diff options
Diffstat (limited to 'lib/CodeGen/MachineBlockPlacement.cpp')
| -rw-r--r-- | lib/CodeGen/MachineBlockPlacement.cpp | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/lib/CodeGen/MachineBlockPlacement.cpp b/lib/CodeGen/MachineBlockPlacement.cpp index 771e7ce..74af1e2 100644 --- a/lib/CodeGen/MachineBlockPlacement.cpp +++ b/lib/CodeGen/MachineBlockPlacement.cpp @@ -25,7 +25,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "block-placement2" #include "llvm/CodeGen/Passes.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/SmallPtrSet.h" @@ -46,6 +45,8 @@ #include <algorithm> using namespace llvm; +#define DEBUG_TYPE "block-placement2" + STATISTIC(NumCondBranches, "Number of conditional branches"); STATISTIC(NumUncondBranches, "Number of uncondittional branches"); STATISTIC(CondBranchTakenFreq, @@ -206,7 +207,7 @@ class MachineBlockPlacement : public MachineFunctionPass { void markChainSuccessors(BlockChain &Chain, MachineBasicBlock *LoopHeaderBB, SmallVectorImpl<MachineBasicBlock *> &BlockWorkList, - const BlockFilterSet *BlockFilter = 0); + const BlockFilterSet *BlockFilter = nullptr); MachineBasicBlock *selectBestSuccessor(MachineBasicBlock *BB, BlockChain &Chain, const BlockFilterSet *BlockFilter); @@ -220,7 +221,7 @@ class MachineBlockPlacement : public MachineFunctionPass { const BlockFilterSet *BlockFilter); void buildChain(MachineBasicBlock *BB, BlockChain &Chain, SmallVectorImpl<MachineBasicBlock *> &BlockWorkList, - const BlockFilterSet *BlockFilter = 0); + const BlockFilterSet *BlockFilter = nullptr); MachineBasicBlock *findBestLoopTop(MachineLoop &L, const BlockFilterSet &LoopBlockSet); MachineBasicBlock *findBestLoopExit(MachineFunction &F, @@ -334,7 +335,7 @@ MachineBasicBlock *MachineBlockPlacement::selectBestSuccessor( const BlockFilterSet *BlockFilter) { const BranchProbability HotProb(4, 5); // 80% - MachineBasicBlock *BestSucc = 0; + MachineBasicBlock *BestSucc = nullptr; // FIXME: Due to the performance of the probability and weight routines in // the MBPI analysis, we manually compute probabilities using the edge // weights. This is suboptimal as it means that the somewhat subtle @@ -432,7 +433,7 @@ MachineBasicBlock *MachineBlockPlacement::selectBestCandidateBlock( }), WorkList.end()); - MachineBasicBlock *BestBlock = 0; + MachineBasicBlock *BestBlock = nullptr; BlockFrequency BestFreq; for (SmallVectorImpl<MachineBasicBlock *>::iterator WBI = WorkList.begin(), WBE = WorkList.end(); @@ -479,7 +480,7 @@ MachineBasicBlock *MachineBlockPlacement::getFirstUnplacedBlock( return *BlockToChain[I]->begin(); } } - return 0; + return nullptr; } void MachineBlockPlacement::buildChain( @@ -560,7 +561,7 @@ MachineBlockPlacement::findBestLoopTop(MachineLoop &L, << getBlockName(L.getHeader()) << "\n"); BlockFrequency BestPredFreq; - MachineBasicBlock *BestPred = 0; + MachineBasicBlock *BestPred = nullptr; for (MachineBasicBlock::pred_iterator PI = L.getHeader()->pred_begin(), PE = L.getHeader()->pred_end(); PI != PE; ++PI) { @@ -616,11 +617,11 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, // header and only rotate if safe. BlockChain &HeaderChain = *BlockToChain[L.getHeader()]; if (!LoopBlockSet.count(*HeaderChain.begin())) - return 0; + return nullptr; BlockFrequency BestExitEdgeFreq; unsigned BestExitLoopDepth = 0; - MachineBasicBlock *ExitingBB = 0; + MachineBasicBlock *ExitingBB = nullptr; // If there are exits to outer loops, loop rotation can severely limit // fallthrough opportunites unless it selects such an exit. Keep a set of // blocks where rotating to exit with that block will reach an outer loop. @@ -709,14 +710,14 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, // Without a candidate exiting block or with only a single block in the // loop, just use the loop header to layout the loop. if (!ExitingBB || L.getNumBlocks() == 1) - return 0; + return nullptr; // Also, if we have exit blocks which lead to outer loops but didn't select // one of them as the exiting block we are rotating toward, disable loop // rotation altogether. if (!BlocksExitingToOuterLoop.empty() && !BlocksExitingToOuterLoop.count(ExitingBB)) - return 0; + return nullptr; DEBUG(dbgs() << " Best exiting block: " << getBlockName(ExitingBB) << "\n"); return ExitingBB; @@ -795,7 +796,7 @@ void MachineBlockPlacement::buildLoopChains(MachineFunction &F, // If we selected just the header for the loop top, look for a potentially // profitable exit block in the event that rotating the loop can eliminate // branches by placing an exit edge at the bottom. - MachineBasicBlock *ExitingBB = 0; + MachineBasicBlock *ExitingBB = nullptr; if (LoopTop == L.getHeader()) ExitingBB = findBestLoopExit(F, L, LoopBlockSet); @@ -883,7 +884,7 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) { // the exact fallthrough behavior for. for (;;) { Cond.clear(); - MachineBasicBlock *TBB = 0, *FBB = 0; // For AnalyzeBranch. + MachineBasicBlock *TBB = nullptr, *FBB = nullptr; // For AnalyzeBranch. if (!TII->AnalyzeBranch(*BB, TBB, FBB, Cond) || !FI->canFallThrough()) break; @@ -895,7 +896,7 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) { DEBUG(dbgs() << "Pre-merging due to unanalyzable fallthrough: " << getBlockName(BB) << " -> " << getBlockName(NextBB) << "\n"); - Chain->merge(NextBB, 0); + Chain->merge(NextBB, nullptr); FI = NextFI; BB = NextBB; } @@ -987,7 +988,7 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) { // than assert when the branch cannot be analyzed in order to remove this // boiler plate. Cond.clear(); - MachineBasicBlock *TBB = 0, *FBB = 0; // For AnalyzeBranch. + MachineBasicBlock *TBB = nullptr, *FBB = nullptr; // For AnalyzeBranch. if (!TII->AnalyzeBranch(*PrevBB, TBB, FBB, Cond)) { // The "PrevBB" is not yet updated to reflect current code layout, so, // o. it may fall-through to a block without explict "goto" instruction @@ -1004,10 +1005,10 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) { PrevBB->updateTerminator(); needUpdateBr = false; Cond.clear(); - TBB = FBB = 0; + TBB = FBB = nullptr; if (TII->AnalyzeBranch(*PrevBB, TBB, FBB, Cond)) { // FIXME: This should never take place. - TBB = FBB = 0; + TBB = FBB = nullptr; } } @@ -1032,7 +1033,7 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) { // Fixup the last block. Cond.clear(); - MachineBasicBlock *TBB = 0, *FBB = 0; // For AnalyzeBranch. + MachineBasicBlock *TBB = nullptr, *FBB = nullptr; // For AnalyzeBranch. if (!TII->AnalyzeBranch(F.back(), TBB, FBB, Cond)) F.back().updateTerminator(); |