X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FCalcSpillWeights.cpp;h=ea16a253a348c1cc42e600ea0d2835fc7b0d0248;hb=70303688bc489a316cb0892499ac4024088fa58a;hp=02adae0eddf3f5706546562d30567ad39ab7eb92;hpb=df30cf9e61e6586b45b74d1312bef1ee758ef94f;p=oota-llvm.git

diff --git a/lib/CodeGen/CalcSpillWeights.cpp b/lib/CodeGen/CalcSpillWeights.cpp
index 02adae0eddf..ea16a253a34 100644
--- a/lib/CodeGen/CalcSpillWeights.cpp
+++ b/lib/CodeGen/CalcSpillWeights.cpp
@@ -25,8 +25,12 @@
 using namespace llvm;
 
 char CalculateSpillWeights::ID = 0;
-INITIALIZE_PASS(CalculateSpillWeights, "calcspillweights",
-                "Calculate spill weights", false, false);
+INITIALIZE_PASS_BEGIN(CalculateSpillWeights, "calcspillweights",
+                "Calculate spill weights", false, false)
+INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
+INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_PASS_END(CalculateSpillWeights, "calcspillweights",
+                "Calculate spill weights", false, false)
 
 void CalculateSpillWeights::getAnalysisUsage(AnalysisUsage &au) const {
   au.addRequired<LiveIntervals>();
@@ -83,8 +87,8 @@ static unsigned copyHint(const MachineInstr *mi, unsigned reg,
 }
 
 void VirtRegAuxInfo::CalculateWeightAndHint(LiveInterval &li) {
-  MachineRegisterInfo &mri = mf_.getRegInfo();
-  const TargetRegisterInfo &tri = *mf_.getTarget().getRegisterInfo();
+  MachineRegisterInfo &mri = MF.getRegInfo();
+  const TargetRegisterInfo &tri = *MF.getTarget().getRegisterInfo();
   MachineBasicBlock *mbb = 0;
   MachineLoop *loop = 0;
   unsigned loopDepth = 0;
@@ -99,6 +103,9 @@ void VirtRegAuxInfo::CalculateWeightAndHint(LiveInterval &li) {
   // Don't recompute a target specific hint.
   bool noHint = mri.getRegAllocationHint(li.reg).first != 0;
 
+  // Don't recompute spill weight for an unspillable register.
+  bool Spillable = li.isSpillable();
+
   for (MachineRegisterInfo::reg_iterator I = mri.reg_begin(li.reg);
        MachineInstr *mi = I.skipInstruction();) {
     if (mi->isIdentityCopy() || mi->isImplicitDef() || mi->isDebugValue())
@@ -106,34 +113,37 @@ void VirtRegAuxInfo::CalculateWeightAndHint(LiveInterval &li) {
     if (!visited.insert(mi))
       continue;
 
-    // Get loop info for mi.
-    if (mi->getParent() != mbb) {
-      mbb = mi->getParent();
-      loop = loops_.getLoopFor(mbb);
-      loopDepth = loop ? loop->getLoopDepth() : 0;
-      isExiting = loop ? loop->isLoopExiting(mbb) : false;
+    float weight = 1.0f;
+    if (Spillable) {
+      // Get loop info for mi.
+      if (mi->getParent() != mbb) {
+        mbb = mi->getParent();
+        loop = Loops.getLoopFor(mbb);
+        loopDepth = loop ? loop->getLoopDepth() : 0;
+        isExiting = loop ? loop->isLoopExiting(mbb) : false;
+      }
+
+      // Calculate instr weight.
+      bool reads, writes;
+      tie(reads, writes) = mi->readsWritesVirtualRegister(li.reg);
+      weight = LiveIntervals::getSpillWeight(writes, reads, loopDepth);
+
+      // Give extra weight to what looks like a loop induction variable update.
+      if (writes && isExiting && LIS.isLiveOutOfMBB(li, mbb))
+        weight *= 3;
+
+      totalWeight += weight;
     }
 
-    // Calculate instr weight.
-    bool reads, writes;
-    tie(reads, writes) = mi->readsWritesVirtualRegister(li.reg);
-    float weight = LiveIntervals::getSpillWeight(writes, reads, loopDepth);
-
-    // Give extra weight to what looks like a loop induction variable update.
-    if (writes && isExiting && lis_.isLiveOutOfMBB(li, mbb))
-      weight *= 3;
-
-    totalWeight += weight;
-
     // Get allocation hints from copies.
     if (noHint || !mi->isCopy())
       continue;
     unsigned hint = copyHint(mi, li.reg, tri, mri);
     if (!hint)
       continue;
-    float hweight = hint_[hint] += weight;
+    float hweight = Hint[hint] += weight;
     if (TargetRegisterInfo::isPhysicalRegister(hint)) {
-      if (hweight > bestPhys && lis_.isAllocatable(hint))
+      if (hweight > bestPhys && LIS.isAllocatable(hint))
         bestPhys = hweight, hintPhys = hint;
     } else {
       if (hweight > bestVirt)
@@ -141,17 +151,21 @@ void VirtRegAuxInfo::CalculateWeightAndHint(LiveInterval &li) {
     }
   }
 
-  hint_.clear();
+  Hint.clear();
 
   // Always prefer the physreg hint.
   if (unsigned hint = hintPhys ? hintPhys : hintVirt) {
     mri.setRegAllocationHint(li.reg, 0, hint);
-    // Weakly boost the spill weifght of hinted registers.
+    // Weakly boost the spill weight of hinted registers.
     totalWeight *= 1.01F;
   }
 
+  // If the live interval was already unspillable, leave it that way.
+  if (!Spillable)
+    return;
+
   // Mark li as unspillable if all live ranges are tiny.
-  if (li.isZeroLength()) {
+  if (li.isZeroLength(LIS.getSlotIndexes())) {
     li.markNotSpillable();
     return;
   }
@@ -162,15 +176,12 @@ void VirtRegAuxInfo::CalculateWeightAndHint(LiveInterval &li) {
   // FIXME: this gets much more complicated once we support non-trivial
   // re-materialization.
   bool isLoad = false;
-  SmallVector<LiveInterval*, 4> spillIs;
-  if (lis_.isReMaterializable(li, spillIs, isLoad)) {
+  if (LIS.isReMaterializable(li, 0, isLoad)) {
     if (isLoad)
       totalWeight *= 0.9F;
     else
       totalWeight *= 0.5F;
   }
 
-  li.weight = totalWeight;
-  lis_.normalizeSpillWeight(li);
+  li.weight = normalizeSpillWeight(totalWeight, li.getSize());
 }
-