X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FMachineRegisterInfo.cpp;h=5d852f26beda66908799a6259dd54d63e739378d;hb=aac07eaeef0b29690f18061abc148a2608cd77de;hp=19c09eee51c02621da5e5c5984c0f0104efa3a35;hpb=84bc5427d6883f73cfeae3da640acd011d35c006;p=oota-llvm.git

diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 19c09eee51c..5d852f26bed 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -1,4 +1,4 @@
-//===-- MachineRegisterInfo.cpp -------------------------------------------===//
+//===-- lib/Codegen/MachineRegisterInfo.cpp -------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -12,9 +12,213 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Support/CommandLine.h"
 using namespace llvm;
 
-MachineRegisterInfo::MachineRegisterInfo(const MRegisterInfo &MRI) {
+MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI) {
   VRegInfo.reserve(256);
-  UsedPhysRegs.resize(MRI.getNumRegs());
+  RegAllocHints.reserve(256);
+  RegClass2VRegMap = new std::vector<unsigned>[TRI.getNumRegClasses()];
+  UsedPhysRegs.resize(TRI.getNumRegs());
+  
+  // Create the physreg use/def lists.
+  PhysRegUseDefLists = new MachineOperand*[TRI.getNumRegs()];
+  memset(PhysRegUseDefLists, 0, sizeof(MachineOperand*)*TRI.getNumRegs());
 }
+
+MachineRegisterInfo::~MachineRegisterInfo() {
+#ifndef NDEBUG
+  for (unsigned i = 0, e = VRegInfo.size(); i != e; ++i)
+    assert(VRegInfo[i].second == 0 && "Vreg use list non-empty still?");
+  for (unsigned i = 0, e = UsedPhysRegs.size(); i != e; ++i)
+    assert(!PhysRegUseDefLists[i] &&
+           "PhysRegUseDefLists has entries after all instructions are deleted");
+#endif
+  delete [] PhysRegUseDefLists;
+  delete [] RegClass2VRegMap;
+}
+
+/// setRegClass - Set the register class of the specified virtual register.
+///
+void
+MachineRegisterInfo::setRegClass(unsigned Reg, const TargetRegisterClass *RC) {
+  unsigned VR = Reg;
+  Reg -= TargetRegisterInfo::FirstVirtualRegister;
+  assert(Reg < VRegInfo.size() && "Invalid vreg!");
+  const TargetRegisterClass *OldRC = VRegInfo[Reg].first;
+  VRegInfo[Reg].first = RC;
+
+  // Remove from old register class's vregs list. This may be slow but
+  // fortunately this operation is rarely needed.
+  std::vector<unsigned> &VRegs = RegClass2VRegMap[OldRC->getID()];
+  std::vector<unsigned>::iterator I = std::find(VRegs.begin(), VRegs.end(), VR);
+  VRegs.erase(I);
+
+  // Add to new register class's vregs list.
+  RegClass2VRegMap[RC->getID()].push_back(VR);
+}
+
+/// createVirtualRegister - Create and return a new virtual register in the
+/// function with the specified register class.
+///
+unsigned
+MachineRegisterInfo::createVirtualRegister(const TargetRegisterClass *RegClass){
+  assert(RegClass && "Cannot create register without RegClass!");
+  // Add a reg, but keep track of whether the vector reallocated or not.
+  void *ArrayBase = VRegInfo.empty() ? 0 : &VRegInfo[0];
+  VRegInfo.push_back(std::make_pair(RegClass, (MachineOperand*)0));
+  RegAllocHints.push_back(std::make_pair(0, 0));
+
+  if (!((&VRegInfo[0] == ArrayBase || VRegInfo.size() == 1)))
+    // The vector reallocated, handle this now.
+    HandleVRegListReallocation();
+  unsigned VR = getLastVirtReg();
+  RegClass2VRegMap[RegClass->getID()].push_back(VR);
+  return VR;
+}
+
+/// HandleVRegListReallocation - We just added a virtual register to the
+/// VRegInfo info list and it reallocated.  Update the use/def lists info
+/// pointers.
+void MachineRegisterInfo::HandleVRegListReallocation() {
+  // The back pointers for the vreg lists point into the previous vector.
+  // Update them to point to their correct slots.
+  for (unsigned i = 0, e = VRegInfo.size(); i != e; ++i) {
+    MachineOperand *List = VRegInfo[i].second;
+    if (!List) continue;
+    // Update the back-pointer to be accurate once more.
+    List->Contents.Reg.Prev = &VRegInfo[i].second;
+  }
+}
+
+/// replaceRegWith - Replace all instances of FromReg with ToReg in the
+/// machine function.  This is like llvm-level X->replaceAllUsesWith(Y),
+/// except that it also changes any definitions of the register as well.
+void MachineRegisterInfo::replaceRegWith(unsigned FromReg, unsigned ToReg) {
+  assert(FromReg != ToReg && "Cannot replace a reg with itself");
+
+  // TODO: This could be more efficient by bulk changing the operands.
+  for (reg_iterator I = reg_begin(FromReg), E = reg_end(); I != E; ) {
+    MachineOperand &O = I.getOperand();
+    ++I;
+    O.setReg(ToReg);
+  }
+}
+
+
+/// getVRegDef - Return the machine instr that defines the specified virtual
+/// register or null if none is found.  This assumes that the code is in SSA
+/// form, so there should only be one definition.
+MachineInstr *MachineRegisterInfo::getVRegDef(unsigned Reg) const {
+  assert(Reg-TargetRegisterInfo::FirstVirtualRegister < VRegInfo.size() &&
+         "Invalid vreg!");
+  // Since we are in SSA form, we can use the first definition.
+  if (!def_empty(Reg))
+    return &*def_begin(Reg);
+  return 0;
+}
+
+bool MachineRegisterInfo::hasOneUse(unsigned RegNo) const {
+  use_iterator UI = use_begin(RegNo);
+  if (UI == use_end())
+    return false;
+  return ++UI == use_end();
+}
+
+bool MachineRegisterInfo::hasOneNonDBGUse(unsigned RegNo) const {
+  use_nodbg_iterator UI = use_nodbg_begin(RegNo);
+  if (UI == use_nodbg_end())
+    return false;
+  return ++UI == use_nodbg_end();
+}
+
+/// clearKillFlags - Iterate over all the uses of the given register and
+/// clear the kill flag from the MachineOperand. This function is used by
+/// optimization passes which extend register lifetimes and need only
+/// preserve conservative kill flag information.
+void MachineRegisterInfo::clearKillFlags(unsigned Reg) const {
+  for (use_iterator UI = use_begin(Reg), UE = use_end(); UI != UE; ++UI)
+    UI.getOperand().setIsKill(false);
+}
+
+bool MachineRegisterInfo::isLiveIn(unsigned Reg) const {
+  for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I)
+    if (I->first == Reg || I->second == Reg)
+      return true;
+  return false;
+}
+
+bool MachineRegisterInfo::isLiveOut(unsigned Reg) const {
+  for (liveout_iterator I = liveout_begin(), E = liveout_end(); I != E; ++I)
+    if (*I == Reg)
+      return true;
+  return false;
+}
+
+/// getLiveInPhysReg - If VReg is a live-in virtual register, return the
+/// corresponding live-in physical register.
+unsigned MachineRegisterInfo::getLiveInPhysReg(unsigned VReg) const {
+  for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I)
+    if (I->second == VReg)
+      return I->first;
+  return 0;
+}
+
+/// getLiveInVirtReg - If PReg is a live-in physical register, return the
+/// corresponding live-in physical register.
+unsigned MachineRegisterInfo::getLiveInVirtReg(unsigned PReg) const {
+  for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I)
+    if (I->first == PReg)
+      return I->second;
+  return 0;
+}
+
+/// EmitLiveInCopies - Emit copies to initialize livein virtual registers
+/// into the given entry block.
+void
+MachineRegisterInfo::EmitLiveInCopies(MachineBasicBlock *EntryMBB,
+                                      const TargetRegisterInfo &TRI,
+                                      const TargetInstrInfo &TII) {
+  // Emit the copies into the top of the block.
+  for (unsigned i = 0, e = LiveIns.size(); i != e; ++i)
+    if (LiveIns[i].second) {
+      if (use_empty(LiveIns[i].second)) {
+        // The livein has no uses. Drop it.
+        //
+        // It would be preferable to have isel avoid creating live-in
+        // records for unused arguments in the first place, but it's
+        // complicated by the debug info code for arguments.
+        LiveIns.erase(LiveIns.begin() + i);
+        --i; --e;
+      } else {
+        // Emit a copy.
+        BuildMI(*EntryMBB, EntryMBB->begin(), DebugLoc(),
+                TII.get(TargetOpcode::COPY), LiveIns[i].second)
+          .addReg(LiveIns[i].first);
+
+        // Add the register to the entry block live-in set.
+        EntryMBB->addLiveIn(LiveIns[i].first);
+      }
+    } else {
+      // Add the register to the entry block live-in set.
+      EntryMBB->addLiveIn(LiveIns[i].first);
+    }
+}
+
+void MachineRegisterInfo::closePhysRegsUsed(const TargetRegisterInfo &TRI) {
+  for (int i = UsedPhysRegs.find_first(); i >= 0;
+       i = UsedPhysRegs.find_next(i))
+         for (const unsigned *SS = TRI.getSubRegisters(i);
+              unsigned SubReg = *SS; ++SS)
+           if (SubReg > unsigned(i))
+             UsedPhysRegs.set(SubReg);
+}
+
+#ifndef NDEBUG
+void MachineRegisterInfo::dumpUses(unsigned Reg) const {
+  for (use_iterator I = use_begin(Reg), E = use_end(); I != E; ++I)
+    I.getOperand().getParent()->dump();
+}
+#endif