CalculateSpillWeights does not need to be a pass
authorArnaud A. de Grandmaison <arnaud.adegm@gmail.com>
Fri, 8 Nov 2013 17:56:29 +0000 (17:56 +0000)
committerArnaud A. de Grandmaison <arnaud.adegm@gmail.com>
Fri, 8 Nov 2013 17:56:29 +0000 (17:56 +0000)
Based on discussions with Lang Hames and Jakob Stoklund Olesen at the hacker's lab, and in the light of upcoming work on the PBQP register allocator, it was though that CalcSpillWeights does not need to be a pass. This change will enable to customize / tune the spill weight computation depending on the allocator.

Update the documentation style while there.

No functionnal change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194269 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/CalcSpillWeights.h
include/llvm/InitializePasses.h
lib/CodeGen/CalcSpillWeights.cpp
lib/CodeGen/CodeGen.cpp
lib/CodeGen/RegAllocBasic.cpp
lib/CodeGen/RegAllocGreedy.cpp
lib/CodeGen/RegAllocPBQP.cpp

index c8ec76410ce71507937c2a3a8e1507f9eed4517e..00d9c6a5e627b4b72a35559e5f4f9d2555382a07 100644 (file)
@@ -21,7 +21,9 @@ namespace llvm {
   class MachineBlockFrequencyInfo;
   class MachineLoopInfo;
 
-  /// normalizeSpillWeight - The spill weight of a live interval is computed as:
+  /// \brief Normalize the spill weight of a live interval
+  ///
+  /// The spill weight of a live interval is computed as:
   ///
   ///   (sum(use freq) + sum(def freq)) / (K + size)
   ///
@@ -38,8 +40,8 @@ namespace llvm {
     return UseDefFreq / (Size + 25*SlotIndex::InstrDist);
   }
 
-  /// VirtRegAuxInfo - Calculate auxiliary information for a virtual
-  /// register such as its spill weight and allocation hint.
+  /// \brief Calculate auxiliary information for a virtual register such as its
+  /// spill weight and allocation hint.
   class VirtRegAuxInfo {
     MachineFunction &MF;
     LiveIntervals &LIS;
@@ -52,29 +54,16 @@ namespace llvm {
                    const MachineBlockFrequencyInfo &mbfi)
         : MF(mf), LIS(lis), Loops(loops), MBFI(mbfi) {}
 
-    /// CalculateWeightAndHint - (re)compute li's spill weight and allocation
-    /// hint.
+    /// \brief (re)compute li's spill weight and allocation hint.
     void CalculateWeightAndHint(LiveInterval &li);
   };
 
-  /// CalculateSpillWeights - Compute spill weights for all virtual register
+  /// \brief Compute spill weights and allocation hints for all virtual register
   /// live intervals.
-  class CalculateSpillWeights : public MachineFunctionPass {
-  public:
-    static char ID;
-
-    CalculateSpillWeights() : MachineFunctionPass(ID) {
-      initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
-    }
-
-    virtual void getAnalysisUsage(AnalysisUsage &au) const;
-
-    virtual bool runOnMachineFunction(MachineFunction &fn);
-
-  private:
-    /// Returns true if the given live interval is zero length.
-    bool isZeroLengthInterval(LiveInterval *li) const;
-  };
+  void calculateSpillWeights(LiveIntervals &LIS,
+                             MachineFunction &MF,
+                             const MachineLoopInfo &MLI,
+                             const MachineBlockFrequencyInfo &MBFI);
 
 }
 
index fe26c2381a323cc2221538ff7e78aced8308cd4d..68825a33a15fe4270b94737373a4dcd105f9840a 100644 (file)
@@ -89,7 +89,6 @@ void initializeCFGSimplifyPassPass(PassRegistry&);
 void initializeFlattenCFGPassPass(PassRegistry&);
 void initializeStructurizeCFGPass(PassRegistry&);
 void initializeCFGViewerPass(PassRegistry&);
-void initializeCalculateSpillWeightsPass(PassRegistry&);
 void initializeCodeGenPreparePass(PassRegistry&);
 void initializeConstantMergePass(PassRegistry&);
 void initializeConstantPropagationPass(PassRegistry&);
index 67a8755cf06470c21d85c2223374088a6f7489f0..d02ee03adbd6b66279ec9898bf9dc1550d25c820 100644 (file)
 #include "llvm/Target/TargetRegisterInfo.h"
 using namespace llvm;
 
-char CalculateSpillWeights::ID = 0;
-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>();
-  au.addRequired<MachineBlockFrequencyInfo>();
-  au.addRequired<MachineLoopInfo>();
-  au.setPreservesAll();
-  MachineFunctionPass::getAnalysisUsage(au);
-}
-
-bool CalculateSpillWeights::runOnMachineFunction(MachineFunction &MF) {
-
+void llvm::calculateSpillWeights(LiveIntervals &LIS,
+                           MachineFunction &MF,
+                           const MachineLoopInfo &MLI,
+                           const MachineBlockFrequencyInfo &MBFI) {
   DEBUG(dbgs() << "********** Compute Spill Weights **********\n"
                << "********** Function: " << MF.getName() << '\n');
 
-  LiveIntervals &LIS = getAnalysis<LiveIntervals>();
   MachineRegisterInfo &MRI = MF.getRegInfo();
-  VirtRegAuxInfo VRAI(MF, LIS, getAnalysis<MachineLoopInfo>(),
-                      getAnalysis<MachineBlockFrequencyInfo>());
+  VirtRegAuxInfo VRAI(MF, LIS, MLI, MBFI);
   for (unsigned i = 0, e = MRI.getNumVirtRegs(); i != e; ++i) {
     unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
     if (MRI.reg_nodbg_empty(Reg))
       continue;
     VRAI.CalculateWeightAndHint(LIS.getInterval(Reg));
   }
-  return false;
 }
 
 // Return the preferred allocation register for reg, given a COPY instruction.
index 920a48e1e8df2a6f6f294c720b658096f5008203..7430c53b8da2456b2bb711cf464990ef1018f5d9 100644 (file)
@@ -22,7 +22,6 @@ using namespace llvm;
 void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeBasicTTIPass(Registry);
   initializeBranchFolderPassPass(Registry);
-  initializeCalculateSpillWeightsPass(Registry);
   initializeDeadMachineInstructionElimPass(Registry);
   initializeEarlyIfConverterPass(Registry);
   initializeExpandPostRAPass(Registry);
index 0c958df3c5aeaead0d86a781ea703de70763fe35..dbcc5ba1c5b112ede6f7c7a16ada6eef39ee9904 100644 (file)
@@ -126,7 +126,6 @@ RABasic::RABasic(): MachineFunctionPass(ID) {
   initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
   initializeRegisterCoalescerPass(*PassRegistry::getPassRegistry());
   initializeMachineSchedulerPass(*PassRegistry::getPassRegistry());
-  initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
   initializeLiveStacksPass(*PassRegistry::getPassRegistry());
   initializeMachineDominatorTreePass(*PassRegistry::getPassRegistry());
   initializeMachineLoopInfoPass(*PassRegistry::getPassRegistry());
@@ -143,7 +142,6 @@ void RABasic::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addPreserved<SlotIndexes>();
   AU.addRequired<LiveDebugVariables>();
   AU.addPreserved<LiveDebugVariables>();
-  AU.addRequired<CalculateSpillWeights>();
   AU.addRequired<LiveStacks>();
   AU.addPreserved<LiveStacks>();
   AU.addRequired<MachineBlockFrequencyInfo>();
index 9ba2e291a13e079d8ec9cb134c588c00f3c47091..5db9502d1014ce22c115bec728ac8b5629f090ef 100644 (file)
@@ -315,7 +315,6 @@ RAGreedy::RAGreedy(): MachineFunctionPass(ID) {
   initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
   initializeRegisterCoalescerPass(*PassRegistry::getPassRegistry());
   initializeMachineSchedulerPass(*PassRegistry::getPassRegistry());
-  initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
   initializeLiveStacksPass(*PassRegistry::getPassRegistry());
   initializeMachineDominatorTreePass(*PassRegistry::getPassRegistry());
   initializeMachineLoopInfoPass(*PassRegistry::getPassRegistry());
@@ -339,7 +338,6 @@ void RAGreedy::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addPreserved<LiveDebugVariables>();
   AU.addRequired<LiveStacks>();
   AU.addPreserved<LiveStacks>();
-  AU.addRequired<CalculateSpillWeights>();
   AU.addRequired<MachineDominatorTree>();
   AU.addPreserved<MachineDominatorTree>();
   AU.addRequired<MachineLoopInfo>();
@@ -1840,6 +1838,8 @@ bool RAGreedy::runOnMachineFunction(MachineFunction &mf) {
   SpillPlacer = &getAnalysis<SpillPlacement>();
   DebugVars = &getAnalysis<LiveDebugVariables>();
 
+  calculateSpillWeights(*LIS, mf, *Loops, *MBFI);
+
   DEBUG(LIS->dump());
 
   SA.reset(new SplitAnalysis(*VRM, *LIS, *Loops));
index 7786ecdf374dab8af26bc14d54098b9ac7eeb290..7523ec3f85b6bee88ace5186f37217d92510be02 100644 (file)
@@ -95,7 +95,6 @@ public:
       : MachineFunctionPass(ID), builder(b.take()), customPassID(cPassID) {
     initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
     initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
-    initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
     initializeLiveStacksPass(*PassRegistry::getPassRegistry());
     initializeVirtRegMapPass(*PassRegistry::getPassRegistry());
   }
@@ -432,7 +431,6 @@ void RegAllocPBQP::getAnalysisUsage(AnalysisUsage &au) const {
   //au.addRequiredID(SplitCriticalEdgesID);
   if (customPassID)
     au.addRequiredID(*customPassID);
-  au.addRequired<CalculateSpillWeights>();
   au.addRequired<LiveStacks>();
   au.addPreserved<LiveStacks>();
   au.addRequired<MachineBlockFrequencyInfo>();
@@ -551,6 +549,8 @@ bool RegAllocPBQP::runOnMachineFunction(MachineFunction &MF) {
   lss = &getAnalysis<LiveStacks>();
   mbfi = &getAnalysis<MachineBlockFrequencyInfo>();
 
+  calculateSpillWeights(*lis, MF, getAnalysis<MachineLoopInfo>(), *mbfi);
+
   vrm = &getAnalysis<VirtRegMap>();
   spiller.reset(createInlineSpiller(*this, MF, *vrm));