1 //===-- PowerPCAsmPrinter.cpp - Print machine instrs 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'.
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 /// createPPCAsmPrinterPass - 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 or not.
93 FunctionPass *createPPCAsmPrinterPass(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 for (unsigned i=0, e = CVA->getNumOperands(); i != e; i++)
235 emitGlobalConstant(CVA->getOperand(i));
238 } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
239 // Print the fields in successive locations. Pad to align if needed!
240 const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
241 unsigned sizeSoFar = 0;
242 for (unsigned i = 0, e = CVS->getNumOperands(); i != e; i++) {
243 const Constant* field = CVS->getOperand(i);
245 // Check if padding is needed and insert one or more 0s.
246 unsigned fieldSize = TD.getTypeSize(field->getType());
247 unsigned padSize = ((i == e-1? cvsLayout->StructSize
248 : cvsLayout->MemberOffsets[i+1])
249 - cvsLayout->MemberOffsets[i]) - fieldSize;
250 sizeSoFar += fieldSize + padSize;
252 // Now print the actual field value
253 emitGlobalConstant(field);
255 // Insert the field padding unless it's zero bytes...
257 O << "\t.space\t " << padSize << "\n";
259 assert(sizeSoFar == cvsLayout->StructSize &&
260 "Layout of constant struct may be incorrect!");
262 } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
263 // FP Constants are printed as integer constants to avoid losing
265 double Val = CFP->getValue();
266 switch (CFP->getType()->getTypeID()) {
267 default: assert(0 && "Unknown floating point type!");
268 case Type::FloatTyID: {
269 union FU { // Abide by C TBAA rules
274 O << ".long\t" << U.UVal << "\t; float " << Val << "\n";
277 case Type::DoubleTyID: {
278 union DU { // Abide by C TBAA rules
288 O << ".long\t" << U.T.MSWord << "\t; double most significant word "
290 O << ".long\t" << U.T.LSWord << "\t; double least significant word "
295 } else if (CV->getType() == Type::ULongTy || CV->getType() == Type::LongTy) {
296 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
297 union DU { // Abide by C TBAA rules
304 U.UVal = CI->getRawValue();
306 O << ".long\t" << U.T.MSWord << "\t; Double-word most significant word "
308 O << ".long\t" << U.T.LSWord << "\t; Double-word least significant word "
314 const Type *type = CV->getType();
316 switch (type->getTypeID()) {
317 case Type::UByteTyID: case Type::SByteTyID:
320 case Type::UShortTyID: case Type::ShortTyID:
324 case Type::PointerTyID:
325 case Type::UIntTyID: case Type::IntTyID:
328 case Type::ULongTyID: case Type::LongTyID:
329 assert (0 && "Should have already output double-word constant.");
330 case Type::FloatTyID: case Type::DoubleTyID:
331 assert (0 && "Should have already output floating point constant.");
333 if (CV == Constant::getNullValue(type)) { // Zero initializer?
334 O << ".space\t" << TD.getTypeSize(type) << "\n";
337 std::cerr << "Can't handle printing: " << *CV;
342 emitConstantValueOnly(CV);
346 /// printConstantPool - Print to the current output stream assembly
347 /// representations of the constants in the constant pool MCP. This is
348 /// used to print out constants which have been "spilled to memory" by
349 /// the code generator.
351 void Printer::printConstantPool(MachineConstantPool *MCP) {
352 const std::vector<Constant*> &CP = MCP->getConstants();
353 const TargetData &TD = TM.getTargetData();
355 if (CP.empty()) return;
357 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
359 O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType())
361 O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t;"
363 emitGlobalConstant(CP[i]);
367 /// runOnMachineFunction - This uses the printMachineInstruction()
368 /// method to print assembly for each instruction.
370 bool Printer::runOnMachineFunction(MachineFunction &MF) {
372 // What's my mangled name?
373 CurrentFnName = Mang->getValueName(MF.getFunction());
375 // Print out constants referenced by the function
376 printConstantPool(MF.getConstantPool());
378 // Print out labels for the function.
380 O << "\t.globl\t" << CurrentFnName << "\n";
382 O << CurrentFnName << ":\n";
384 // Print out code for the function.
385 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
387 // Print a label for the basic block.
388 O << ".LBB" << CurrentFnName << "_" << I->getNumber() << ":\t; "
389 << I->getBasicBlock()->getName() << "\n";
390 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
392 // Print the assembly for the instruction.
394 printMachineInstruction(II);
399 // We didn't modify anything.
403 void Printer::printOp(const MachineOperand &MO,
404 bool elideOffsetKeyword /* = false */) {
405 const MRegisterInfo &RI = *TM.getRegisterInfo();
408 switch (MO.getType()) {
409 case MachineOperand::MO_VirtualRegister:
410 if (Value *V = MO.getVRegValueOrNull()) {
411 O << "<" << V->getName() << ">";
415 case MachineOperand::MO_MachineRegister:
416 case MachineOperand::MO_CCRegister:
417 O << LowercaseString(RI.get(MO.getReg()).Name);
420 case MachineOperand::MO_SignExtendedImmed:
421 case MachineOperand::MO_UnextendedImmed:
422 std::cerr << "printOp() does not handle immediate values\n";
426 case MachineOperand::MO_PCRelativeDisp:
427 std::cerr << "Shouldn't use addPCDisp() when building PPC MachineInstrs";
431 case MachineOperand::MO_MachineBasicBlock: {
432 MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
433 O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
434 << "_" << MBBOp->getNumber() << "\t; "
435 << MBBOp->getBasicBlock()->getName();
439 case MachineOperand::MO_ConstantPoolIndex:
440 O << ".CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex();
443 case MachineOperand::MO_ExternalSymbol:
444 O << MO.getSymbolName();
447 case MachineOperand::MO_GlobalAddress:
448 if (!elideOffsetKeyword) {
449 GlobalValue *GV = MO.getGlobal();
450 std::string Name = Mang->getValueName(GV);
452 // Dynamically-resolved functions need a stub for the function
453 Function *F = dyn_cast<Function>(GV);
454 if (F && F->isExternal() &&
455 TM.CalledFunctions.find(F) != TM.CalledFunctions.end()) {
456 FnStubs.insert(Name);
457 O << "L" << Name << "$stub";
461 // External global variables need a non-lazily-resolved stub
462 if (!GV->hasInternalLinkage() &&
463 TM.AddressTaken.find(GV) != TM.AddressTaken.end()) {
464 GVStubs.insert(Name);
465 O << "L" << Name << "$non_lazy_ptr";
469 O << Mang->getValueName(GV);
474 O << "<unknown operand type: " << MO.getType() << ">";
479 void Printer::printImmOp(const MachineOperand &MO, unsigned ArgType) {
480 int Imm = MO.getImmedValue();
481 if (ArgType == PPCII::Simm16 || ArgType == PPCII::Disimm16) {
483 } else if (ArgType == PPCII::Zimm16) {
484 O << (unsigned short)Imm;
490 /// printMachineInstruction -- Print out a single PPC LLVM instruction
491 /// MI in Darwin syntax to the current output stream.
493 void Printer::printMachineInstruction(const MachineInstr *MI) {
494 unsigned Opcode = MI->getOpcode();
495 const TargetInstrInfo &TII = *TM.getInstrInfo();
496 const TargetInstrDescriptor &Desc = TII.get(Opcode);
499 unsigned ArgCount = MI->getNumOperands();
500 unsigned ArgType[] = {
501 (Desc.TSFlags >> PPCII::Arg0TypeShift) & PPCII::ArgTypeMask,
502 (Desc.TSFlags >> PPCII::Arg1TypeShift) & PPCII::ArgTypeMask,
503 (Desc.TSFlags >> PPCII::Arg2TypeShift) & PPCII::ArgTypeMask,
504 (Desc.TSFlags >> PPCII::Arg3TypeShift) & PPCII::ArgTypeMask,
505 (Desc.TSFlags >> PPCII::Arg4TypeShift) & PPCII::ArgTypeMask
507 assert(((Desc.TSFlags & PPCII::VMX) == 0) &&
508 "Instruction requires VMX support");
509 assert(((Desc.TSFlags & PPCII::PPC64) == 0) &&
510 "Instruction requires 64 bit support");
513 // CALLpcrel and CALLindirect are handled specially here to print only the
514 // appropriate number of args that the assembler expects. This is because
515 // may have many arguments appended to record the uses of registers that are
516 // holding arguments to the called function.
517 if (Opcode == PPC::COND_BRANCH) {
518 std::cerr << "Error: untranslated conditional branch psuedo instruction!\n";
520 } else if (Opcode == PPC::IMPLICIT_DEF) {
521 O << "; IMPLICIT DEF ";
522 printOp(MI->getOperand(0));
525 } else if (Opcode == PPC::CALLpcrel) {
526 O << TII.getName(Opcode) << " ";
527 printOp(MI->getOperand(0));
530 } else if (Opcode == PPC::CALLindirect) {
531 O << TII.getName(Opcode) << " ";
532 printImmOp(MI->getOperand(0), ArgType[0]);
534 printImmOp(MI->getOperand(1), ArgType[0]);
537 } else if (Opcode == PPC::MovePCtoLR) {
538 // FIXME: should probably be converted to cout.width and cout.fill
539 O << "bl \"L0000" << LabelNumber << "$pb\"\n";
540 O << "\"L0000" << LabelNumber << "$pb\":\n";
542 printOp(MI->getOperand(0));
547 O << TII.getName(Opcode) << " ";
548 if (Opcode == PPC::LOADLoDirect || Opcode == PPC::LOADLoIndirect) {
549 printOp(MI->getOperand(0));
551 printOp(MI->getOperand(2));
552 O << "-\"L0000" << LabelNumber << "$pb\")";
554 if (MI->getOperand(1).getReg() == PPC::R0)
557 printOp(MI->getOperand(1));
559 } else if (Opcode == PPC::LOADHiAddr) {
560 printOp(MI->getOperand(0));
562 if (MI->getOperand(1).getReg() == PPC::R0)
565 printOp(MI->getOperand(1));
567 printOp(MI->getOperand(2));
568 O << "-\"L0000" << LabelNumber << "$pb\")\n";
569 } else if (ArgCount == 3 && ArgType[1] == PPCII::Disimm16) {
570 printOp(MI->getOperand(0));
572 printImmOp(MI->getOperand(1), ArgType[1]);
574 if (MI->getOperand(2).hasAllocatedReg() &&
575 MI->getOperand(2).getReg() == PPC::R0)
578 printOp(MI->getOperand(2));
581 for (i = 0; i < ArgCount; ++i) {
583 if (i == 1 && ArgCount == 3 && ArgType[2] == PPCII::Simm16 &&
584 MI->getOperand(1).hasAllocatedReg() &&
585 MI->getOperand(1).getReg() == PPC::R0) {
587 // for long branch support, bc $+8
588 } else if (i == 1 && ArgCount == 2 && MI->getOperand(1).isImmediate() &&
589 TII.isBranch(MI->getOpcode())) {
591 assert(8 == MI->getOperand(i).getImmedValue()
592 && "branch off PC not to pc+8?");
593 //printOp(MI->getOperand(i));
594 } else if (MI->getOperand(i).isImmediate()) {
595 printImmOp(MI->getOperand(i), ArgType[i]);
597 printOp(MI->getOperand(i));
599 if (ArgCount - 1 == i)
607 bool Printer::doInitialization(Module &M) {
608 Mang = new Mangler(M, true);
609 return false; // success
612 // SwitchSection - Switch to the specified section of the executable if we are
613 // not already in it!
615 static void SwitchSection(std::ostream &OS, std::string &CurSection,
616 const char *NewSection) {
617 if (CurSection != NewSection) {
618 CurSection = NewSection;
619 if (!CurSection.empty())
620 OS << "\t" << NewSection << "\n";
624 bool Printer::doFinalization(Module &M) {
625 const TargetData &TD = TM.getTargetData();
626 std::string CurSection;
628 // Print out module-level global variables here.
629 for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
630 if (I->hasInitializer()) { // External global require no code
632 std::string name = Mang->getValueName(I);
633 Constant *C = I->getInitializer();
634 unsigned Size = TD.getTypeSize(C->getType());
635 unsigned Align = TD.getTypeAlignment(C->getType());
637 if (C->isNullValue() && /* FIXME: Verify correct */
638 (I->hasInternalLinkage() || I->hasWeakLinkage())) {
639 SwitchSection(O, CurSection, ".data");
640 if (I->hasInternalLinkage())
641 O << ".lcomm " << name << "," << TD.getTypeSize(C->getType())
642 << "," << (unsigned)TD.getTypeAlignment(C->getType());
644 O << ".comm " << name << "," << TD.getTypeSize(C->getType());
646 WriteAsOperand(O, I, true, true, &M);
649 switch (I->getLinkage()) {
650 case GlobalValue::LinkOnceLinkage:
651 O << ".section __TEXT,__textcoal_nt,coalesced,no_toc\n"
652 << ".weak_definition " << name << '\n'
653 << ".private_extern " << name << '\n'
654 << ".section __DATA,__datacoal_nt,coalesced,no_toc\n";
655 LinkOnceStubs.insert(name);
657 case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak.
658 // Nonnull linkonce -> weak
659 O << "\t.weak " << name << "\n";
660 SwitchSection(O, CurSection, "");
661 O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
663 case GlobalValue::AppendingLinkage:
664 // FIXME: appending linkage variables should go into a section of
665 // their name or something. For now, just emit them as external.
666 case GlobalValue::ExternalLinkage:
667 // If external or appending, declare as a global symbol
668 O << "\t.globl " << name << "\n";
670 case GlobalValue::InternalLinkage:
671 SwitchSection(O, CurSection, ".data");
675 O << "\t.align " << Align << "\n";
676 O << name << ":\t\t\t\t; ";
677 WriteAsOperand(O, I, true, true, &M);
679 WriteAsOperand(O, C, false, false, &M);
681 emitGlobalConstant(C);
685 // Output stubs for link-once variables
686 if (LinkOnceStubs.begin() != LinkOnceStubs.end())
687 O << ".data\n.align 2\n";
688 for (std::set<std::string>::iterator i = LinkOnceStubs.begin(),
689 e = LinkOnceStubs.end(); i != e; ++i) {
690 O << *i << "$non_lazy_ptr:\n"
691 << "\t.long\t" << *i << '\n';
694 // Output stubs for dynamically-linked functions
695 for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
699 O << ".section __TEXT,__picsymbolstub1,symbol_stubs,pure_instructions,32\n";
701 O << "L" << *i << "$stub:\n";
702 O << "\t.indirect_symbol " << *i << "\n";
704 O << "\tbcl 20,31,L0$" << *i << "\n";
705 O << "L0$" << *i << ":\n";
707 O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
709 O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
710 O << "\tmtctr r12\n";
713 O << ".lazy_symbol_pointer\n";
714 O << "L" << *i << "$lazy_ptr:\n";
715 O << "\t.indirect_symbol " << *i << "\n";
716 O << "\t.long dyld_stub_binding_helper\n";
721 // Output stubs for external global variables
722 if (GVStubs.begin() != GVStubs.end())
723 O << ".data\n.non_lazy_symbol_pointer\n";
724 for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
726 O << "L" << *i << "$non_lazy_ptr:\n";
727 O << "\t.indirect_symbol " << *i << "\n";
732 return false; // success
735 } // End llvm namespace