Let me introduce you to the early stages of the llvm backend for the alpha processor
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19764 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Alpha/AlphaAsmPrinter.cpp b/lib/Target/Alpha/AlphaAsmPrinter.cpp
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--- /dev/null
+++ b/lib/Target/Alpha/AlphaAsmPrinter.cpp
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+//===-- AlphaAsmPrinter.cpp - Alpha LLVM assembly writer --------------===//
+//
+// 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 GAS-format Alpha assembly language.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Alpha.h"
+#include "AlphaInstrInfo.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/Assembly/Writer.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/MRegisterInfo.h"
+#include "llvm/Target/TargetInstrInfo.h"
+
+#include "llvm/Support/Mangler.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/CommandLine.h"
+#include <cctype>
+using namespace llvm;
+
+namespace {
+ Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
+
+ struct AlphaAsmPrinter : public AsmPrinter {
+
+ /// Unique incrementer for label values for referencing Global values.
+ ///
+ unsigned LabelNumber;
+
+ AlphaAsmPrinter(std::ostream &o, TargetMachine &tm)
+ : AsmPrinter(o, tm), LabelNumber(0)
+ { }
+
+ /// We name each basic block in a Function with a unique number, so
+ /// that we can consistently refer to them later. This is cleared
+ /// at the beginning of each call to runOnMachineFunction().
+ ///
+ typedef std::map<const Value *, unsigned> ValueMapTy;
+ ValueMapTy NumberForBB;
+
+ virtual const char *getPassName() const {
+ return "Alpha Assembly Printer";
+ }
+ bool printInstruction(const MachineInstr *MI);
+ void printOp(const MachineOperand &MO, bool IsCallOp = false);
+ void printConstantPool(MachineConstantPool *MCP);
+ void printOperand(const MachineInstr *MI, int opNum, MVT::ValueType VT);
+ void printBaseOffsetPair (const MachineInstr *MI, int i, bool brackets=true);
+ void printMachineInstruction(const MachineInstr *MI);
+ bool runOnMachineFunction(MachineFunction &F);
+ bool doInitialization(Module &M);
+ bool doFinalization(Module &M);
+ };
+} // end of anonymous namespace
+
+/// createAlphaCodePrinterPass - Returns a pass that prints the Alpha
+/// 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.
+///
+FunctionPass *llvm::createAlphaCodePrinterPass (std::ostream &o,
+ TargetMachine &tm) {
+ return new AlphaAsmPrinter(o, tm);
+}
+
+#include "AlphaGenAsmWriter.inc"
+
+void AlphaAsmPrinter::printOperand(const MachineInstr *MI, int opNum, MVT::ValueType VT)
+{
+ const MachineOperand &MO = MI->getOperand(opNum);
+ if (MO.getType() == MachineOperand::MO_MachineRegister) {
+ assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physreg??");
+ O << LowercaseString(TM.getRegisterInfo()->get(MO.getReg()).Name);
+ } else if (MO.isImmediate()) {
+ O << MO.getImmedValue();
+ } else {
+ printOp(MO);
+ }
+}
+
+
+void AlphaAsmPrinter::printOp(const MachineOperand &MO, bool IsCallOp) {
+ 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:
+ O << LowercaseString(RI.get(MO.getReg()).Name);
+ 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 << "$LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
+ << "_" << MBBOp->getNumber() << "\t" << CommentString << " "
+ << MBBOp->getBasicBlock()->getName();
+ return;
+ }
+
+ case MachineOperand::MO_ConstantPoolIndex:
+ O << "$CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex();
+ return;
+
+ case MachineOperand::MO_ExternalSymbol:
+ O << MO.getSymbolName();
+ return;
+
+ case MachineOperand::MO_GlobalAddress:
+ //std::cerr << "Global Addresses? Are you kidding?\n"
+ //abort();
+ O << Mang->getValueName(MO.getGlobal());
+ return;
+
+ default:
+ O << "<unknown operand type: " << MO.getType() << ">";
+ return;
+ }
+}
+
+/// printMachineInstruction -- Print out a single Alpha MI to
+/// the current output stream.
+///
+void AlphaAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
+ ++EmittedInsts;
+ if (printInstruction(MI))
+ return; // Printer was automatically generated
+
+ assert(0 && "Unhandled instruction in asm writer!");
+ abort();
+ return;
+}
+
+
+/// runOnMachineFunction - This uses the printMachineInstruction()
+/// method to print assembly for each instruction.
+///
+bool AlphaAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
+ setupMachineFunction(MF);
+ O << "\n\n";
+
+ if (CurrentFnName.compare("main") == 0)
+ {
+ O << "\n\n#HACK\n\t.text\n\t.ent __main\n__main:\n\tret $31,($26),1\n\t.end __main\n#ENDHACK\n\n";
+ }
+
+ // Print out constants referenced by the function
+ printConstantPool(MF.getConstantPool());
+
+ // Print out labels for the function.
+ O << "\t.text\n";
+ emitAlignment(2);
+ O << "\t.globl\t" << CurrentFnName << "\n";
+ O << "\t.ent\t" << CurrentFnName << "\n";
+
+ O << CurrentFnName << ":\n";
+
+ // Print out code for the function.
+ for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
+ I != E; ++I) {
+ // Print a label for the basic block.
+ O << "$LBB" << CurrentFnName << "_" << I->getNumber() << ":\t"
+ << CommentString << " " << 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 << "\t.end\t" << CurrentFnName << "\n";
+
+ // We didn't modify anything.
+ return false;
+}
+
+
+/// 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 AlphaAsmPrinter::printConstantPool(MachineConstantPool *MCP) {
+ const std::vector<Constant*> &CP = MCP->getConstants();
+ const TargetData &TD = TM.getTargetData();
+
+ if (CP.empty()) return;
+
+ abort();
+// for (unsigned i = 0, e = CP.size(); i != e; ++i) {
+// O << "\t.section\t.rodata\n";
+// emitAlignment(TD.getTypeAlignmentShift(CP[i]->getType()));
+// O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t" << CommentString
+// << *CP[i] << "\n";
+// //emitGlobalConstant(CP[i]);
+// }
+}
+
+bool AlphaAsmPrinter::doInitialization(Module &M)
+{
+ AsmPrinter::doInitialization(M);
+ O << "\t.arch ev56\n";
+ return false;
+}
+
+
+// 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 AlphaAsmPrinter::doFinalization(Module &M) {
+ const TargetData &TD = TM.getTargetData();
+ std::string CurSection;
+
+ for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
+ if (I->hasInitializer()) { // External global require no code
+ O << "\n\n";
+ std::string name = Mang->getValueName(I);
+ Constant *C = I->getInitializer();
+ unsigned Size = TD.getTypeSize(C->getType());
+ unsigned Align = TD.getTypeAlignmentShift(C->getType());
+
+ if (C->isNullValue() &&
+ (I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
+ I->hasWeakLinkage() /* FIXME: Verify correct */)) {
+ SwitchSection(O, CurSection, ".data");
+ if (I->hasInternalLinkage())
+ O << "\t.local " << name << "\n";
+
+ O << "\t.comm " << name << "," << TD.getTypeSize(C->getType())
+ << "," << (1 << Align);
+ O << "\t\t# ";
+ WriteAsOperand(O, I, true, true, &M);
+ O << "\n";
+ } else {
+ switch (I->getLinkage()) {
+ case GlobalValue::LinkOnceLinkage:
+ case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak.
+ // Nonnull linkonce -> weak
+ O << "\t.weak " << name << "\n";
+ SwitchSection(O, CurSection, "");
+ O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
+ break;
+ case GlobalValue::AppendingLinkage:
+ // FIXME: appending linkage variables should go into a section of
+ // their name or something. For now, just emit them as external.
+ case GlobalValue::ExternalLinkage:
+ // If external or appending, declare as a global symbol
+ O << "\t.globl " << name << "\n";
+ // FALL THROUGH
+ case GlobalValue::InternalLinkage:
+ if (C->isNullValue())
+ SwitchSection(O, CurSection, ".bss");
+ else
+ SwitchSection(O, CurSection, ".data");
+ break;
+ case GlobalValue::GhostLinkage:
+ std::cerr << "GhostLinkage cannot appear in X86AsmPrinter!\n";
+ abort();
+ }
+
+ emitAlignment(Align);
+ O << "\t.type " << name << ",@object\n";
+ O << "\t.size " << name << "," << Size << "\n";
+ O << name << ":\t\t\t\t# ";
+ WriteAsOperand(O, I, true, true, &M);
+ O << " = ";
+ WriteAsOperand(O, C, false, false, &M);
+ O << "\n";
+ emitGlobalConstant(C);
+ }
+ }
+
+ AsmPrinter::doFinalization(M);
+ return false;
+}