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>(
97                         cast<PointerType>(GV->getType())->getElementType())) {
98 
99     MCSymbol *SymGlob = OutContext.getOrCreateSymbol(
100                           Twine(Sym->getName() + StringRef(".globound")));
101     OutStreamer->EmitSymbolAttribute(SymGlob, MCSA_Global);
102     OutStreamer->EmitAssignment(SymGlob,
103                                 MCConstantExpr::create(ATy->getNumElements(),
104                                                        OutContext));
105     if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
106         GV->hasCommonLinkage()) {
107       OutStreamer->EmitSymbolAttribute(SymGlob, MCSA_Weak);
108     }
109   }
110 }
111 
EmitGlobalVariable(const GlobalVariable * GV)112 void XCoreAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
113   // Check to see if this is a special global used by LLVM, if so, emit it.
114   if (!GV->hasInitializer() ||
115       EmitSpecialLLVMGlobal(GV))
116     return;
117 
118   const DataLayout &DL = getDataLayout();
119   OutStreamer->SwitchSection(
120       getObjFileLowering().SectionForGlobal(GV, *Mang, TM));
121 
122   MCSymbol *GVSym = getSymbol(GV);
123   const Constant *C = GV->getInitializer();
124   unsigned Align = (unsigned)DL.getPreferredTypeAlignmentShift(C->getType());
125 
126   // Mark the start of the global
127   getTargetStreamer().emitCCTopData(GVSym->getName());
128 
129   switch (GV->getLinkage()) {
130   case GlobalValue::AppendingLinkage:
131     report_fatal_error("AppendingLinkage is not supported by this target!");
132   case GlobalValue::LinkOnceAnyLinkage:
133   case GlobalValue::LinkOnceODRLinkage:
134   case GlobalValue::WeakAnyLinkage:
135   case GlobalValue::WeakODRLinkage:
136   case GlobalValue::ExternalLinkage:
137   case GlobalValue::CommonLinkage:
138     emitArrayBound(GVSym, GV);
139     OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
140 
141     if (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
142         GV->hasCommonLinkage())
143       OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
144     // FALL THROUGH
145   case GlobalValue::InternalLinkage:
146   case GlobalValue::PrivateLinkage:
147     break;
148   default:
149     llvm_unreachable("Unknown linkage type!");
150   }
151 
152   EmitAlignment(Align > 2 ? Align : 2, GV);
153 
154   if (GV->isThreadLocal()) {
155     report_fatal_error("TLS is not supported by this target!");
156   }
157   unsigned Size = DL.getTypeAllocSize(C->getType());
158   if (MAI->hasDotTypeDotSizeDirective()) {
159     OutStreamer->EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
160     OutStreamer->emitELFSize(cast<MCSymbolELF>(GVSym),
161                              MCConstantExpr::create(Size, OutContext));
162   }
163   OutStreamer->EmitLabel(GVSym);
164 
165   EmitGlobalConstant(DL, C);
166   // The ABI requires that unsigned scalar types smaller than 32 bits
167   // are padded to 32 bits.
168   if (Size < 4)
169     OutStreamer->EmitZeros(4 - Size);
170 
171   // Mark the end of the global
172   getTargetStreamer().emitCCBottomData(GVSym->getName());
173 }
174 
EmitFunctionBodyStart()175 void XCoreAsmPrinter::EmitFunctionBodyStart() {
176   MCInstLowering.Initialize(Mang, &MF->getContext());
177 }
178 
179 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
180 /// the last basic block in the function.
EmitFunctionBodyEnd()181 void XCoreAsmPrinter::EmitFunctionBodyEnd() {
182   // Emit function end directives
183   getTargetStreamer().emitCCBottomFunction(CurrentFnSym->getName());
184 }
185 
EmitFunctionEntryLabel()186 void XCoreAsmPrinter::EmitFunctionEntryLabel() {
187   // Mark the start of the function
188   getTargetStreamer().emitCCTopFunction(CurrentFnSym->getName());
189   OutStreamer->EmitLabel(CurrentFnSym);
190 }
191 
192 void XCoreAsmPrinter::
printInlineJT(const MachineInstr * MI,int opNum,raw_ostream & O,const std::string & directive)193 printInlineJT(const MachineInstr *MI, int opNum, raw_ostream &O,
194               const std::string &directive) {
195   unsigned JTI = MI->getOperand(opNum).getIndex();
196   const MachineFunction *MF = MI->getParent()->getParent();
197   const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
198   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
199   const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
200   O << "\t" << directive << " ";
201   for (unsigned i = 0, e = JTBBs.size(); i != e; ++i) {
202     MachineBasicBlock *MBB = JTBBs[i];
203     if (i > 0)
204       O << ",";
205     MBB->getSymbol()->print(O, MAI);
206   }
207 }
208 
printOperand(const MachineInstr * MI,int opNum,raw_ostream & O)209 void XCoreAsmPrinter::printOperand(const MachineInstr *MI, int opNum,
210                                    raw_ostream &O) {
211   const DataLayout &DL = getDataLayout();
212   const MachineOperand &MO = MI->getOperand(opNum);
213   switch (MO.getType()) {
214   case MachineOperand::MO_Register:
215     O << XCoreInstPrinter::getRegisterName(MO.getReg());
216     break;
217   case MachineOperand::MO_Immediate:
218     O << MO.getImm();
219     break;
220   case MachineOperand::MO_MachineBasicBlock:
221     MO.getMBB()->getSymbol()->print(O, MAI);
222     break;
223   case MachineOperand::MO_GlobalAddress:
224     getSymbol(MO.getGlobal())->print(O, MAI);
225     break;
226   case MachineOperand::MO_ConstantPoolIndex:
227     O << DL.getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << '_'
228       << MO.getIndex();
229     break;
230   case MachineOperand::MO_BlockAddress:
231     GetBlockAddressSymbol(MO.getBlockAddress())->print(O, MAI);
232     break;
233   default:
234     llvm_unreachable("not implemented");
235   }
236 }
237 
238 /// PrintAsmOperand - Print out an operand for an inline asm expression.
239 ///
PrintAsmOperand(const MachineInstr * MI,unsigned OpNo,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)240 bool XCoreAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
241                                       unsigned AsmVariant,const char *ExtraCode,
242                                       raw_ostream &O) {
243   // Print the operand if there is no operand modifier.
244   if (!ExtraCode || !ExtraCode[0]) {
245     printOperand(MI, OpNo, O);
246     return false;
247   }
248 
249   // Otherwise fallback on the default implementation.
250   return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O);
251 }
252 
253 bool XCoreAsmPrinter::
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNum,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)254 PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
255                       unsigned AsmVariant, const char *ExtraCode,
256                       raw_ostream &O) {
257   if (ExtraCode && ExtraCode[0]) {
258     return true; // Unknown modifier.
259   }
260   printOperand(MI, OpNum, O);
261   O << '[';
262   printOperand(MI, OpNum + 1, O);
263   O << ']';
264   return false;
265 }
266 
EmitInstruction(const MachineInstr * MI)267 void XCoreAsmPrinter::EmitInstruction(const MachineInstr *MI) {
268   SmallString<128> Str;
269   raw_svector_ostream O(Str);
270 
271   switch (MI->getOpcode()) {
272   case XCore::DBG_VALUE:
273     llvm_unreachable("Should be handled target independently");
274   case XCore::ADD_2rus:
275     if (MI->getOperand(2).getImm() == 0) {
276       O << "\tmov "
277         << XCoreInstPrinter::getRegisterName(MI->getOperand(0).getReg()) << ", "
278         << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg());
279       OutStreamer->EmitRawText(O.str());
280       return;
281     }
282     break;
283   case XCore::BR_JT:
284   case XCore::BR_JT32:
285     O << "\tbru "
286       << XCoreInstPrinter::getRegisterName(MI->getOperand(1).getReg()) << '\n';
287     if (MI->getOpcode() == XCore::BR_JT)
288       printInlineJT(MI, 0, O);
289     else
290       printInlineJT32(MI, 0, O);
291     O << '\n';
292     OutStreamer->EmitRawText(O.str());
293     return;
294   }
295 
296   MCInst TmpInst;
297   MCInstLowering.Lower(MI, TmpInst);
298 
299   EmitToStreamer(*OutStreamer, TmpInst);
300 }
301 
302 // Force static initialization.
LLVMInitializeXCoreAsmPrinter()303 extern "C" void LLVMInitializeXCoreAsmPrinter() {
304   RegisterAsmPrinter<XCoreAsmPrinter> X(TheXCoreTarget);
305 }
306