X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FInterferenceCache.cpp;h=a8e711e33bdf1354f0743b0ceedd2ed9a69239f3;hb=b2c79f2f630ed3e7da31ff8adb3014fb0ab47412;hp=0aff128c16d0416521fa51964d5d1ca1591d68e1;hpb=f34ae32a6bf06f0d80b0bcbbe56d5488781f4f3c;p=oota-llvm.git

diff --git a/lib/CodeGen/InterferenceCache.cpp b/lib/CodeGen/InterferenceCache.cpp
index 0aff128c16d..a8e711e33bd 100644
--- a/lib/CodeGen/InterferenceCache.cpp
+++ b/lib/CodeGen/InterferenceCache.cpp
@@ -1,4 +1,4 @@
-//===-- InterferenceCache.h - Caching per-block interference ---*- C++ -*--===//
+//===-- InterferenceCache.cpp - Caching per-block interference ---------*--===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -13,121 +13,181 @@
 
 #define DEBUG_TYPE "regalloc"
 #include "InterferenceCache.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 
 using namespace llvm;
 
+// Static member used for null interference cursors.
+InterferenceCache::BlockInterference InterferenceCache::Cursor::NoInterference;
+
 void InterferenceCache::init(MachineFunction *mf,
                              LiveIntervalUnion *liuarray,
                              SlotIndexes *indexes,
-                            const TargetRegisterInfo *tri) {
+                             LiveIntervals *lis,
+                             const TargetRegisterInfo *tri) {
   MF = mf;
   LIUArray = liuarray;
   TRI = tri;
   PhysRegEntries.assign(TRI->getNumRegs(), 0);
   for (unsigned i = 0; i != CacheEntries; ++i)
-    Entries[i].clear(indexes);
+    Entries[i].clear(mf, indexes, lis);
 }
 
 InterferenceCache::Entry *InterferenceCache::get(unsigned PhysReg) {
   unsigned E = PhysRegEntries[PhysReg];
   if (E < CacheEntries && Entries[E].getPhysReg() == PhysReg) {
     if (!Entries[E].valid(LIUArray, TRI))
-      Entries[E].revalidate();
+      Entries[E].revalidate(LIUArray, TRI);
     return &Entries[E];
   }
   // No valid entry exists, pick the next round-robin entry.
   E = RoundRobin;
   if (++RoundRobin == CacheEntries)
     RoundRobin = 0;
-  Entries[E].reset(PhysReg, LIUArray, TRI, MF);
-  PhysRegEntries[PhysReg] = E;
-  return &Entries[E];
+  for (unsigned i = 0; i != CacheEntries; ++i) {
+    // Skip entries that are in use.
+    if (Entries[E].hasRefs()) {
+      if (++E == CacheEntries)
+        E = 0;
+      continue;
+    }
+    Entries[E].reset(PhysReg, LIUArray, TRI, MF);
+    PhysRegEntries[PhysReg] = E;
+    return &Entries[E];
+  }
+  llvm_unreachable("Ran out of interference cache entries.");
 }
 
 /// revalidate - LIU contents have changed, update tags.
-void InterferenceCache::Entry::revalidate() {
+void InterferenceCache::Entry::revalidate(LiveIntervalUnion *LIUArray,
+                                          const TargetRegisterInfo *TRI) {
   // Invalidate all block entries.
   ++Tag;
   // Invalidate all iterators.
   PrevPos = SlotIndex();
-  for (unsigned i = 0, e = Aliases.size(); i != e; ++i)
-    Aliases[i].second = Aliases[i].first->getTag();
+  unsigned i = 0;
+  for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units, ++i)
+    RegUnits[i].VirtTag = LIUArray[*Units].getTag();
 }
 
 void InterferenceCache::Entry::reset(unsigned physReg,
                                      LiveIntervalUnion *LIUArray,
                                      const TargetRegisterInfo *TRI,
                                      const MachineFunction *MF) {
+  assert(!hasRefs() && "Cannot reset cache entry with references");
   // LIU's changed, invalidate cache.
   ++Tag;
   PhysReg = physReg;
   Blocks.resize(MF->getNumBlockIDs());
-  Aliases.clear();
-  for (const unsigned *AS = TRI->getOverlaps(PhysReg); *AS; ++AS) {
-    LiveIntervalUnion *LIU = LIUArray + *AS;
-    Aliases.push_back(std::make_pair(LIU, LIU->getTag()));
-  }
 
   // Reset iterators.
   PrevPos = SlotIndex();
-  unsigned e = Aliases.size();
-  Iters.resize(e);
-  for (unsigned i = 0; i != e; ++i)
-    Iters[i].setMap(Aliases[i].first->getMap());
+  RegUnits.clear();
+  for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
+    RegUnits.push_back(LIUArray[*Units]);
+    RegUnits.back().Fixed = &LIS->getRegUnit(*Units);
+  }
 }
 
 bool InterferenceCache::Entry::valid(LiveIntervalUnion *LIUArray,
                                      const TargetRegisterInfo *TRI) {
-  unsigned i = 0, e = Aliases.size();
-  for (const unsigned *AS = TRI->getOverlaps(PhysReg); *AS; ++AS, ++i) {
-    LiveIntervalUnion *LIU = LIUArray + *AS;
-    if (i == e ||  Aliases[i].first != LIU)
+  unsigned i = 0, e = RegUnits.size();
+  for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units, ++i) {
+    if (i == e)
       return false;
-    if (LIU->changedSince(Aliases[i].second))
+    if (LIUArray[*Units].changedSince(RegUnits[i].VirtTag))
       return false;
   }
   return i == e;
 }
 
 void InterferenceCache::Entry::update(unsigned MBBNum) {
-  BlockInterference *BI = &Blocks[MBBNum];
-  BI->Tag = Tag;
-  BI->First = BI->Last = SlotIndex();
-
   SlotIndex Start, Stop;
   tie(Start, Stop) = Indexes->getMBBRange(MBBNum);
 
   // Use advanceTo only when possible.
   if (PrevPos != Start) {
-    if (!PrevPos.isValid() || Start < PrevPos)
-      for (unsigned i = 0, e = Iters.size(); i != e; ++i)
-        Iters[i].find(Start);
-    else
-      for (unsigned i = 0, e = Iters.size(); i != e; ++i)
-        Iters[i].advanceTo(Start);
+    if (!PrevPos.isValid() || Start < PrevPos) {
+      for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) {
+        RegUnitInfo &RUI = RegUnits[i];
+        RUI.VirtI.find(Start);
+        RUI.FixedI = RUI.Fixed->find(Start);
+      }
+    } else {
+      for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) {
+        RegUnitInfo &RUI = RegUnits[i];
+        RUI.VirtI.advanceTo(Start);
+        if (RUI.FixedI != RUI.Fixed->end())
+          RUI.FixedI = RUI.Fixed->advanceTo(RUI.FixedI, Start);
+      }
+    }
     PrevPos = Start;
   }
 
-  // Check for first interference.
-  for (unsigned i = 0, e = Iters.size(); i != e; ++i) {
-    Iter &I = Iters[i];
-    if (!I.valid())
-      continue;
-    SlotIndex StartI = I.start();
-    if (StartI >= Stop)
-      continue;
-    if (!BI->First.isValid() || StartI < BI->First)
-      BI->First = StartI;
-  }
+  MachineFunction::const_iterator MFI = MF->getBlockNumbered(MBBNum);
+  BlockInterference *BI = &Blocks[MBBNum];
+  ArrayRef<SlotIndex> RegMaskSlots;
+  ArrayRef<const uint32_t*> RegMaskBits;
+  for (;;) {
+    BI->Tag = Tag;
+    BI->First = BI->Last = SlotIndex();
+
+    // Check for first interference from virtregs.
+    for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) {
+      LiveIntervalUnion::SegmentIter &I = RegUnits[i].VirtI;
+      if (!I.valid())
+        continue;
+      SlotIndex StartI = I.start();
+      if (StartI >= Stop)
+        continue;
+      if (!BI->First.isValid() || StartI < BI->First)
+        BI->First = StartI;
+    }
+
+    // Same thing for fixed interference.
+    for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) {
+      LiveInterval::const_iterator I = RegUnits[i].FixedI;
+      LiveInterval::const_iterator E = RegUnits[i].Fixed->end();
+      if (I == E)
+        continue;
+      SlotIndex StartI = I->start;
+      if (StartI >= Stop)
+        continue;
+      if (!BI->First.isValid() || StartI < BI->First)
+        BI->First = StartI;
+    }
 
-  // No interference in block.
-  if (!BI->First.isValid())
-    return;
+    // Also check for register mask interference.
+    RegMaskSlots = LIS->getRegMaskSlotsInBlock(MBBNum);
+    RegMaskBits = LIS->getRegMaskBitsInBlock(MBBNum);
+    SlotIndex Limit = BI->First.isValid() ? BI->First : Stop;
+    for (unsigned i = 0, e = RegMaskSlots.size();
+         i != e && RegMaskSlots[i] < Limit; ++i)
+      if (MachineOperand::clobbersPhysReg(RegMaskBits[i], PhysReg)) {
+        // Register mask i clobbers PhysReg before the LIU interference.
+        BI->First = RegMaskSlots[i];
+        break;
+      }
 
-  // Check for last interference.
-  for (unsigned i = 0, e = Iters.size(); i != e; ++i) {
-    Iter &I = Iters[i];
+    PrevPos = Stop;
+    if (BI->First.isValid())
+      break;
+
+    // No interference in this block? Go ahead and precompute the next block.
+    if (++MFI == MF->end())
+      return;
+    MBBNum = MFI->getNumber();
+    BI = &Blocks[MBBNum];
+    if (BI->Tag == Tag)
+      return;
+    tie(Start, Stop) = Indexes->getMBBRange(MBBNum);
+  }
+
+  // Check for last interference in block.
+  for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) {
+    LiveIntervalUnion::SegmentIter &I = RegUnits[i].VirtI;
     if (!I.valid() || I.start() >= Stop)
       continue;
     I.advanceTo(Stop);
@@ -140,5 +200,32 @@ void InterferenceCache::Entry::update(unsigned MBBNum) {
     if (Backup)
       ++I;
   }
-  PrevPos = Stop;
+
+  // Fixed interference.
+  for (unsigned i = 0, e = RegUnits.size(); i != e; ++i) {
+    LiveInterval::iterator &I = RegUnits[i].FixedI;
+    LiveInterval *LI = RegUnits[i].Fixed;
+    if (I == LI->end() || I->start >= Stop)
+      continue;
+    I = LI->advanceTo(I, Stop);
+    bool Backup = I == LI->end() || I->start >= Stop;
+    if (Backup)
+      --I;
+    SlotIndex StopI = I->end;
+    if (!BI->Last.isValid() || StopI > BI->Last)
+      BI->Last = StopI;
+    if (Backup)
+      ++I;
+  }
+
+  // Also check for register mask interference.
+  SlotIndex Limit = BI->Last.isValid() ? BI->Last : Start;
+  for (unsigned i = RegMaskSlots.size();
+       i && RegMaskSlots[i-1].getDeadSlot() > Limit; --i)
+    if (MachineOperand::clobbersPhysReg(RegMaskBits[i-1], PhysReg)) {
+      // Register mask i-1 clobbers PhysReg after the LIU interference.
+      // Model the regmask clobber as a dead def.
+      BI->Last = RegMaskSlots[i-1].getDeadSlot();
+      break;
+    }
 }