X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FMachineRegisterInfo.cpp;h=631c43c6b32116951d1a9c361633dd8ce5bd3c65;hb=9a526495e0c06c4014d7500788cad1929fd244d3;hp=402be479eac305be81caeca43a6f921d4d7ec5c2;hpb=49b4589978ca181537c8ae694ac4c8d58d27a09a;p=oota-llvm.git

diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 402be479eac..631c43c6b32 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -20,7 +20,7 @@ using namespace llvm;
 MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI) {
   VRegInfo.reserve(256);
   RegAllocHints.reserve(256);
-  RegClass2VRegMap.resize(TRI.getNumRegClasses()+1); // RC ID starts at 1.
+  RegClass2VRegMap = new std::vector<unsigned>[TRI.getNumRegClasses()];
   UsedPhysRegs.resize(TRI.getNumRegs());
   
   // Create the physreg use/def lists.
@@ -37,6 +37,7 @@ MachineRegisterInfo::~MachineRegisterInfo() {
            "PhysRegUseDefLists has entries after all instructions are deleted");
 #endif
   delete [] PhysRegUseDefLists;
+  delete [] RegClass2VRegMap;
 }
 
 /// setRegClass - Set the register class of the specified virtual register.
@@ -52,7 +53,7 @@ MachineRegisterInfo::setRegClass(unsigned Reg, const TargetRegisterClass *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);
+  std::vector<unsigned>::iterator I = std::find(VRegs.begin(), VRegs.end(), VR);
   VRegs.erase(I);
 
   // Add to new register class's vregs list.
@@ -165,78 +166,13 @@ unsigned MachineRegisterInfo::getLiveInPhysReg(unsigned VReg) const {
   return 0;
 }
 
-static cl::opt<bool>
-SchedLiveInCopies("schedule-livein-copies", cl::Hidden,
-                  cl::desc("Schedule copies of livein registers"),
-                  cl::init(false));
-
-/// EmitLiveInCopy - Emit a copy for a live in physical register. If the
-/// physical register has only a single copy use, then coalesced the copy
-/// if possible.
-static void EmitLiveInCopy(MachineBasicBlock *MBB,
-                           MachineBasicBlock::iterator &InsertPos,
-                           unsigned VirtReg, unsigned PhysReg,
-                           const TargetRegisterClass *RC,
-                           DenseMap<MachineInstr*, unsigned> &CopyRegMap,
-                           const MachineRegisterInfo &MRI,
-                           const TargetRegisterInfo &TRI,
-                           const TargetInstrInfo &TII) {
-  unsigned NumUses = 0;
-  MachineInstr *UseMI = NULL;
-  for (MachineRegisterInfo::use_iterator UI = MRI.use_begin(VirtReg),
-         UE = MRI.use_end(); UI != UE; ++UI) {
-    UseMI = &*UI;
-    if (++NumUses > 1)
-      break;
-  }
-
-  // If the number of uses is not one, or the use is not a move instruction,
-  // don't coalesce. Also, only coalesce away a virtual register to virtual
-  // register copy.
-  bool Coalesced = false;
-  unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
-  if (NumUses == 1 &&
-      TII.isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubReg, DstSubReg) &&
-      TargetRegisterInfo::isVirtualRegister(DstReg)) {
-    VirtReg = DstReg;
-    Coalesced = true;
-  }
-
-  // Now find an ideal location to insert the copy.
-  MachineBasicBlock::iterator Pos = InsertPos;
-  while (Pos != MBB->begin()) {
-    MachineInstr *PrevMI = prior(Pos);
-    DenseMap<MachineInstr*, unsigned>::iterator RI = CopyRegMap.find(PrevMI);
-    // copyRegToReg might emit multiple instructions to do a copy.
-    unsigned CopyDstReg = (RI == CopyRegMap.end()) ? 0 : RI->second;
-    if (CopyDstReg && !TRI.regsOverlap(CopyDstReg, PhysReg))
-      // This is what the BB looks like right now:
-      // r1024 = mov r0
-      // ...
-      // r1    = mov r1024
-      //
-      // We want to insert "r1025 = mov r1". Inserting this copy below the
-      // move to r1024 makes it impossible for that move to be coalesced.
-      //
-      // r1025 = mov r1
-      // r1024 = mov r0
-      // ...
-      // r1    = mov 1024
-      // r2    = mov 1025
-      break; // Woot! Found a good location.
-    --Pos;
-  }
-
-  bool Emitted = TII.copyRegToReg(*MBB, Pos, VirtReg, PhysReg, RC, RC,
-                                  DebugLoc());
-  assert(Emitted && "Unable to issue a live-in copy instruction!\n");
-  (void) Emitted;
-
-  CopyRegMap.insert(std::make_pair(prior(Pos), VirtReg));
-  if (Coalesced) {
-    if (&*InsertPos == UseMI) ++InsertPos;
-    MBB->erase(UseMI);
-  }
+/// 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
@@ -245,34 +181,21 @@ void
 MachineRegisterInfo::EmitLiveInCopies(MachineBasicBlock *EntryMBB,
                                       const TargetRegisterInfo &TRI,
                                       const TargetInstrInfo &TII) {
-  if (SchedLiveInCopies) {
-    // Emit the copies at a heuristically-determined location in the block.
-    DenseMap<MachineInstr*, unsigned> CopyRegMap;
-    MachineBasicBlock::iterator InsertPos = EntryMBB->begin();
-    for (MachineRegisterInfo::livein_iterator LI = livein_begin(),
-           E = livein_end(); LI != E; ++LI)
-      if (LI->second) {
-        const TargetRegisterClass *RC = getRegClass(LI->second);
-        EmitLiveInCopy(EntryMBB, InsertPos, LI->second, LI->first,
-                       RC, CopyRegMap, *this, TRI, TII);
-      }
-  } else {
-    // Emit the copies into the top of the block.
-    for (MachineRegisterInfo::livein_iterator LI = livein_begin(),
-           E = livein_end(); LI != E; ++LI)
-      if (LI->second) {
-        const TargetRegisterClass *RC = getRegClass(LI->second);
-        bool Emitted = TII.copyRegToReg(*EntryMBB, EntryMBB->begin(),
-                                        LI->second, LI->first, RC, RC,
-                                        DebugLoc());
-        assert(Emitted && "Unable to issue a live-in copy instruction!\n");
-        (void) Emitted;
-      }
-  }
+  // Emit the copies into the top of the block.
+  for (MachineRegisterInfo::livein_iterator LI = livein_begin(),
+         E = livein_end(); LI != E; ++LI)
+    if (LI->second) {
+      const TargetRegisterClass *RC = getRegClass(LI->second);
+      bool Emitted = TII.copyRegToReg(*EntryMBB, EntryMBB->begin(),
+                                      LI->second, LI->first, RC, RC,
+                                      DebugLoc());
+      assert(Emitted && "Unable to issue a live-in copy instruction!\n");
+      (void) Emitted;
+    }
 
   // Add function live-ins to entry block live-in set.
   for (MachineRegisterInfo::livein_iterator I = livein_begin(),
-       E = livein_end(); I != E; ++I)
+         E = livein_end(); I != E; ++I)
     EntryMBB->addLiveIn(I->first);
 }