1 //===-- Mips16ISelDAGToDAG.cpp - A Dag to Dag Inst Selector for Mips16 ----===//
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 // Subclass of MipsDAGToDAGISel specialized for mips16.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "mips-isel"
15 #include "Mips16ISelDAGToDAG.h"
17 #include "MCTargetDesc/MipsBaseInfo.h"
18 #include "MipsAnalyzeImmediate.h"
19 #include "MipsMachineFunction.h"
20 #include "MipsRegisterInfo.h"
21 #include "llvm/CodeGen/MachineConstantPool.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineInstrBuilder.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/CodeGen/SelectionDAGNodes.h"
27 #include "llvm/IR/GlobalValue.h"
28 #include "llvm/IR/Instructions.h"
29 #include "llvm/IR/Intrinsics.h"
30 #include "llvm/IR/Type.h"
31 #include "llvm/Support/CFG.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include "llvm/Target/TargetMachine.h"
38 bool Mips16DAGToDAGISel::runOnMachineFunction(MachineFunction &MF) {
39 if (!Subtarget.inMips16Mode())
41 return MipsDAGToDAGISel::runOnMachineFunction(MF);
43 /// Select multiply instructions.
44 std::pair<SDNode*, SDNode*>
45 Mips16DAGToDAGISel::selectMULT(SDNode *N, unsigned Opc, SDLoc DL, EVT Ty,
46 bool HasLo, bool HasHi) {
47 SDNode *Lo = 0, *Hi = 0;
48 SDNode *Mul = CurDAG->getMachineNode(Opc, DL, MVT::Glue, N->getOperand(0),
50 SDValue InFlag = SDValue(Mul, 0);
53 unsigned Opcode = Mips::Mflo16;
54 Lo = CurDAG->getMachineNode(Opcode, DL, Ty, MVT::Glue, InFlag);
55 InFlag = SDValue(Lo, 1);
58 unsigned Opcode = Mips::Mfhi16;
59 Hi = CurDAG->getMachineNode(Opcode, DL, Ty, InFlag);
61 return std::make_pair(Lo, Hi);
64 void Mips16DAGToDAGISel::initGlobalBaseReg(MachineFunction &MF) {
65 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
67 if (!MipsFI->globalBaseRegSet())
70 MachineBasicBlock &MBB = MF.front();
71 MachineBasicBlock::iterator I = MBB.begin();
72 MachineRegisterInfo &RegInfo = MF.getRegInfo();
73 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
74 DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
75 unsigned V0, V1, V2, GlobalBaseReg = MipsFI->getGlobalBaseReg();
76 const TargetRegisterClass *RC =
77 (const TargetRegisterClass*)&Mips::CPU16RegsRegClass;
79 V0 = RegInfo.createVirtualRegister(RC);
80 V1 = RegInfo.createVirtualRegister(RC);
81 V2 = RegInfo.createVirtualRegister(RC);
83 BuildMI(MBB, I, DL, TII.get(Mips::LiRxImmX16), V0)
84 .addExternalSymbol("_gp_disp", MipsII::MO_ABS_HI);
85 BuildMI(MBB, I, DL, TII.get(Mips::AddiuRxPcImmX16), V1)
86 .addExternalSymbol("_gp_disp", MipsII::MO_ABS_LO);
87 BuildMI(MBB, I, DL, TII.get(Mips::SllX16), V2).addReg(V0).addImm(16);
88 BuildMI(MBB, I, DL, TII.get(Mips::AdduRxRyRz16), GlobalBaseReg)
89 .addReg(V1).addReg(V2);
92 // Insert instructions to initialize the Mips16 SP Alias register in the
93 // first MBB of the function.
95 void Mips16DAGToDAGISel::initMips16SPAliasReg(MachineFunction &MF) {
96 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
98 if (!MipsFI->mips16SPAliasRegSet())
101 MachineBasicBlock &MBB = MF.front();
102 MachineBasicBlock::iterator I = MBB.begin();
103 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
104 DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
105 unsigned Mips16SPAliasReg = MipsFI->getMips16SPAliasReg();
107 BuildMI(MBB, I, DL, TII.get(Mips::MoveR3216), Mips16SPAliasReg)
111 void Mips16DAGToDAGISel::processFunctionAfterISel(MachineFunction &MF) {
112 initGlobalBaseReg(MF);
113 initMips16SPAliasReg(MF);
116 /// getMips16SPAliasReg - Output the instructions required to put the
117 /// SP into a Mips16 accessible aliased register.
118 SDValue Mips16DAGToDAGISel::getMips16SPAliasReg() {
119 unsigned Mips16SPAliasReg =
120 MF->getInfo<MipsFunctionInfo>()->getMips16SPAliasReg();
121 return CurDAG->getRegister(Mips16SPAliasReg, TLI->getPointerTy());
124 void Mips16DAGToDAGISel::getMips16SPRefReg(SDNode *Parent, SDValue &AliasReg) {
125 SDValue AliasFPReg = CurDAG->getRegister(Mips::S0, TLI->getPointerTy());
127 switch (Parent->getOpcode()) {
129 LoadSDNode *SD = dyn_cast<LoadSDNode>(Parent);
130 switch (SD->getMemoryVT().getSizeInBits()) {
133 AliasReg = TM.getFrameLowering()->hasFP(*MF)?
134 AliasFPReg: getMips16SPAliasReg();
140 StoreSDNode *SD = dyn_cast<StoreSDNode>(Parent);
141 switch (SD->getMemoryVT().getSizeInBits()) {
144 AliasReg = TM.getFrameLowering()->hasFP(*MF)?
145 AliasFPReg: getMips16SPAliasReg();
152 AliasReg = CurDAG->getRegister(Mips::SP, TLI->getPointerTy());
157 bool Mips16DAGToDAGISel::selectAddr16(
158 SDNode *Parent, SDValue Addr, SDValue &Base, SDValue &Offset,
160 EVT ValTy = Addr.getValueType();
162 Alias = CurDAG->getTargetConstant(0, ValTy);
164 // if Address is FI, get the TargetFrameIndex.
165 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
166 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy);
167 Offset = CurDAG->getTargetConstant(0, ValTy);
168 getMips16SPRefReg(Parent, Alias);
171 // on PIC code Load GA
172 if (Addr.getOpcode() == MipsISD::Wrapper) {
173 Base = Addr.getOperand(0);
174 Offset = Addr.getOperand(1);
177 if (TM.getRelocationModel() != Reloc::PIC_) {
178 if ((Addr.getOpcode() == ISD::TargetExternalSymbol ||
179 Addr.getOpcode() == ISD::TargetGlobalAddress))
182 // Addresses of the form FI+const or FI|const
183 if (CurDAG->isBaseWithConstantOffset(Addr)) {
184 ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1));
185 if (isInt<16>(CN->getSExtValue())) {
187 // If the first operand is a FI, get the TargetFI Node
188 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>
189 (Addr.getOperand(0))) {
190 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy);
191 getMips16SPRefReg(Parent, Alias);
194 Base = Addr.getOperand(0);
196 Offset = CurDAG->getTargetConstant(CN->getZExtValue(), ValTy);
200 // Operand is a result from an ADD.
201 if (Addr.getOpcode() == ISD::ADD) {
202 // When loading from constant pools, load the lower address part in
203 // the instruction itself. Example, instead of:
204 // lui $2, %hi($CPI1_0)
205 // addiu $2, $2, %lo($CPI1_0)
208 // lui $2, %hi($CPI1_0)
209 // lwc1 $f0, %lo($CPI1_0)($2)
210 if (Addr.getOperand(1).getOpcode() == MipsISD::Lo ||
211 Addr.getOperand(1).getOpcode() == MipsISD::GPRel) {
212 SDValue Opnd0 = Addr.getOperand(1).getOperand(0);
213 if (isa<ConstantPoolSDNode>(Opnd0) || isa<GlobalAddressSDNode>(Opnd0) ||
214 isa<JumpTableSDNode>(Opnd0)) {
215 Base = Addr.getOperand(0);
221 // If an indexed floating point load/store can be emitted, return false.
222 const LSBaseSDNode *LS = dyn_cast<LSBaseSDNode>(Parent);
225 (LS->getMemoryVT() == MVT::f32 || LS->getMemoryVT() == MVT::f64) &&
226 Subtarget.hasFPIdx())
230 Offset = CurDAG->getTargetConstant(0, ValTy);
234 /// Select instructions not customized! Used for
235 /// expanded, promoted and normal instructions
236 std::pair<bool, SDNode*> Mips16DAGToDAGISel::selectNode(SDNode *Node) {
237 unsigned Opcode = Node->getOpcode();
241 // Instruction Selection not handled by the auto-generated
242 // tablegen selection should be handled here.
244 EVT NodeTy = Node->getValueType(0);
252 SDValue InFlag = Node->getOperand(2), CmpLHS;
253 unsigned Opc = InFlag.getOpcode(); (void)Opc;
254 assert(((Opc == ISD::ADDC || Opc == ISD::ADDE) ||
255 (Opc == ISD::SUBC || Opc == ISD::SUBE)) &&
256 "(ADD|SUB)E flag operand must come from (ADD|SUB)C/E insn");
259 if (Opcode == ISD::ADDE) {
260 CmpLHS = InFlag.getValue(0);
261 MOp = Mips::AdduRxRyRz16;
263 CmpLHS = InFlag.getOperand(0);
264 MOp = Mips::SubuRxRyRz16;
267 SDValue Ops[] = { CmpLHS, InFlag.getOperand(1) };
269 SDValue LHS = Node->getOperand(0);
270 SDValue RHS = Node->getOperand(1);
272 EVT VT = LHS.getValueType();
274 unsigned Sltu_op = Mips::SltuRxRyRz16;
275 SDNode *Carry = CurDAG->getMachineNode(Sltu_op, DL, VT, Ops);
276 unsigned Addu_op = Mips::AdduRxRyRz16;
277 SDNode *AddCarry = CurDAG->getMachineNode(Addu_op, DL, VT,
278 SDValue(Carry,0), RHS);
280 SDNode *Result = CurDAG->SelectNodeTo(Node, MOp, VT, MVT::Glue, LHS,
281 SDValue(AddCarry,0));
282 return std::make_pair(true, Result);
285 /// Mul with two results
287 case ISD::UMUL_LOHI: {
288 MultOpc = (Opcode == ISD::UMUL_LOHI ? Mips::MultuRxRy16 : Mips::MultRxRy16);
289 std::pair<SDNode*, SDNode*> LoHi = selectMULT(Node, MultOpc, DL, NodeTy,
291 if (!SDValue(Node, 0).use_empty())
292 ReplaceUses(SDValue(Node, 0), SDValue(LoHi.first, 0));
294 if (!SDValue(Node, 1).use_empty())
295 ReplaceUses(SDValue(Node, 1), SDValue(LoHi.second, 0));
297 return std::make_pair(true, (SDNode*)NULL);
302 MultOpc = (Opcode == ISD::MULHU ? Mips::MultuRxRy16 : Mips::MultRxRy16);
303 SDNode *Result = selectMULT(Node, MultOpc, DL, NodeTy, false, true).second;
304 return std::make_pair(true, Result);
308 return std::make_pair(false, (SDNode*)NULL);
311 FunctionPass *llvm::createMips16ISelDag(MipsTargetMachine &TM) {
312 return new Mips16DAGToDAGISel(TM);