1 //===-- Printer.cpp - Convert LLVM code to PowerPC assembly ---------------===//
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 PowerPC assembly language. This printer is
12 // the output mechanism used by `llc' and `lli -print-machineinstrs'.
14 // Documentation at http://developer.apple.com/documentation/DeveloperTools/
15 // Reference/Assembler/ASMIntroduction/chapter_1_section_1.html
17 //===----------------------------------------------------------------------===//
19 #define DEBUG_TYPE "asmprinter"
21 #include "PowerPCInstrInfo.h"
22 #include "PowerPCTargetMachine.h"
23 #include "llvm/Constants.h"
24 #include "llvm/DerivedTypes.h"
25 #include "llvm/Module.h"
26 #include "llvm/Assembly/Writer.h"
27 #include "llvm/CodeGen/MachineConstantPool.h"
28 #include "llvm/CodeGen/MachineFunctionPass.h"
29 #include "llvm/CodeGen/MachineInstr.h"
30 #include "llvm/Target/TargetMachine.h"
31 #include "llvm/Support/Mangler.h"
32 #include "Support/CommandLine.h"
33 #include "Support/Debug.h"
34 #include "Support/Statistic.h"
35 #include "Support/StringExtras.h"
41 Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
43 struct Printer : public MachineFunctionPass {
44 /// Output stream on which we're printing assembly code.
48 /// Target machine description which we query for reg. names, data
51 PowerPCTargetMachine &TM;
53 /// Name-mangler for global names.
56 std::set<std::string> FnStubs, GVStubs, LinkOnceStubs;
57 std::set<std::string> Strings;
59 Printer(std::ostream &o, TargetMachine &tm) : O(o),
60 TM(reinterpret_cast<PowerPCTargetMachine&>(tm)), LabelNumber(0) {}
62 /// Cache of mangled name for current function. This is
63 /// recalculated at the beginning of each call to
64 /// runOnMachineFunction().
66 std::string CurrentFnName;
68 /// Unique incrementer for label values for referencing Global values.
72 virtual const char *getPassName() const {
73 return "PowerPC Assembly Printer";
76 void printMachineInstruction(const MachineInstr *MI);
77 void printOp(const MachineOperand &MO, bool elideOffsetKeyword = false);
78 void printImmOp(const MachineOperand &MO, unsigned ArgType);
79 void printConstantPool(MachineConstantPool *MCP);
80 bool runOnMachineFunction(MachineFunction &F);
81 bool doInitialization(Module &M);
82 bool doFinalization(Module &M);
83 void emitGlobalConstant(const Constant* CV);
84 void emitConstantValueOnly(const Constant *CV);
86 } // end of anonymous namespace
88 /// createPPCCodePrinterPass - Returns a pass that prints the PPC
89 /// assembly code for a MachineFunction to the given output stream,
90 /// using the given target machine description. This should work
91 /// regardless of whether the function is in SSA form.
93 FunctionPass *createPPCCodePrinterPass(std::ostream &o,TargetMachine &tm) {
94 return new Printer(o, tm);
97 /// isStringCompatible - Can we treat the specified array as a string?
98 /// Only if it is an array of ubytes or non-negative sbytes.
100 static bool isStringCompatible(const ConstantArray *CVA) {
101 const Type *ETy = cast<ArrayType>(CVA->getType())->getElementType();
102 if (ETy == Type::UByteTy) return true;
103 if (ETy != Type::SByteTy) return false;
105 for (unsigned i = 0; i < CVA->getNumOperands(); ++i)
106 if (cast<ConstantSInt>(CVA->getOperand(i))->getValue() < 0)
112 /// toOctal - Convert the low order bits of X into an octal digit.
114 static inline char toOctal(int X) {
118 /// getAsCString - Return the specified array as a C compatible
119 /// string, only if the predicate isStringCompatible is true.
121 static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
122 assert(isStringCompatible(CVA) && "Array is not string compatible!");
125 for (unsigned i = 0; i < CVA->getNumOperands(); ++i) {
126 unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
130 } else if (C == '\\') {
132 } else if (isprint(C)) {
136 case '\b': O << "\\b"; break;
137 case '\f': O << "\\f"; break;
138 case '\n': O << "\\n"; break;
139 case '\r': O << "\\r"; break;
140 case '\t': O << "\\t"; break;
143 O << toOctal(C >> 6);
144 O << toOctal(C >> 3);
145 O << toOctal(C >> 0);
153 // Print out the specified constant, without a storage class. Only the
154 // constants valid in constant expressions can occur here.
155 void Printer::emitConstantValueOnly(const Constant *CV) {
156 if (CV->isNullValue())
158 else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
159 assert(CB == ConstantBool::True);
161 } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
163 else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
165 else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
166 // This is a constant address for a global variable or function. Use the
167 // name of the variable or function as the address value.
168 O << Mang->getValueName(GV);
169 else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
170 const TargetData &TD = TM.getTargetData();
171 switch (CE->getOpcode()) {
172 case Instruction::GetElementPtr: {
173 // generate a symbolic expression for the byte address
174 const Constant *ptrVal = CE->getOperand(0);
175 std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
176 if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
178 emitConstantValueOnly(ptrVal);
179 O << ") + " << Offset;
181 emitConstantValueOnly(ptrVal);
185 case Instruction::Cast: {
186 // Support only non-converting or widening casts for now, that is, ones
187 // that do not involve a change in value. This assertion is really gross,
188 // and may not even be a complete check.
189 Constant *Op = CE->getOperand(0);
190 const Type *OpTy = Op->getType(), *Ty = CE->getType();
192 // Remember, kids, pointers on x86 can be losslessly converted back and
193 // forth into 32-bit or wider integers, regardless of signedness. :-P
194 assert(((isa<PointerType>(OpTy)
195 && (Ty == Type::LongTy || Ty == Type::ULongTy
196 || Ty == Type::IntTy || Ty == Type::UIntTy))
197 || (isa<PointerType>(Ty)
198 && (OpTy == Type::LongTy || OpTy == Type::ULongTy
199 || OpTy == Type::IntTy || OpTy == Type::UIntTy))
200 || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
201 && OpTy->isLosslesslyConvertibleTo(Ty))))
202 && "FIXME: Don't yet support this kind of constant cast expr");
204 emitConstantValueOnly(Op);
208 case Instruction::Add:
210 emitConstantValueOnly(CE->getOperand(0));
212 emitConstantValueOnly(CE->getOperand(1));
216 assert(0 && "Unsupported operator!");
219 assert(0 && "Unknown constant value!");
223 // Print a constant value or values, with the appropriate storage class as a
225 void Printer::emitGlobalConstant(const Constant *CV) {
226 const TargetData &TD = TM.getTargetData();
228 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
229 if (isStringCompatible(CVA)) {
231 printAsCString(O, CVA);
233 } else { // Not a string. Print the values in successive locations
234 const std::vector<Use> &constValues = CVA->getValues();
235 for (unsigned i=0; i < constValues.size(); i++)
236 emitGlobalConstant(cast<Constant>(constValues[i].get()));
239 } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
240 // Print the fields in successive locations. Pad to align if needed!
241 const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
242 const std::vector<Use>& constValues = CVS->getValues();
243 unsigned sizeSoFar = 0;
244 for (unsigned i=0, N = constValues.size(); i < N; i++) {
245 const Constant* field = cast<Constant>(constValues[i].get());
247 // Check if padding is needed and insert one or more 0s.
248 unsigned fieldSize = TD.getTypeSize(field->getType());
249 unsigned padSize = ((i == N-1? cvsLayout->StructSize
250 : cvsLayout->MemberOffsets[i+1])
251 - cvsLayout->MemberOffsets[i]) - fieldSize;
252 sizeSoFar += fieldSize + padSize;
254 // Now print the actual field value
255 emitGlobalConstant(field);
257 // Insert the field padding unless it's zero bytes...
259 O << "\t.space\t " << padSize << "\n";
261 assert(sizeSoFar == cvsLayout->StructSize &&
262 "Layout of constant struct may be incorrect!");
264 } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
265 // FP Constants are printed as integer constants to avoid losing
267 double Val = CFP->getValue();
268 switch (CFP->getType()->getTypeID()) {
269 default: assert(0 && "Unknown floating point type!");
270 case Type::FloatTyID: {
271 union FU { // Abide by C TBAA rules
276 O << ".long\t" << U.UVal << "\t; float " << Val << "\n";
279 case Type::DoubleTyID: {
280 union DU { // Abide by C TBAA rules
290 O << ".long\t" << U.T.MSWord << "\t; double most significant word "
292 O << ".long\t" << U.T.LSWord << "\t; double least significant word "
297 } else if (CV->getType()->getPrimitiveSize() == 64) {
298 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
299 union DU { // Abide by C TBAA rules
306 U.UVal = CI->getRawValue();
308 O << ".long\t" << U.T.MSWord << "\t; Double-word most significant word "
310 O << ".long\t" << U.T.LSWord << "\t; Double-word least significant word "
316 const Type *type = CV->getType();
318 switch (type->getTypeID()) {
319 case Type::UByteTyID: case Type::SByteTyID:
322 case Type::UShortTyID: case Type::ShortTyID:
326 case Type::PointerTyID:
327 case Type::UIntTyID: case Type::IntTyID:
330 case Type::ULongTyID: case Type::LongTyID:
331 assert (0 && "Should have already output double-word constant.");
332 case Type::FloatTyID: case Type::DoubleTyID:
333 assert (0 && "Should have already output floating point constant.");
335 if (CV == Constant::getNullValue(type)) { // Zero initializer?
336 O << ".space\t" << TD.getTypeSize(type) << "\n";
339 std::cerr << "Can't handle printing: " << *CV;
344 emitConstantValueOnly(CV);
348 /// printConstantPool - Print to the current output stream assembly
349 /// representations of the constants in the constant pool MCP. This is
350 /// used to print out constants which have been "spilled to memory" by
351 /// the code generator.
353 void Printer::printConstantPool(MachineConstantPool *MCP) {
354 const std::vector<Constant*> &CP = MCP->getConstants();
355 const TargetData &TD = TM.getTargetData();
357 if (CP.empty()) return;
359 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
361 O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType())
363 O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t;"
365 emitGlobalConstant(CP[i]);
369 /// runOnMachineFunction - This uses the printMachineInstruction()
370 /// method to print assembly for each instruction.
372 bool Printer::runOnMachineFunction(MachineFunction &MF) {
374 // What's my mangled name?
375 CurrentFnName = Mang->getValueName(MF.getFunction());
377 // Print out constants referenced by the function
378 printConstantPool(MF.getConstantPool());
380 // Print out labels for the function.
382 O << "\t.globl\t" << CurrentFnName << "\n";
384 O << CurrentFnName << ":\n";
386 // Print out code for the function.
387 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
389 // Print a label for the basic block.
390 O << ".LBB" << CurrentFnName << "_" << I->getNumber() << ":\t; "
391 << I->getBasicBlock()->getName() << "\n";
392 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
394 // Print the assembly for the instruction.
396 printMachineInstruction(II);
401 // We didn't modify anything.
405 void Printer::printOp(const MachineOperand &MO,
406 bool elideOffsetKeyword /* = false */) {
407 const MRegisterInfo &RI = *TM.getRegisterInfo();
410 switch (MO.getType()) {
411 case MachineOperand::MO_VirtualRegister:
412 if (Value *V = MO.getVRegValueOrNull()) {
413 O << "<" << V->getName() << ">";
417 case MachineOperand::MO_MachineRegister:
418 case MachineOperand::MO_CCRegister:
419 O << LowercaseString(RI.get(MO.getReg()).Name);
422 case MachineOperand::MO_SignExtendedImmed:
423 case MachineOperand::MO_UnextendedImmed:
424 std::cerr << "printOp() does not handle immediate values\n";
428 case MachineOperand::MO_PCRelativeDisp:
429 std::cerr << "Shouldn't use addPCDisp() when building PPC MachineInstrs";
433 case MachineOperand::MO_MachineBasicBlock: {
434 MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
435 O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
436 << "_" << MBBOp->getNumber() << "\t; "
437 << MBBOp->getBasicBlock()->getName();
441 case MachineOperand::MO_ConstantPoolIndex:
442 O << ".CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex();
445 case MachineOperand::MO_ExternalSymbol:
446 O << MO.getSymbolName();
449 case MachineOperand::MO_GlobalAddress:
450 if (!elideOffsetKeyword) {
451 GlobalValue *GV = MO.getGlobal();
452 std::string Name = Mang->getValueName(GV);
454 // Dynamically-resolved functions need a stub for the function
455 Function *F = dyn_cast<Function>(GV);
456 if (F && F->isExternal() &&
457 TM.CalledFunctions.find(F) != TM.CalledFunctions.end()) {
458 FnStubs.insert(Name);
459 O << "L" << Name << "$stub";
463 // External global variables need a non-lazily-resolved stub
464 if (!GV->hasInternalLinkage() &&
465 TM.AddressTaken.find(GV) != TM.AddressTaken.end()) {
466 GVStubs.insert(Name);
467 O << "L" << Name << "$non_lazy_ptr";
471 O << Mang->getValueName(GV);
476 O << "<unknown operand type: " << MO.getType() << ">";
481 void Printer::printImmOp(const MachineOperand &MO, unsigned ArgType) {
482 int Imm = MO.getImmedValue();
483 if (ArgType == PPC32II::Simm16 || ArgType == PPC32II::Disimm16) {
485 } else if (ArgType == PPC32II::Zimm16) {
486 O << (unsigned short)Imm;
492 /// printMachineInstruction -- Print out a single PPC32 LLVM instruction
493 /// MI in Darwin syntax to the current output stream.
495 void Printer::printMachineInstruction(const MachineInstr *MI) {
496 unsigned Opcode = MI->getOpcode();
497 const TargetInstrInfo &TII = *TM.getInstrInfo();
498 const TargetInstrDescriptor &Desc = TII.get(Opcode);
501 unsigned ArgCount = MI->getNumOperands();
502 unsigned ArgType[] = {
503 (Desc.TSFlags >> PPC32II::Arg0TypeShift) & PPC32II::ArgTypeMask,
504 (Desc.TSFlags >> PPC32II::Arg1TypeShift) & PPC32II::ArgTypeMask,
505 (Desc.TSFlags >> PPC32II::Arg2TypeShift) & PPC32II::ArgTypeMask,
506 (Desc.TSFlags >> PPC32II::Arg3TypeShift) & PPC32II::ArgTypeMask,
507 (Desc.TSFlags >> PPC32II::Arg4TypeShift) & PPC32II::ArgTypeMask
509 assert(((Desc.TSFlags & PPC32II::VMX) == 0) &&
510 "Instruction requires VMX support");
511 assert(((Desc.TSFlags & PPC32II::PPC64) == 0) &&
512 "Instruction requires 64 bit support");
515 // CALLpcrel and CALLindirect are handled specially here to print only the
516 // appropriate number of args that the assembler expects. This is because
517 // may have many arguments appended to record the uses of registers that are
518 // holding arguments to the called function.
519 if (Opcode == PPC32::COND_BRANCH) {
520 std::cerr << "Error: untranslated conditional branch psuedo instruction!\n";
522 } else if (Opcode == PPC32::IMPLICIT_DEF) {
523 O << "; IMPLICIT DEF ";
524 printOp(MI->getOperand(0));
527 } else if (Opcode == PPC32::CALLpcrel) {
528 O << TII.getName(Opcode) << " ";
529 printOp(MI->getOperand(0));
532 } else if (Opcode == PPC32::CALLindirect) {
533 O << TII.getName(Opcode) << " ";
534 printImmOp(MI->getOperand(0), ArgType[0]);
536 printImmOp(MI->getOperand(1), ArgType[0]);
539 } else if (Opcode == PPC32::MovePCtoLR) {
540 // FIXME: should probably be converted to cout.width and cout.fill
541 O << "bl \"L0000" << LabelNumber << "$pb\"\n";
542 O << "\"L0000" << LabelNumber << "$pb\":\n";
544 printOp(MI->getOperand(0));
549 O << TII.getName(Opcode) << " ";
550 if (Opcode == PPC32::LOADLoDirect || Opcode == PPC32::LOADLoIndirect) {
551 printOp(MI->getOperand(0));
553 printOp(MI->getOperand(2));
554 O << "-\"L0000" << LabelNumber << "$pb\")";
556 if (MI->getOperand(1).getReg() == PPC32::R0)
559 printOp(MI->getOperand(1));
561 } else if (Opcode == PPC32::LOADHiAddr) {
562 printOp(MI->getOperand(0));
564 if (MI->getOperand(1).getReg() == PPC32::R0)
567 printOp(MI->getOperand(1));
569 printOp(MI->getOperand(2));
570 O << "-\"L0000" << LabelNumber << "$pb\")\n";
571 } else if (ArgCount == 3 && ArgType[1] == PPC32II::Disimm16) {
572 printOp(MI->getOperand(0));
574 printImmOp(MI->getOperand(1), ArgType[1]);
576 if (MI->getOperand(2).hasAllocatedReg() &&
577 MI->getOperand(2).getReg() == PPC32::R0)
580 printOp(MI->getOperand(2));
583 for (i = 0; i < ArgCount; ++i) {
585 if (i == 1 && ArgCount == 3 && ArgType[2] == PPC32II::Simm16 &&
586 MI->getOperand(1).hasAllocatedReg() &&
587 MI->getOperand(1).getReg() == PPC32::R0) {
589 // for long branch support, bc $+8
590 } else if (i == 1 && ArgCount == 2 && MI->getOperand(1).isImmediate() &&
591 TII.isBranch(MI->getOpcode())) {
593 assert(8 == MI->getOperand(i).getImmedValue()
594 && "branch off PC not to pc+8?");
595 //printOp(MI->getOperand(i));
596 } else if (MI->getOperand(i).isImmediate()) {
597 printImmOp(MI->getOperand(i), ArgType[i]);
599 printOp(MI->getOperand(i));
601 if (ArgCount - 1 == i)
609 bool Printer::doInitialization(Module &M) {
610 Mang = new Mangler(M, true);
611 return false; // success
614 // SwitchSection - Switch to the specified section of the executable if we are
615 // not already in it!
617 static void SwitchSection(std::ostream &OS, std::string &CurSection,
618 const char *NewSection) {
619 if (CurSection != NewSection) {
620 CurSection = NewSection;
621 if (!CurSection.empty())
622 OS << "\t" << NewSection << "\n";
626 bool Printer::doFinalization(Module &M) {
627 const TargetData &TD = TM.getTargetData();
628 std::string CurSection;
630 // Print out module-level global variables here.
631 for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
632 if (I->hasInitializer()) { // External global require no code
634 std::string name = Mang->getValueName(I);
635 Constant *C = I->getInitializer();
636 unsigned Size = TD.getTypeSize(C->getType());
637 unsigned Align = TD.getTypeAlignment(C->getType());
639 if (C->isNullValue() && /* FIXME: Verify correct */
640 (I->hasInternalLinkage() || I->hasWeakLinkage())) {
641 SwitchSection(O, CurSection, ".data");
642 if (I->hasInternalLinkage())
643 O << ".lcomm " << name << "," << TD.getTypeSize(C->getType())
644 << "," << (unsigned)TD.getTypeAlignment(C->getType());
646 O << ".comm " << name << "," << TD.getTypeSize(C->getType());
648 WriteAsOperand(O, I, true, true, &M);
651 switch (I->getLinkage()) {
652 case GlobalValue::LinkOnceLinkage:
653 O << ".section __TEXT,__textcoal_nt,coalesced,no_toc\n"
654 << ".weak_definition " << name << '\n'
655 << ".private_extern " << name << '\n'
656 << ".section __DATA,__datacoal_nt,coalesced,no_toc\n";
657 LinkOnceStubs.insert(name);
659 case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak.
660 // Nonnull linkonce -> weak
661 O << "\t.weak " << name << "\n";
662 SwitchSection(O, CurSection, "");
663 O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
665 case GlobalValue::AppendingLinkage:
666 // FIXME: appending linkage variables should go into a section of
667 // their name or something. For now, just emit them as external.
668 case GlobalValue::ExternalLinkage:
669 // If external or appending, declare as a global symbol
670 O << "\t.globl " << name << "\n";
672 case GlobalValue::InternalLinkage:
673 SwitchSection(O, CurSection, ".data");
677 O << "\t.align " << Align << "\n";
678 O << name << ":\t\t\t\t; ";
679 WriteAsOperand(O, I, true, true, &M);
681 WriteAsOperand(O, C, false, false, &M);
683 emitGlobalConstant(C);
687 // Output stubs for link-once variables
688 if (LinkOnceStubs.begin() != LinkOnceStubs.end())
689 O << ".data\n.align 2\n";
690 for (std::set<std::string>::iterator i = LinkOnceStubs.begin(),
691 e = LinkOnceStubs.end(); i != e; ++i) {
692 O << *i << "$non_lazy_ptr:\n"
693 << "\t.long\t" << *i << '\n';
696 // Output stubs for dynamically-linked functions
697 for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
701 O << ".section __TEXT,__picsymbolstub1,symbol_stubs,pure_instructions,32\n";
703 O << "L" << *i << "$stub:\n";
704 O << "\t.indirect_symbol " << *i << "\n";
706 O << "\tbcl 20,31,L0$" << *i << "\n";
707 O << "L0$" << *i << ":\n";
709 O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
711 O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
712 O << "\tmtctr r12\n";
715 O << ".lazy_symbol_pointer\n";
716 O << "L" << *i << "$lazy_ptr:\n";
717 O << "\t.indirect_symbol " << *i << "\n";
718 O << "\t.long dyld_stub_binding_helper\n";
723 // Output stubs for external global variables
724 if (GVStubs.begin() != GVStubs.end())
725 O << ".data\n.non_lazy_symbol_pointer\n";
726 for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
728 O << "L" << *i << "$non_lazy_ptr:\n";
729 O << "\t.indirect_symbol " << *i << "\n";
734 return false; // success
737 } // End llvm namespace