and so it begins...

PHASE 1: write instruction selector
PHASE 2: ???
PHASE 3: profit!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20652 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/IA64/IA64AsmPrinter.cpp b/lib/Target/IA64/IA64AsmPrinter.cpp
new file mode 100644
index 0000000..fff828f
--- /dev/null
+++ b/lib/Target/IA64/IA64AsmPrinter.cpp
@@ -0,0 +1,399 @@
+//===-- IA64AsmPrinter.cpp - Print out IA64 LLVM as assembly --------------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Duraid Madina 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 assembly accepted by the GNU binutils 'gas'
+// assembler. The Intel 'ias' and HP-UX 'as' assemblers *may* choke on this
+// output, but if so that's a bug I'd like to hear about: please file a bug
+// report in bugzilla. FYI, the excellent 'ias' assembler is bundled with
+// the Intel C/C++ compiler for Itanium Linux.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IA64.h"
+#include "IA64TargetMachine.h"
+#include "llvm/Module.h"
+#include "llvm/Assembly/Writer.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Support/Mangler.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+namespace {
+  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
+
+  struct IA64SharedAsmPrinter : public AsmPrinter {
+
+    std::set<std::string> ExternalFunctionNames;
+    
+    IA64SharedAsmPrinter(std::ostream &O, TargetMachine &TM)
+      : AsmPrinter(O, TM) { }
+
+    void printConstantPool(MachineConstantPool *MCP);
+    bool doFinalization(Module &M);
+  };
+}
+
+static bool isScale(const MachineOperand &MO) {
+  return MO.isImmediate() &&
+    (MO.getImmedValue() == 1 || MO.getImmedValue() == 2 ||
+     MO.getImmedValue() == 4 || MO.getImmedValue() == 8);
+}
+
+static bool isMem(const MachineInstr *MI, unsigned Op) {
+  if (MI->getOperand(Op).isFrameIndex()) return true;
+  if (MI->getOperand(Op).isConstantPoolIndex()) return true;
+  return Op+4 <= MI->getNumOperands() &&
+    MI->getOperand(Op  ).isRegister() && isScale(MI->getOperand(Op+1)) &&
+    MI->getOperand(Op+2).isRegister() && (MI->getOperand(Op+3).isImmediate() ||
+        MI->getOperand(Op+3).isGlobalAddress());
+}
+
+// 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";
+  }
+}
+
+/// 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 IA64SharedAsmPrinter::printConstantPool(MachineConstantPool *MCP) {
+  const std::vector<Constant*> &CP = MCP->getConstants();
+  const TargetData &TD = TM.getTargetData();
+ 
+  if (CP.empty()) return;
+
+  O << "\n\t.section .data\n"; // would be nice to have this rodata? hmmm
+  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
+    emitAlignment(TD.getTypeAlignmentShift(CP[i]->getType()));
+    O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t" << CommentString
+      << *CP[i] << "\n";
+    emitGlobalConstant(CP[i]);
+  }
+}
+
+bool IA64SharedAsmPrinter::doFinalization(Module &M) {
+  const TargetData &TD = TM.getTargetData();
+  std::string CurSection;
+
+  // Print out module-level global variables here.
+  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.common " << 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.global " << name << "\n";
+          // FALL THROUGH
+        case GlobalValue::InternalLinkage:
+          if (C->isNullValue())
+            SwitchSection(O, CurSection, ".data"); // FIXME: this was
+	  // '.bss', but in ia64-land .bss means "nobits" (i.e. uninitialized)
+	  // hmm.
+          else
+            SwitchSection(O, CurSection, ".data");
+          break;
+        case GlobalValue::GhostLinkage:
+          std::cerr << "GhostLinkage cannot appear in IA64AsmPrinter!\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);
+      }
+    }
+
+  // we print out ".global X \n .type X, @function" for each external function
+  O << "\n\n// br.call targets referenced (and not defined) above: \n";
+  for (std::set<std::string>::iterator i = ExternalFunctionNames.begin(),
+       e = ExternalFunctionNames.end(); i!=e; ++i) {
+    O << "\t.global " << *i << "\n\t.type " << *i << ", @function\n";
+  }
+  O << "\n\n";
+ 
+  AsmPrinter::doFinalization(M);
+  return false; // success
+}
+
+namespace {
+  struct IA64AsmPrinter : public IA64SharedAsmPrinter {
+    IA64AsmPrinter(std::ostream &O, TargetMachine &TM)
+      : IA64SharedAsmPrinter(O, TM) {
+
+      CommentString = "//";
+      Data8bitsDirective = "\tdata1\t";
+      Data16bitsDirective = "\tdata2\t";
+      Data32bitsDirective = "\tdata4\t";
+      Data64bitsDirective = "\tdata8\t";
+      ZeroDirective = "\t.skip\t";
+      AsciiDirective = "\tstring\t";
+
+    }
+
+    virtual const char *getPassName() const {
+      return "IA64 Assembly Printer";
+    }
+
+    /// printInstruction - This method is automatically generated by tablegen
+    /// from the instruction set description.  This method returns true if the
+    /// machine instruction was sufficiently described to print it, otherwise it
+    /// returns false.
+    bool printInstruction(const MachineInstr *MI);
+
+    // This method is used by the tablegen'erated instruction printer.
+    void printOperand(const MachineInstr *MI, unsigned OpNo, MVT::ValueType VT){
+      const MachineOperand &MO = MI->getOperand(OpNo);
+      if (MO.getType() == MachineOperand::MO_MachineRegister) {
+        assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physref??");
+        //XXX Bug Workaround: See note in Printer::doInitialization about %.
+        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
+      } else {
+        printOp(MO);
+      }
+    }
+    
+    void printS16ImmOperand(const MachineInstr *MI, unsigned OpNo,
+                            MVT::ValueType VT) {
+      O << (short)MI->getOperand(OpNo).getImmedValue();
+    }
+    void printU16ImmOperand(const MachineInstr *MI, unsigned OpNo,
+                            MVT::ValueType VT) {
+      O << (unsigned short)MI->getOperand(OpNo).getImmedValue();
+    }
+    void printS21ImmOperand(const MachineInstr *MI, unsigned OpNo,
+                            MVT::ValueType VT) {
+      O << (int)MI->getOperand(OpNo).getImmedValue(); // FIXME (21, not 32!)
+    }
+    void printS32ImmOperand(const MachineInstr *MI, unsigned OpNo,
+                            MVT::ValueType VT) {
+      O << (int)MI->getOperand(OpNo).getImmedValue();
+    }
+    void printU32ImmOperand(const MachineInstr *MI, unsigned OpNo,
+                            MVT::ValueType VT) {
+      O << (unsigned int)MI->getOperand(OpNo).getImmedValue();
+    }
+    void printU64ImmOperand(const MachineInstr *MI, unsigned OpNo,
+                            MVT::ValueType VT) {
+      O << (uint64_t)MI->getOperand(OpNo).getImmedValue();
+    }
+   
+    void printCallOperand(const MachineInstr *MI, unsigned OpNo,
+                          MVT::ValueType VT) {
+      printOp(MI->getOperand(OpNo), true); // this is a br.call instruction 
+    }
+
+    void printMachineInstruction(const MachineInstr *MI);
+    void printOp(const MachineOperand &MO, bool isBRCALLinsn= false);
+    bool runOnMachineFunction(MachineFunction &F);    
+    bool doInitialization(Module &M);
+  };
+} // end of anonymous namespace
+
+
+// Include the auto-generated portion of the assembly writer.
+#include "IA64GenAsmWriter.inc"
+
+
+/// runOnMachineFunction - This uses the printMachineInstruction()
+/// method to print assembly for each instruction.
+///
+bool IA64AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
+  setupMachineFunction(MF);
+  O << "\n\n";
+
+  // Print out constants referenced by the function
+  printConstantPool(MF.getConstantPool());
+
+  // Print out labels for the function.
+  O << "\n\t.section .text, \"ax\", \"progbits\"\n";
+              // ^^  means "Allocated instruXions in mem, initialized"
+  emitAlignment(4);
+  O << "\t.global\t" << CurrentFnName << "\n";
+  O << "\t.type\t" << CurrentFnName << ", @function\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 if there are any predecessors.
+    if (I->pred_begin() != I->pred_end())
+      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);
+    }
+  }
+
+  // We didn't modify anything.
+  return false;
+}
+
+void IA64AsmPrinter::printOp(const MachineOperand &MO,
+                                 bool isBRCALLinsn /* = false */) {
+  const MRegisterInfo &RI = *TM.getRegisterInfo();
+  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 << RI.get(MO.getReg()).Name;
+    return;
+  }
+
+  case MachineOperand::MO_SignExtendedImmed:
+  case MachineOperand::MO_UnextendedImmed:
+    O << /*(unsigned int)*/MO.getImmedValue();
+    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_PCRelativeDisp:
+    std::cerr << "Shouldn't use addPCDisp() when building IA64 MachineInstrs";
+    abort ();
+    return;
+
+  case MachineOperand::MO_ConstantPoolIndex: {
+    O << "@gprel(.CPI" << CurrentFnName << "_"
+      << MO.getConstantPoolIndex() << ")";
+    return;
+  }
+
+  case MachineOperand::MO_GlobalAddress: {
+
+    // functions need @ltoff(@fptr(fn_name)) form
+    GlobalValue *GV = MO.getGlobal();
+    Function *F = dyn_cast<Function>(GV);
+
+    bool Needfptr=false; // if we're computing an address @ltoff(X), do
+                         // we need to decorate it so it becomes
+			 // @ltoff(@fptr(X)) ?
+    if(F && !isBRCALLinsn && F->isExternal())
+      Needfptr=true;
+   
+    // if this is the target of a call instruction, we should define
+    // the function somewhere (GNU gas has no problem without this, but
+    // Intel ias rightly complains of an 'undefined symbol')
+  
+    if(F && isBRCALLinsn && F->isExternal())
+      ExternalFunctionNames.insert(Mang->getValueName(MO.getGlobal()));
+    
+    if (!isBRCALLinsn)
+      O << "@ltoff(";
+    if (Needfptr)
+      O << "@fptr(";
+    O << Mang->getValueName(MO.getGlobal());
+    if (Needfptr)
+      O << ")"; // close fptr(
+    if (!isBRCALLinsn)
+      O << ")"; // close ltoff(
+    int Offset = MO.getOffset();
+    if (Offset > 0)
+      O << " + " << Offset;
+    else if (Offset < 0)
+      O << " - " << -Offset;
+    return;
+  }
+  case MachineOperand::MO_ExternalSymbol:
+    O << MO.getSymbolName();
+    return;
+  default:
+    O << "<AsmPrinter: unknown operand type: " << MO.getType() << " >"; return;    
+  }
+}
+
+/// printMachineInstruction -- Print out a single IA64 LLVM instruction
+/// MI to the current output stream.
+///
+void IA64AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
+  
+  ++EmittedInsts;
+  
+  // Call the autogenerated instruction printer routines.
+  printInstruction(MI);
+}
+
+bool IA64AsmPrinter::doInitialization(Module &M) {
+  AsmPrinter::doInitialization(M);
+  
+  O << "\t.psr	  lsb\n"  // should be "msb" on HP-UX, for starters
+    << "\t.radix  C\n"
+    << "\t.psr	  abi64\n"; // we only support 64 bits for now
+  return false;
+}
+
+/// createIA64CodePrinterPass - Returns a pass that prints the IA64
+/// assembly code for a MachineFunction to the given output stream, using
+/// the given target machine description.
+///
+FunctionPass *llvm::createIA64CodePrinterPass(std::ostream &o,TargetMachine &tm){
+  return new IA64AsmPrinter(o, tm);
+}
+
+