X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FRegisterScavenging.cpp;h=75ebdaa357f789754ba6a96999b4f103c26644eb;hb=9bcad42c3aadab118b6ed5f30f2ea0d87228fd3f;hp=55a66ba54828598789ec099878413f8709bf6285;hpb=b6cfeb63f8192724362565567a4cb4aa642baa1d;p=oota-llvm.git

diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index 55a66ba5482..75ebdaa357f 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -31,9 +31,8 @@ using namespace llvm;
 
 /// setUsed - Set the register and its sub-registers as being used.
 void RegScavenger::setUsed(unsigned Reg) {
-  RegsAvailable.reset(Reg);
-
-  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+  for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+       SubRegs.isValid(); ++SubRegs)
     RegsAvailable.reset(*SubRegs);
 }
 
@@ -45,8 +44,8 @@ bool RegScavenger::isAliasUsed(unsigned Reg) const {
 }
 
 void RegScavenger::initRegState() {
-  for (SmallVector<ScavengedInfo, 2>::iterator I = Scavenged.begin(),
-       IE = Scavenged.end(); I != IE; ++I) {
+  for (SmallVectorImpl<ScavengedInfo>::iterator I = Scavenged.begin(),
+         IE = Scavenged.end(); I != IE; ++I) {
     I->Reg = 0;
     I->Restore = NULL;
   }
@@ -105,35 +104,16 @@ void RegScavenger::enterBasicBlock(MachineBasicBlock *mbb) {
 }
 
 void RegScavenger::addRegWithSubRegs(BitVector &BV, unsigned Reg) {
-  BV.set(Reg);
-  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+  for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+       SubRegs.isValid(); ++SubRegs)
     BV.set(*SubRegs);
 }
 
-void RegScavenger::forward() {
-  // Move ptr forward.
-  if (!Tracking) {
-    MBBI = MBB->begin();
-    Tracking = true;
-  } else {
-    assert(MBBI != MBB->end() && "Already past the end of the basic block!");
-    MBBI = llvm::next(MBBI);
-  }
-  assert(MBBI != MBB->end() && "Already at the end of the basic block!");
+void RegScavenger::determineKillsAndDefs() {
+  assert(Tracking && "Must be tracking to determine kills and defs");
 
   MachineInstr *MI = MBBI;
-
-  for (SmallVector<ScavengedInfo, 2>::iterator I = Scavenged.begin(),
-       IE = Scavenged.end(); I != IE; ++I) {
-    if (I->Restore != MI)
-      continue;
-
-    I->Reg = 0;
-    I->Restore = NULL;
-  }
-
-  if (MI->isDebugValue())
-    return;
+  assert(!MI->isDebugValue() && "Debug values have no kills or defs");
 
   // Find out which registers are early clobbered, killed, defined, and marked
   // def-dead in this instruction.
@@ -167,6 +147,53 @@ void RegScavenger::forward() {
         addRegWithSubRegs(DefRegs, Reg);
     }
   }
+}
+
+void RegScavenger::unprocess() {
+  assert(Tracking && "Cannot unprocess because we're not tracking");
+
+  MachineInstr *MI = MBBI;
+  if (!MI->isDebugValue()) {
+    determineKillsAndDefs();
+
+    // Commit the changes.
+    setUsed(KillRegs);
+    setUnused(DefRegs);
+  }
+
+  if (MBBI == MBB->begin()) {
+    MBBI = MachineBasicBlock::iterator(NULL);
+    Tracking = false;
+  } else
+    --MBBI;
+}
+
+void RegScavenger::forward() {
+  // Move ptr forward.
+  if (!Tracking) {
+    MBBI = MBB->begin();
+    Tracking = true;
+  } else {
+    assert(MBBI != MBB->end() && "Already past the end of the basic block!");
+    MBBI = llvm::next(MBBI);
+  }
+  assert(MBBI != MBB->end() && "Already at the end of the basic block!");
+
+  MachineInstr *MI = MBBI;
+
+  for (SmallVectorImpl<ScavengedInfo>::iterator I = Scavenged.begin(),
+         IE = Scavenged.end(); I != IE; ++I) {
+    if (I->Restore != MI)
+      continue;
+
+    I->Reg = 0;
+    I->Restore = NULL;
+  }
+
+  if (MI->isDebugValue())
+    return;
+
+  determineKillsAndDefs();
 
   // Verify uses and defs.
 #ifndef NDEBUG
@@ -341,7 +368,7 @@ unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC,
   // Exclude all the registers being used by the instruction.
   for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
     MachineOperand &MO = I->getOperand(i);
-    if (MO.isReg() && MO.getReg() != 0 &&
+    if (MO.isReg() && MO.getReg() != 0 && !(MO.isUse() && MO.isUndef()) &&
         !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
       Candidates.reset(MO.getReg());
   }