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Diffstat (limited to 'contrib/llvm/lib/CodeGen/SlotIndexes.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/SlotIndexes.cpp | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/SlotIndexes.cpp b/contrib/llvm/lib/CodeGen/SlotIndexes.cpp new file mode 100644 index 0000000..6110ef5 --- /dev/null +++ b/contrib/llvm/lib/CodeGen/SlotIndexes.cpp @@ -0,0 +1,226 @@ +//===-- SlotIndexes.cpp - Slot Indexes Pass ------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "slotindexes" + +#include "llvm/CodeGen/SlotIndexes.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; +static RegisterPass<SlotIndexes> X("slotindexes", "Slot index numbering"); + +IndexListEntry* IndexListEntry::getEmptyKeyEntry() { + return &*IndexListEntryEmptyKey; +} + +IndexListEntry* IndexListEntry::getTombstoneKeyEntry() { + return &*IndexListEntryTombstoneKey; +} + + +void SlotIndexes::getAnalysisUsage(AnalysisUsage &au) const { + au.setPreservesAll(); + MachineFunctionPass::getAnalysisUsage(au); +} + +void SlotIndexes::releaseMemory() { + mi2iMap.clear(); + mbb2IdxMap.clear(); + idx2MBBMap.clear(); + terminatorGaps.clear(); + clearList(); +} + +bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) { + + // Compute numbering as follows: + // Grab an iterator to the start of the index list. + // Iterate over all MBBs, and within each MBB all MIs, keeping the MI + // iterator in lock-step (though skipping it over indexes which have + // null pointers in the instruction field). + // At each iteration assert that the instruction pointed to in the index + // is the same one pointed to by the MI iterator. This + + // FIXME: This can be simplified. The mi2iMap_, Idx2MBBMap, etc. should + // only need to be set up once after the first numbering is computed. + + mf = &fn; + initList(); + + // Check that the list contains only the sentinal. + assert(indexListHead->getNext() == 0 && + "Index list non-empty at initial numbering?"); + assert(idx2MBBMap.empty() && + "Index -> MBB mapping non-empty at initial numbering?"); + assert(mbb2IdxMap.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; + + push_back(createEntry(0, index)); + + // Iterate over the function. + for (MachineFunction::iterator mbbItr = mf->begin(), mbbEnd = mf->end(); + mbbItr != mbbEnd; ++mbbItr) { + MachineBasicBlock *mbb = &*mbbItr; + + // 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; + if (mi->isDebugValue()) + continue; + + if (miItr == mbb->getFirstTerminator()) { + push_back(createEntry(0, index)); + terminatorGaps.insert( + std::make_pair(mbb, SlotIndex(back(), SlotIndex::PHI_BIT))); + index += SlotIndex::NUM; + } + + // Insert a store index for the instr. + push_back(createEntry(mi, index)); + + // Save this base index in the maps. + 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; + } + + if (mbb->getFirstTerminator() == mbb->end()) { + push_back(createEntry(0, index)); + terminatorGaps.insert( + std::make_pair(mbb, SlotIndex(back(), SlotIndex::PHI_BIT))); + index += SlotIndex::NUM; + } + + // One blank instruction at the end. + push_back(createEntry(0, index)); + + SlotIndex blockEndIndex(back(), SlotIndex::LOAD); + mbb2IdxMap.insert( + std::make_pair(mbb, std::make_pair(blockStartIndex, blockEndIndex))); + + idx2MBBMap.push_back(IdxMBBPair(blockStartIndex, mbb)); + } + + // Sort the Idx2MBBMap + std::sort(idx2MBBMap.begin(), idx2MBBMap.end(), Idx2MBBCompare()); + + DEBUG(dump()); + + // And we're done! + return false; +} + +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. + + functionSize = 0; + unsigned index = 0; + + for (IndexListEntry *curEntry = front(); curEntry != getTail(); + curEntry = curEntry->getNext()) { + + curEntry->setIndex(index); + + if (curEntry->getInstr() == 0) { + // MBB start entry or terminator gap. 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; + } + } +} + +void SlotIndexes::dump() const { + for (const IndexListEntry *itr = front(); itr != getTail(); + itr = itr->getNext()) { + dbgs() << itr->getIndex() << " "; + + if (itr->getInstr() != 0) { + dbgs() << *itr->getInstr(); + } else { + dbgs() << "\n"; + } + } + + 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"; + } +} + +// Print a SlotIndex to a raw_ostream. +void SlotIndex::print(raw_ostream &os) const { + os << getIndex(); + if (isPHI()) + os << "*"; +} + +// Dump a SlotIndex to stderr. +void SlotIndex::dump() const { + print(dbgs()); + dbgs() << "\n"; +} + |