1 files changed, 40 insertions, 79 deletions

diff --git a/lib/CodeGen/SlotIndexes.cpp b/lib/CodeGen/SlotIndexes.cpp
index 6e3fa90e4341e..ca79cafcf4be9 100644
--- a/lib/CodeGen/SlotIndexes.cpp
+++ b/lib/CodeGen/SlotIndexes.cpp
@@ -10,47 +10,20 @@
 #define DEBUG_TYPE "slotindexes"
 
 #include "llvm/CodeGen/SlotIndexes.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/ManagedStatic.h"
 #include "llvm/Target/TargetInstrInfo.h"
 
 using namespace llvm;
 
-
-// Yep - these are thread safe. See the header for details. 
-namespace {
-
-
-  class EmptyIndexListEntry : public IndexListEntry {
-  public:
-    EmptyIndexListEntry() : IndexListEntry(EMPTY_KEY) {}
-  };
-
-  class TombstoneIndexListEntry : public IndexListEntry {
-  public:
-    TombstoneIndexListEntry() : IndexListEntry(TOMBSTONE_KEY) {}
-  };
-
-  // The following statics are thread safe. They're read only, and you
-  // can't step from them to any other list entries.
-  ManagedStatic<EmptyIndexListEntry> IndexListEntryEmptyKey;
-  ManagedStatic<TombstoneIndexListEntry> IndexListEntryTombstoneKey;
-}
-
 char SlotIndexes::ID = 0;
 INITIALIZE_PASS(SlotIndexes, "slotindexes",
                 "Slot index numbering", false, false)
 
-IndexListEntry* IndexListEntry::getEmptyKeyEntry() {
-  return &*IndexListEntryEmptyKey;
-}
-
-IndexListEntry* IndexListEntry::getTombstoneKeyEntry() {
-  return &*IndexListEntryTombstoneKey;
-}
-
+STATISTIC(NumLocalRenum,  "Number of local renumberings");
+STATISTIC(NumGlobalRenum, "Number of global renumberings");
 
 void SlotIndexes::getAnalysisUsage(AnalysisUsage &au) const {
   au.setPreservesAll();
@@ -59,7 +32,7 @@ void SlotIndexes::getAnalysisUsage(AnalysisUsage &au) const {
 
 void SlotIndexes::releaseMemory() {
   mi2iMap.clear();
-  mbb2IdxMap.clear();
+  MBBRanges.clear();
   idx2MBBMap.clear();
   clearList();
 }
@@ -85,13 +58,15 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) {
          "Index list non-empty at initial numbering?");
   assert(idx2MBBMap.empty() &&
          "Index -> MBB mapping non-empty at initial numbering?");
-  assert(mbb2IdxMap.empty() &&
+  assert(MBBRanges.empty() &&
          "MBB -> Index mapping non-empty at initial numbering?");
   assert(mi2iMap.empty() &&
          "MachineInstr -> Index mapping non-empty at initial numbering?");
 
   functionSize = 0;
   unsigned index = 0;
+  MBBRanges.resize(mf->getNumBlockIDs());
+  idx2MBBMap.reserve(mf->size());
 
   push_back(createEntry(0, index));
 
@@ -103,8 +78,6 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) {
     // Insert an index for the MBB start.
     SlotIndex blockStartIndex(back(), SlotIndex::LOAD);
 
-    index += SlotIndex::NUM;
-
     for (MachineBasicBlock::iterator miItr = mbb->begin(), miEnd = mbb->end();
          miItr != miEnd; ++miItr) {
       MachineInstr *mi = miItr;
@@ -112,32 +85,19 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) {
         continue;
 
       // Insert a store index for the instr.
-      push_back(createEntry(mi, index));
+      push_back(createEntry(mi, index += SlotIndex::InstrDist));
 
       // Save this base index in the maps.
-      mi2iMap.insert(
-        std::make_pair(mi, SlotIndex(back(), SlotIndex::LOAD)));
+      mi2iMap.insert(std::make_pair(mi, SlotIndex(back(), SlotIndex::LOAD)));
  
       ++functionSize;
-
-      unsigned Slots = mi->getDesc().getNumDefs();
-      if (Slots == 0)
-        Slots = 1;
-
-      index += (Slots + 1) * SlotIndex::NUM;
     }
 
-    // We insert two blank instructions between basic blocks.
-    // One to represent live-out registers and one to represent live-ins.
-    push_back(createEntry(0, index));
-    index += SlotIndex::NUM;
-
-    push_back(createEntry(0, index));
-
-    SlotIndex blockEndIndex(back(), SlotIndex::LOAD);
-    mbb2IdxMap.insert(
-      std::make_pair(mbb, std::make_pair(blockStartIndex, blockEndIndex)));
+    // We insert one blank instructions between basic blocks.
+    push_back(createEntry(0, index += SlotIndex::InstrDist));
 
+    MBBRanges[mbb->getNumber()].first = blockStartIndex;
+    MBBRanges[mbb->getNumber()].second = SlotIndex(back(), SlotIndex::LOAD);
     idx2MBBMap.push_back(IdxMBBPair(blockStartIndex, mbb));
   }
 
@@ -151,38 +111,41 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) {
 }
 
 void SlotIndexes::renumberIndexes() {
-
   // Renumber updates the index of every element of the index list.
-  // If all instrs in the function have been allocated an index (which has been
-  // placed in the index list in the order of instruction iteration) then the
-  // resulting numbering will match what would have been generated by the
-  // pass during the initial numbering of the function if the new instructions
-  // had been present.
   DEBUG(dbgs() << "\n*** Renumbering SlotIndexes ***\n");
+  ++NumGlobalRenum;
 
-  functionSize = 0;
   unsigned index = 0;
 
   for (IndexListEntry *curEntry = front(); curEntry != getTail();
        curEntry = curEntry->getNext()) {
-
     curEntry->setIndex(index);
-
-    if (curEntry->getInstr() == 0) {
-      // MBB start entry. Just step index by 1.
-      index += SlotIndex::NUM;
-    }
-    else {
-      ++functionSize;
-      unsigned Slots = curEntry->getInstr()->getDesc().getNumDefs();
-      if (Slots == 0)
-        Slots = 1;
-
-      index += (Slots + 1) * SlotIndex::NUM;
-    }
+    index += SlotIndex::InstrDist;
   }
 }
 
+// Renumber indexes locally after curEntry was inserted, but failed to get a new
+// index.
+void SlotIndexes::renumberIndexes(IndexListEntry *curEntry) {
+  // Number indexes with half the default spacing so we can catch up quickly.
+  const unsigned Space = SlotIndex::InstrDist/2;
+  assert((Space & 3) == 0 && "InstrDist must be a multiple of 2*NUM");
+
+  IndexListEntry *start = curEntry->getPrev();
+  unsigned index = start->getIndex();
+  IndexListEntry *tail = getTail();
+  do {
+    curEntry->setIndex(index += Space);
+    curEntry = curEntry->getNext();
+    // If the next index is bigger, we have caught up.
+  } while (curEntry != tail && curEntry->getIndex() <= index);
+
+  DEBUG(dbgs() << "\n*** Renumbered SlotIndexes " << start->getIndex() << '-'
+               << index << " ***\n");
+  ++NumLocalRenum;
+}
+
+
 void SlotIndexes::dump() const {
   for (const IndexListEntry *itr = front(); itr != getTail();
        itr = itr->getNext()) {
@@ -195,11 +158,9 @@ void SlotIndexes::dump() const {
     }
   }
 
-  for (MBB2IdxMap::const_iterator itr = mbb2IdxMap.begin();
-       itr != mbb2IdxMap.end(); ++itr) {
-    dbgs() << "MBB " << itr->first->getNumber() << " (" << itr->first << ") - ["
-           << itr->second.first << ", " << itr->second.second << "]\n";
-  }
+  for (unsigned i = 0, e = MBBRanges.size(); i != e; ++i)
+    dbgs() << "BB#" << i << "\t[" << MBBRanges[i].first << ';'
+           << MBBRanges[i].second << ")\n";
 }
 
 // Print a SlotIndex to a raw_ostream.