1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
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 implements the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/DerivedTypes.h"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "llvm/Constants.h"
17 #include "llvm/Module.h"
18 #include "llvm/CodeGen/MachineConstantPool.h"
19 #include "llvm/Support/Mangler.h"
20 #include "llvm/Support/MathExtras.h"
21 #include "llvm/Target/TargetMachine.h"
26 AsmPrinter::AsmPrinter(std::ostream &o, TargetMachine &tm)
27 : FunctionNumber(0), O(o), TM(tm),
30 PrivateGlobalPrefix("."),
31 GlobalVarAddrPrefix(""),
32 GlobalVarAddrSuffix(""),
33 FunctionAddrPrefix(""),
34 FunctionAddrSuffix(""),
35 ZeroDirective("\t.zero\t"),
36 AsciiDirective("\t.ascii\t"),
37 AscizDirective("\t.asciz\t"),
38 Data8bitsDirective("\t.byte\t"),
39 Data16bitsDirective("\t.short\t"),
40 Data32bitsDirective("\t.long\t"),
41 Data64bitsDirective("\t.quad\t"),
42 AlignDirective("\t.align\t"),
43 AlignmentIsInBytes(true),
44 SwitchToSectionDirective("\t.section\t"),
45 ConstantPoolSection("\t.section .rodata\n"),
46 StaticCtorsSection("\t.section .ctors,\"aw\",@progbits"),
47 StaticDtorsSection("\t.section .dtors,\"aw\",@progbits"),
49 COMMDirective("\t.comm\t"),
50 COMMDirectiveTakesAlignment(true),
51 HasDotTypeDotSizeDirective(true) {
55 /// SwitchSection - Switch to the specified section of the executable if we
56 /// are not already in it!
58 void AsmPrinter::SwitchSection(const char *NewSection, const GlobalValue *GV) {
61 if (GV && GV->hasSection())
62 NS = SwitchToSectionDirective + GV->getSection();
64 NS = std::string("\t")+NewSection;
66 if (CurrentSection != NS) {
68 if (!CurrentSection.empty())
69 O << CurrentSection << '\n';
73 bool AsmPrinter::doInitialization(Module &M) {
74 Mang = new Mangler(M, GlobalPrefix);
76 if (!M.getModuleInlineAsm().empty())
77 O << CommentString << " Start of file scope inline assembly\n"
78 << M.getModuleInlineAsm()
79 << "\n" << CommentString << " End of file scope inline assembly\n";
81 SwitchSection("", 0); // Reset back to no section.
83 if (MachineDebugInfo *DebugInfo = getAnalysisToUpdate<MachineDebugInfo>()) {
84 DebugInfo->AnalyzeModule(M);
90 bool AsmPrinter::doFinalization(Module &M) {
91 delete Mang; Mang = 0;
95 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
96 // What's my mangled name?
97 CurrentFnName = Mang->getValueName(MF.getFunction());
98 IncrementFunctionNumber();
101 /// EmitConstantPool - Print to the current output stream assembly
102 /// representations of the constants in the constant pool MCP. This is
103 /// used to print out constants which have been "spilled to memory" by
104 /// the code generator.
106 void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) {
107 const std::vector<std::pair<Constant*, unsigned> > &CP = MCP->getConstants();
108 if (CP.empty()) return;
109 const TargetData &TD = TM.getTargetData();
111 SwitchSection(ConstantPoolSection, 0);
112 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
113 // FIXME: force doubles to be naturally aligned. We should handle this
114 // more correctly in the future.
115 unsigned Alignment = CP[i].second;
116 if (Alignment == 0) {
117 Alignment = TD.getTypeAlignmentShift(CP[i].first->getType());
118 if (CP[i].first->getType() == Type::DoubleTy && Alignment < 3)
122 EmitAlignment(Alignment);
123 O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << '_' << i
124 << ":\t\t\t\t\t" << CommentString << *CP[i].first << '\n';
125 EmitGlobalConstant(CP[i].first);
129 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
130 /// special global used by LLVM. If so, emit it and return true, otherwise
131 /// do nothing and return false.
132 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
133 assert(GV->hasInitializer() && GV->hasAppendingLinkage() &&
134 "Not a special LLVM global!");
136 if (GV->getName() == "llvm.used")
137 return true; // No need to emit this at all.
139 if (GV->getName() == "llvm.global_ctors" && GV->use_empty()) {
140 SwitchSection(StaticCtorsSection, 0);
142 EmitXXStructorList(GV->getInitializer());
146 if (GV->getName() == "llvm.global_dtors" && GV->use_empty()) {
147 SwitchSection(StaticDtorsSection, 0);
149 EmitXXStructorList(GV->getInitializer());
156 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
157 /// function pointers, ignoring the init priority.
158 void AsmPrinter::EmitXXStructorList(Constant *List) {
159 // Should be an array of '{ int, void ()* }' structs. The first value is the
160 // init priority, which we ignore.
161 if (!isa<ConstantArray>(List)) return;
162 ConstantArray *InitList = cast<ConstantArray>(List);
163 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
164 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
165 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
167 if (CS->getOperand(1)->isNullValue())
168 return; // Found a null terminator, exit printing.
169 // Emit the function pointer.
170 EmitGlobalConstant(CS->getOperand(1));
175 // EmitAlignment - Emit an alignment directive to the specified power of two.
176 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
177 if (GV && GV->getAlignment())
178 NumBits = Log2_32(GV->getAlignment());
179 if (NumBits == 0) return; // No need to emit alignment.
180 if (AlignmentIsInBytes) NumBits = 1 << NumBits;
181 O << AlignDirective << NumBits << "\n";
184 /// EmitZeros - Emit a block of zeros.
186 void AsmPrinter::EmitZeros(uint64_t NumZeros) const {
189 O << ZeroDirective << NumZeros << "\n";
191 for (; NumZeros; --NumZeros)
192 O << Data8bitsDirective << "0\n";
197 // Print out the specified constant, without a storage class. Only the
198 // constants valid in constant expressions can occur here.
199 void AsmPrinter::EmitConstantValueOnly(const Constant *CV) {
200 if (CV->isNullValue() || isa<UndefValue>(CV))
202 else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
203 assert(CB == ConstantBool::True);
205 } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
206 if (((CI->getValue() << 32) >> 32) == CI->getValue())
209 O << (uint64_t)CI->getValue();
210 else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
212 else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) {
213 // This is a constant address for a global variable or function. Use the
214 // name of the variable or function as the address value, possibly
215 // decorating it with GlobalVarAddrPrefix/Suffix or
216 // FunctionAddrPrefix/Suffix (these all default to "" )
217 if (isa<Function>(GV))
218 O << FunctionAddrPrefix << Mang->getValueName(GV) << FunctionAddrSuffix;
220 O << GlobalVarAddrPrefix << Mang->getValueName(GV) << GlobalVarAddrSuffix;
221 } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
222 const TargetData &TD = TM.getTargetData();
223 switch(CE->getOpcode()) {
224 case Instruction::GetElementPtr: {
225 // generate a symbolic expression for the byte address
226 const Constant *ptrVal = CE->getOperand(0);
227 std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
228 if (int64_t Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
231 EmitConstantValueOnly(ptrVal);
233 O << ") + " << Offset;
235 O << ") - " << -Offset;
237 EmitConstantValueOnly(ptrVal);
241 case Instruction::Cast: {
242 // Support only non-converting or widening casts for now, that is, ones
243 // that do not involve a change in value. This assertion is really gross,
244 // and may not even be a complete check.
245 Constant *Op = CE->getOperand(0);
246 const Type *OpTy = Op->getType(), *Ty = CE->getType();
248 // Remember, kids, pointers can be losslessly converted back and forth
249 // into 32-bit or wider integers, regardless of signedness. :-P
250 assert(((isa<PointerType>(OpTy)
251 && (Ty == Type::LongTy || Ty == Type::ULongTy
252 || Ty == Type::IntTy || Ty == Type::UIntTy))
253 || (isa<PointerType>(Ty)
254 && (OpTy == Type::LongTy || OpTy == Type::ULongTy
255 || OpTy == Type::IntTy || OpTy == Type::UIntTy))
256 || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
257 && OpTy->isLosslesslyConvertibleTo(Ty))))
258 && "FIXME: Don't yet support this kind of constant cast expr");
259 EmitConstantValueOnly(Op);
262 case Instruction::Add:
264 EmitConstantValueOnly(CE->getOperand(0));
266 EmitConstantValueOnly(CE->getOperand(1));
270 assert(0 && "Unsupported operator!");
273 assert(0 && "Unknown constant value!");
277 /// toOctal - Convert the low order bits of X into an octal digit.
279 static inline char toOctal(int X) {
283 /// printAsCString - Print the specified array as a C compatible string, only if
284 /// the predicate isString is true.
286 static void printAsCString(std::ostream &O, const ConstantArray *CVA,
288 assert(CVA->isString() && "Array is not string compatible!");
291 for (unsigned i = 0; i != LastElt; ++i) {
293 (unsigned char)cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
297 } else if (C == '\\') {
299 } else if (isprint(C)) {
303 case '\b': O << "\\b"; break;
304 case '\f': O << "\\f"; break;
305 case '\n': O << "\\n"; break;
306 case '\r': O << "\\r"; break;
307 case '\t': O << "\\t"; break;
310 O << toOctal(C >> 6);
311 O << toOctal(C >> 3);
312 O << toOctal(C >> 0);
320 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
322 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
323 const TargetData &TD = TM.getTargetData();
325 if (CV->isNullValue() || isa<UndefValue>(CV)) {
326 EmitZeros(TD.getTypeSize(CV->getType()));
328 } else if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
329 if (CVA->isString()) {
330 unsigned NumElts = CVA->getNumOperands();
331 if (AscizDirective && NumElts &&
332 cast<ConstantInt>(CVA->getOperand(NumElts-1))->getRawValue() == 0) {
334 printAsCString(O, CVA, NumElts-1);
337 printAsCString(O, CVA, NumElts);
340 } else { // Not a string. Print the values in successive locations
341 for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i)
342 EmitGlobalConstant(CVA->getOperand(i));
345 } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
346 // Print the fields in successive locations. Pad to align if needed!
347 const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
348 uint64_t sizeSoFar = 0;
349 for (unsigned i = 0, e = CVS->getNumOperands(); i != e; ++i) {
350 const Constant* field = CVS->getOperand(i);
352 // Check if padding is needed and insert one or more 0s.
353 uint64_t fieldSize = TD.getTypeSize(field->getType());
354 uint64_t padSize = ((i == e-1? cvsLayout->StructSize
355 : cvsLayout->MemberOffsets[i+1])
356 - cvsLayout->MemberOffsets[i]) - fieldSize;
357 sizeSoFar += fieldSize + padSize;
359 // Now print the actual field value
360 EmitGlobalConstant(field);
362 // Insert the field padding unless it's zero bytes...
365 assert(sizeSoFar == cvsLayout->StructSize &&
366 "Layout of constant struct may be incorrect!");
368 } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
369 // FP Constants are printed as integer constants to avoid losing
371 double Val = CFP->getValue();
372 if (CFP->getType() == Type::DoubleTy) {
373 if (Data64bitsDirective)
374 O << Data64bitsDirective << DoubleToBits(Val) << "\t" << CommentString
375 << " double value: " << Val << "\n";
376 else if (TD.isBigEndian()) {
377 O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
378 << "\t" << CommentString << " double most significant word "
380 O << Data32bitsDirective << unsigned(DoubleToBits(Val))
381 << "\t" << CommentString << " double least significant word "
384 O << Data32bitsDirective << unsigned(DoubleToBits(Val))
385 << "\t" << CommentString << " double least significant word " << Val
387 O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
388 << "\t" << CommentString << " double most significant word " << Val
393 O << Data32bitsDirective << FloatToBits(Val) << "\t" << CommentString
394 << " float " << Val << "\n";
397 } else if (CV->getType() == Type::ULongTy || CV->getType() == Type::LongTy) {
398 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
399 uint64_t Val = CI->getRawValue();
401 if (Data64bitsDirective)
402 O << Data64bitsDirective << Val << "\n";
403 else if (TD.isBigEndian()) {
404 O << Data32bitsDirective << unsigned(Val >> 32)
405 << "\t" << CommentString << " Double-word most significant word "
407 O << Data32bitsDirective << unsigned(Val)
408 << "\t" << CommentString << " Double-word least significant word "
411 O << Data32bitsDirective << unsigned(Val)
412 << "\t" << CommentString << " Double-word least significant word "
414 O << Data32bitsDirective << unsigned(Val >> 32)
415 << "\t" << CommentString << " Double-word most significant word "
420 } else if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(CV)) {
421 const PackedType *PTy = CP->getType();
423 for (unsigned I = 0, E = PTy->getNumElements(); I < E; ++I)
424 EmitGlobalConstant(CP->getOperand(I));
429 const Type *type = CV->getType();
430 switch (type->getTypeID()) {
432 case Type::UByteTyID: case Type::SByteTyID:
433 O << Data8bitsDirective;
435 case Type::UShortTyID: case Type::ShortTyID:
436 O << Data16bitsDirective;
438 case Type::PointerTyID:
439 if (TD.getPointerSize() == 8) {
440 O << Data64bitsDirective;
443 //Fall through for pointer size == int size
444 case Type::UIntTyID: case Type::IntTyID:
445 O << Data32bitsDirective;
447 case Type::ULongTyID: case Type::LongTyID:
448 assert(Data64bitsDirective &&"Target cannot handle 64-bit constant exprs!");
449 O << Data64bitsDirective;
451 case Type::FloatTyID: case Type::DoubleTyID:
452 assert (0 && "Should have already output floating point constant.");
454 assert (0 && "Can't handle printing this type of thing");
457 EmitConstantValueOnly(CV);
461 /// printInlineAsm - This method formats and prints the specified machine
462 /// instruction that is an inline asm.
463 void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
464 unsigned NumOperands = MI->getNumOperands();
466 // Count the number of register definitions.
467 unsigned NumDefs = 0;
468 for (; MI->getOperand(NumDefs).isDef(); ++NumDefs)
469 assert(NumDefs != NumOperands-1 && "No asm string?");
471 assert(MI->getOperand(NumDefs).isExternalSymbol() && "No asm string?");
473 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
474 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
476 // The variant of the current asmprinter: FIXME: change.
477 int AsmPrinterVariant = 0;
479 int CurVariant = -1; // The number of the {.|.|.} region we are in.
480 const char *LastEmitted = AsmStr; // One past the last character emitted.
482 while (*LastEmitted) {
483 switch (*LastEmitted) {
485 // Not a special case, emit the string section literally.
486 const char *LiteralEnd = LastEmitted+1;
487 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
488 *LiteralEnd != '}' && *LiteralEnd != '$')
490 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
491 O.write(LastEmitted, LiteralEnd-LastEmitted);
492 LastEmitted = LiteralEnd;
496 ++LastEmitted; // Consume '$' character.
497 if (*LastEmitted == '$') { // $$ -> $
498 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
500 ++LastEmitted; // Consume second '$' character.
504 bool HasCurlyBraces = false;
505 if (*LastEmitted == '{') { // ${variable}
506 ++LastEmitted; // Consume '{' character.
507 HasCurlyBraces = true;
510 const char *IDStart = LastEmitted;
512 long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
513 if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
514 std::cerr << "Bad $ operand number in inline asm string: '"
520 if (HasCurlyBraces) {
521 if (*LastEmitted != '}') {
522 std::cerr << "Bad ${} expression in inline asm string: '"
526 ++LastEmitted; // Consume '}' character.
529 if ((unsigned)Val >= NumOperands-1) {
530 std::cerr << "Invalid $ operand number in inline asm string: '"
535 // Okay, we finally have an operand number. Ask the target to print this
537 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
538 if (const_cast<AsmPrinter*>(this)->
539 PrintAsmOperand(MI, Val+1, AsmPrinterVariant)) {
540 std::cerr << "Invalid operand found in inline asm: '"
548 ++LastEmitted; // Consume '{' character.
549 if (CurVariant != -1) {
550 std::cerr << "Nested variants found in inline asm string: '"
554 CurVariant = 0; // We're in the first variant now.
557 ++LastEmitted; // consume '|' character.
558 if (CurVariant == -1) {
559 std::cerr << "Found '|' character outside of variant in inline asm "
560 << "string: '" << AsmStr << "'\n";
563 ++CurVariant; // We're in the next variant.
566 ++LastEmitted; // consume '}' character.
567 if (CurVariant == -1) {
568 std::cerr << "Found '}' character outside of variant in inline asm "
569 << "string: '" << AsmStr << "'\n";
579 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
580 /// instruction, using the specified assembler variant. Targets should
581 /// overried this to format as appropriate.
582 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
583 unsigned AsmVariant) {
584 // Target doesn't support this yet!