llvm-6502/lib/Target/PowerPC/PPC64AsmPrinter.cpp
2004-08-19 21:56:12 +00:00

701 lines
22 KiB
C++

//===-- PPC64AsmPrinter.cpp - Print machine instrs to PowerPC assembly ----===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a printer that converts from our internal representation
// of machine-dependent LLVM code to PowerPC assembly language. This printer is
// the output mechanism used by `llc'.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "asmprinter"
#include "PowerPC.h"
#include "PowerPCInstrInfo.h"
#include "PPC64TargetMachine.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/Support/Mangler.h"
#include "Support/CommandLine.h"
#include "Support/Debug.h"
#include "Support/MathExtras.h"
#include "Support/Statistic.h"
#include "Support/StringExtras.h"
#include <set>
namespace llvm {
namespace {
Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
struct Printer : public MachineFunctionPass {
/// Output stream on which we're printing assembly code.
///
std::ostream &O;
/// Target machine description which we query for reg. names, data
/// layout, etc.
///
PPC64TargetMachine &TM;
/// Name-mangler for global names.
///
Mangler *Mang;
/// Map for labels corresponding to global variables
///
std::map<const GlobalVariable*,std::string> GVToLabelMap;
Printer(std::ostream &o, TargetMachine &tm) : O(o),
TM(reinterpret_cast<PPC64TargetMachine&>(tm)), LabelNumber(0) {}
/// Cache of mangled name for current function. This is
/// recalculated at the beginning of each call to
/// runOnMachineFunction().
///
std::string CurrentFnName;
/// Unique incrementer for label values for referencing Global values.
///
unsigned LabelNumber;
virtual const char *getPassName() const {
return "PPC64 Assembly Printer";
}
void printMachineInstruction(const MachineInstr *MI);
void printOp(const MachineOperand &MO, bool elideOffsetKeyword = false);
void printImmOp(const MachineOperand &MO, unsigned ArgType);
void printConstantPool(MachineConstantPool *MCP);
bool runOnMachineFunction(MachineFunction &F);
bool doInitialization(Module &M);
bool doFinalization(Module &M);
void emitGlobalConstant(const Constant* CV);
void emitConstantValueOnly(const Constant *CV);
};
} // end of anonymous namespace
/// createPPC64AsmPrinterPass - Returns a pass that prints the PPC
/// assembly code for a MachineFunction to the given output stream,
/// using the given target machine description. This should work
/// regardless of whether the function is in SSA form or not.
///
FunctionPass *createPPC64AsmPrinter(std::ostream &o,TargetMachine &tm) {
return new Printer(o, tm);
}
/// isStringCompatible - Can we treat the specified array as a string?
/// Only if it is an array of ubytes or non-negative sbytes.
///
static bool isStringCompatible(const ConstantArray *CVA) {
const Type *ETy = cast<ArrayType>(CVA->getType())->getElementType();
if (ETy == Type::UByteTy) return true;
if (ETy != Type::SByteTy) return false;
for (unsigned i = 0; i < CVA->getNumOperands(); ++i)
if (cast<ConstantSInt>(CVA->getOperand(i))->getValue() < 0)
return false;
return true;
}
/// toOctal - Convert the low order bits of X into an octal digit.
///
static inline char toOctal(int X) {
return (X&7)+'0';
}
// Possible states while outputting ASCII strings
namespace {
enum StringSection {
None,
Alpha,
Numeric
};
}
/// SwitchStringSection - manage the changes required to output bytes as
/// characters in a string vs. numeric decimal values
///
static inline void SwitchStringSection(std::ostream &O, StringSection NewSect,
StringSection &Current) {
if (Current == None) {
if (NewSect == Alpha)
O << "\t.byte \"";
else if (NewSect == Numeric)
O << "\t.byte ";
} else if (Current == Alpha) {
if (NewSect == None)
O << "\"";
else if (NewSect == Numeric)
O << "\"\n"
<< "\t.byte ";
} else if (Current == Numeric) {
if (NewSect == Alpha)
O << '\n'
<< "\t.byte \"";
else if (NewSect == Numeric)
O << ", ";
}
Current = NewSect;
}
/// getAsCString - Return the specified array as a C compatible
/// string, only if the predicate isStringCompatible is true.
///
static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
assert(isStringCompatible(CVA) && "Array is not string compatible!");
if (CVA->getNumOperands() == 0)
return;
StringSection Current = None;
for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i) {
unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
if (C == '"') {
SwitchStringSection(O, Alpha, Current);
O << "\"\"";
} else if (isprint(C)) {
SwitchStringSection(O, Alpha, Current);
O << C;
} else {
SwitchStringSection(O, Numeric, Current);
O << utostr((unsigned)C);
}
}
SwitchStringSection(O, None, Current);
O << '\n';
}
// Print out the specified constant, without a storage class. Only the
// constants valid in constant expressions can occur here.
void Printer::emitConstantValueOnly(const Constant *CV) {
if (CV->isNullValue())
O << "0";
else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
assert(CB == ConstantBool::True);
O << "1";
} else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
O << CI->getValue();
else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
O << CI->getValue();
else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
// This is a constant address for a global variable or function. Use the
// name of the variable or function as the address value.
O << Mang->getValueName(GV);
else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
const TargetData &TD = TM.getTargetData();
switch (CE->getOpcode()) {
case Instruction::GetElementPtr: {
// generate a symbolic expression for the byte address
const Constant *ptrVal = CE->getOperand(0);
std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
O << "(";
emitConstantValueOnly(ptrVal);
O << ") + " << Offset;
} else {
emitConstantValueOnly(ptrVal);
}
break;
}
case Instruction::Cast: {
// Support only non-converting or widening casts for now, that is, ones
// that do not involve a change in value. This assertion is really gross,
// and may not even be a complete check.
Constant *Op = CE->getOperand(0);
const Type *OpTy = Op->getType(), *Ty = CE->getType();
// Remember, kids, pointers on x86 can be losslessly converted back and
// forth into 32-bit or wider integers, regardless of signedness. :-P
assert(((isa<PointerType>(OpTy)
&& (Ty == Type::LongTy || Ty == Type::ULongTy
|| Ty == Type::IntTy || Ty == Type::UIntTy))
|| (isa<PointerType>(Ty)
&& (OpTy == Type::LongTy || OpTy == Type::ULongTy
|| OpTy == Type::IntTy || OpTy == Type::UIntTy))
|| (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
&& OpTy->isLosslesslyConvertibleTo(Ty))))
&& "FIXME: Don't yet support this kind of constant cast expr");
O << "(";
emitConstantValueOnly(Op);
O << ")";
break;
}
case Instruction::Add:
O << "(";
emitConstantValueOnly(CE->getOperand(0));
O << ") + (";
emitConstantValueOnly(CE->getOperand(1));
O << ")";
break;
default:
assert(0 && "Unsupported operator!");
}
} else {
assert(0 && "Unknown constant value!");
}
}
// Print a constant value or values, with the appropriate storage class as a
// prefix.
void Printer::emitGlobalConstant(const Constant *CV) {
const TargetData &TD = TM.getTargetData();
if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
if (isStringCompatible(CVA)) {
printAsCString(O, CVA);
} else { // Not a string. Print the values in successive locations
for (unsigned i=0, e = CVA->getNumOperands(); i != e; i++)
emitGlobalConstant(CVA->getOperand(i));
}
return;
} else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
// Print the fields in successive locations. Pad to align if needed!
const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
unsigned sizeSoFar = 0;
for (unsigned i = 0, e = CVS->getNumOperands(); i != e; i++) {
const Constant* field = CVS->getOperand(i);
// Check if padding is needed and insert one or more 0s.
unsigned fieldSize = TD.getTypeSize(field->getType());
unsigned padSize = ((i == e-1? cvsLayout->StructSize
: cvsLayout->MemberOffsets[i+1])
- cvsLayout->MemberOffsets[i]) - fieldSize;
sizeSoFar += fieldSize + padSize;
// Now print the actual field value
emitGlobalConstant(field);
// Insert the field padding unless it's zero bytes...
if (padSize)
O << "\t.space\t " << padSize << "\n";
}
assert(sizeSoFar == cvsLayout->StructSize &&
"Layout of constant struct may be incorrect!");
return;
} else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
// FP Constants are printed as integer constants to avoid losing
// precision...
double Val = CFP->getValue();
switch (CFP->getType()->getTypeID()) {
default: assert(0 && "Unknown floating point type!");
case Type::FloatTyID: {
union FU { // Abide by C TBAA rules
float FVal;
unsigned UVal;
} U;
U.FVal = Val;
O << "\t.long " << U.UVal << "\t# float " << Val << "\n";
return;
}
case Type::DoubleTyID: {
union DU { // Abide by C TBAA rules
double FVal;
uint64_t UVal;
struct {
uint32_t MSWord;
uint32_t LSWord;
} T;
} U;
U.FVal = Val;
O << ".long " << U.T.MSWord << "\t# double most significant word "
<< Val << "\n";
O << ".long " << U.T.LSWord << "\t# double least significant word "
<< Val << "\n";
return;
}
}
} else if (CV->getType() == Type::ULongTy || CV->getType() == Type::LongTy) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
union DU { // Abide by C TBAA rules
int64_t UVal;
struct {
uint32_t MSWord;
uint32_t LSWord;
} T;
} U;
U.UVal = CI->getRawValue();
O << ".long " << U.T.MSWord << "\t# Double-word most significant word "
<< U.UVal << "\n";
O << ".long " << U.T.LSWord << "\t# Double-word least significant word "
<< U.UVal << "\n";
return;
}
}
const Type *type = CV->getType();
O << "\t";
switch (type->getTypeID()) {
case Type::UByteTyID: case Type::SByteTyID:
O << "\t.byte";
break;
case Type::UShortTyID: case Type::ShortTyID:
O << "\t.short";
break;
case Type::BoolTyID:
case Type::PointerTyID:
case Type::UIntTyID: case Type::IntTyID:
O << "\t.long";
break;
case Type::ULongTyID: case Type::LongTyID:
assert (0 && "Should have already output double-word constant.");
case Type::FloatTyID: case Type::DoubleTyID:
assert (0 && "Should have already output floating point constant.");
default:
if (CV == Constant::getNullValue(type)) { // Zero initializer?
O << "\t.space " << TD.getTypeSize(type) << "\n";
return;
}
std::cerr << "Can't handle printing: " << *CV;
abort();
break;
}
O << ' ';
emitConstantValueOnly(CV);
O << '\n';
}
/// printConstantPool - Print to the current output stream assembly
/// representations of the constants in the constant pool MCP. This is
/// used to print out constants which have been "spilled to memory" by
/// the code generator.
///
void Printer::printConstantPool(MachineConstantPool *MCP) {
const std::vector<Constant*> &CP = MCP->getConstants();
const TargetData &TD = TM.getTargetData();
if (CP.empty()) return;
for (unsigned i = 0, e = CP.size(); i != e; ++i) {
O << "\t.const\n";
O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType())
<< "\n";
O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t;"
<< *CP[i] << "\n";
emitGlobalConstant(CP[i]);
}
}
/// runOnMachineFunction - This uses the printMachineInstruction()
/// method to print assembly for each instruction.
///
bool Printer::runOnMachineFunction(MachineFunction &MF) {
CurrentFnName = MF.getFunction()->getName();
// Print out constants referenced by the function
printConstantPool(MF.getConstantPool());
// Print out header for the function.
O << "\t.csect .text[PR]\n"
<< "\t.align 2\n"
<< "\t.globl " << CurrentFnName << '\n'
<< "\t.globl ." << CurrentFnName << '\n'
<< "\t.csect " << CurrentFnName << "[DS],3\n"
<< CurrentFnName << ":\n"
<< "\t.llong ." << CurrentFnName << ", TOC[tc0], 0\n"
<< "\t.csect .text[PR]\n"
<< '.' << CurrentFnName << ":\n";
// Print out code for the function.
for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
I != E; ++I) {
// Print a label for the basic block.
O << "LBB" << CurrentFnName << "_" << I->getNumber() << ":\t# "
<< I->getBasicBlock()->getName() << "\n";
for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
II != E; ++II) {
// Print the assembly for the instruction.
O << "\t";
printMachineInstruction(II);
}
}
++LabelNumber;
O << "LT.." << CurrentFnName << ":\n"
<< "\t.long 0\n"
<< "\t.byte 0,0,32,65,128,0,0,0\n"
<< "\t.long LT.." << CurrentFnName << "-." << CurrentFnName << '\n'
<< "\t.short 3\n"
<< "\t.byte \"" << CurrentFnName << "\"\n"
<< "\t.align 2\n";
// We didn't modify anything.
return false;
}
void Printer::printOp(const MachineOperand &MO,
bool elideOffsetKeyword /* = false */) {
const MRegisterInfo &RI = *TM.getRegisterInfo();
int new_symbol;
switch (MO.getType()) {
case MachineOperand::MO_VirtualRegister:
if (Value *V = MO.getVRegValueOrNull()) {
O << "<" << V->getName() << ">";
return;
}
// FALLTHROUGH
case MachineOperand::MO_MachineRegister:
case MachineOperand::MO_CCRegister: {
// On AIX, do not print out the 'R' (GPR) or 'F' (FPR) in reg names
const char *regName = RI.get(MO.getReg()).Name;
if (regName[0] == 'R' || regName[0] == 'F')
O << &regName[1];
else
O << regName;
return;
}
case MachineOperand::MO_SignExtendedImmed:
case MachineOperand::MO_UnextendedImmed:
std::cerr << "printOp() does not handle immediate values\n";
abort();
return;
case MachineOperand::MO_PCRelativeDisp:
std::cerr << "Shouldn't use addPCDisp() when building PPC MachineInstrs";
abort();
return;
case MachineOperand::MO_MachineBasicBlock: {
MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
<< "_" << MBBOp->getNumber() << "\t# "
<< MBBOp->getBasicBlock()->getName();
return;
}
case MachineOperand::MO_ConstantPoolIndex:
O << ".CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex();
return;
case MachineOperand::MO_ExternalSymbol:
O << MO.getSymbolName();
return;
case MachineOperand::MO_GlobalAddress:
if (!elideOffsetKeyword) {
GlobalValue *GV = MO.getGlobal();
if (Function *F = dyn_cast<Function>(GV)) {
O << Mang->getValueName(F);
} else if (GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
// output the label name
O << GVToLabelMap[GVar];
}
}
return;
default:
O << "<unknown operand type: " << MO.getType() << ">";
return;
}
}
void Printer::printImmOp(const MachineOperand &MO, unsigned ArgType) {
int Imm = MO.getImmedValue();
if (ArgType == PPCII::Simm16 || ArgType == PPCII::Disimm16) {
O << (short)Imm;
} else {
O << Imm;
}
}
/// printMachineInstruction -- Print out a single PPC LLVM instruction
/// MI in Darwin syntax to the current output stream.
///
void Printer::printMachineInstruction(const MachineInstr *MI) {
unsigned Opcode = MI->getOpcode();
const TargetInstrInfo &TII = *TM.getInstrInfo();
const TargetInstrDescriptor &Desc = TII.get(Opcode);
unsigned i;
unsigned ArgCount = MI->getNumOperands();
unsigned ArgType[] = {
(Desc.TSFlags >> PPCII::Arg0TypeShift) & PPCII::ArgTypeMask,
(Desc.TSFlags >> PPCII::Arg1TypeShift) & PPCII::ArgTypeMask,
(Desc.TSFlags >> PPCII::Arg2TypeShift) & PPCII::ArgTypeMask,
(Desc.TSFlags >> PPCII::Arg3TypeShift) & PPCII::ArgTypeMask,
(Desc.TSFlags >> PPCII::Arg4TypeShift) & PPCII::ArgTypeMask
};
assert(((Desc.TSFlags & PPCII::VMX) == 0) &&
"Instruction requires VMX support");
++EmittedInsts;
// CALLpcrel and CALLindirect are handled specially here to print only the
// appropriate number of args that the assembler expects. This is because
// may have many arguments appended to record the uses of registers that are
// holding arguments to the called function.
if (Opcode == PPC::COND_BRANCH) {
std::cerr << "Error: untranslated conditional branch psuedo instruction!\n";
abort();
} else if (Opcode == PPC::IMPLICIT_DEF) {
O << "# IMPLICIT DEF ";
printOp(MI->getOperand(0));
O << "\n";
return;
} else if (Opcode == PPC::CALLpcrel) {
O << TII.getName(Opcode) << " ";
printOp(MI->getOperand(0));
O << "\n";
return;
} else if (Opcode == PPC::CALLindirect) {
O << TII.getName(Opcode) << " ";
printImmOp(MI->getOperand(0), ArgType[0]);
O << ", ";
printImmOp(MI->getOperand(1), ArgType[0]);
O << "\n";
return;
} else if (Opcode == PPC::MovePCtoLR) {
// FIXME: should probably be converted to cout.width and cout.fill
O << "bl \"L0000" << LabelNumber << "$pb\"\n";
O << "\"L0000" << LabelNumber << "$pb\":\n";
O << "\tmflr ";
printOp(MI->getOperand(0));
O << "\n";
return;
}
O << LowercaseString(TII.getName(Opcode)) << " ";
if (Opcode == PPC::BLR || Opcode == PPC::NOP) {
O << "\n";
} else if (ArgCount == 3 &&
(ArgType[1] == PPCII::Disimm16 || ArgType[1] == PPCII::Disimm14)) {
printOp(MI->getOperand(0));
O << ", ";
MachineOperand MO = MI->getOperand(1);
if (MO.isImmediate())
printImmOp(MO, ArgType[1]);
else
printOp(MO);
O << "(";
printOp(MI->getOperand(2));
O << ")\n";
} else {
for (i = 0; i < ArgCount; ++i) {
// addi and friends
if (i == 1 && ArgCount == 3 && ArgType[2] == PPCII::Simm16 &&
MI->getOperand(1).hasAllocatedReg() &&
MI->getOperand(1).getReg() == PPC::R0) {
O << "0";
// for long branch support, bc $+8
} else if (i == 1 && ArgCount == 2 && MI->getOperand(1).isImmediate() &&
TII.isBranch(MI->getOpcode())) {
O << "$+8";
assert(8 == MI->getOperand(i).getImmedValue()
&& "branch off PC not to pc+8?");
//printOp(MI->getOperand(i));
} else if (MI->getOperand(i).isImmediate()) {
printImmOp(MI->getOperand(i), ArgType[i]);
} else {
printOp(MI->getOperand(i));
}
if (ArgCount - 1 == i)
O << "\n";
else
O << ", ";
}
}
}
// SwitchSection - Switch to the specified section of the executable if we are
// not already in it!
//
static void SwitchSection(std::ostream &OS, std::string &CurSection,
const char *NewSection) {
if (CurSection != NewSection) {
CurSection = NewSection;
if (!CurSection.empty())
OS << "\t" << NewSection << "\n";
}
}
bool Printer::doInitialization(Module &M) {
const TargetData &TD = TM.getTargetData();
std::string CurSection;
O << "\t.machine \"ppc64\"\n"
<< "\t.toc\n"
<< "\t.csect .text[PR]\n";
// Print out module-level global variables
for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I) {
if (!I->hasInitializer())
continue;
std::string Name = I->getName();
Constant *C = I->getInitializer();
// N.B.: We are defaulting to writable strings
if (I->hasExternalLinkage()) {
O << "\t.globl " << Name << '\n'
<< "\t.csect .data[RW],3\n";
} else {
O << "\t.csect _global.rw_c[RW],3\n";
}
O << Name << ":\n";
emitGlobalConstant(C);
}
// Output labels for globals
if (M.gbegin() != M.gend()) O << "\t.toc\n";
for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I) {
const GlobalVariable *GV = I;
// Do not output labels for unused variables
if (GV->isExternal() && GV->use_begin() == GV->use_end())
continue;
std::string Name = GV->getName();
std::string Label = "LC.." + utostr(LabelNumber++);
GVToLabelMap[GV] = Label;
O << Label << ":\n"
<< "\t.tc " << Name << "[TC]," << Name;
if (GV->isExternal()) O << "[RW]";
O << '\n';
}
Mang = new Mangler(M, ".");
return false; // success
}
bool Printer::doFinalization(Module &M) {
const TargetData &TD = TM.getTargetData();
// Print out module-level global variables
for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I) {
if (I->hasInitializer() || I->hasExternalLinkage())
continue;
std::string Name = I->getName();
if (I->hasInternalLinkage()) {
O << "\t.lcomm " << Name << ",16,_global.bss_c";
} else {
O << "\t.comm " << Name << "," << TD.getTypeSize(I->getType())
<< "," << log2((unsigned)TD.getTypeAlignment(I->getType()));
}
O << "\t\t# ";
WriteAsOperand(O, I, true, true, &M);
O << "\n";
}
O << "_section_.text:\n"
<< "\t.csect .data[RW],3\n"
<< "\t.llong _section_.text\n";
delete Mang;
return false; // success
}
} // End llvm namespace