It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
new file mode 100644
index 0000000..c762ae5
--- /dev/null
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -0,0 +1,483 @@
+//===-- MachineFunction.cpp -----------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+//
+// Collect native machine code information for a function.  This allows
+// target-specific information about the generated code to be stored with each
+// function.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DerivedTypes.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/SSARegMap.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Function.h"
+#include "llvm/Instructions.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/GraphWriter.h"
+#include "llvm/Support/LeakDetector.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Config/config.h"
+#include <fstream>
+#include <sstream>
+using namespace llvm;
+
+static AnnotationID MF_AID(
+  AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
+
+// Out of line virtual function to home classes.
+void MachineFunctionPass::virtfn() {}
+
+namespace {
+  struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
+    static char ID;
+
+    std::ostream *OS;
+    const std::string Banner;
+
+    Printer (std::ostream *_OS, const std::string &_Banner) 
+      : MachineFunctionPass((intptr_t)&ID), OS (_OS), Banner (_Banner) { }
+
+    const char *getPassName() const { return "MachineFunction Printer"; }
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesAll();
+    }
+
+    bool runOnMachineFunction(MachineFunction &MF) {
+      (*OS) << Banner;
+      MF.print (*OS);
+      return false;
+    }
+  };
+  char Printer::ID = 0;
+}
+
+/// Returns a newly-created MachineFunction Printer pass. The default output
+/// stream is std::cerr; the default banner is empty.
+///
+FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
+                                                     const std::string &Banner){
+  return new Printer(OS, Banner);
+}
+
+namespace {
+  struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
+    static char ID;
+    Deleter() : MachineFunctionPass((intptr_t)&ID) {}
+
+    const char *getPassName() const { return "Machine Code Deleter"; }
+
+    bool runOnMachineFunction(MachineFunction &MF) {
+      // Delete the annotation from the function now.
+      MachineFunction::destruct(MF.getFunction());
+      return true;
+    }
+  };
+  char Deleter::ID = 0;
+}
+
+/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
+/// the current function, which should happen after the function has been
+/// emitted to a .s file or to memory.
+FunctionPass *llvm::createMachineCodeDeleter() {
+  return new Deleter();
+}
+
+
+
+//===---------------------------------------------------------------------===//
+// MachineFunction implementation
+//===---------------------------------------------------------------------===//
+
+MachineBasicBlock* ilist_traits<MachineBasicBlock>::createSentinel() {
+  MachineBasicBlock* dummy = new MachineBasicBlock();
+  LeakDetector::removeGarbageObject(dummy);
+  return dummy;
+}
+
+void ilist_traits<MachineBasicBlock>::transferNodesFromList(
+  iplist<MachineBasicBlock, ilist_traits<MachineBasicBlock> >& toList,
+  ilist_iterator<MachineBasicBlock> first,
+  ilist_iterator<MachineBasicBlock> last) {
+  if (Parent != toList.Parent)
+    for (; first != last; ++first)
+      first->Parent = toList.Parent;
+}
+
+MachineFunction::MachineFunction(const Function *F,
+                                 const TargetMachine &TM)
+  : Annotation(MF_AID), Fn(F), Target(TM) {
+  SSARegMapping = new SSARegMap();
+  MFInfo = 0;
+  FrameInfo = new MachineFrameInfo();
+  ConstantPool = new MachineConstantPool(TM.getTargetData());
+  UsedPhysRegs.resize(TM.getRegisterInfo()->getNumRegs());
+  
+  // Set up jump table.
+  const TargetData &TD = *TM.getTargetData();
+  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
+  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
+  unsigned Alignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty)
+                             : TD.getPointerABIAlignment();
+  JumpTableInfo = new MachineJumpTableInfo(EntrySize, Alignment);
+  
+  BasicBlocks.Parent = this;
+}
+
+MachineFunction::~MachineFunction() {
+  BasicBlocks.clear();
+  delete SSARegMapping;
+  delete MFInfo;
+  delete FrameInfo;
+  delete ConstantPool;
+  delete JumpTableInfo;
+}
+
+
+/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
+/// recomputes them.  This guarantees that the MBB numbers are sequential,
+/// dense, and match the ordering of the blocks within the function.  If a
+/// specific MachineBasicBlock is specified, only that block and those after
+/// it are renumbered.
+void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
+  if (empty()) { MBBNumbering.clear(); return; }
+  MachineFunction::iterator MBBI, E = end();
+  if (MBB == 0)
+    MBBI = begin();
+  else
+    MBBI = MBB;
+  
+  // Figure out the block number this should have.
+  unsigned BlockNo = 0;
+  if (MBBI != begin())
+    BlockNo = prior(MBBI)->getNumber()+1;
+  
+  for (; MBBI != E; ++MBBI, ++BlockNo) {
+    if (MBBI->getNumber() != (int)BlockNo) {
+      // Remove use of the old number.
+      if (MBBI->getNumber() != -1) {
+        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
+               "MBB number mismatch!");
+        MBBNumbering[MBBI->getNumber()] = 0;
+      }
+      
+      // If BlockNo is already taken, set that block's number to -1.
+      if (MBBNumbering[BlockNo])
+        MBBNumbering[BlockNo]->setNumber(-1);
+
+      MBBNumbering[BlockNo] = MBBI;
+      MBBI->setNumber(BlockNo);
+    }
+  }    
+
+  // Okay, all the blocks are renumbered.  If we have compactified the block
+  // numbering, shrink MBBNumbering now.
+  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
+  MBBNumbering.resize(BlockNo);
+}
+
+
+void MachineFunction::dump() const { print(*cerr.stream()); }
+
+void MachineFunction::print(std::ostream &OS) const {
+  OS << "# Machine code for " << Fn->getName () << "():\n";
+
+  // Print Frame Information
+  getFrameInfo()->print(*this, OS);
+  
+  // Print JumpTable Information
+  getJumpTableInfo()->print(OS);
+
+  // Print Constant Pool
+  getConstantPool()->print(OS);
+  
+  const MRegisterInfo *MRI = getTarget().getRegisterInfo();
+  
+  if (livein_begin() != livein_end()) {
+    OS << "Live Ins:";
+    for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I) {
+      if (MRI)
+        OS << " " << MRI->getName(I->first);
+      else
+        OS << " Reg #" << I->first;
+      
+      if (I->second)
+        OS << " in VR#" << I->second << " ";
+    }
+    OS << "\n";
+  }
+  if (liveout_begin() != liveout_end()) {
+    OS << "Live Outs:";
+    for (liveout_iterator I = liveout_begin(), E = liveout_end(); I != E; ++I)
+      if (MRI)
+        OS << " " << MRI->getName(*I);
+      else
+        OS << " Reg #" << *I;
+    OS << "\n";
+  }
+  
+  for (const_iterator BB = begin(); BB != end(); ++BB)
+    BB->print(OS);
+
+  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
+}
+
+/// CFGOnly flag - This is used to control whether or not the CFG graph printer
+/// prints out the contents of basic blocks or not.  This is acceptable because
+/// this code is only really used for debugging purposes.
+///
+static bool CFGOnly = false;
+
+namespace llvm {
+  template<>
+  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
+    static std::string getGraphName(const MachineFunction *F) {
+      return "CFG for '" + F->getFunction()->getName() + "' function";
+    }
+
+    static std::string getNodeLabel(const MachineBasicBlock *Node,
+                                    const MachineFunction *Graph) {
+      if (CFGOnly && Node->getBasicBlock() &&
+          !Node->getBasicBlock()->getName().empty())
+        return Node->getBasicBlock()->getName() + ":";
+
+      std::ostringstream Out;
+      if (CFGOnly) {
+        Out << Node->getNumber() << ':';
+        return Out.str();
+      }
+
+      Node->print(Out);
+
+      std::string OutStr = Out.str();
+      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
+
+      // Process string output to make it nicer...
+      for (unsigned i = 0; i != OutStr.length(); ++i)
+        if (OutStr[i] == '\n') {                            // Left justify
+          OutStr[i] = '\\';
+          OutStr.insert(OutStr.begin()+i+1, 'l');
+        }
+      return OutStr;
+    }
+  };
+}
+
+void MachineFunction::viewCFG() const
+{
+#ifndef NDEBUG
+  ViewGraph(this, "mf" + getFunction()->getName());
+#else
+  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
+       << "systems with Graphviz or gv!\n";
+#endif // NDEBUG
+}
+
+void MachineFunction::viewCFGOnly() const
+{
+  CFGOnly = true;
+  viewCFG();
+  CFGOnly = false;
+}
+
+// The next two methods are used to construct and to retrieve
+// the MachineCodeForFunction object for the given function.
+// construct() -- Allocates and initializes for a given function and target
+// get()       -- Returns a handle to the object.
+//                This should not be called before "construct()"
+//                for a given Function.
+//
+MachineFunction&
+MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
+{
+  assert(Fn->getAnnotation(MF_AID) == 0 &&
+         "Object already exists for this function!");
+  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
+  Fn->addAnnotation(mcInfo);
+  return *mcInfo;
+}
+
+void MachineFunction::destruct(const Function *Fn) {
+  bool Deleted = Fn->deleteAnnotation(MF_AID);
+  assert(Deleted && "Machine code did not exist for function!");
+}
+
+MachineFunction& MachineFunction::get(const Function *F)
+{
+  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
+  assert(mc && "Call construct() method first to allocate the object");
+  return *mc;
+}
+
+void MachineFunction::clearSSARegMap() {
+  delete SSARegMapping;
+  SSARegMapping = 0;
+}
+
+//===----------------------------------------------------------------------===//
+//  MachineFrameInfo implementation
+//===----------------------------------------------------------------------===//
+
+void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
+  int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
+
+  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
+    const StackObject &SO = Objects[i];
+    OS << "  <fi #" << (int)(i-NumFixedObjects) << ">: ";
+    if (SO.Size == 0)
+      OS << "variable sized";
+    else
+      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
+    OS << " alignment is " << SO.Alignment << " byte"
+       << (SO.Alignment != 1 ? "s," : ",");
+
+    if (i < NumFixedObjects)
+      OS << " fixed";
+    if (i < NumFixedObjects || SO.SPOffset != -1) {
+      int64_t Off = SO.SPOffset - ValOffset;
+      OS << " at location [SP";
+      if (Off > 0)
+        OS << "+" << Off;
+      else if (Off < 0)
+        OS << Off;
+      OS << "]";
+    }
+    OS << "\n";
+  }
+
+  if (HasVarSizedObjects)
+    OS << "  Stack frame contains variable sized objects\n";
+}
+
+void MachineFrameInfo::dump(const MachineFunction &MF) const {
+  print(MF, *cerr.stream());
+}
+
+
+//===----------------------------------------------------------------------===//
+//  MachineJumpTableInfo implementation
+//===----------------------------------------------------------------------===//
+
+/// getJumpTableIndex - Create a new jump table entry in the jump table info
+/// or return an existing one.
+///
+unsigned MachineJumpTableInfo::getJumpTableIndex(
+                               const std::vector<MachineBasicBlock*> &DestBBs) {
+  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
+  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
+    if (JumpTables[i].MBBs == DestBBs)
+      return i;
+  
+  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
+  return JumpTables.size()-1;
+}
+
+
+void MachineJumpTableInfo::print(std::ostream &OS) const {
+  // FIXME: this is lame, maybe we could print out the MBB numbers or something
+  // like {1, 2, 4, 5, 3, 0}
+  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
+    OS << "  <jt #" << i << "> has " << JumpTables[i].MBBs.size() 
+       << " entries\n";
+  }
+}
+
+void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
+
+
+//===----------------------------------------------------------------------===//
+//  MachineConstantPool implementation
+//===----------------------------------------------------------------------===//
+
+const Type *MachineConstantPoolEntry::getType() const {
+  if (isMachineConstantPoolEntry())
+      return Val.MachineCPVal->getType();
+  return Val.ConstVal->getType();
+}
+
+MachineConstantPool::~MachineConstantPool() {
+  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
+    if (Constants[i].isMachineConstantPoolEntry())
+      delete Constants[i].Val.MachineCPVal;
+}
+
+/// getConstantPoolIndex - Create a new entry in the constant pool or return
+/// an existing one.  User must specify an alignment in bytes for the object.
+///
+unsigned MachineConstantPool::getConstantPoolIndex(Constant *C, 
+                                                   unsigned Alignment) {
+  assert(Alignment && "Alignment must be specified!");
+  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
+  
+  // Check to see if we already have this constant.
+  //
+  // FIXME, this could be made much more efficient for large constant pools.
+  unsigned AlignMask = (1 << Alignment)-1;
+  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
+    if (Constants[i].Val.ConstVal == C && (Constants[i].Offset & AlignMask)== 0)
+      return i;
+  
+  unsigned Offset = 0;
+  if (!Constants.empty()) {
+    Offset = Constants.back().getOffset();
+    Offset += TD->getTypeSize(Constants.back().getType());
+    Offset = (Offset+AlignMask)&~AlignMask;
+  }
+  
+  Constants.push_back(MachineConstantPoolEntry(C, Offset));
+  return Constants.size()-1;
+}
+
+unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
+                                                   unsigned Alignment) {
+  assert(Alignment && "Alignment must be specified!");
+  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
+  
+  // Check to see if we already have this constant.
+  //
+  // FIXME, this could be made much more efficient for large constant pools.
+  unsigned AlignMask = (1 << Alignment)-1;
+  int Idx = V->getExistingMachineCPValue(this, Alignment);
+  if (Idx != -1)
+    return (unsigned)Idx;
+  
+  unsigned Offset = 0;
+  if (!Constants.empty()) {
+    Offset = Constants.back().getOffset();
+    Offset += TD->getTypeSize(Constants.back().getType());
+    Offset = (Offset+AlignMask)&~AlignMask;
+  }
+  
+  Constants.push_back(MachineConstantPoolEntry(V, Offset));
+  return Constants.size()-1;
+}
+
+
+void MachineConstantPool::print(std::ostream &OS) const {
+  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
+    OS << "  <cp #" << i << "> is";
+    if (Constants[i].isMachineConstantPoolEntry())
+      Constants[i].Val.MachineCPVal->print(OS);
+    else
+      OS << *(Value*)Constants[i].Val.ConstVal;
+    OS << " , offset=" << Constants[i].getOffset();
+    OS << "\n";
+  }
+}
+
+void MachineConstantPool::dump() const { print(*cerr.stream()); }