CalculateSpillWeights does not need to be a pass

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

7 files changed, 20 insertions, 52 deletions

diff --git a/include/llvm/CodeGen/CalcSpillWeights.h b/include/llvm/CodeGen/CalcSpillWeights.h
index c8ec764..00d9c6a 100644
--- a/include/llvm/CodeGen/CalcSpillWeights.h
+++ b/include/llvm/CodeGen/CalcSpillWeights.h
@@ -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);
 
 }
 
diff --git a/include/llvm/InitializePasses.h b/include/llvm/InitializePasses.h
index fe26c23..68825a3 100644
--- a/include/llvm/InitializePasses.h
+++ b/include/llvm/InitializePasses.h
@@ -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&);
diff --git a/lib/CodeGen/CalcSpillWeights.cpp b/lib/CodeGen/CalcSpillWeights.cpp
index 67a8755..d02ee03 100644
--- a/lib/CodeGen/CalcSpillWeights.cpp
+++ b/lib/CodeGen/CalcSpillWeights.cpp
@@ -22,38 +22,21 @@
 #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.
diff --git a/lib/CodeGen/CodeGen.cpp b/lib/CodeGen/CodeGen.cpp
index 920a48e..7430c53 100644
--- a/lib/CodeGen/CodeGen.cpp
+++ b/lib/CodeGen/CodeGen.cpp
@@ -22,7 +22,6 @@ using namespace llvm;
 void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeBasicTTIPass(Registry);
   initializeBranchFolderPassPass(Registry);
-  initializeCalculateSpillWeightsPass(Registry);
   initializeDeadMachineInstructionElimPass(Registry);
   initializeEarlyIfConverterPass(Registry);
   initializeExpandPostRAPass(Registry);
diff --git a/lib/CodeGen/RegAllocBasic.cpp b/lib/CodeGen/RegAllocBasic.cpp
index 0c958df..dbcc5ba 100644
--- a/lib/CodeGen/RegAllocBasic.cpp
+++ b/lib/CodeGen/RegAllocBasic.cpp
@@ -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>();
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index 9ba2e29..5db9502 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -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));
diff --git a/lib/CodeGen/RegAllocPBQP.cpp b/lib/CodeGen/RegAllocPBQP.cpp
index 7786ecd..7523ec3 100644
--- a/lib/CodeGen/RegAllocPBQP.cpp
+++ b/lib/CodeGen/RegAllocPBQP.cpp
@@ -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));