[llvm-commits] [llvm] r110975 - in /llvm/trunk/lib/CodeGen: SplitKit.cpp SplitKit.h

[Jakob Stoklund Olesen]

Author: stoklund
Date: Thu Aug 12 18:02:55 2010
New Revision: 110975

URL: http://llvm.org/viewvc/llvm-project?rev=110975&view=rev
Log:
Update the SplitAnalysis statistics as uses are moved from curli to the new
split intervals. THis means the analysis can be used for multiple splits as long
as curli doesn't shrink.

Modified:
    llvm/trunk/lib/CodeGen/SplitKit.cpp
    llvm/trunk/lib/CodeGen/SplitKit.h

Modified: llvm/trunk/lib/CodeGen/SplitKit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SplitKit.cpp?rev=110975&r1=110974&r2=110975&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SplitKit.cpp (original)
+++ llvm/trunk/lib/CodeGen/SplitKit.cpp Thu Aug 12 18:02:55 2010
@@ -70,7 +70,7 @@
     if (usingBlocks_[MBB]++)
       continue;
     if (MachineLoop *Loop = loops_.getLoopFor(MBB))
-      usingLoops_.insert(Loop);
+      usingLoops_[Loop]++;
   }
   DEBUG(dbgs() << "  counted "
                << usingInstrs_.size() << " instrs, "
@@ -78,6 +78,34 @@
                << usingLoops_.size()  << " loops.\n");
 }
 
+/// removeUse - Update statistics by noting that MI no longer uses curli.
+void SplitAnalysis::removeUse(const MachineInstr *MI) {
+  if (!usingInstrs_.erase(MI))
+    return;
+
+  // Decrement MBB count.
+  const MachineBasicBlock *MBB = MI->getParent();
+  BlockCountMap::iterator bi = usingBlocks_.find(MBB);
+  assert(bi != usingBlocks_.end() && "MBB missing");
+  assert(bi->second && "0 count in map");
+  if (--bi->second)
+    return;
+  // No more uses in MBB.
+  usingBlocks_.erase(bi);
+
+  // Decrement loop count.
+  MachineLoop *Loop = loops_.getLoopFor(MBB);
+  if (!Loop)
+    return;
+  LoopCountMap::iterator li = usingLoops_.find(Loop);
+  assert(li != usingLoops_.end() && "Loop missing");
+  assert(li->second && "0 count in map");
+  if (--li->second)
+    return;
+  // No more blocks in Loop.
+  usingLoops_.erase(li);
+}
+
 // Get three sets of basic blocks surrounding a loop: Blocks inside the loop,
 // predecessor blocks, and exit blocks.
 void SplitAnalysis::getLoopBlocks(const MachineLoop *Loop, LoopBlocks &Blocks) {
@@ -219,13 +247,14 @@
 
   // Find first-class and second class candidate loops.
   // We prefer to split around loops where curli is used outside the periphery.
-  for (LoopPtrSet::const_iterator I = usingLoops_.begin(),
+  for (LoopCountMap::const_iterator I = usingLoops_.begin(),
        E = usingLoops_.end(); I != E; ++I) {
-    getLoopBlocks(*I, Blocks);
+    const MachineLoop *Loop = I->first;
+    getLoopBlocks(Loop, Blocks);
 
     // FIXME: We need an SSA updater to properly handle multiple exit blocks.
     if (Blocks.Exits.size() > 1) {
-      DEBUG(dbgs() << "  multiple exits from " << **I);
+      DEBUG(dbgs() << "  multiple exits from " << *Loop);
       continue;
     }
 
@@ -238,21 +267,21 @@
       LPS = &SecondLoops;
       break;
     case ContainedInLoop:
-      DEBUG(dbgs() << "  contained in " << **I);
+      DEBUG(dbgs() << "  contained in " << *Loop);
       continue;
     case SinglePeripheral:
-      DEBUG(dbgs() << "  single peripheral use in " << **I);
+      DEBUG(dbgs() << "  single peripheral use in " << *Loop);
       continue;
     }
     // Will it be possible to split around this loop?
     getCriticalExits(Blocks, CriticalExits);
     DEBUG(dbgs() << "  " << CriticalExits.size() << " critical exits from "
-                 << **I);
+                 << *Loop);
     if (!canSplitCriticalExits(Blocks, CriticalExits))
       continue;
     // This is a possible split.
     assert(LPS);
-    LPS->insert(*I);
+    LPS->insert(Loop);
   }
 
   DEBUG(dbgs() << "  getBestSplitLoop found " << Loops.size() << " + "

Modified: llvm/trunk/lib/CodeGen/SplitKit.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SplitKit.h?rev=110975&r1=110974&r2=110975&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SplitKit.h (original)
+++ llvm/trunk/lib/CodeGen/SplitKit.h Thu Aug 12 18:02:55 2010
@@ -45,9 +45,9 @@
   typedef DenseMap<const MachineBasicBlock*, unsigned> BlockCountMap;
   BlockCountMap usingBlocks_;
 
-  // Loops where the curent interval is used.
-  typedef SmallPtrSet<const MachineLoop*, 16> LoopPtrSet;
-  LoopPtrSet usingLoops_;
+  // The number of basic block using curli in each loop.
+  typedef DenseMap<const MachineLoop*, unsigned> LoopCountMap;
+  LoopCountMap usingLoops_;
 
 private:
   // Current live interval.
@@ -68,6 +68,9 @@
   /// split.
   void analyze(const LiveInterval *li);
 
+  /// removeUse - Update statistics by noting that mi no longer uses curli.
+  void removeUse(const MachineInstr *mi);
+
   const LiveInterval *getCurLI() { return curli_; }
 
   /// clear - clear all data structures so SplitAnalysis is ready to analyze a
@@ -75,6 +78,7 @@
   void clear();
 
   typedef SmallPtrSet<const MachineBasicBlock*, 16> BlockPtrSet;
+  typedef SmallPtrSet<const MachineLoop*, 16> LoopPtrSet;
 
   // Sets of basic blocks surrounding a machine loop.
   struct LoopBlocks {