1 //===-- MipsISelDAGToDAG.cpp - A Dag to Dag Inst Selector for Mips --------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines an instruction selector for the MIPS target.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MipsISelDAGToDAG.h"
15 #include "MCTargetDesc/MipsBaseInfo.h"
16 #include "Mips.h"
17 #include "Mips16ISelDAGToDAG.h"
18 #include "MipsMachineFunction.h"
19 #include "MipsRegisterInfo.h"
20 #include "MipsSEISelDAGToDAG.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/CFG.h"
28 #include "llvm/IR/GlobalValue.h"
29 #include "llvm/IR/Instructions.h"
30 #include "llvm/IR/Intrinsics.h"
31 #include "llvm/IR/Type.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"
36 using namespace llvm;
37 
38 #define DEBUG_TYPE "mips-isel"
39 
40 //===----------------------------------------------------------------------===//
41 // Instruction Selector Implementation
42 //===----------------------------------------------------------------------===//
43 
44 //===----------------------------------------------------------------------===//
45 // MipsDAGToDAGISel - MIPS specific code to select MIPS machine
46 // instructions for SelectionDAG operations.
47 //===----------------------------------------------------------------------===//
48 
49 bool MipsDAGToDAGISel::runOnMachineFunction(MachineFunction &MF) {
50   Subtarget = &static_cast<const MipsSubtarget &>(MF.getSubtarget());
51   bool Ret = SelectionDAGISel::runOnMachineFunction(MF);
52 
53   processFunctionAfterISel(MF);
54 
55   return Ret;
56 }
57 
58 /// getGlobalBaseReg - Output the instructions required to put the
59 /// GOT address into a register.
60 SDNode *MipsDAGToDAGISel::getGlobalBaseReg() {
61   unsigned GlobalBaseReg = MF->getInfo<MipsFunctionInfo>()->getGlobalBaseReg();
62   return CurDAG->getRegister(GlobalBaseReg, getTargetLowering()->getPointerTy(
63                                                 CurDAG->getDataLayout()))
64       .getNode();
65 }
66 
67 /// ComplexPattern used on MipsInstrInfo
68 /// Used on Mips Load/Store instructions
69 bool MipsDAGToDAGISel::selectAddrRegImm(SDValue Addr, SDValue &Base,
70                                         SDValue &Offset) const {
71   llvm_unreachable("Unimplemented function.");
72   return false;
73 }
74 
75 bool MipsDAGToDAGISel::selectAddrDefault(SDValue Addr, SDValue &Base,
76                                          SDValue &Offset) const {
77   llvm_unreachable("Unimplemented function.");
78   return false;
79 }
80 
81 bool MipsDAGToDAGISel::selectIntAddr(SDValue Addr, SDValue &Base,
82                                      SDValue &Offset) const {
83   llvm_unreachable("Unimplemented function.");
84   return false;
85 }
86 
87 bool MipsDAGToDAGISel::selectIntAddr11MM(SDValue Addr, SDValue &Base,
88                                        SDValue &Offset) const {
89   llvm_unreachable("Unimplemented function.");
90   return false;
91 }
92 
93 bool MipsDAGToDAGISel::selectIntAddr12MM(SDValue Addr, SDValue &Base,
94                                        SDValue &Offset) const {
95   llvm_unreachable("Unimplemented function.");
96   return false;
97 }
98 
99 bool MipsDAGToDAGISel::selectIntAddr16MM(SDValue Addr, SDValue &Base,
100                                        SDValue &Offset) const {
101   llvm_unreachable("Unimplemented function.");
102   return false;
103 }
104 
105 bool MipsDAGToDAGISel::selectIntAddrLSL2MM(SDValue Addr, SDValue &Base,
106                                            SDValue &Offset) const {
107   llvm_unreachable("Unimplemented function.");
108   return false;
109 }
110 
111 bool MipsDAGToDAGISel::selectIntAddrSImm10(SDValue Addr, SDValue &Base,
112                                            SDValue &Offset) const {
113   llvm_unreachable("Unimplemented function.");
114   return false;
115 }
116 
117 bool MipsDAGToDAGISel::selectIntAddrSImm10Lsl1(SDValue Addr, SDValue &Base,
118                                                SDValue &Offset) const {
119   llvm_unreachable("Unimplemented function.");
120   return false;
121 }
122 
123 bool MipsDAGToDAGISel::selectIntAddrSImm10Lsl2(SDValue Addr, SDValue &Base,
124                                                SDValue &Offset) const {
125   llvm_unreachable("Unimplemented function.");
126   return false;
127 }
128 
129 bool MipsDAGToDAGISel::selectIntAddrSImm10Lsl3(SDValue Addr, SDValue &Base,
130                                                SDValue &Offset) const {
131   llvm_unreachable("Unimplemented function.");
132   return false;
133 }
134 
135 bool MipsDAGToDAGISel::selectAddr16(SDValue Addr, SDValue &Base,
136                                     SDValue &Offset) {
137   llvm_unreachable("Unimplemented function.");
138   return false;
139 }
140 
141 bool MipsDAGToDAGISel::selectAddr16SP(SDValue Addr, SDValue &Base,
142                                       SDValue &Offset) {
143   llvm_unreachable("Unimplemented function.");
144   return false;
145 }
146 
147 bool MipsDAGToDAGISel::selectVSplat(SDNode *N, APInt &Imm,
148                                     unsigned MinSizeInBits) const {
149   llvm_unreachable("Unimplemented function.");
150   return false;
151 }
152 
153 bool MipsDAGToDAGISel::selectVSplatUimm1(SDValue N, SDValue &Imm) const {
154   llvm_unreachable("Unimplemented function.");
155   return false;
156 }
157 
158 bool MipsDAGToDAGISel::selectVSplatUimm2(SDValue N, SDValue &Imm) const {
159   llvm_unreachable("Unimplemented function.");
160   return false;
161 }
162 
163 bool MipsDAGToDAGISel::selectVSplatUimm3(SDValue N, SDValue &Imm) const {
164   llvm_unreachable("Unimplemented function.");
165   return false;
166 }
167 
168 bool MipsDAGToDAGISel::selectVSplatUimm4(SDValue N, SDValue &Imm) const {
169   llvm_unreachable("Unimplemented function.");
170   return false;
171 }
172 
173 bool MipsDAGToDAGISel::selectVSplatUimm5(SDValue N, SDValue &Imm) const {
174   llvm_unreachable("Unimplemented function.");
175   return false;
176 }
177 
178 bool MipsDAGToDAGISel::selectVSplatUimm6(SDValue N, SDValue &Imm) const {
179   llvm_unreachable("Unimplemented function.");
180   return false;
181 }
182 
183 bool MipsDAGToDAGISel::selectVSplatUimm8(SDValue N, SDValue &Imm) const {
184   llvm_unreachable("Unimplemented function.");
185   return false;
186 }
187 
188 bool MipsDAGToDAGISel::selectVSplatSimm5(SDValue N, SDValue &Imm) const {
189   llvm_unreachable("Unimplemented function.");
190   return false;
191 }
192 
193 bool MipsDAGToDAGISel::selectVSplatUimmPow2(SDValue N, SDValue &Imm) const {
194   llvm_unreachable("Unimplemented function.");
195   return false;
196 }
197 
198 bool MipsDAGToDAGISel::selectVSplatUimmInvPow2(SDValue N, SDValue &Imm) const {
199   llvm_unreachable("Unimplemented function.");
200   return false;
201 }
202 
203 bool MipsDAGToDAGISel::selectVSplatMaskL(SDValue N, SDValue &Imm) const {
204   llvm_unreachable("Unimplemented function.");
205   return false;
206 }
207 
208 bool MipsDAGToDAGISel::selectVSplatMaskR(SDValue N, SDValue &Imm) const {
209   llvm_unreachable("Unimplemented function.");
210   return false;
211 }
212 
213 /// Select instructions not customized! Used for
214 /// expanded, promoted and normal instructions
215 void MipsDAGToDAGISel::Select(SDNode *Node) {
216   unsigned Opcode = Node->getOpcode();
217 
218   // Dump information about the Node being selected
219   DEBUG(errs() << "Selecting: "; Node->dump(CurDAG); errs() << "\n");
220 
221   // If we have a custom node, we already have selected!
222   if (Node->isMachineOpcode()) {
223     DEBUG(errs() << "== "; Node->dump(CurDAG); errs() << "\n");
224     Node->setNodeId(-1);
225     return;
226   }
227 
228   // See if subclasses can handle this node.
229   if (trySelect(Node))
230     return;
231 
232   switch(Opcode) {
233   default: break;
234 
235   // Get target GOT address.
236   case ISD::GLOBAL_OFFSET_TABLE:
237     ReplaceNode(Node, getGlobalBaseReg());
238     return;
239 
240 #ifndef NDEBUG
241   case ISD::LOAD:
242   case ISD::STORE:
243     assert((Subtarget->systemSupportsUnalignedAccess() ||
244             cast<MemSDNode>(Node)->getMemoryVT().getSizeInBits() / 8 <=
245             cast<MemSDNode>(Node)->getAlignment()) &&
246            "Unexpected unaligned loads/stores.");
247     break;
248 #endif
249   }
250 
251   // Select the default instruction
252   SelectCode(Node);
253 }
254 
255 bool MipsDAGToDAGISel::
256 SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID,
257                              std::vector<SDValue> &OutOps) {
258   // All memory constraints can at least accept raw pointers.
259   switch(ConstraintID) {
260   default:
261     llvm_unreachable("Unexpected asm memory constraint");
262   case InlineAsm::Constraint_i:
263   case InlineAsm::Constraint_m:
264   case InlineAsm::Constraint_R:
265   case InlineAsm::Constraint_ZC:
266     OutOps.push_back(Op);
267     return false;
268   }
269   return true;
270 }
271