1 //===-- XCoreAsmPrinter.cpp - XCore LLVM assembly writer ------------------===//
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 a printer that converts from our internal representation
11 // of machine-dependent LLVM code to the XAS-format XCore assembly language.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "XCore.h"
16 #include "InstPrinter/XCoreInstPrinter.h"
17 #include "XCoreInstrInfo.h"
18 #include "XCoreMCInstLower.h"
19 #include "XCoreSubtarget.h"
20 #include "XCoreTargetMachine.h"
21 #include "XCoreTargetStreamer.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/CodeGen/AsmPrinter.h"
25 #include "llvm/CodeGen/MachineConstantPool.h"
26 #include "llvm/CodeGen/MachineFunctionPass.h"
27 #include "llvm/CodeGen/MachineInstr.h"
28 #include "llvm/CodeGen/MachineJumpTableInfo.h"
29 #include "llvm/CodeGen/MachineModuleInfo.h"
30 #include "llvm/IR/Constants.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/DebugInfo.h"
33 #include "llvm/IR/DerivedTypes.h"
34 #include "llvm/IR/Mangler.h"
35 #include "llvm/IR/Module.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/MCExpr.h"
38 #include "llvm/MC/MCInst.h"
39 #include "llvm/MC/MCStreamer.h"
40 #include "llvm/MC/MCSymbolELF.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/TargetRegistry.h"
43 #include "llvm/Support/raw_ostream.h"
44 #include "llvm/Target/TargetLoweringObjectFile.h"
45 #include <algorithm>
46 #include <cctype>
47 using namespace llvm;
48 
49 #define DEBUG_TYPE "asm-printer"
50 
51 namespace {
52   class XCoreAsmPrinter : public AsmPrinter {
53     XCoreMCInstLower MCInstLowering;
54     XCoreTargetStreamer &getTargetStreamer();
55 
56   public:
XCoreAsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)57     explicit XCoreAsmPrinter(TargetMachine &TM,
58                              std::unique_ptr<MCStreamer> Streamer)
59         : AsmPrinter(TM, std::move(Streamer)), MCInstLowering(*this) {}
60 
getPassName() const61     const char *getPassName() const override {
62       return "XCore Assembly Printer";
63     }
64 
65     void printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
66                        const std::string &directive = ".jmptable");
printInlineJT32(const MachineInstr * MI,int opNum,raw_ostream & O)67     void printInlineJT32(const MachineInstr *MI, int opNum, raw_ostream &O) {
68       printInlineJT(MI, opNum, O, ".jmptable32");
69     }
70     void printOperand(const MachineInstr *MI, int opNum, raw_ostream &O);
71     bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
72                          unsigned AsmVariant, const char *ExtraCode,
73                          raw_ostream &O) override;
74     bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
75                                unsigned AsmVariant, const char *ExtraCode,
76                                raw_ostream &O) override;
77 
78     void emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV);
79     void EmitGlobalVariable(const GlobalVariable *GV) override;
80 
81     void EmitFunctionEntryLabel() override;
82     void EmitInstruction(const MachineInstr *MI) override;
83     void EmitFunctionBodyStart() override;
84     void EmitFunctionBodyEnd() override;
85   };
86 } // end of anonymous namespace
87 
getTargetStreamer()88 XCoreTargetStreamer &XCoreAsmPrinter::getTargetStreamer() {
89   return static_cast<XCoreTargetStreamer&>(*OutStreamer->getTargetStreamer());
90 }
91 
emitArrayBound(MCSymbol * Sym,const GlobalVariable * GV)92 void XCoreAsmPrinter::emitArrayBound(MCSymbol *Sym, const GlobalVariable *GV) {
93   assert( ( GV->hasExternalLinkage() || GV->hasWeakLinkage() ||
94             GV->hasLinkOnceLinkage() || GV->hasCommonLinkage() ) &&
95           "Unexpected linkage");
96   if (ArrayType *ATy = dyn_cast<ArrayType>(GV->getValueType())) {
97 
98     MCSymbol *SymGlob = OutContext.getOrCreateSymbol(
99                           Twine(Sym->getName() + StringRef(".globound")));
100     OutStreamer->EmitSymbolAttribute(SymGlob, MCSA_Global);
101     OutStreamer->EmitAssignment(SymGlob,
102                                 MCConstantExpr::create(ATy->getNumElements(),
103                                                        OutContext));
104     if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
105         GV->hasCommonLinkage()) {
106       OutStreamer->EmitSymbolAttribute(SymGlob, MCSA_Weak);
107     }
108   }
109 }
110 
EmitGlobalVariable(const GlobalVariable * GV)111 void XCoreAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
112   // Check to see if this is a special global used by LLVM, if so, emit it.
113   if (!GV->hasInitializer() ||
114       EmitSpecialLLVMGlobal(GV))
115     return;
116 
117   const DataLayout &DL = getDataLayout();
118   OutStreamer->SwitchSection(
119       getObjFileLowering().SectionForGlobal(GV, *Mang, TM));
120 
121   MCSymbol *GVSym = getSymbol(GV);
122   const Constant *C = GV->getInitializer();
123   unsigned Align = (unsigned)DL.getPreferredTypeAlignmentShift(C->getType());
124 
125   // Mark the start of the global
126   getTargetStreamer().emitCCTopData(GVSym->getName());
127 
128   switch (GV->getLinkage()) {
129   case GlobalValue::AppendingLinkage:
130     report_fatal_error("AppendingLinkage is not supported by this target!");
131   case GlobalValue::LinkOnceAnyLinkage:
132   case GlobalValue::LinkOnceODRLinkage:
133   case GlobalValue::WeakAnyLinkage:
134   case GlobalValue::WeakODRLinkage:
135   case GlobalValue::ExternalLinkage:
136   case GlobalValue::CommonLinkage:
137     emitArrayBound(GVSym, GV);
138     OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
139 
140     if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
141         GV->hasCommonLinkage())
142       OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
143     // FALL THROUGH
144   case GlobalValue::InternalLinkage:
145   case GlobalValue::PrivateLinkage:
146     break;
147   default:
148     llvm_unreachable("Unknown linkage type!");
149   }
150 
151   EmitAlignment(Align > 2 ? Align : 2, GV);
152 
153   if (GV->isThreadLocal()) {
154     report_fatal_error("TLS is not supported by this target!");
155   }
156   unsigned Size = DL.getTypeAllocSize(C->getType());
157   if (MAI->hasDotTypeDotSizeDirective()) {
158     OutStreamer->EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
159     OutStreamer->emitELFSize(cast<MCSymbolELF>(GVSym),
160                              MCConstantExpr::create(Size, OutContext));
161   }
162   OutStreamer->EmitLabel(GVSym);
163 
164   EmitGlobalConstant(DL, C);
165   // The ABI requires that unsigned scalar types smaller than 32 bits
166   // are padded to 32 bits.
167   if (Size < 4)
168     OutStreamer->EmitZeros(4 - Size);
169 
170   // Mark the end of the global
171   getTargetStreamer().emitCCBottomData(GVSym->getName());
172 }
173 
EmitFunctionBodyStart()174 void XCoreAsmPrinter::EmitFunctionBodyStart() {
175   MCInstLowering.Initialize(Mang, &MF->getContext());
176 }
177 
178 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
179 /// the last basic block in the function.
EmitFunctionBodyEnd()180 void XCoreAsmPrinter::EmitFunctionBodyEnd() {
181   // Emit function end directives
182   getTargetStreamer().emitCCBottomFunction(CurrentFnSym->getName());
183 }
184 
EmitFunctionEntryLabel()185 void XCoreAsmPrinter::EmitFunctionEntryLabel() {
186   // Mark the start of the function
187   getTargetStreamer().emitCCTopFunction(CurrentFnSym->getName());
188   OutStreamer->EmitLabel(CurrentFnSym);
189 }
190 
191 void XCoreAsmPrinter::
printInlineJT(const MachineInstr * MI,int opNum,raw_ostream & O,const std::string & directive)192 printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
193               const std::string &directive) {
194   unsigned JTI = MI->getOperand(opNum).getIndex();
195   const MachineFunction *MF = MI->getParent()->getParent();
196   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
197   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
198   const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
199   O << "\t" << directive << " ";
200   for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
201     MachineBasicBlock *MBB = JTBBs[i];
202     if (i > 0)
203       O << ",";
204     MBB->getSymbol()->print(O, MAI);
205   }
206 }
207 
printOperand(const MachineInstr * MI,int opNum,raw_ostream & O)208 void XCoreAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
209                                    raw_ostream &O) {
210   const DataLayout &DL = getDataLayout();
211   const MachineOperand &MO = MI->getOperand(opNum);
212   switch (MO.getType()) {
213   case MachineOperand::MO_Register:
214     O << XCoreInstPrinter::getRegisterName(MO.getReg());
215     break;
216   case MachineOperand::MO_Immediate:
217     O << MO.getImm();
218     break;
219   case MachineOperand::MO_MachineBasicBlock:
220     MO.getMBB()->getSymbol()->print(O, MAI);
221     break;
222   case MachineOperand::MO_GlobalAddress:
223     getSymbol(MO.getGlobal())->print(O, MAI);
224     break;
225   case MachineOperand::MO_ConstantPoolIndex:
226     O << DL.getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << '_'
227       << MO.getIndex();
228     break;
229   case MachineOperand::MO_BlockAddress:
230     GetBlockAddressSymbol(MO.getBlockAddress())->print(O, MAI);
231     break;
232   default:
233     llvm_unreachable("not implemented");
234   }
235 }
236 
237 /// PrintAsmOperand - Print out an operand for an inline asm expression.
238 ///
PrintAsmOperand(const MachineInstr * MI,unsigned OpNo,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)239 bool XCoreAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
240                                       unsigned AsmVariant,const char *ExtraCode,
241                                       raw_ostream &O) {
242   // Print the operand if there is no operand modifier.
243   if (!ExtraCode || !ExtraCode[0]) {
244     printOperand(MI, OpNo, O);
245     return false;
246   }
247 
248   // Otherwise fallback on the default implementation.
249   return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O);
250 }
251 
252 bool XCoreAsmPrinter::
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNum,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)253 PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
254                       unsigned AsmVariant, const char *ExtraCode,
255                       raw_ostream &O) {
256   if (ExtraCode && ExtraCode[0]) {
257     return true; // Unknown modifier.
258   }
259   printOperand(MI, OpNum, O);
260   O << '[';
261   printOperand(MI, OpNum + 1, O);
262   O << ']';
263   return false;
264 }
265 
EmitInstruction(const MachineInstr * MI)266 void XCoreAsmPrinter::EmitInstruction(const MachineInstr *MI) {
267   SmallString<128> Str;
268   raw_svector_ostream O(Str);
269 
270   switch (MI->getOpcode()) {
271   case XCore::DBG_VALUE:
272     llvm_unreachable("Should be handled target independently");
273   case XCore::ADD_2rus:
274     if (MI->getOperand(2).getImm() == 0) {
275       O << "\tmov "
276         << XCoreInstPrinter::getRegisterName(MI->getOperand(0).getReg()) << ", "
277         << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg());
278       OutStreamer->EmitRawText(O.str());
279       return;
280     }
281     break;
282   case XCore::BR_JT:
283   case XCore::BR_JT32:
284     O << "\tbru "
285       << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg()) << '\n';
286     if (MI->getOpcode() == XCore::BR_JT)
287       printInlineJT(MI, 0, O);
288     else
289       printInlineJT32(MI, 0, O);
290     O << '\n';
291     OutStreamer->EmitRawText(O.str());
292     return;
293   }
294 
295   MCInst TmpInst;
296   MCInstLowering.Lower(MI, TmpInst);
297 
298   EmitToStreamer(*OutStreamer, TmpInst);
299 }
300 
301 // Force static initialization.
LLVMInitializeXCoreAsmPrinter()302 extern "C" void LLVMInitializeXCoreAsmPrinter() {
303   RegisterAsmPrinter<XCoreAsmPrinter> X(TheXCoreTarget);
304 }
305