use assertions instead of unreachable for logic errors.

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

diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp
index 1c5222c38e7cbf08ab88008d90e662592747cb6f..2d49beb7d7615dc1fb826a33d7067cb6ea61da0c 100644 (file)
--- a/lib/CodeGen/PreAllocSplitting.cpp
+++ b/lib/CodeGen/PreAllocSplitting.cpp
@@ -481,32 +481,21 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
     
     // Search for the use in this block that precedes the instruction we care 
     // about, going to the fallback case if we don't find it.    
-    if (UseI == MBB->begin())
-      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
-                                            Uses, NewVNs, LiveOut, Phis,
-                                            IsTopLevel, IsIntraBlock);
-    
     MachineBasicBlock::iterator Walker = UseI;
-    --Walker;
     bool found = false;
     while (Walker != MBB->begin()) {
+      --Walker;
       if (BlockUses.count(Walker)) {
         found = true;
         break;
       }
-      --Walker;
-    }
-        
-    // Must check begin() too.
-    if (!found) {
-      if (BlockUses.count(Walker))
-        found = true;
-      else
-        return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
-                                              Uses, NewVNs, LiveOut, Phis,
-                                              IsTopLevel, IsIntraBlock);
     }
 
+    if (!found)
+      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+                                            Uses, NewVNs, LiveOut, Phis,
+                                            IsTopLevel, IsIntraBlock);
+
     SlotIndex UseIndex = LIs->getInstructionIndex(Walker);
     UseIndex = UseIndex.getUseIndex();
     SlotIndex EndIndex;
@@ -533,17 +522,11 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
     // This case is basically a merging of the two preceding case, with the
     // special note that checking for defs must take precedence over checking
     // for uses, because of two-address instructions.
-    
-    if (UseI == MBB->begin())
-      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs, Uses,
-                                            NewVNs, LiveOut, Phis,
-                                            IsTopLevel, IsIntraBlock);
-    
     MachineBasicBlock::iterator Walker = UseI;
-    --Walker;
     bool foundDef = false;
     bool foundUse = false;
     while (Walker != MBB->begin()) {
+      --Walker;
       if (BlockDefs.count(Walker)) {
         foundDef = true;
         break;
@@ -551,21 +534,13 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
         foundUse = true;
         break;
       }
-      --Walker;
-    }
-        
-    // Must check begin() too.
-    if (!foundDef && !foundUse) {
-      if (BlockDefs.count(Walker))
-        foundDef = true;
-      else if (BlockUses.count(Walker))
-        foundUse = true;
-      else
-        return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
-                                              Uses, NewVNs, LiveOut, Phis,
-                                              IsTopLevel, IsIntraBlock);
     }
 
+    if (!foundDef && !foundUse)
+      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+                                            Uses, NewVNs, LiveOut, Phis,
+                                            IsTopLevel, IsIntraBlock);
+
     SlotIndex StartIndex = LIs->getInstructionIndex(Walker);
     StartIndex = foundDef ? StartIndex.getDefIndex() : StartIndex.getUseIndex();
     SlotIndex EndIndex;
@@ -690,7 +665,7 @@ PreAllocSplitting::PerformPHIConstructionFallBack(MachineBasicBlock::iterator Us
 
 /// ReconstructLiveInterval - Recompute a live interval from scratch.
 void PreAllocSplitting::ReconstructLiveInterval(LiveInterval* LI) {
-  BumpPtrAllocator& Alloc = LIs->getVNInfoAllocator();
+  VNInfo::Allocator& Alloc = LIs->getVNInfoAllocator();
   
   // Clear the old ranges and valnos;
   LI->clear();
@@ -711,8 +686,7 @@ void PreAllocSplitting::ReconstructLiveInterval(LiveInterval* LI) {
     SlotIndex DefIdx = LIs->getInstructionIndex(&*DI);
     DefIdx = DefIdx.getDefIndex();
     
-    assert(DI->getOpcode() != TargetInstrInfo::PHI &&
-           "PHI instr in code during pre-alloc splitting.");
+    assert(!DI->isPHI() && "PHI instr in code during pre-alloc splitting.");
     VNInfo* NewVN = LI->getNextValue(DefIdx, 0, true, Alloc);
     
     // If the def is a move, set the copy field.
@@ -1022,7 +996,7 @@ MachineInstr* PreAllocSplitting::FoldRestore(unsigned vreg,
 /// so it would not cross the barrier that's being processed. Shrink wrap
 /// (minimize) the live interval to the last uses.
 bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
-  DEBUG(errs() << "Pre-alloc splitting " << LI->reg << " for " << *Barrier
+  DEBUG(dbgs() << "Pre-alloc splitting " << LI->reg << " for " << *Barrier
                << "  result: ");
 
   CurrLI = LI;
@@ -1039,7 +1013,7 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
 
   // If this would create a new join point, do not split.
   if (DefMI && createsNewJoin(LR, DefMI->getParent(), Barrier->getParent())) {
-    DEBUG(errs() << "FAILED (would create a new join point).\n");
+    DEBUG(dbgs() << "FAILED (would create a new join point).\n");
     return false;
   }
 
@@ -1056,13 +1030,13 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
   MachineBasicBlock::iterator RestorePt =
     findRestorePoint(BarrierMBB, Barrier, LR->end, RefsInMBB);
   if (RestorePt == BarrierMBB->end()) {
-    DEBUG(errs() << "FAILED (could not find a suitable restore point).\n");
+    DEBUG(dbgs() << "FAILED (could not find a suitable restore point).\n");
     return false;
   }
 
   if (DefMI && LIs->isReMaterializable(*LI, ValNo, DefMI))
     if (Rematerialize(LI->reg, ValNo, DefMI, RestorePt, RefsInMBB)) {
-      DEBUG(errs() << "success (remat).\n");
+      DEBUG(dbgs() << "success (remat).\n");
       return true;
     }
 
@@ -1081,7 +1055,7 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
       MachineBasicBlock::iterator SpillPt = 
         findSpillPoint(BarrierMBB, Barrier, NULL, RefsInMBB);
       if (SpillPt == BarrierMBB->begin()) {
-        DEBUG(errs() << "FAILED (could not find a suitable spill point).\n");
+        DEBUG(dbgs() << "FAILED (could not find a suitable spill point).\n");
         return false; // No gap to insert spill.
       }
       // Add spill.
@@ -1096,7 +1070,7 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
     // If it's already split, just restore the value. There is no need to spill
     // the def again.
     if (!DefMI) {
-      DEBUG(errs() << "FAILED (def is dead).\n");
+      DEBUG(dbgs() << "FAILED (def is dead).\n");
       return false; // Def is dead. Do nothing.
     }
     
@@ -1111,13 +1085,13 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
         SpillPt = findSpillPoint(BarrierMBB, Barrier, DefMI,
                                  RefsInMBB);
         if (SpillPt == DefMBB->begin()) {
-          DEBUG(errs() << "FAILED (could not find a suitable spill point).\n");
+          DEBUG(dbgs() << "FAILED (could not find a suitable spill point).\n");
           return false; // No gap to insert spill.
         }
       } else {
         SpillPt = llvm::next(MachineBasicBlock::iterator(DefMI));
         if (SpillPt == DefMBB->end()) {
-          DEBUG(errs() << "FAILED (could not find a suitable spill point).\n");
+          DEBUG(dbgs() << "FAILED (could not find a suitable spill point).\n");
           return false; // No gap to insert spill.
         }
       }
@@ -1160,7 +1134,7 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
   }
   
   ++NumSplits;
-  DEBUG(errs() << "success.\n");
+  DEBUG(dbgs() << "success.\n");
   return true;
 }