1 //===-- SparcV8AsmPrinter.cpp - SparcV8 LLVM assembly writer --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains a printer that converts from our internal representation
11 // of machine-dependent LLVM code to GAS-format Sparc V8 assembly language.
13 //===----------------------------------------------------------------------===//
16 #include "SparcV8InstrInfo.h"
17 #include "llvm/Constants.h"
18 #include "llvm/DerivedTypes.h"
19 #include "llvm/Module.h"
20 #include "llvm/Assembly/Writer.h"
21 #include "llvm/CodeGen/MachineFunctionPass.h"
22 #include "llvm/CodeGen/MachineConstantPool.h"
23 #include "llvm/CodeGen/MachineInstr.h"
24 #include "llvm/Target/TargetMachine.h"
25 #include "llvm/Support/Mangler.h"
26 #include "Support/Statistic.h"
27 #include "Support/StringExtras.h"
28 #include "Support/CommandLine.h"
32 Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
34 struct V8Printer : public MachineFunctionPass {
35 /// Output stream on which we're printing assembly code.
39 /// Target machine description which we query for reg. names, data
44 /// Name-mangler for global names.
48 V8Printer(std::ostream &o, TargetMachine &tm) : O(o), TM(tm) { }
50 /// We name each basic block in a Function with a unique number, so
51 /// that we can consistently refer to them later. This is cleared
52 /// at the beginning of each call to runOnMachineFunction().
54 typedef std::map<const Value *, unsigned> ValueMapTy;
55 ValueMapTy NumberForBB;
57 /// Cache of mangled name for current function. This is
58 /// recalculated at the beginning of each call to
59 /// runOnMachineFunction().
61 std::string CurrentFnName;
63 virtual const char *getPassName() const {
64 return "SparcV8 Assembly Printer";
67 void emitConstantValueOnly(const Constant *CV);
68 void emitGlobalConstant(const Constant *CV);
69 void printConstantPool(MachineConstantPool *MCP);
70 void printMachineInstruction(const MachineInstr *MI);
71 bool runOnMachineFunction(MachineFunction &F);
72 bool doInitialization(Module &M);
73 bool doFinalization(Module &M);
75 } // end of anonymous namespace
77 /// createSparcV8CodePrinterPass - Returns a pass that prints the SparcV8
78 /// assembly code for a MachineFunction to the given output stream,
79 /// using the given target machine description. This should work
80 /// regardless of whether the function is in SSA form.
82 FunctionPass *llvm::createSparcV8CodePrinterPass (std::ostream &o,
84 return new V8Printer(o, tm);
87 /// toOctal - Convert the low order bits of X into an octal digit.
89 static inline char toOctal(int X) {
93 /// getAsCString - Return the specified array as a C compatible
94 /// string, only if the predicate isStringCompatible is true.
96 static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
97 assert(CVA->isString() && "Array is not string compatible!");
100 for (unsigned i = 0; i != CVA->getNumOperands(); ++i) {
101 unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
105 } else if (C == '\\') {
107 } else if (isprint(C)) {
111 case '\b': O << "\\b"; break;
112 case '\f': O << "\\f"; break;
113 case '\n': O << "\\n"; break;
114 case '\r': O << "\\r"; break;
115 case '\t': O << "\\t"; break;
118 O << toOctal(C >> 6);
119 O << toOctal(C >> 3);
120 O << toOctal(C >> 0);
128 // Print out the specified constant, without a storage class. Only the
129 // constants valid in constant expressions can occur here.
130 void V8Printer::emitConstantValueOnly(const Constant *CV) {
131 if (CV->isNullValue())
133 else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
134 assert(CB == ConstantBool::True);
136 } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
137 if (((CI->getValue() << 32) >> 32) == CI->getValue())
140 O << (unsigned long long)CI->getValue();
141 else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
143 else if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(CV))
144 // This is a constant address for a global variable or function. Use the
145 // name of the variable or function as the address value.
146 O << Mang->getValueName(CPR->getValue());
147 else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
148 const TargetData &TD = TM.getTargetData();
149 switch(CE->getOpcode()) {
150 case Instruction::GetElementPtr: {
151 // generate a symbolic expression for the byte address
152 const Constant *ptrVal = CE->getOperand(0);
153 std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
154 if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
156 emitConstantValueOnly(ptrVal);
157 O << ") + " << Offset;
159 emitConstantValueOnly(ptrVal);
163 case Instruction::Cast: {
164 // Support only non-converting or widening casts for now, that is, ones
165 // that do not involve a change in value. This assertion is really gross,
166 // and may not even be a complete check.
167 Constant *Op = CE->getOperand(0);
168 const Type *OpTy = Op->getType(), *Ty = CE->getType();
170 // Pointers on ILP32 machines can be losslessly converted back and
171 // forth into 32-bit or wider integers, regardless of signedness.
172 assert(((isa<PointerType>(OpTy)
173 && (Ty == Type::LongTy || Ty == Type::ULongTy
174 || Ty == Type::IntTy || Ty == Type::UIntTy))
175 || (isa<PointerType>(Ty)
176 && (OpTy == Type::LongTy || OpTy == Type::ULongTy
177 || OpTy == Type::IntTy || OpTy == Type::UIntTy))
178 || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
179 && OpTy->isLosslesslyConvertibleTo(Ty))))
180 && "FIXME: Don't yet support this kind of constant cast expr");
182 emitConstantValueOnly(Op);
186 case Instruction::Add:
188 emitConstantValueOnly(CE->getOperand(0));
190 emitConstantValueOnly(CE->getOperand(1));
194 assert(0 && "Unsupported operator!");
197 assert(0 && "Unknown constant value!");
201 // Print a constant value or values, with the appropriate storage class as a
203 void V8Printer::emitGlobalConstant(const Constant *CV) {
204 const TargetData &TD = TM.getTargetData();
206 if (CV->isNullValue()) {
207 O << "\t.zero\t " << TD.getTypeSize(CV->getType()) << "\n";
209 } else if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
210 if (CVA->isString()) {
212 printAsCString(O, CVA);
214 } else { // Not a string. Print the values in successive locations
215 const std::vector<Use> &constValues = CVA->getValues();
216 for (unsigned i=0; i < constValues.size(); i++)
217 emitGlobalConstant(cast<Constant>(constValues[i].get()));
220 } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
221 // Print the fields in successive locations. Pad to align if needed!
222 const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
223 const std::vector<Use>& constValues = CVS->getValues();
224 unsigned sizeSoFar = 0;
225 for (unsigned i=0, N = constValues.size(); i < N; i++) {
226 const Constant* field = cast<Constant>(constValues[i].get());
228 // Check if padding is needed and insert one or more 0s.
229 unsigned fieldSize = TD.getTypeSize(field->getType());
230 unsigned padSize = ((i == N-1? cvsLayout->StructSize
231 : cvsLayout->MemberOffsets[i+1])
232 - cvsLayout->MemberOffsets[i]) - fieldSize;
233 sizeSoFar += fieldSize + padSize;
235 // Now print the actual field value
236 emitGlobalConstant(field);
238 // Insert the field padding unless it's zero bytes...
240 O << "\t.zero\t " << padSize << "\n";
242 assert(sizeSoFar == cvsLayout->StructSize &&
243 "Layout of constant struct may be incorrect!");
245 } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
246 // FP Constants are printed as integer constants to avoid losing
248 double Val = CFP->getValue();
249 switch (CFP->getType()->getPrimitiveID()) {
250 default: assert(0 && "Unknown floating point type!");
251 case Type::FloatTyID: {
252 union FU { // Abide by C TBAA rules
257 O << ".long\t" << U.UVal << "\t# float " << Val << "\n";
260 case Type::DoubleTyID: {
261 union DU { // Abide by C TBAA rules
266 O << ".quad\t" << U.UVal << "\t# double " << Val << "\n";
272 const Type *type = CV->getType();
274 switch (type->getPrimitiveID()) {
275 case Type::BoolTyID: case Type::UByteTyID: case Type::SByteTyID:
278 case Type::UShortTyID: case Type::ShortTyID:
281 case Type::FloatTyID: case Type::PointerTyID:
282 case Type::UIntTyID: case Type::IntTyID:
285 case Type::DoubleTyID:
286 case Type::ULongTyID: case Type::LongTyID:
290 assert (0 && "Can't handle printing this type of thing");
294 emitConstantValueOnly(CV);
298 /// printConstantPool - Print to the current output stream assembly
299 /// representations of the constants in the constant pool MCP. This is
300 /// used to print out constants which have been "spilled to memory" by
301 /// the code generator.
303 void V8Printer::printConstantPool(MachineConstantPool *MCP) {
304 const std::vector<Constant*> &CP = MCP->getConstants();
305 const TargetData &TD = TM.getTargetData();
307 if (CP.empty()) return;
309 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
310 O << "\t.section .rodata\n";
311 O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType())
313 O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t#"
315 emitGlobalConstant(CP[i]);
319 /// runOnMachineFunction - This uses the printMachineInstruction()
320 /// method to print assembly for each instruction.
322 bool V8Printer::runOnMachineFunction(MachineFunction &MF) {
323 // BBNumber is used here so that a given Printer will never give two
324 // BBs the same name. (If you have a better way, please let me know!)
325 static unsigned BBNumber = 0;
328 // What's my mangled name?
329 CurrentFnName = Mang->getValueName(MF.getFunction());
331 // Print out constants referenced by the function
332 printConstantPool(MF.getConstantPool());
334 // Print out labels for the function.
336 O << "\t.align 16\n";
337 O << "\t.globl\t" << CurrentFnName << "\n";
338 O << "\t.type\t" << CurrentFnName << ", @function\n";
339 O << CurrentFnName << ":\n";
341 // Number each basic block so that we can consistently refer to them
342 // in PC-relative references.
344 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
346 NumberForBB[I->getBasicBlock()] = BBNumber++;
349 // Print out code for the function.
350 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
352 // Print a label for the basic block.
353 O << ".LBB" << NumberForBB[I->getBasicBlock()] << ":\t# "
354 << I->getBasicBlock()->getName() << "\n";
355 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
357 // Print the assembly for the instruction.
359 printMachineInstruction(II);
363 // We didn't modify anything.
367 /// printMachineInstruction -- Print out a single SparcV8 LLVM instruction
368 /// MI in GAS syntax to the current output stream.
370 void V8Printer::printMachineInstruction(const MachineInstr *MI) {
371 unsigned Opcode = MI->getOpcode();
372 const TargetInstrInfo &TII = TM.getInstrInfo();
373 const TargetInstrDescriptor &Desc = TII.get(Opcode);
374 O << Desc.Name << "\n"; // not yet done
377 bool V8Printer::doInitialization(Module &M) {
378 Mang = new Mangler(M);
379 return false; // success
382 // SwitchSection - Switch to the specified section of the executable if we are
383 // not already in it!
385 static void SwitchSection(std::ostream &OS, std::string &CurSection,
386 const char *NewSection) {
387 if (CurSection != NewSection) {
388 CurSection = NewSection;
389 if (!CurSection.empty())
390 OS << "\t" << NewSection << "\n";
394 bool V8Printer::doFinalization(Module &M) {
395 const TargetData &TD = TM.getTargetData();
396 std::string CurSection;
398 // Print out module-level global variables here.
399 for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
400 if (I->hasInitializer()) { // External global require no code
402 std::string name = Mang->getValueName(I);
403 Constant *C = I->getInitializer();
404 unsigned Size = TD.getTypeSize(C->getType());
405 unsigned Align = TD.getTypeAlignment(C->getType());
407 if (C->isNullValue() &&
408 (I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
409 I->hasWeakLinkage() /* FIXME: Verify correct */)) {
410 SwitchSection(O, CurSection, ".data");
411 if (I->hasInternalLinkage())
412 O << "\t.local " << name << "\n";
414 O << "\t.comm " << name << "," << TD.getTypeSize(C->getType())
415 << "," << (unsigned)TD.getTypeAlignment(C->getType());
417 WriteAsOperand(O, I, true, true, &M);
420 switch (I->getLinkage()) {
421 case GlobalValue::LinkOnceLinkage:
422 case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak.
423 // Nonnull linkonce -> weak
424 O << "\t.weak " << name << "\n";
425 SwitchSection(O, CurSection, "");
426 O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
429 case GlobalValue::AppendingLinkage:
430 // FIXME: appending linkage variables should go into a section of
431 // their name or something. For now, just emit them as external.
432 case GlobalValue::ExternalLinkage:
433 // If external or appending, declare as a global symbol
434 O << "\t.globl " << name << "\n";
436 case GlobalValue::InternalLinkage:
437 if (C->isNullValue())
438 SwitchSection(O, CurSection, ".bss");
440 SwitchSection(O, CurSection, ".data");
444 O << "\t.align " << Align << "\n";
445 O << "\t.type " << name << ",@object\n";
446 O << "\t.size " << name << "," << Size << "\n";
447 O << name << ":\t\t\t\t# ";
448 WriteAsOperand(O, I, true, true, &M);
450 WriteAsOperand(O, C, false, false, &M);
452 emitGlobalConstant(C);
457 return false; // success