Refactor the handling of lexical block and inline scope ranges

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

diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index c08d955540602dd5c723d26db07fdf247d5f5fe1..3a02aaec3448e30eb30fbef6b27b781805c57a9c 100644 (file)
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -160,10 +160,14 @@ class RAGreedy : public MachineFunctionPass,
     unsigned BrokenHints; ///< Total number of broken hints.
     float MaxWeight;      ///< Maximum spill weight evicted.
 
-    EvictionCost(unsigned B = 0) : BrokenHints(B), MaxWeight(0) {}
+    EvictionCost(): BrokenHints(0), MaxWeight(0) {}
 
     bool isMax() const { return BrokenHints == ~0u; }
 
+    void setMax() { BrokenHints = ~0u; }
+
+    void setBrokenHints(unsigned NHints) { BrokenHints = NHints; }
+
     bool operator<(const EvictionCost &O) const {
       if (BrokenHints != O.BrokenHints)
         return BrokenHints < O.BrokenHints;
@@ -217,7 +221,7 @@ class RAGreedy : public MachineFunctionPass,
     }
   };
 
-  /// Candidate info for for each PhysReg in AllocationOrder.
+  /// Candidate info for each PhysReg in AllocationOrder.
   /// This vector never shrinks, but grows to the size of the largest register
   /// class.
   SmallVector<GlobalSplitCandidate, 32> GlobalCand;
@@ -471,7 +475,8 @@ unsigned RAGreedy::tryAssign(LiveInterval &VirtReg,
   if (unsigned Hint = MRI->getSimpleHint(VirtReg.reg))
     if (Order.isHint(Hint)) {
       DEBUG(dbgs() << "missed hint " << PrintReg(Hint, TRI) << '\n');
-      EvictionCost MaxCost(1);
+      EvictionCost MaxCost;
+      MaxCost.setBrokenHints(1);
       if (canEvictInterference(VirtReg, Hint, true, MaxCost)) {
         evictInterference(VirtReg, Hint, NewVRegs);
         return Hint;
@@ -543,7 +548,11 @@ bool RAGreedy::shouldEvict(LiveInterval &A, bool IsHint,
   if (CanSplit && IsHint && !BreaksHint)
     return true;
 
-  return A.weight > B.weight;
+  if (A.weight > B.weight) {
+    DEBUG(dbgs() << "should evict: " << B << " w= " << B.weight << '\n');
+    return true;
+  }
+  return false;
 }
 
 /// canEvictInterference - Return true if all interferences between VirtReg and
@@ -618,6 +627,9 @@ bool RAGreedy::canEvictInterference(LiveInterval &VirtReg, unsigned PhysReg,
         return false;
       if (Urgent)
         continue;
+      // Apply the eviction policy for non-urgent evictions.
+      if (!shouldEvict(VirtReg, IsHint, *Intf, BreaksHint))
+        return false;
       // If !MaxCost.isMax(), then we're just looking for a cheap register.
       // Evicting another local live range in this case could lead to suboptimal
       // coloring.
@@ -625,9 +637,6 @@ bool RAGreedy::canEvictInterference(LiveInterval &VirtReg, unsigned PhysReg,
           !canReassign(*Intf, PhysReg)) {
         return false;
       }
-      // Finally, apply the eviction policy for non-urgent evictions.
-      if (!shouldEvict(VirtReg, IsHint, *Intf, BreaksHint))
-        return false;
     }
   }
   MaxCost = Cost;
@@ -685,7 +694,8 @@ unsigned RAGreedy::tryEvict(LiveInterval &VirtReg,
   NamedRegionTimer T("Evict", TimerGroupName, TimePassesIsEnabled);
 
   // Keep track of the cheapest interference seen so far.
-  EvictionCost BestCost(~0u);
+  EvictionCost BestCost;
+  BestCost.setMax();
   unsigned BestPhys = 0;
   unsigned OrderLimit = Order.getOrder().size();