs the hi 16 bits from a 32 bit constant.
279 // HA16 - computes the hi bits required if the lo bits are add/subtracted in
281 static unsigned Lo16(unsigned x) { return x & 0x0000FFFF; }
282 static unsigned Hi16(unsigned x) { return Lo16(x >> 16); }
283 static unsigned HA16(unsigned x) { return Hi16((signed)x - (signed short)x); }
285 // isIntImmediate - This method tests to see if a constant operand.
286 // If so Imm will receive the 32 bit value.
287 static bool isIntImmediate(SDOperand N, unsigned& Imm) {
288 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N)) {
289 Imm = (unsigned)CN->getSignExtended();
295 /// SelectBitfieldInsert - turn an or of two masked values into
296 /// the rotate left word immediate then mask insert (rlwimi) instruction.
297 /// Returns true on success, false if the caller still needs to select OR.
299 /// Patterns matched:
300 /// 1. or shl, and 5. or and, and
301 /// 2. or and, shl 6. or shl, shr
302 /// 3. or shr, and 7. or shr, shl
304 SDNode *PPCDAGToDAGISel::SelectBitfieldInsert(SDNode *N) {
305 bool IsRotate = false;
306 unsigned TgtMask = 0xFFFFFFFF, InsMask = 0xFFFFFFFF, SH = 0;
309 SDOperand Op0 = N->getOperand(0);
310 SDOperand Op1 = N->getOperand(1);
312 unsigned Op0Opc = Op0.getOpcode();
313 unsigned Op1Opc = Op1.getOpcode();
315 // Verify that we have the correct opcodes
316 if (ISD::SHL != Op0Opc && ISD::SRL != Op0Opc && ISD::AND != Op0Opc)
318 if (ISD::SHL != Op1Opc && ISD::SRL != Op1Opc && ISD::AND != Op1Opc)
321 // Generate Mask value for Target
322 if (isIntImmediate(Op0.getOperand(1), Value)) {
324 case ISD::SHL: TgtMask <<= Value; break;
325 case ISD::SRL: TgtMask >>= Value; break;
326 case ISD::AND: TgtMask &= Value; break;
332 // Generate Mask value for Insert
333 if (!isIntImmediate(Op1.getOperand(1), Value))
340 if (Op0Opc == ISD::SRL) IsRotate = true;
346 if (Op0Opc == ISD::SHL) IsRotate = true;
353 // If both of the inputs are ANDs and one of them has a logical shift by
354 // constant as its input, make that AND the inserted value so that we can
355 // combine the shift into the rotate part of the rlwimi instruction
356 bool IsAndWithShiftOp = false;
357 if (Op0Opc == ISD::AND && Op1Opc == ISD::AND) {
358 if (Op1.getOperand(0).getOpcode() == ISD::SHL ||
359 Op1.getOperand(0).getOpcode() == ISD::SRL) {
360 if (isIntImmediate(Op1.getOperand(0).getOperand(1), Value)) {
361 SH = Op1.getOperand(0).getOpcode() == ISD::SHL ? Value : 32 - Value;
362 IsAndWithShiftOp = true;
364 } else if (Op0.getOperand(0).getOpcode() == ISD::SHL ||
365 Op0.getOperand(0).getOpcode() == ISD::SRL) {
366 if (isIntImmediate(Op0.getOperand(0).getOperand(1), Value)) {
368 std::swap(TgtMask, InsMask);
369 SH = Op1.getOperand(0).getOpcode() == ISD::SHL ? Value : 32 - Value;
370 IsAndWithShiftOp = true;
375 // Verify that the Target mask and Insert mask together form a full word mask
376 // and that the Insert mask is a run of set bits (which implies both are runs
377 // of set bits). Given that, Select the arguments and generate the rlwimi
380 if (((TgtMask & InsMask) == 0) && isRunOfOnes(InsMask, MB, ME)) {
381 bool fullMask = (TgtMask ^ InsMask) == 0xFFFFFFFF;
382 bool Op0IsAND = Op0Opc == ISD::AND;
383 // Check for rotlwi / rotrwi here, a special case of bitfield insert
384 // where both bitfield halves are sourced from the same value.
385 if (IsRotate && fullMask &&
386 N->getOperand(0).getOperand(0) == N->getOperand(1).getOperand(0)) {
387 Op0 = CurDAG->getTargetNode(PPC::RLWINM, MVT::i32,
388 Select(N->getOperand(0).getOperand(0)),
389 getI32Imm(SH), getI32Imm(0), getI32Imm(31));
392 SDOperand Tmp1 = (Op0IsAND && fullMask) ? Select(Op0.getOperand(0))
394 SDOperand Tmp2 = IsAndWithShiftOp ? Select(Op1.getOperand(0).getOperand(0))
395 : Select(Op1.getOperand(0));
396 Op0 = CurDAG->getTargetNode(PPC::RLWIMI, MVT::i32, Tmp1, Tmp2,
397 getI32Imm(SH), getI32Imm(MB), getI32Imm(ME));
403 /// SelectAddr - Given the specified address, return the two operands for a
404 /// load/store instruction, and return true if it should be an indexed [r+r]
406 bool PPCDAGToDAGISel::SelectAddr(SDOperand Addr, SDOperand &Op1,
409 if (Addr.getOpcode() == ISD::ADD) {
410 if (isIntImmediate(Addr.getOperand(1), imm) && isInt16(imm)) {
411 Op1 = getI32Imm(Lo16(imm));
412 if (FrameIndexSDNode *FI =
413 dyn_cast<FrameIndexSDNode>(Addr.getOperand(0))) {
415 Op2 = CurDAG->getTargetFrameIndex(FI->getIndex(), MVT::i32);
417 Op2 = Select(Addr.getOperand(0));
420 } else if (Addr.getOperand(1).getOpcode() == PPCISD::Lo) {
421 // Match LOAD (ADD (X, Lo(G))).
422 assert(!cast<ConstantSDNode>(Addr.getOperand(1).getOperand(1))->getValue()
423 && "Cannot handle constant offsets yet!");
424 Op1 = Addr.getOperand(1).getOperand(0); // The global address.
425 assert(Op1.getOpcode() == ISD::TargetGlobalAddress ||
426 Op1.getOpcode() == ISD::TargetConstantPool);
427 Op2 = Select(Addr.getOperand(0));
428 return false; // [&g+r]
430 Op1 = Select(Addr.getOperand(0));
431 Op2 = Select(Addr.getOperand(1));
432 return true; // [r+r]
436 if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Addr))
437 Op2 = CurDAG->getTargetFrameIndex(FI->getIndex(), MVT::i32);
444 /// SelectAddrIndexed - Given the specified addressed, force it to be
445 /// represented as an indexed [r+r] operation, rather than possibly
446 /// returning [r+imm] as SelectAddr may.
447 void PPCDAGToDAGISel::SelectAddrIndexed(SDOperand Addr, SDOperand &Op1,
449 if (Addr.getOpcode() == ISD::ADD) {
450 Op1 = Select(Addr.getOperand(0));
451 Op2 = Select(Addr.getOperand(1));
455 if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Addr)) {
456 Op1 = CurDAG->getTargetNode(PPC::LI, MVT::i32, getI32Imm(0));
457 Op2 = CurDAG->getTargetFrameIndex(FI->getIndex(), MVT::i32);
460 Op1 = CurDAG->getTargetNode(PPC::LI, MVT::i32, getI32Imm(0));
464 /// SelectCC - Select a comparison of the specified values with the specified
465 /// condition code, returning the CR# of the expression.
466 SDOperand PPCDAGToDAGISel::SelectCC(SDOperand LHS, SDOperand RHS,
468 // Always select the LHS.
471 // Use U to determine whether the SETCC immediate range is signed or not.
472 if (MVT::isInteger(LHS.getValueType())) {
473 bool U = ISD::isUnsignedIntSetCC(CC);
475 if (isIntImmediate(RHS, Imm) &&
476 ((U && isUInt16(Imm)) || (!U && isInt16(Imm))))
477 return CurDAG->getTargetNode(U ? PPC::CMPLWI : PPC::CMPWI, MVT::i32,
478 LHS, getI32Imm(Lo16(Imm)));
479 return CurDAG->getTargetNode(U ? PPC::CMPLW : PPC::CMPW, MVT::i32,
481 } else if (LHS.getValueType() == MVT::f32) {
482 return CurDAG->getTargetNode(PPC::FCMPUS, MVT::i32, LHS, Select(RHS));
484 return CurDAG->getTargetNode(PPC::FCMPUD, MVT::i32, LHS, Select(RHS));
488 /// getBCCForSetCC - Returns the PowerPC condition branch mnemonic corresponding
490 static unsigned getBCCForSetCC(ISD::CondCode CC) {
492 default: assert(0 && "Unknown condition!"); abort();
493 case ISD::SETOEQ: // FIXME: This is incorrect see PR642.
494 case ISD::SETEQ: return PPC::BEQ;
495 case ISD::SETONE: // FIXME: This is incorrect see PR642.
496 case ISD::SETNE: return PPC::BNE;
497 case ISD::SETOLT: // FIXME: This is incorrect see PR642.
499 case ISD::SETLT: return PPC::BLT;
500 case ISD::SETOLE: // FIXME: This is incorrect see PR642.
502 case ISD::SETLE: return PPC::BLE;
503 case ISD::SETOGT: // FIXME: This is incorrect see PR642.
505 case ISD::SETGT: return PPC::BGT;
506 case ISD::SETOGE: // FIXME: This is incorrect see PR642.
508 case ISD::SETGE: return PPC::BGE;
510 case ISD::SETO: return PPC::BUN;
511 case ISD::SETUO: return PPC::BNU;
516 /// getCRIdxForSetCC - Return the index of the condition register field
517 /// associated with the SetCC condition, and whether or not the field is
518 /// treated as inverted. That is, lt = 0; ge = 0 inverted.
519 static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool& Inv) {
521 default: assert(0 && "Unknown condition!"); abort();
522 case ISD::SETOLT: // FIXME: This is incorrect see PR642.
524 case ISD::SETLT: Inv = false; return 0;
525 case ISD::SETOGE: // FIXME: This is incorrect see PR642.
527 case ISD::SETGE: Inv = true; return 0;
528 case ISD::SETOGT: // FIXME: This is incorrect see PR642.
530 case ISD::SETGT: Inv = false; return 1;
531 case ISD::SETOLE: // FIXME: This is incorrect see PR642.
533 case ISD::SETLE: Inv = true; return 1;
534 case ISD::SETOEQ: // FIXME: This is incorrect see PR642.
535 case ISD::SETEQ: Inv = false; return 2;
536 case ISD::SETONE: // FIXME: This is incorrect see PR642.
537 case ISD::SETNE: Inv = true; return 2;
538 case ISD::SETO: Inv = true; return 3;
539 case ISD::SETUO: Inv = false; return 3;
544 SDOperand PPCDAGToDAGISel::SelectDYNAMIC_STACKALLOC(SDOperand Op) {
547 // FIXME: We are currently ignoring the requested alignment for handling
548 // greater than the stack alignment. This will need to be revisited at some
549 // point. Align = N.getOperand(2);
550 if (!isa<ConstantSDNode>(N->getOperand(2)) ||
551 cast<ConstantSDNode>(N->getOperand(2))->getValue() != 0) {
552 std::cerr << "Cannot allocate stack object with greater alignment than"
553 << " the stack alignment yet!";
556 SDOperand Chain = Select(N->getOperand(0));
557 SDOperand Amt = Select(N->getOperand(1));
559 SDOperand R1Reg = CurDAG->getRegister(PPC::R1, MVT::i32);
561 SDOperand R1Val = CurDAG->getCopyFromReg(Chain, PPC::R1, MVT::i32);
562 Chain = R1Val.getValue(1);
564 // Subtract the amount (guaranteed to be a multiple of the stack alignment)
565 // from the stack pointer, giving us the result pointer.
566 SDOperand Result = CurDAG->getTargetNode(PPC::SUBF, MVT::i32, Amt, R1Val);
568 // Copy this result back into R1.
569 Chain = CurDAG->getNode(ISD::CopyToReg, MVT::Other, Chain, R1Reg, Result);
571 // Copy this result back out of R1 to make sure we're not using the stack
572 // space without decrementing the stack pointer.
573 Result = CurDAG->getCopyFromReg(Chain, PPC::R1, MVT::i32);
575 // Finally, replace the DYNAMIC_STACKALLOC with the copyfromreg.
576 CodeGenMap[Op.getValue(0)] = Result;
577 CodeGenMap[Op.getValue(1)] = Result.getValue(1);
578 return SDOperand(Result.Val, Op.ResNo);
581 SDOperand PPCDAGToDAGISel::SelectADD_PARTS(SDOperand Op) {
583 SDOperand LHSL = Select(N->getOperand(0));
584 SDOperand LHSH = Select(N->getOperand(1));
587 bool ME = false, ZE = false;
588 if (isIntImmediate(N->getOperand(3), Imm)) {
589 ME = (signed)Imm == -1;
593 std::vector<SDOperand> Result;
594 SDOperand CarryFromLo;
595 if (isIntImmediate(N->getOperand(2), Imm) &&
596 ((signed)Imm >= -32768 || (signed)Imm < 32768)) {
597 // Codegen the low 32 bits of the add. Interestingly, there is no
598 // shifted form of add immediate carrying.
599 CarryFromLo = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
600 LHSL, getI32Imm(Imm));
602 CarryFromLo = CurDAG->getTargetNode(PPC::ADDC, MVT::i32, MVT::Flag,
603 LHSL, Select(N->getOperand(2)));
605 CarryFromLo = CarryFromLo.getValue(1);
607 // Codegen the high 32 bits, adding zero, minus one, or the full value
608 // along with the carry flag produced by addc/addic.
611 ResultHi = CurDAG->getTargetNode(PPC::ADDZE, MVT::i32, LHSH, CarryFromLo);
613 ResultHi = CurDAG->getTargetNode(PPC::ADDME, MVT::i32, LHSH, CarryFromLo);
615 ResultHi = CurDAG->getTargetNode(PPC::ADDE, MVT::i32, LHSH,
616 Select(N->getOperand(3)), CarryFromLo);
617 Result.push_back(CarryFromLo.getValue(0));
618 Result.push_back(ResultHi);
620 CodeGenMap[Op.getValue(0)] = Result[0];
621 CodeGenMap[Op.getValue(1)] = Result[1];
622 return Result[Op.ResNo];
624 SDOperand PPCDAGToDAGISel::SelectSUB_PARTS(SDOperand Op) {
626 SDOperand LHSL = Select(N->getOperand(0));
627 SDOperand LHSH = Select(N->getOperand(1));
628 SDOperand RHSL = Select(N->getOperand(2));
629 SDOperand RHSH = Select(N->getOperand(3));
631 std::vector<SDOperand> Result;
632 Result.push_back(CurDAG->getTargetNode(PPC::SUBFC, MVT::i32, MVT::Flag,
634 Result.push_back(CurDAG->getTargetNode(PPC::SUBFE, MVT::i32, RHSH, LHSH,
635 Result[0].getValue(1)));
636 CodeGenMap[Op.getValue(0)] = Result[0];
637 CodeGenMap[Op.getValue(1)] = Result[1];
638 return Result[Op.ResNo];
641 SDOperand PPCDAGToDAGISel::SelectSETCC(SDOperand Op) {
644 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
645 if (isIntImmediate(N->getOperand(1), Imm)) {
646 // We can codegen setcc op, imm very efficiently compared to a brcond.
647 // Check for those cases here.
650 SDOperand Op = Select(N->getOperand(0));
654 Op = CurDAG->getTargetNode(PPC::CNTLZW, MVT::i32, Op);
655 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Op, getI32Imm(27),
656 getI32Imm(5), getI32Imm(31));
658 SDOperand AD = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
660 return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op,
664 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Op, getI32Imm(1),
665 getI32Imm(31), getI32Imm(31));
667 SDOperand T = CurDAG->getTargetNode(PPC::NEG, MVT::i32, Op);
668 T = CurDAG->getTargetNode(PPC::ANDC, MVT::i32, T, Op);;
669 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, T, getI32Imm(1),
670 getI32Imm(31), getI32Imm(31));
673 } else if (Imm == ~0U) { // setcc op, -1
674 SDOperand Op = Select(N->getOperand(0));
678 Op = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
680 return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
681 CurDAG->getTargetNode(PPC::LI, MVT::i32,
685 Op = CurDAG->getTargetNode(PPC::NOR, MVT::i32, Op, Op);
686 SDOperand AD = CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
688 return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op,
692 SDOperand AD = CurDAG->getTargetNode(PPC::ADDI, MVT::i32, Op,
694 SDOperand AN = CurDAG->getTargetNode(PPC::AND, MVT::i32, AD, Op);
695 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, AN, getI32Imm(1),
696 getI32Imm(31), getI32Imm(31));
699 Op = CurDAG->getTargetNode(PPC::RLWINM, MVT::i32, Op, getI32Imm(1),
700 getI32Imm(31), getI32Imm(31));
701 return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Op, getI32Imm(1));
707 unsigned Idx = getCRIdxForSetCC(CC, Inv);
708 SDOperand CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC);
711 // Force the ccreg into CR7.
712 SDOperand CR7Reg = CurDAG->getRegister(PPC::CR7, MVT::i32);
714 SDOperand InFlag(0, 0); // Null incoming flag value.
715 CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), CR7Reg, CCReg,
718 if (TLI.getTargetMachine().getSubtarget<PPCSubtarget>().isGigaProcessor())
719 IntCR = CurDAG->getTargetNode(PPC::MFOCRF, MVT::i32, CR7Reg, CCReg);
721 IntCR = CurDAG->getTargetNode(PPC::MFCR, MVT::i32, CCReg);
724 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, IntCR,
725 getI32Imm((32-(3-Idx)) & 31),
726 getI32Imm(31), getI32Imm(31));
729 CurDAG->getTargetNode(PPC::RLWINM, MVT::i32, IntCR,
730 getI32Imm((32-(3-Idx)) & 31),
731 getI32Imm(31),getI32Imm(31));
732 return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1));
736 /// isCallCompatibleAddress - Return true if the specified 32-bit value is
737 /// representable in the immediate field of a Bx instruction.
738 static bool isCallCompatibleAddress(ConstantSDNode *C) {
739 int Addr = C->getValue();
740 if (Addr & 3) return false; // Low 2 bits are implicitly zero.
741 return (Addr << 6 >> 6) == Addr; // Top 6 bits have to be sext of immediate.
744 SDOperand PPCDAGToDAGISel::SelectCALL(SDOperand Op) {
746 SDOperand Chain = Select(N->getOperand(0));
749 std::vector<SDOperand> CallOperands;
751 if (GlobalAddressSDNode *GASD =
752 dyn_cast<GlobalAddressSDNode>(N->getOperand(1))) {
753 CallOpcode = PPC::BL;
754 CallOperands.push_back(N->getOperand(1));
755 } else if (ExternalSymbolSDNode *ESSDN =
756 dyn_cast<ExternalSymbolSDNode>(N->getOperand(1))) {
757 CallOpcode = PPC::BL;
758 CallOperands.push_back(N->getOperand(1));
759 } else if (isa<ConstantSDNode>(N->getOperand(1)) &&
760 isCallCompatibleAddress(cast<ConstantSDNode>(N->getOperand(1)))) {
761 ConstantSDNode *C = cast<ConstantSDNode>(N->getOperand(1));
762 CallOpcode = PPC::BLA;
763 CallOperands.push_back(getI32Imm((int)C->getValue() >> 2));
765 // Copy the callee address into the CTR register.
766 SDOperand Callee = Select(N->getOperand(1));
767 Chain = CurDAG->getTargetNode(PPC::MTCTR, MVT::Other, Callee, Chain);
769 // Copy the callee address into R12 on darwin.
770 SDOperand R12 = CurDAG->getRegister(PPC::R12, MVT::i32);
771 Chain = CurDAG->getNode(ISD::CopyToReg, MVT::Other, Chain, R12, Callee);
773 CallOperands.push_back(R12);
774 CallOpcode = PPC::BCTRL;
777 unsigned GPR_idx = 0, FPR_idx = 0;
778 static const unsigned GPR[] = {
779 PPC::R3, PPC::R4, PPC::R5, PPC::R6,
780 PPC::R7, PPC::R8, PPC::R9, PPC::R10,
782 static const unsigned FPR[] = {
783 PPC::F1, PPC::F2, PPC::F3, PPC::F4, PPC::F5, PPC::F6, PPC::F7,
784 PPC::F8, PPC::F9, PPC::F10, PPC::F11, PPC::F12, PPC::F13
787 SDOperand InFlag; // Null incoming flag value.
789 for (unsigned i = 2, e = N->getNumOperands(); i != e; ++i) {
790 unsigned DestReg = 0;
791 MVT::ValueType RegTy = N->getOperand(i).getValueType();
792 if (RegTy == MVT::i32) {
793 assert(GPR_idx < 8 && "Too many int args");
794 DestReg = GPR[GPR_idx++];
796 assert(MVT::isFloatingPoint(N->getOperand(i).getValueType()) &&
797 "Unpromoted integer arg?");
798 assert(FPR_idx < 13 && "Too many fp args");
799 DestReg = FPR[FPR_idx++];
802 if (N->getOperand(i).getOpcode() != ISD::UNDEF) {
803 SDOperand Val = Select(N->getOperand(i));
804 Chain = CurDAG->getCopyToReg(Chain, DestReg, Val, InFlag);
805 InFlag = Chain.getValue(1);
806 CallOperands.push_back(CurDAG->getRegister(DestReg, RegTy));
810 // Finally, once everything is in registers to pass to the call, emit the
813 CallOperands.push_back(InFlag); // Strong dep on register copies.
815 CallOperands.push_back(Chain); // Weak dep on whatever occurs before
816 Chain = CurDAG->getTargetNode(CallOpcode, MVT::Other, MVT::Flag,
819 std::vector<SDOperand> CallResults;
821 // If the call has results, copy the values out of the ret val registers.
822 switch (N->getValueType(0)) {
823 default: assert(0 && "Unexpected ret value!");
824 case MVT::Other: break;
826 if (N->getValueType(1) == MVT::i32) {
827 Chain = CurDAG->getCopyFromReg(Chain, PPC::R4, MVT::i32,
828 Chain.getValue(1)).getValue(1);
829 CallResults.push_back(Chain.getValue(0));
830 Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32,
831 Chain.getValue(2)).getValue(1);
832 CallResults.push_back(Chain.getValue(0));
834 Chain = CurDAG->getCopyFromReg(Chain, PPC::R3, MVT::i32,
835 Chain.getValue(1)).getValue(1);
836 CallResults.push_back(Chain.getValue(0));
841 Chain = CurDAG->getCopyFromReg(Chain, PPC::F1, N->getValueType(0),
842 Chain.getValue(1)).getValue(1);
843 CallResults.push_back(Chain.getValue(0));
847 CallResults.push_back(Chain);
848 for (unsigned i = 0, e = CallResults.size(); i != e; ++i)
849 CodeGenMap[Op.getValue(i)] = CallResults[i];
850 return CallResults[Op.ResNo];
853 // Select - Convert the specified operand from a target-independent to a
854 // target-specific node if it hasn't already been changed.
855 SDOperand PPCDAGToDAGISel::Select(SDOperand Op) {
857 if (N->getOpcode() >= ISD::BUILTIN_OP_END &&
858 N->getOpcode() < PPCISD::FIRST_NUMBER)
859 return Op; // Already selected.
861 // If this has already been converted, use it.
862 std::map<SDOperand, SDOperand>::iterator CGMI = CodeGenMap.find(Op);
863 if (CGMI != CodeGenMap.end()) return CGMI->second;
865 switch (N->getOpcode()) {
867 case ISD::BasicBlock: return CodeGenMap[Op] = Op;
868 case ISD::DYNAMIC_STACKALLOC: return SelectDYNAMIC_STACKALLOC(Op);
869 case ISD::ADD_PARTS: return SelectADD_PARTS(Op);
870 case ISD::SUB_PARTS: return SelectSUB_PARTS(Op);
871 case ISD::SETCC: return SelectSETCC(Op);
872 case ISD::CALL: return SelectCALL(Op);
873 case ISD::TAILCALL: return SelectCALL(Op);
874 case PPCISD::GlobalBaseReg: return getGlobalBaseReg();
876 case ISD::FrameIndex: {
877 int FI = cast<FrameIndexSDNode>(N)->getIndex();
879 return CurDAG->SelectNodeTo(N, PPC::ADDI, MVT::i32,
880 CurDAG->getTargetFrameIndex(FI, MVT::i32),
882 return CodeGenMap[Op] =
883 CurDAG->getTargetNode(PPC::ADDI, MVT::i32,
884 CurDAG->getTargetFrameIndex(FI, MVT::i32),
888 // FIXME: since this depends on the setting of the carry flag from the srawi
889 // we should really be making notes about that for the scheduler.
890 // FIXME: It sure would be nice if we could cheaply recognize the
891 // srl/add/sra pattern the dag combiner will generate for this as
892 // sra/addze rather than having to handle sdiv ourselves. oh well.
894 if (isIntImmediate(N->getOperand(1), Imm)) {
895 if ((signed)Imm > 0 && isPowerOf2_32(Imm)) {
897 CurDAG->getTargetNode(PPC::SRAWI, MVT::i32, MVT::Flag,
898 Select(N->getOperand(0)),
899 getI32Imm(Log2_32(Imm)));
900 return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
901 Op.getValue(0), Op.getValue(1));
902 } else if ((signed)Imm < 0 && isPowerOf2_32(-Imm)) {
904 CurDAG->getTargetNode(PPC::SRAWI, MVT::i32, MVT::Flag,
905 Select(N->getOperand(0)),
906 getI32Imm(Log2_32(-Imm)));
908 CurDAG->getTargetNode(PPC::ADDZE, MVT::i32, Op.getValue(0),
910 return CurDAG->SelectNodeTo(N, PPC::NEG, MVT::i32, PT);
914 // Other cases are autogenerated.
919 // If this is an and of a value rotated between 0 and 31 bits and then and'd
920 // with a mask, emit rlwinm
921 if (isIntImmediate(N->getOperand(1), Imm) && (isShiftedMask_32(Imm) ||
922 isShiftedMask_32(~Imm))) {
925 if (isRotateAndMask(N->getOperand(0).Val, Imm, false, SH, MB, ME)) {
926 Val = Select(N->getOperand(0).getOperand(0));
927 } else if (Imm == 0) {
928 // AND X, 0 -> 0, not "rlwinm 32".
929 return Select(N->getOperand(1));
931 Val = Select(N->getOperand(0));
932 isRunOfOnes(Imm, MB, ME);
935 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Val, getI32Imm(SH),
936 getI32Imm(MB), getI32Imm(ME));
939 // Other cases are autogenerated.
943 if (SDNode *I = SelectBitfieldInsert(N))
944 return CodeGenMap[Op] = SDOperand(I, 0);
946 // Other cases are autogenerated.
949 unsigned Imm, SH, MB, ME;
950 if (isOpcWithIntImmediate(N->getOperand(0).Val, ISD::AND, Imm) &&
951 isRotateAndMask(N, Imm, true, SH, MB, ME)) {
952 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32,
953 Select(N->getOperand(0).getOperand(0)),
954 getI32Imm(SH), getI32Imm(MB), getI32Imm(ME));
957 // Other cases are autogenerated.
961 unsigned Imm, SH, MB, ME;
962 if (isOpcWithIntImmediate(N->getOperand(0).Val, ISD::AND, Imm) &&
963 isRotateAndMask(N, Imm, true, SH, MB, ME)) {
964 return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32,
965 Select(N->getOperand(0).getOperand(0)),
966 getI32Imm(SH & 0x1F), getI32Imm(MB),
970 // Other cases are autogenerated.
974 SDOperand Val = Select(N->getOperand(0));
975 MVT::ValueType Ty = N->getValueType(0);
976 if (N->getOperand(0).Val->hasOneUse()) {
978 switch (Val.isTargetOpcode() ? Val.getTargetOpcode() : 0) {
979 default: Opc = 0; break;
980 case PPC::FABSS: Opc = PPC::FNABSS; break;
981 case PPC::FABSD: Opc = PPC::FNABSD; break;
982 case PPC::FMADD: Opc = PPC::FNMADD; break;
983 case PPC::FMADDS: Opc = PPC::FNMADDS; break;
984 case PPC::FMSUB: Opc = PPC::FNMSUB; break;
985 case PPC::FMSUBS: Opc = PPC::FNMSUBS; break;
987 // If we inverted the opcode, then emit the new instruction with the
988 // inverted opcode and the original instruction's operands. Otherwise,
989 // fall through and generate a fneg instruction.
991 if (Opc == PPC::FNABSS || Opc == PPC::FNABSD)
992 return CurDAG->SelectNodeTo(N, Opc, Ty, Val.getOperand(0));
994 return CurDAG->SelectNodeTo(N, Opc, Ty, Val.getOperand(0),
995 Val.getOperand(1), Val.getOperand(2));
998 // Other cases are autogenerated.
1004 case ISD::SEXTLOAD: {
1006 // If this is a vector load, then force this to be indexed addressing, since
1007 // altivec does not have immediate offsets for loads.
1009 if (N->getOpcode() == ISD::LOAD && MVT::isVector(N->getValueType(0))) {
1010 SelectAddrIndexed(N->getOperand(1), Op1, Op2);
1012 isIdx = SelectAddr(N->getOperand(1), Op1, Op2);
1014 MVT::ValueType TypeBeingLoaded = (N->getOpcode() == ISD::LOAD) ?
1015 N->getValueType(0) : cast<VTSDNode>(N->getOperand(3))->getVT();
1018 switch (TypeBeingLoaded) {
1019 default: N->dump(); assert(0 && "Cannot load this type!");
1021 case MVT::i8: Opc = isIdx ? PPC::LBZX : PPC::LBZ; break;
1023 if (N->getOpcode() == ISD::SEXTLOAD) { // SEXT load?
1024 Opc = isIdx ? PPC::LHAX : PPC::LHA;
1026 Opc = isIdx ? PPC::LHZX : PPC::LHZ;
1029 case MVT::i32: Opc = isIdx ? PPC::LWZX : PPC::LWZ; break;
1030 case MVT::f32: Opc = isIdx ? PPC::LFSX : PPC::LFS; break;
1031 case MVT::f64: Opc = isIdx ? PPC::LFDX : PPC::LFD; break;
1032 case MVT::v4f32: Opc = PPC::LVX; break;
1035 // If this is an f32 -> f64 load, emit the f32 load, then use an 'extending
1037 if (TypeBeingLoaded != MVT::f32 || N->getOpcode() == ISD::LOAD) {
1038 return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), MVT::Other,
1039 Op1, Op2, Select(N->getOperand(0))).
1042 std::vector<SDOperand> Ops;
1045 Ops.push_back(Select(N->getOperand(0)));
1046 SDOperand Res = CurDAG->getTargetNode(Opc, MVT::f32, MVT::Other, Ops);
1047 SDOperand Ext = CurDAG->getTargetNode(PPC::FMRSD, MVT::f64, Res);
1048 CodeGenMap[Op.getValue(0)] = Ext;
1049 CodeGenMap[Op.getValue(1)] = Res.getValue(1);
1051 return Res.getValue(1);
1056 case ISD::TRUNCSTORE:
1058 SDOperand AddrOp1, AddrOp2;
1059 // If this is a vector store, then force this to be indexed addressing,
1060 // since altivec does not have immediate offsets for stores.
1062 if (N->getOpcode() == ISD::STORE &&
1063 MVT::isVector(N->getOperand(1).getValueType())) {
1064 SelectAddrIndexed(N->getOperand(2), AddrOp1, AddrOp2);
1066 isIdx = SelectAddr(N->getOperand(2), AddrOp1, AddrOp2);
1070 if (N->getOpcode() == ISD::STORE) {
1071 switch (N->getOperand(1).getValueType()) {
1072 default: assert(0 && "unknown Type in store");
1073 case MVT::i32: Opc = isIdx ? PPC::STWX : PPC::STW; break;
1074 case MVT::f64: Opc = isIdx ? PPC::STFDX : PPC::STFD; break;
1075 case MVT::f32: Opc = isIdx ? PPC::STFSX : PPC::STFS; break;
1076 case MVT::v4f32: Opc = PPC::STVX;
1078 } else { //ISD::TRUNCSTORE
1079 switch(cast<VTSDNode>(N->getOperand(4))->getVT()) {
1080 default: assert(0 && "unknown Type in store");
1081 case MVT::i8: Opc = isIdx ? PPC::STBX : PPC::STB; break;
1082 case MVT::i16: Opc = isIdx ? PPC::STHX : PPC::STH; break;
1086 return CurDAG->SelectNodeTo(N, Opc, MVT::Other, Select(N->getOperand(1)),
1087 AddrOp1, AddrOp2, Select(N->getOperand(0)));
1090 case ISD::SELECT_CC: {
1091 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
1093 // handle the setcc cases here. select_cc lhs, 0, 1, 0, cc
1094 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
1095 if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N->getOperand(2)))
1096 if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N->getOperand(3)))
1097 if (N1C->isNullValue() && N3C->isNullValue() &&
1098 N2C->getValue() == 1ULL && CC == ISD::SETNE) {
1099 SDOperand LHS = Select(N->getOperand(0));
1101 CurDAG->getTargetNode(PPC::ADDIC, MVT::i32, MVT::Flag,
1102 LHS, getI32Imm(~0U));
1103 return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, Tmp, LHS,
1107 SDOperand CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC);
1108 unsigned BROpc = getBCCForSetCC(CC);
1110 bool isFP = MVT::isFloatingPoint(N->getValueType(0));
1111 unsigned SelectCCOp;
1112 if (MVT::isInteger(N->getValueType(0)))
1113 SelectCCOp = PPC::SELECT_CC_Int;
1114 else if (N->getValueType(0) == MVT::f32)
1115 SelectCCOp = PPC::SELECT_CC_F4;
1117 SelectCCOp = PPC::SELECT_CC_F8;
1118 return CurDAG->SelectNodeTo(N, SelectCCOp, N->getValueType(0), CCReg,
1119 Select(N->getOperand(2)),
1120 Select(N->getOperand(3)),
1125 SDOperand Chain = Select(N->getOperand(0)); // Token chain.
1127 if (N->getNumOperands() == 2) {
1128 SDOperand Val = Select(N->getOperand(1));
1129 if (N->getOperand(1).getValueType() == MVT::i32) {
1130 Chain = CurDAG->getCopyToReg(Chain, PPC::R3, Val);
1132 assert(MVT::isFloatingPoint(N->getOperand(1).getValueType()));
1133 Chain = CurDAG->getCopyToReg(Chain, PPC::F1, Val);
1135 } else if (N->getNumOperands() > 1) {
1136 assert(N->getOperand(1).getValueType() == MVT::i32 &&
1137 N->getOperand(2).getValueType() == MVT::i32 &&
1138 N->getNumOperands() == 3 && "Unknown two-register ret value!");
1139 Chain = CurDAG->getCopyToReg(Chain, PPC::R4, Select(N->getOperand(1)));
1140 Chain = CurDAG->getCopyToReg(Chain, PPC::R3, Select(N->getOperand(2)));
1143 // Finally, select this to a blr (return) instruction.
1144 return CurDAG->SelectNodeTo(N, PPC::BLR, MVT::Other, Chain);
1147 case ISD::BRTWOWAY_CC: {
1148 SDOperand Chain = Select(N->getOperand(0));
1149 MachineBasicBlock *Dest =
1150 cast<BasicBlockSDNode>(N->getOperand(4))->getBasicBlock();
1151 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
1152 SDOperand CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC);
1154 // If this is a two way branch, then grab the fallthrough basic block
1155 // argument and build a PowerPC branch pseudo-op, suitable for long branch
1156 // conversion if necessary by the branch selection pass. Otherwise, emit a
1157 // standard conditional branch.
1158 if (N->getOpcode() == ISD::BRTWOWAY_CC) {
1159 SDOperand CondTrueBlock = N->getOperand(4);
1160 SDOperand CondFalseBlock = N->getOperand(5);
1162 // If the false case is the current basic block, then this is a self loop.
1163 // We do not want to emit "Loop: ... brcond Out; br Loop", as it adds an
1164 // extra dispatch group to the loop. Instead, invert the condition and
1165 // emit "Loop: ... br!cond Loop; br Out
1166 if (cast<BasicBlockSDNode>(CondFalseBlock)->getBasicBlock() == BB) {
1167 std::swap(CondTrueBlock, CondFalseBlock);
1168 CC = getSetCCInverse(CC,
1169 MVT::isInteger(N->getOperand(2).getValueType()));
1172 unsigned Opc = getBCCForSetCC(CC);
1173 SDOperand CB = CurDAG->getTargetNode(PPC::COND_BRANCH, MVT::Other,
1174 CondCode, getI32Imm(Opc),
1175 CondTrueBlock, CondFalseBlock,
1177 return CurDAG->SelectNodeTo(N, PPC::B, MVT::Other, CondFalseBlock, CB);
1179 // Iterate to the next basic block
1180 ilist<MachineBasicBlock>::iterator It = BB;
1183 // If the fallthrough path is off the end of the function, which would be
1184 // undefined behavior, set it to be the same as the current block because
1185 // we have nothing better to set it to, and leaving it alone will cause
1186 // the PowerPC Branch Selection pass to crash.
1187 if (It == BB->getParent()->end()) It = Dest;
1188 return CurDAG->SelectNodeTo(N, PPC::COND_BRANCH, MVT::Other, CondCode,
1189 getI32Imm(getBCCForSetCC(CC)),
1190 N->getOperand(4), CurDAG->getBasicBlock(It),
1196 return SelectCode(Op);
1200 /// createPPCISelDag - This pass converts a legalized DAG into a
1201 /// PowerPC-specific DAG, ready for instruction scheduling.
1203 FunctionPass *llvm::createPPCISelDag(TargetMachine &TM) {
1204 return new PPCDAGToDAGISel(TM);