X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FRegisterScavenging.cpp;h=d673794e1b9392ab3e660d175ebe6063807e8424;hb=ed84062812c7b8a82d0e8128a22aa1aa07a14d79;hp=3cb44b6d2537b5838f4acf17fea27074630fd5f2;hpb=9f946a24d9e69559d1e0aeb6d128c2fa19846c92;p=oota-llvm.git

diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index 3cb44b6d253..d673794e1b9 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -37,16 +37,13 @@ using namespace llvm;
 void RegScavenger::setUsed(unsigned Reg) {
   RegsAvailable.reset(Reg);
 
-  for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
-       unsigned SubReg = *SubRegs; ++SubRegs)
-    RegsAvailable.reset(SubReg);
+  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+    RegsAvailable.reset(*SubRegs);
 }
 
 bool RegScavenger::isAliasUsed(unsigned Reg) const {
-  if (isUsed(Reg))
-    return true;
-  for (const unsigned *R = TRI->getAliasSet(Reg); *R; ++R)
-    if (isUsed(*R))
+  for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
+    if (isUsed(*AI))
       return true;
   return false;
 }
@@ -59,9 +56,6 @@ void RegScavenger::initRegState() {
   // All registers started out unused.
   RegsAvailable.set();
 
-  // Reserved registers are always used.
-  RegsAvailable ^= ReservedRegs;
-
   if (!MBB)
     return;
 
@@ -86,6 +80,11 @@ void RegScavenger::enterBasicBlock(MachineBasicBlock *mbb) {
   assert((NumPhysRegs == 0 || NumPhysRegs == TRI->getNumRegs()) &&
          "Target changed?");
 
+  // It is not possible to use the register scavenger after late optimization
+  // passes that don't preserve accurate liveness information.
+  assert(MRI->tracksLiveness() &&
+         "Cannot use register scavenger with inaccurate liveness");
+
   // Self-initialize.
   if (!MBB) {
     NumPhysRegs = TRI->getNumRegs();
@@ -98,7 +97,7 @@ void RegScavenger::enterBasicBlock(MachineBasicBlock *mbb) {
 
     // Create callee-saved registers bitvector.
     CalleeSavedRegs.resize(NumPhysRegs);
-    const unsigned *CSRegs = TRI->getCalleeSavedRegs(&MF);
+    const uint16_t *CSRegs = TRI->getCalleeSavedRegs(&MF);
     if (CSRegs != NULL)
       for (unsigned i = 0; CSRegs[i]; ++i)
         CalleeSavedRegs.set(CSRegs[i]);
@@ -112,8 +111,8 @@ void RegScavenger::enterBasicBlock(MachineBasicBlock *mbb) {
 
 void RegScavenger::addRegWithSubRegs(BitVector &BV, unsigned Reg) {
   BV.set(Reg);
-  for (const unsigned *R = TRI->getSubRegisters(Reg); *R; R++)
-    BV.set(*R);
+  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+    BV.set(*SubRegs);
 }
 
 void RegScavenger::forward() {
@@ -148,6 +147,8 @@ void RegScavenger::forward() {
   DefRegs.reset();
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
     const MachineOperand &MO = MI->getOperand(i);
+    if (MO.isRegMask())
+      (isPred ? DefRegs : KillRegs).setBitsNotInMask(MO.getRegMask());
     if (!MO.isReg())
       continue;
     unsigned Reg = MO.getReg();
@@ -191,9 +192,8 @@ void RegScavenger::forward() {
         // Ideally we would like a way to model this, but leaving the
         // insert_subreg around causes both correctness and performance issues.
         bool SubUsed = false;
-        for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
-             unsigned SubReg = *SubRegs; ++SubRegs)
-          if (isUsed(SubReg)) {
+        for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+          if (isUsed(*SubRegs)) {
             SubUsed = true;
             break;
           }
@@ -223,9 +223,11 @@ void RegScavenger::forward() {
 
 void RegScavenger::getRegsUsed(BitVector &used, bool includeReserved) {
   used = RegsAvailable;
-  if (!includeReserved)
-    used |= ReservedRegs;
   used.flip();
+  if (includeReserved)
+    used |= ReservedRegs;
+  else
+    used.reset(ReservedRegs);
 }
 
 unsigned RegScavenger::FindUnusedReg(const TargetRegisterClass *RC) const {
@@ -279,6 +281,8 @@ unsigned RegScavenger::findSurvivorReg(MachineBasicBlock::iterator StartMI,
     // Remove any candidates touched by instruction.
     for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
       const MachineOperand &MO = MI->getOperand(i);
+      if (MO.isRegMask())
+        Candidates.clearBitsNotInMask(MO.getRegMask());
       if (!MO.isReg() || MO.isUndef() || !MO.getReg())
         continue;
       if (TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
@@ -288,9 +292,8 @@ unsigned RegScavenger::findSurvivorReg(MachineBasicBlock::iterator StartMI,
           isVirtKillInsn = true;
         continue;
       }
-      Candidates.reset(MO.getReg());
-      for (const unsigned *R = TRI->getAliasSet(MO.getReg()); *R; R++)
-        Candidates.reset(*R);
+      for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid(); ++AI)
+        Candidates.reset(*AI);
     }
     // If we're not in a virtual reg's live range, this is a valid
     // restore point.