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

1 files changed, 319 insertions, 0 deletions

diff --git a/lib/Target/Alpha/AlphaAsmPrinter.cpp b/lib/Target/Alpha/AlphaAsmPrinter.cpp
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+++ 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;
+}