1 //===-- XCoreRegisterInfo.cpp - XCore Register Information ----------------===//
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 contains the XCore implementation of the MRegisterInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "XCoreRegisterInfo.h"
15 #include "XCore.h"
16 #include "XCoreMachineFunctionInfo.h"
17 #include "llvm/ADT/BitVector.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/CodeGen/MachineFrameInfo.h"
20 #include "llvm/CodeGen/MachineFunction.h"
21 #include "llvm/CodeGen/MachineInstrBuilder.h"
22 #include "llvm/CodeGen/MachineModuleInfo.h"
23 #include "llvm/CodeGen/MachineRegisterInfo.h"
24 #include "llvm/CodeGen/RegisterScavenging.h"
25 #include "llvm/IR/Function.h"
26 #include "llvm/IR/Type.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/raw_ostream.h"
30 #include "llvm/Target/TargetFrameLowering.h"
31 #include "llvm/Target/TargetInstrInfo.h"
32 #include "llvm/Target/TargetMachine.h"
33 #include "llvm/Target/TargetOptions.h"
34
35 #define GET_REGINFO_TARGET_DESC
36 #include "XCoreGenRegisterInfo.inc"
37
38 using namespace llvm;
39
XCoreRegisterInfo()40 XCoreRegisterInfo::XCoreRegisterInfo()
41 : XCoreGenRegisterInfo(XCore::LR) {
42 }
43
44 // helper functions
isImmUs(unsigned val)45 static inline bool isImmUs(unsigned val) {
46 return val <= 11;
47 }
48
isImmU6(unsigned val)49 static inline bool isImmU6(unsigned val) {
50 return val < (1 << 6);
51 }
52
isImmU16(unsigned val)53 static inline bool isImmU16(unsigned val) {
54 return val < (1 << 16);
55 }
56
needsFrameMoves(const MachineFunction & MF)57 bool XCoreRegisterInfo::needsFrameMoves(const MachineFunction &MF) {
58 return MF.getMMI().hasDebugInfo() ||
59 MF.getFunction()->needsUnwindTableEntry();
60 }
61
getCalleeSavedRegs(const MachineFunction * MF) const62 const uint16_t* XCoreRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF)
63 const {
64 static const uint16_t CalleeSavedRegs[] = {
65 XCore::R4, XCore::R5, XCore::R6, XCore::R7,
66 XCore::R8, XCore::R9, XCore::R10, XCore::LR,
67 0
68 };
69 return CalleeSavedRegs;
70 }
71
getReservedRegs(const MachineFunction & MF) const72 BitVector XCoreRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
73 BitVector Reserved(getNumRegs());
74 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
75
76 Reserved.set(XCore::CP);
77 Reserved.set(XCore::DP);
78 Reserved.set(XCore::SP);
79 Reserved.set(XCore::LR);
80 if (TFI->hasFP(MF)) {
81 Reserved.set(XCore::R10);
82 }
83 return Reserved;
84 }
85
86 bool
requiresRegisterScavenging(const MachineFunction & MF) const87 XCoreRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
88 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
89
90 // TODO can we estimate stack size?
91 return TFI->hasFP(MF);
92 }
93
94 bool
trackLivenessAfterRegAlloc(const MachineFunction & MF) const95 XCoreRegisterInfo::trackLivenessAfterRegAlloc(const MachineFunction &MF) const {
96 return requiresRegisterScavenging(MF);
97 }
98
99 bool
useFPForScavengingIndex(const MachineFunction & MF) const100 XCoreRegisterInfo::useFPForScavengingIndex(const MachineFunction &MF) const {
101 return false;
102 }
103
104 void
eliminateFrameIndex(MachineBasicBlock::iterator II,int SPAdj,unsigned FIOperandNum,RegScavenger * RS) const105 XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
106 int SPAdj, unsigned FIOperandNum,
107 RegScavenger *RS) const {
108 assert(SPAdj == 0 && "Unexpected");
109 MachineInstr &MI = *II;
110 DebugLoc dl = MI.getDebugLoc();
111 MachineOperand &FrameOp = MI.getOperand(FIOperandNum);
112 int FrameIndex = FrameOp.getIndex();
113
114 MachineFunction &MF = *MI.getParent()->getParent();
115 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
116 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
117 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
118 int StackSize = MF.getFrameInfo()->getStackSize();
119
120 #ifndef NDEBUG
121 DEBUG(errs() << "\nFunction : "
122 << MF.getName() << "\n");
123 DEBUG(errs() << "<--------->\n");
124 DEBUG(MI.print(errs()));
125 DEBUG(errs() << "FrameIndex : " << FrameIndex << "\n");
126 DEBUG(errs() << "FrameOffset : " << Offset << "\n");
127 DEBUG(errs() << "StackSize : " << StackSize << "\n");
128 #endif
129
130 Offset += StackSize;
131
132 unsigned FrameReg = getFrameRegister(MF);
133
134 // Special handling of DBG_VALUE instructions.
135 if (MI.isDebugValue()) {
136 MI.getOperand(FIOperandNum).ChangeToRegister(FrameReg, false /*isDef*/);
137 MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
138 return;
139 }
140
141 // fold constant into offset.
142 Offset += MI.getOperand(FIOperandNum + 1).getImm();
143 MI.getOperand(FIOperandNum + 1).ChangeToImmediate(0);
144
145 assert(Offset%4 == 0 && "Misaligned stack offset");
146
147 DEBUG(errs() << "Offset : " << Offset << "\n" << "<--------->\n");
148
149 Offset/=4;
150
151 bool FP = TFI->hasFP(MF);
152
153 unsigned Reg = MI.getOperand(0).getReg();
154 bool isKill = MI.getOpcode() == XCore::STWFI && MI.getOperand(0).isKill();
155
156 assert(XCore::GRRegsRegClass.contains(Reg) && "Unexpected register operand");
157
158 MachineBasicBlock &MBB = *MI.getParent();
159
160 if (FP) {
161 bool isUs = isImmUs(Offset);
162
163 if (!isUs) {
164 if (!RS)
165 report_fatal_error("eliminateFrameIndex Frame size too big: " +
166 Twine(Offset));
167 unsigned ScratchReg = RS->scavengeRegister(&XCore::GRRegsRegClass, II,
168 SPAdj);
169 loadConstant(MBB, II, ScratchReg, Offset, dl);
170 switch (MI.getOpcode()) {
171 case XCore::LDWFI:
172 BuildMI(MBB, II, dl, TII.get(XCore::LDW_3r), Reg)
173 .addReg(FrameReg)
174 .addReg(ScratchReg, RegState::Kill);
175 break;
176 case XCore::STWFI:
177 BuildMI(MBB, II, dl, TII.get(XCore::STW_l3r))
178 .addReg(Reg, getKillRegState(isKill))
179 .addReg(FrameReg)
180 .addReg(ScratchReg, RegState::Kill);
181 break;
182 case XCore::LDAWFI:
183 BuildMI(MBB, II, dl, TII.get(XCore::LDAWF_l3r), Reg)
184 .addReg(FrameReg)
185 .addReg(ScratchReg, RegState::Kill);
186 break;
187 default:
188 llvm_unreachable("Unexpected Opcode");
189 }
190 } else {
191 switch (MI.getOpcode()) {
192 case XCore::LDWFI:
193 BuildMI(MBB, II, dl, TII.get(XCore::LDW_2rus), Reg)
194 .addReg(FrameReg)
195 .addImm(Offset);
196 break;
197 case XCore::STWFI:
198 BuildMI(MBB, II, dl, TII.get(XCore::STW_2rus))
199 .addReg(Reg, getKillRegState(isKill))
200 .addReg(FrameReg)
201 .addImm(Offset);
202 break;
203 case XCore::LDAWFI:
204 BuildMI(MBB, II, dl, TII.get(XCore::LDAWF_l2rus), Reg)
205 .addReg(FrameReg)
206 .addImm(Offset);
207 break;
208 default:
209 llvm_unreachable("Unexpected Opcode");
210 }
211 }
212 } else {
213 bool isU6 = isImmU6(Offset);
214 if (!isU6 && !isImmU16(Offset))
215 report_fatal_error("eliminateFrameIndex Frame size too big: " +
216 Twine(Offset));
217
218 switch (MI.getOpcode()) {
219 int NewOpcode;
220 case XCore::LDWFI:
221 NewOpcode = (isU6) ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6;
222 BuildMI(MBB, II, dl, TII.get(NewOpcode), Reg)
223 .addImm(Offset);
224 break;
225 case XCore::STWFI:
226 NewOpcode = (isU6) ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
227 BuildMI(MBB, II, dl, TII.get(NewOpcode))
228 .addReg(Reg, getKillRegState(isKill))
229 .addImm(Offset);
230 break;
231 case XCore::LDAWFI:
232 NewOpcode = (isU6) ? XCore::LDAWSP_ru6 : XCore::LDAWSP_lru6;
233 BuildMI(MBB, II, dl, TII.get(NewOpcode), Reg)
234 .addImm(Offset);
235 break;
236 default:
237 llvm_unreachable("Unexpected Opcode");
238 }
239 }
240 // Erase old instruction.
241 MBB.erase(II);
242 }
243
244 void XCoreRegisterInfo::
loadConstant(MachineBasicBlock & MBB,MachineBasicBlock::iterator I,unsigned DstReg,int64_t Value,DebugLoc dl) const245 loadConstant(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
246 unsigned DstReg, int64_t Value, DebugLoc dl) const {
247 // TODO use mkmsk if possible.
248 if (!isImmU16(Value)) {
249 // TODO use constant pool.
250 report_fatal_error("loadConstant value too big " + Twine(Value));
251 }
252 int Opcode = isImmU6(Value) ? XCore::LDC_ru6 : XCore::LDC_lru6;
253 const TargetInstrInfo &TII = *MBB.getParent()->getTarget().getInstrInfo();
254 BuildMI(MBB, I, dl, TII.get(Opcode), DstReg).addImm(Value);
255 }
256
getFrameRegister(const MachineFunction & MF) const257 unsigned XCoreRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
258 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
259
260 return TFI->hasFP(MF) ? XCore::R10 : XCore::SP;
261 }
262