X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FMachineCopyPropagation.cpp;h=4f48e2cd9720a96d3ada07f5fec611ba3174e22f;hb=566fb9fe3ed767be7218fb1608ec6a284067d3b0;hp=4a793281b2cd7e8f8cde8b9e89a896a9fc1f3d61;hpb=fb9ebbf236974beac31705eaeb9f50ab585af6ab;p=oota-llvm.git

diff --git a/lib/CodeGen/MachineCopyPropagation.cpp b/lib/CodeGen/MachineCopyPropagation.cpp
index 4a793281b2c..4f48e2cd972 100644
--- a/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/lib/CodeGen/MachineCopyPropagation.cpp
@@ -13,19 +13,19 @@
 
 #define DEBUG_TYPE "codegen-cp"
 #include "llvm/CodeGen/Passes.h"
-#include "llvm/Pass.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Pass.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
 using namespace llvm;
 
 STATISTIC(NumDeletes, "Number of dead copies deleted");
@@ -33,6 +33,7 @@ STATISTIC(NumDeletes, "Number of dead copies deleted");
 namespace {
   class MachineCopyPropagation : public MachineFunctionPass {
     const TargetRegisterInfo *TRI;
+    const TargetInstrInfo *TII;
     MachineRegisterInfo *MRI;
 
   public:
@@ -51,6 +52,7 @@ namespace {
                                  SourceMap &SrcMap,
                                  DenseMap<unsigned, MachineInstr*> &AvailCopyMap);
     bool CopyPropagateBlock(MachineBasicBlock &MBB);
+    void removeCopy(MachineInstr *MI);
   };
 }
 char MachineCopyPropagation::ID = 0;
@@ -124,6 +126,16 @@ static bool isNopCopy(MachineInstr *CopyMI, unsigned Def, unsigned Src,
   return false;
 }
 
+// Remove MI from the function because it has been determined it is dead.
+// Turn it into a noop KILL instruction if it has super-register liveness
+// adjustments.
+void MachineCopyPropagation::removeCopy(MachineInstr *MI) {
+  if (MI->getNumOperands() == 2)
+    MI->eraseFromParent();
+  else
+    MI->setDesc(TII->get(TargetOpcode::KILL));
+}
+
 bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
   SmallSetVector<MachineInstr*, 8> MaybeDeadCopies;  // Candidates for deletion
   DenseMap<unsigned, MachineInstr*> AvailCopyMap;    // Def -> available copies map
@@ -169,7 +181,7 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
           for (MachineBasicBlock::iterator I = CopyMI, E = MI; I != E; ++I)
             I->clearRegisterKills(Def, TRI);
 
-          MI->eraseFromParent();
+          removeCopy(MI);
           Changed = true;
           ++NumDeletes;
           continue;
@@ -201,9 +213,8 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
         CopyMap.erase(*AI);
         AvailCopyMap.erase(*AI);
       }
-      CopyMap[Def] = MI;
-      AvailCopyMap[Def] = MI;
-      for (MCSubRegIterator SR(Def, TRI); SR.isValid(); ++SR) {
+      for (MCSubRegIterator SR(Def, TRI, /*IncludeSelf=*/true); SR.isValid();
+           ++SR) {
         CopyMap[*SR] = MI;
         AvailCopyMap[*SR] = MI;
       }
@@ -262,7 +273,7 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
         unsigned Reg = (*DI)->getOperand(0).getReg();
         if (MRI->isReserved(Reg) || !MaskMO.clobbersPhysReg(Reg))
           continue;
-        (*DI)->eraseFromParent();
+        removeCopy(*DI);
         Changed = true;
         ++NumDeletes;
       }
@@ -298,7 +309,7 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
            DI = MaybeDeadCopies.begin(), DE = MaybeDeadCopies.end();
          DI != DE; ++DI) {
       if (!MRI->isReserved((*DI)->getOperand(0).getReg())) {
-        (*DI)->eraseFromParent();
+        removeCopy(*DI);
         Changed = true;
         ++NumDeletes;
       }
@@ -312,6 +323,7 @@ bool MachineCopyPropagation::runOnMachineFunction(MachineFunction &MF) {
   bool Changed = false;
 
   TRI = MF.getTarget().getRegisterInfo();
+  TII = MF.getTarget().getInstrInfo();
   MRI = &MF.getRegInfo();
 
   for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)