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/CodeGen/AsmPrinter.h"
15 #include "llvm/Constants.h"
16 #include "llvm/Instruction.h"
17 #include "llvm/Support/Mangler.h"
18 #include "llvm/Target/TargetMachine.h"
21 bool AsmPrinter::doInitialization(Module &M) {
22 Mang = new Mangler(M, GlobalPrefix);
26 bool AsmPrinter::doFinalization(Module &M) {
27 delete Mang; Mang = 0;
31 void AsmPrinter::setupMachineFunction(MachineFunction &MF) {
32 // What's my mangled name?
33 CurrentFnName = Mang->getValueName((Value*)MF.getFunction());
36 // emitAlignment - Emit an alignment directive to the specified power of two.
37 void AsmPrinter::emitAlignment(unsigned NumBits) const {
38 if (AlignmentIsInBytes) NumBits = 1 << NumBits;
39 O << AlignDirective << NumBits << "\n";
42 /// emitZeros - Emit a block of zeros.
44 void AsmPrinter::emitZeros(unsigned NumZeros) const {
47 O << ZeroDirective << NumZeros << "\n";
49 if (NumZeros >= 8 && Data64bitsDirective) {
50 for (; NumZeros >= 8; NumZeros -= 8)
51 O << Data64bitsDirective << "0\n";
53 for (; NumZeros >= 4; NumZeros -= 4)
54 O << Data32bitsDirective << "0\n";
55 for (; NumZeros; --NumZeros)
56 O << Data8bitsDirective << "0\n";
61 // Print out the specified constant, without a storage class. Only the
62 // constants valid in constant expressions can occur here.
63 void AsmPrinter::emitConstantValueOnly(const Constant *CV) {
64 if (CV->isNullValue())
66 else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
67 assert(CB == ConstantBool::True);
69 } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
70 if (((CI->getValue() << 32) >> 32) == CI->getValue())
73 O << (unsigned long long)CI->getValue();
74 else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
76 else if (isa<GlobalValue>((Value*)CV))
77 // This is a constant address for a global variable or function. Use the
78 // name of the variable or function as the address value.
79 O << Mang->getValueName(CV);
80 else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
81 const TargetData &TD = TM.getTargetData();
82 switch(CE->getOpcode()) {
83 case Instruction::GetElementPtr: {
84 // generate a symbolic expression for the byte address
85 const Constant *ptrVal = CE->getOperand(0);
86 std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
87 if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
89 emitConstantValueOnly(ptrVal);
90 O << ") + " << Offset;
92 emitConstantValueOnly(ptrVal);
96 case Instruction::Cast: {
97 // Support only non-converting or widening casts for now, that is, ones
98 // that do not involve a change in value. This assertion is really gross,
99 // and may not even be a complete check.
100 Constant *Op = CE->getOperand(0);
101 const Type *OpTy = Op->getType(), *Ty = CE->getType();
103 // Remember, kids, pointers can be losslessly converted back and forth
104 // into 32-bit or wider integers, regardless of signedness. :-P
105 assert(((isa<PointerType>(OpTy)
106 && (Ty == Type::LongTy || Ty == Type::ULongTy
107 || Ty == Type::IntTy || Ty == Type::UIntTy))
108 || (isa<PointerType>(Ty)
109 && (OpTy == Type::LongTy || OpTy == Type::ULongTy
110 || OpTy == Type::IntTy || OpTy == Type::UIntTy))
111 || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
112 && OpTy->isLosslesslyConvertibleTo(Ty))))
113 && "FIXME: Don't yet support this kind of constant cast expr");
115 emitConstantValueOnly(Op);
119 case Instruction::Add:
121 emitConstantValueOnly(CE->getOperand(0));
123 emitConstantValueOnly(CE->getOperand(1));
127 assert(0 && "Unsupported operator!");
130 assert(0 && "Unknown constant value!");
134 /// toOctal - Convert the low order bits of X into an octal digit.
136 static inline char toOctal(int X) {
140 /// getAsCString - Return the specified array as a C compatible string, only if
141 /// the predicate isString is true.
143 static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
144 assert(CVA->isString() && "Array is not string compatible!");
147 for (unsigned i = 0; i != CVA->getNumOperands(); ++i) {
148 unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
152 } else if (C == '\\') {
154 } else if (isprint(C)) {
158 case '\b': O << "\\b"; break;
159 case '\f': O << "\\f"; break;
160 case '\n': O << "\\n"; break;
161 case '\r': O << "\\r"; break;
162 case '\t': O << "\\t"; break;
165 O << toOctal(C >> 6);
166 O << toOctal(C >> 3);
167 O << toOctal(C >> 0);
175 /// emitGlobalConstant - Print a general LLVM constant to the .s file.
177 void AsmPrinter::emitGlobalConstant(const Constant *CV) {
178 const TargetData &TD = TM.getTargetData();
180 if (CV->isNullValue()) {
181 emitZeros(TD.getTypeSize(CV->getType()));
183 } else if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
184 if (CVA->isString()) {
186 printAsCString(O, CVA);
188 } else { // Not a string. Print the values in successive locations
189 for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i)
190 emitGlobalConstant(CVA->getOperand(i));
193 } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
194 // Print the fields in successive locations. Pad to align if needed!
195 const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
196 unsigned sizeSoFar = 0;
197 for (unsigned i = 0, e = CVS->getNumOperands(); i != e; ++i) {
198 const Constant* field = CVS->getOperand(i);
200 // Check if padding is needed and insert one or more 0s.
201 unsigned fieldSize = TD.getTypeSize(field->getType());
202 unsigned padSize = ((i == e-1? cvsLayout->StructSize
203 : cvsLayout->MemberOffsets[i+1])
204 - cvsLayout->MemberOffsets[i]) - fieldSize;
205 sizeSoFar += fieldSize + padSize;
207 // Now print the actual field value
208 emitGlobalConstant(field);
210 // Insert the field padding unless it's zero bytes...
213 assert(sizeSoFar == cvsLayout->StructSize &&
214 "Layout of constant struct may be incorrect!");
216 } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
217 // FP Constants are printed as integer constants to avoid losing
219 double Val = CFP->getValue();
220 if (CFP->getType() == Type::DoubleTy) {
221 union DU { // Abide by C TBAA rules
227 if (Data64bitsDirective)
228 O << Data64bitsDirective << U.UVal << "\t" << CommentChar
229 << " double value: " << Val << "\n";
230 else if (TD.isBigEndian()) {
231 O << Data32bitsDirective << unsigned(U.UVal >> 32)
232 << "\t" << CommentChar << " double most significant word "
234 O << Data32bitsDirective << unsigned(U.UVal)
235 << "\t" << CommentChar << " double least significant word "
238 O << Data32bitsDirective << unsigned(U.UVal)
239 << "\t" << CommentChar << " double least significant word " << Val
241 O << Data32bitsDirective << unsigned(U.UVal >> 32)
242 << "\t" << CommentChar << " double most significant word " << Val
247 union FU { // Abide by C TBAA rules
253 O << Data32bitsDirective << U.UVal << "\t" << CommentChar
254 << " float " << Val << "\n";
257 } else if (CV->getType() == Type::ULongTy || CV->getType() == Type::LongTy) {
258 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
259 uint64_t Val = CI->getRawValue();
261 if (Data64bitsDirective)
262 O << Data64bitsDirective << Val << "\n";
263 else if (TD.isBigEndian()) {
264 O << Data32bitsDirective << unsigned(Val >> 32)
265 << "\t" << CommentChar << " Double-word most significant word "
267 O << Data32bitsDirective << unsigned(Val)
268 << "\t" << CommentChar << " Double-word least significant word "
271 O << Data32bitsDirective << unsigned(Val)
272 << "\t" << CommentChar << " Double-word least significant word "
274 O << Data32bitsDirective << unsigned(Val >> 32)
275 << "\t" << CommentChar << " Double-word most significant word "
282 const Type *type = CV->getType();
283 switch (type->getTypeID()) {
284 case Type::UByteTyID: case Type::SByteTyID:
285 O << Data8bitsDirective;
287 case Type::UShortTyID: case Type::ShortTyID:
288 O << Data16bitsDirective;
291 case Type::PointerTyID:
292 case Type::UIntTyID: case Type::IntTyID:
293 O << Data32bitsDirective;
295 case Type::ULongTyID: case Type::LongTyID:
296 assert (0 && "Should have already output double-word constant.");
297 case Type::FloatTyID: case Type::DoubleTyID:
298 assert (0 && "Should have already output floating point constant.");
300 assert (0 && "Can't handle printing this type of thing");
303 emitConstantValueOnly(CV);