Revert r129518, "Change ELF systems to use CFI for producing the EH tables. This...

[oota-llvm.git] / lib / CodeGen / VirtRegMap.cpp

diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index b44df474112a771ff260aeab7b259483f52a5562..7a7ea69e27fca567ad9ccbe04dbe2dacf1c43c5c 100644 (file)
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -24,6 +24,7 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetRegisterInfo.h"
@@ -88,14 +89,14 @@ bool VirtRegMap::runOnMachineFunction(MachineFunction &mf) {
 }
 
 void VirtRegMap::grow() {
-  unsigned LastVirtReg = MF->getRegInfo().getLastVirtReg();
-  Virt2PhysMap.grow(LastVirtReg);
-  Virt2StackSlotMap.grow(LastVirtReg);
-  Virt2ReMatIdMap.grow(LastVirtReg);
-  Virt2SplitMap.grow(LastVirtReg);
-  Virt2SplitKillMap.grow(LastVirtReg);
-  ReMatMap.grow(LastVirtReg);
-  ImplicitDefed.resize(MF->getRegInfo().getNumVirtRegs());
+  unsigned NumRegs = MF->getRegInfo().getNumVirtRegs();
+  Virt2PhysMap.resize(NumRegs);
+  Virt2StackSlotMap.resize(NumRegs);
+  Virt2ReMatIdMap.resize(NumRegs);
+  Virt2SplitMap.resize(NumRegs);
+  Virt2SplitKillMap.resize(NumRegs);
+  ReMatMap.resize(NumRegs);
+  ImplicitDefed.resize(NumRegs);
 }
 
 unsigned VirtRegMap::createSpillSlot(const TargetRegisterClass *RC) {
@@ -115,11 +116,10 @@ unsigned VirtRegMap::createSpillSlot(const TargetRegisterClass *RC) {
 unsigned VirtRegMap::getRegAllocPref(unsigned virtReg) {
   std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(virtReg);
   unsigned physReg = Hint.second;
-  if (physReg &&
-      TargetRegisterInfo::isVirtualRegister(physReg) && hasPhys(physReg))
+  if (TargetRegisterInfo::isVirtualRegister(physReg) && hasPhys(physReg))
     physReg = getPhys(physReg);
   if (Hint.first == 0)
-    return (physReg && TargetRegisterInfo::isPhysicalRegister(physReg))
+    return (TargetRegisterInfo::isPhysicalRegister(physReg))
       ? physReg : 0;
   return TRI->ResolveRegAllocHint(Hint.first, physReg, *MF);
 }
@@ -255,6 +255,82 @@ bool VirtRegMap::FindUnusedRegisters(LiveIntervals* LIs) {
   return AnyUnused;
 }
 
+void VirtRegMap::rewrite(SlotIndexes *Indexes) {
+  DEBUG(dbgs() << "********** REWRITE VIRTUAL REGISTERS **********\n"
+               << "********** Function: "
+               << MF->getFunction()->getName() << '\n');
+  DEBUG(dump());
+  SmallVector<unsigned, 8> SuperKills;
+
+  for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
+       MBBI != MBBE; ++MBBI) {
+    DEBUG(MBBI->print(dbgs(), Indexes));
+    for (MachineBasicBlock::iterator MII = MBBI->begin(), MIE = MBBI->end();
+         MII != MIE;) {
+      MachineInstr *MI = MII;
+      ++MII;
+
+      for (MachineInstr::mop_iterator MOI = MI->operands_begin(),
+           MOE = MI->operands_end(); MOI != MOE; ++MOI) {
+        MachineOperand &MO = *MOI;
+        if (!MO.isReg() || !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
+          continue;
+        unsigned VirtReg = MO.getReg();
+        unsigned PhysReg = getPhys(VirtReg);
+        assert(PhysReg != NO_PHYS_REG && "Instruction uses unmapped VirtReg");
+
+        // Preserve semantics of sub-register operands.
+        if (MO.getSubReg()) {
+          // A virtual register kill refers to the whole register, so we may
+          // have to add <imp-use,kill> operands for the super-register.
+          if (MO.isUse() && MO.isKill() && !MO.isUndef())
+            SuperKills.push_back(PhysReg);
+
+          // We don't have to deal with sub-register defs because
+          // LiveIntervalAnalysis already added the necessary <imp-def>
+          // operands.
+
+          // PhysReg operands cannot have subregister indexes.
+          PhysReg = TRI->getSubReg(PhysReg, MO.getSubReg());
+          assert(PhysReg && "Invalid SubReg for physical register");
+          MO.setSubReg(0);
+        }
+        // Rewrite. Note we could have used MachineOperand::substPhysReg(), but
+        // we need the inlining here.
+        MO.setReg(PhysReg);
+      }
+
+      // Add any missing super-register kills after rewriting the whole
+      // instruction.
+      while (!SuperKills.empty())
+        MI->addRegisterKilled(SuperKills.pop_back_val(), TRI, true);
+
+      DEBUG(dbgs() << "> " << *MI);
+
+      // Finally, remove any identity copies.
+      if (MI->isIdentityCopy()) {
+        if (MI->getNumOperands() == 2) {
+          DEBUG(dbgs() << "Deleting identity copy.\n");
+          RemoveMachineInstrFromMaps(MI);
+          if (Indexes)
+            Indexes->removeMachineInstrFromMaps(MI);
+          // It's safe to erase MI because MII has already been incremented.
+          MI->eraseFromParent();
+        } else {
+          // Transform identity copy to a KILL to deal with subregisters.
+          MI->setDesc(TII->get(TargetOpcode::KILL));
+          DEBUG(dbgs() << "Identity copy: " << *MI);
+        }
+      }
+    }
+  }
+
+  // Tell MRI about physical registers in use.
+  for (unsigned Reg = 1, RegE = TRI->getNumRegs(); Reg != RegE; ++Reg)
+    if (!MRI->reg_nodbg_empty(Reg))
+      MRI->setPhysRegUsed(Reg);
+}
+
 void VirtRegMap::print(raw_ostream &OS, const Module* M) const {
   const TargetRegisterInfo* TRI = MF->getTarget().getRegisterInfo();
   const MachineRegisterInfo &MRI = MF->getRegInfo();
@@ -263,20 +339,16 @@ void VirtRegMap::print(raw_ostream &OS, const Module* M) const {
   for (unsigned i = 0, e = MRI.getNumVirtRegs(); i != e; ++i) {
     unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
     if (Virt2PhysMap[Reg] != (unsigned)VirtRegMap::NO_PHYS_REG) {
-      OS << '[';
-      TRI->printReg(Reg, OS);
-      OS << " -> ";
-      TRI->printReg(Virt2PhysMap[Reg], OS);
-      OS << "] " << MRI.getRegClass(i)->getName() << "\n";
+      OS << '[' << PrintReg(Reg, TRI) << " -> "
+         << PrintReg(Virt2PhysMap[Reg], TRI) << "] "
+         << MRI.getRegClass(Reg)->getName() << "\n";
     }
   }
 
   for (unsigned i = 0, e = MRI.getNumVirtRegs(); i != e; ++i) {
     unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
     if (Virt2StackSlotMap[Reg] != VirtRegMap::NO_STACK_SLOT) {
-      OS << '[';
-      TRI->printReg(Reg, OS);
-      OS << " -> fi#" << Virt2StackSlotMap[Reg]
+      OS << '[' << PrintReg(Reg, TRI) << " -> fi#" << Virt2StackSlotMap[Reg]
          << "] " << MRI.getRegClass(Reg)->getName() << "\n";
     }
   }