#include "llvm/Support/Allocator.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#define DEBUG_TYPE "block-placement"
STATISTIC(NumCondBranches, "Number of conditional branches");
-STATISTIC(NumUncondBranches, "Number of uncondittional branches");
+STATISTIC(NumUncondBranches, "Number of unconditional branches");
STATISTIC(CondBranchTakenFreq,
"Potential frequency of taking conditional branches");
STATISTIC(UncondBranchTakenFreq,
"post dominator, out of line."),
cl::init(false), cl::Hidden);
+static cl::opt<unsigned> OutlineOptionalThreshold(
+ "outline-optional-threshold",
+ cl::desc("Don't outline optional branches that are a single block with an "
+ "instruction count below this threshold"),
+ cl::init(4), cl::Hidden);
+
namespace {
class BlockChain;
/// \brief Type for our function-wide basic block -> block chain mapping.
// Update the incoming blocks to point to this chain, and add them to the
// chain structure.
- for (BlockChain::iterator BI = Chain->begin(), BE = Chain->end(); BI != BE;
- ++BI) {
- Blocks.push_back(*BI);
- assert(BlockToChain[*BI] == Chain && "Incoming blocks not in chain");
- BlockToChain[*BI] = this;
+ for (MachineBasicBlock *ChainBB : *Chain) {
+ Blocks.push_back(ChainBB);
+ assert(BlockToChain[ChainBB] == Chain && "Incoming blocks not in chain");
+ BlockToChain[ChainBB] = this;
}
}
#ifndef NDEBUG
/// \brief Dump the blocks in this chain.
LLVM_DUMP_METHOD void dump() {
- for (iterator I = begin(), E = end(); I != E; ++I)
- (*I)->dump();
+ for (MachineBasicBlock *MBB : *this)
+ MBB->dump();
}
#endif // NDEBUG
const BlockFilterSet *BlockFilter) {
// Walk all the blocks in this chain, marking their successors as having
// a predecessor placed.
- for (BlockChain::iterator CBI = Chain.begin(), CBE = Chain.end(); CBI != CBE;
- ++CBI) {
+ for (MachineBasicBlock *MBB : Chain) {
// Add any successors for which this is the only un-placed in-loop
// predecessor to the worklist as a viable candidate for CFG-neutral
// placement. No subsequent placement of this block will violate the CFG
// shape, so we get to use heuristics to choose a favorable placement.
- for (MachineBasicBlock::succ_iterator SI = (*CBI)->succ_begin(),
- SE = (*CBI)->succ_end();
- SI != SE; ++SI) {
- if (BlockFilter && !BlockFilter->count(*SI))
+ for (MachineBasicBlock *Succ : MBB->successors()) {
+ if (BlockFilter && !BlockFilter->count(Succ))
continue;
- BlockChain &SuccChain = *BlockToChain[*SI];
+ BlockChain &SuccChain = *BlockToChain[Succ];
// Disregard edges within a fixed chain, or edges to the loop header.
- if (&Chain == &SuccChain || *SI == LoopHeaderBB)
+ if (&Chain == &SuccChain || Succ == LoopHeaderBB)
continue;
// This is a cross-chain edge that is within the loop, so decrement the
// dominates all terminators of the MachineFunction. If it does, other
// successors must be optional. Don't do this for cold branches.
if (OutlineOptionalBranches && SuccProb > HotProb.getCompl() &&
- UnavoidableBlocks.count(Succ) > 0)
- return Succ;
+ UnavoidableBlocks.count(Succ) > 0) {
+ auto HasShortOptionalBranch = [&]() {
+ for (MachineBasicBlock *Pred : Succ->predecessors()) {
+ // Check whether there is an unplaced optional branch.
+ if (Pred == Succ || (BlockFilter && !BlockFilter->count(Pred)) ||
+ BlockToChain[Pred] == &Chain)
+ continue;
+ // Check whether the optional branch has exactly one BB.
+ if (Pred->pred_size() > 1 || *Pred->pred_begin() != BB)
+ continue;
+ // Check whether the optional branch is small.
+ if (Pred->size() < OutlineOptionalThreshold)
+ return true;
+ }
+ return false;
+ };
+ if (!HasShortOptionalBranch())
+ return Succ;
+ }
// Only consider successors which are either "hot", or wouldn't violate
// any CFG constraints.
MachineBasicBlock *BestBlock = nullptr;
BlockFrequency BestFreq;
- for (SmallVectorImpl<MachineBasicBlock *>::iterator WBI = WorkList.begin(),
- WBE = WorkList.end();
- WBI != WBE; ++WBI) {
- BlockChain &SuccChain = *BlockToChain[*WBI];
+ for (MachineBasicBlock *MBB : WorkList) {
+ BlockChain &SuccChain = *BlockToChain[MBB];
if (&SuccChain == &Chain) {
- DEBUG(dbgs() << " " << getBlockName(*WBI) << " -> Already merged!\n");
+ DEBUG(dbgs() << " " << getBlockName(MBB) << " -> Already merged!\n");
continue;
}
assert(SuccChain.LoopPredecessors == 0 && "Found CFG-violating block");
- BlockFrequency CandidateFreq = MBFI->getBlockFreq(*WBI);
- DEBUG(dbgs() << " " << getBlockName(*WBI) << " -> ";
+ BlockFrequency CandidateFreq = MBFI->getBlockFreq(MBB);
+ DEBUG(dbgs() << " " << getBlockName(MBB) << " -> ";
MBFI->printBlockFreq(dbgs(), CandidateFreq) << " (freq)\n");
if (BestBlock && BestFreq >= CandidateFreq)
continue;
- BestBlock = *WBI;
+ BestBlock = MBB;
BestFreq = CandidateFreq;
}
return BestBlock;
const BlockFilterSet *BlockFilter) {
for (MachineFunction::iterator I = PrevUnplacedBlockIt, E = F.end(); I != E;
++I) {
- if (BlockFilter && !BlockFilter->count(I))
+ if (BlockFilter && !BlockFilter->count(&*I))
continue;
- if (BlockToChain[I] != &PlacedChain) {
+ if (BlockToChain[&*I] != &PlacedChain) {
PrevUnplacedBlockIt = I;
// Now select the head of the chain to which the unplaced block belongs
// as the block to place. This will force the entire chain to be placed,
// and satisfies the requirements of merging chains.
- return *BlockToChain[I]->begin();
+ return *BlockToChain[&*I]->begin();
}
}
return nullptr;
BlockFrequency BestPredFreq;
MachineBasicBlock *BestPred = nullptr;
- for (MachineBasicBlock::pred_iterator PI = L.getHeader()->pred_begin(),
- PE = L.getHeader()->pred_end();
- PI != PE; ++PI) {
- MachineBasicBlock *Pred = *PI;
+ for (MachineBasicBlock *Pred : L.getHeader()->predecessors()) {
if (!LoopBlockSet.count(Pred))
continue;
DEBUG(dbgs() << " header pred: " << getBlockName(Pred) << ", "
DEBUG(dbgs() << "Finding best loop exit for: " << getBlockName(L.getHeader())
<< "\n");
- for (MachineLoop::block_iterator I = L.block_begin(), E = L.block_end();
- I != E; ++I) {
- BlockChain &Chain = *BlockToChain[*I];
+ for (MachineBasicBlock *MBB : L.getBlocks()) {
+ BlockChain &Chain = *BlockToChain[MBB];
// Ensure that this block is at the end of a chain; otherwise it could be
- // mid-way through an inner loop or a successor of an analyzable branch.
- if (*I != *std::prev(Chain.end()))
+ // mid-way through an inner loop or a successor of an unanalyzable branch.
+ if (MBB != *std::prev(Chain.end()))
continue;
// Now walk the successors. We need to establish whether this has a viable
// the MBPI analysis, we use the internal weights and manually compute the
// probabilities to avoid quadratic behavior.
uint32_t WeightScale = 0;
- uint32_t SumWeight = MBPI->getSumForBlock(*I, WeightScale);
- for (MachineBasicBlock::succ_iterator SI = (*I)->succ_begin(),
- SE = (*I)->succ_end();
- SI != SE; ++SI) {
- if ((*SI)->isLandingPad())
+ uint32_t SumWeight = MBPI->getSumForBlock(MBB, WeightScale);
+ for (MachineBasicBlock *Succ : MBB->successors()) {
+ if (Succ->isEHPad())
continue;
- if (*SI == *I)
+ if (Succ == MBB)
continue;
- BlockChain &SuccChain = *BlockToChain[*SI];
+ BlockChain &SuccChain = *BlockToChain[Succ];
// Don't split chains, either this chain or the successor's chain.
if (&Chain == &SuccChain) {
- DEBUG(dbgs() << " exiting: " << getBlockName(*I) << " -> "
- << getBlockName(*SI) << " (chain conflict)\n");
+ DEBUG(dbgs() << " exiting: " << getBlockName(MBB) << " -> "
+ << getBlockName(Succ) << " (chain conflict)\n");
continue;
}
- uint32_t SuccWeight = MBPI->getEdgeWeight(*I, *SI);
- if (LoopBlockSet.count(*SI)) {
- DEBUG(dbgs() << " looping: " << getBlockName(*I) << " -> "
- << getBlockName(*SI) << " (" << SuccWeight << ")\n");
+ uint32_t SuccWeight = MBPI->getEdgeWeight(MBB, Succ);
+ if (LoopBlockSet.count(Succ)) {
+ DEBUG(dbgs() << " looping: " << getBlockName(MBB) << " -> "
+ << getBlockName(Succ) << " (" << SuccWeight << ")\n");
HasLoopingSucc = true;
continue;
}
unsigned SuccLoopDepth = 0;
- if (MachineLoop *ExitLoop = MLI->getLoopFor(*SI)) {
+ if (MachineLoop *ExitLoop = MLI->getLoopFor(Succ)) {
SuccLoopDepth = ExitLoop->getLoopDepth();
if (ExitLoop->contains(&L))
- BlocksExitingToOuterLoop.insert(*I);
+ BlocksExitingToOuterLoop.insert(MBB);
}
BranchProbability SuccProb(SuccWeight / WeightScale, SumWeight);
- BlockFrequency ExitEdgeFreq = MBFI->getBlockFreq(*I) * SuccProb;
- DEBUG(dbgs() << " exiting: " << getBlockName(*I) << " -> "
- << getBlockName(*SI) << " [L:" << SuccLoopDepth << "] (";
+ BlockFrequency ExitEdgeFreq = MBFI->getBlockFreq(MBB) * SuccProb;
+ DEBUG(dbgs() << " exiting: " << getBlockName(MBB) << " -> "
+ << getBlockName(Succ) << " [L:" << SuccLoopDepth << "] (";
MBFI->printBlockFreq(dbgs(), ExitEdgeFreq) << ")\n");
// Note that we bias this toward an existing layout successor to retain
// incoming order in the absence of better information. The exit must have
// a frequency higher than the current exit before we consider breaking
// the layout.
BranchProbability Bias(100 - ExitBlockBias, 100);
- if (!ExitingBB || BestExitLoopDepth < SuccLoopDepth ||
+ if (!ExitingBB || SuccLoopDepth > BestExitLoopDepth ||
ExitEdgeFreq > BestExitEdgeFreq ||
- ((*I)->isLayoutSuccessor(*SI) &&
+ (MBB->isLayoutSuccessor(Succ) &&
!(ExitEdgeFreq < BestExitEdgeFreq * Bias))) {
BestExitEdgeFreq = ExitEdgeFreq;
- ExitingBB = *I;
+ ExitingBB = MBB;
}
}
- // Restore the old exiting state, no viable looping successor was found.
if (!HasLoopingSucc) {
+ // Restore the old exiting state, no viable looping successor was found.
ExitingBB = OldExitingBB;
BestExitEdgeFreq = OldBestExitEdgeFreq;
continue;
MachineBasicBlock *Top = *LoopChain.begin();
bool ViableTopFallthrough = false;
- for (MachineBasicBlock::pred_iterator PI = Top->pred_begin(),
- PE = Top->pred_end();
- PI != PE; ++PI) {
- BlockChain *PredChain = BlockToChain[*PI];
- if (!LoopBlockSet.count(*PI) &&
- (!PredChain || *PI == *std::prev(PredChain->end()))) {
+ for (MachineBasicBlock *Pred : Top->predecessors()) {
+ BlockChain *PredChain = BlockToChain[Pred];
+ if (!LoopBlockSet.count(Pred) &&
+ (!PredChain || Pred == *std::prev(PredChain->end()))) {
ViableTopFallthrough = true;
break;
}
// introduce an unnecessary branch.
if (ViableTopFallthrough) {
MachineBasicBlock *Bottom = *std::prev(LoopChain.end());
- for (MachineBasicBlock::succ_iterator SI = Bottom->succ_begin(),
- SE = Bottom->succ_end();
- SI != SE; ++SI) {
- BlockChain *SuccChain = BlockToChain[*SI];
- if (!LoopBlockSet.count(*SI) &&
- (!SuccChain || *SI == *SuccChain->begin()))
+ for (MachineBasicBlock *Succ : Bottom->successors()) {
+ BlockChain *SuccChain = BlockToChain[Succ];
+ if (!LoopBlockSet.count(Succ) &&
+ (!SuccChain || Succ == *SuccChain->begin()))
return;
}
}
MachineLoop &L) {
// First recurse through any nested loops, building chains for those inner
// loops.
- for (MachineLoop::iterator LI = L.begin(), LE = L.end(); LI != LE; ++LI)
- buildLoopChains(F, **LI);
+ for (MachineLoop *InnerLoop : L)
+ buildLoopChains(F, *InnerLoop);
SmallVector<MachineBasicBlock *, 16> BlockWorkList;
BlockFilterSet LoopBlockSet(L.block_begin(), L.block_end());
SmallPtrSet<BlockChain *, 4> UpdatedPreds;
assert(LoopChain.LoopPredecessors == 0);
UpdatedPreds.insert(&LoopChain);
- for (MachineLoop::block_iterator BI = L.block_begin(), BE = L.block_end();
- BI != BE; ++BI) {
- BlockChain &Chain = *BlockToChain[*BI];
+ for (MachineBasicBlock *LoopBB : L.getBlocks()) {
+ BlockChain &Chain = *BlockToChain[LoopBB];
if (!UpdatedPreds.insert(&Chain).second)
continue;
assert(Chain.LoopPredecessors == 0);
- for (BlockChain::iterator BCI = Chain.begin(), BCE = Chain.end();
- BCI != BCE; ++BCI) {
- assert(BlockToChain[*BCI] == &Chain);
- for (MachineBasicBlock::pred_iterator PI = (*BCI)->pred_begin(),
- PE = (*BCI)->pred_end();
- PI != PE; ++PI) {
- if (BlockToChain[*PI] == &Chain || !LoopBlockSet.count(*PI))
+ for (MachineBasicBlock *ChainBB : Chain) {
+ assert(BlockToChain[ChainBB] == &Chain);
+ for (MachineBasicBlock *Pred : ChainBB->predecessors()) {
+ if (BlockToChain[Pred] == &Chain || !LoopBlockSet.count(Pred))
continue;
++Chain.LoopPredecessors;
}
<< " Loop header: " << getBlockName(*L.block_begin()) << "\n"
<< " Chain header: " << getBlockName(*LoopChain.begin()) << "\n";
}
- for (BlockChain::iterator BCI = LoopChain.begin(), BCE = LoopChain.end();
- BCI != BCE; ++BCI) {
- dbgs() << " ... " << getBlockName(*BCI) << "\n";
- if (!LoopBlockSet.erase(*BCI)) {
+ for (MachineBasicBlock *ChainBB : LoopChain) {
+ dbgs() << " ... " << getBlockName(ChainBB) << "\n";
+ if (!LoopBlockSet.erase(ChainBB)) {
// We don't mark the loop as bad here because there are real situations
// where this can occur. For example, with an unanalyzable fallthrough
// from a loop block to a non-loop block or vice versa.
dbgs() << "Loop chain contains a block not contained by the loop!\n"
<< " Loop header: " << getBlockName(*L.block_begin()) << "\n"
<< " Chain header: " << getBlockName(*LoopChain.begin()) << "\n"
- << " Bad block: " << getBlockName(*BCI) << "\n";
+ << " Bad block: " << getBlockName(ChainBB) << "\n";
}
}
if (!LoopBlockSet.empty()) {
BadLoop = true;
- for (BlockFilterSet::iterator LBI = LoopBlockSet.begin(),
- LBE = LoopBlockSet.end();
- LBI != LBE; ++LBI)
+ for (MachineBasicBlock *LoopBB : LoopBlockSet)
dbgs() << "Loop contains blocks never placed into a chain!\n"
<< " Loop header: " << getBlockName(*L.block_begin()) << "\n"
<< " Chain header: " << getBlockName(*LoopChain.begin()) << "\n"
- << " Bad block: " << getBlockName(*LBI) << "\n";
+ << " Bad block: " << getBlockName(LoopBB) << "\n";
}
assert(!BadLoop && "Detected problems with the placement of this loop.");
});
// the assumptions of the remaining algorithm.
SmallVector<MachineOperand, 4> Cond; // For AnalyzeBranch.
for (MachineFunction::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
- MachineBasicBlock *BB = FI;
+ MachineBasicBlock *BB = &*FI;
BlockChain *Chain =
new (ChainAllocator.Allocate()) BlockChain(BlockToChain, BB);
// Also, merge any blocks which we cannot reason about and must preserve
if (!TII->AnalyzeBranch(*BB, TBB, FBB, Cond) || !FI->canFallThrough())
break;
- MachineFunction::iterator NextFI(std::next(FI));
- MachineBasicBlock *NextBB = NextFI;
+ MachineFunction::iterator NextFI = std::next(FI);
+ MachineBasicBlock *NextBB = &*NextFI;
// Ensure that the layout successor is a viable block, as we know that
// fallthrough is a possibility.
assert(NextFI != FE && "Can't fallthrough past the last block.");
}
// Build any loop-based chains.
- for (MachineLoopInfo::iterator LI = MLI->begin(), LE = MLI->end(); LI != LE;
- ++LI)
- buildLoopChains(F, **LI);
+ for (MachineLoop *L : *MLI)
+ buildLoopChains(F, *L);
SmallVector<MachineBasicBlock *, 16> BlockWorkList;
SmallPtrSet<BlockChain *, 4> UpdatedPreds;
- for (MachineFunction::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
- MachineBasicBlock *BB = &*FI;
- BlockChain &Chain = *BlockToChain[BB];
+ for (MachineBasicBlock &MBB : F) {
+ BlockChain &Chain = *BlockToChain[&MBB];
if (!UpdatedPreds.insert(&Chain).second)
continue;
assert(Chain.LoopPredecessors == 0);
- for (BlockChain::iterator BCI = Chain.begin(), BCE = Chain.end();
- BCI != BCE; ++BCI) {
- assert(BlockToChain[*BCI] == &Chain);
- for (MachineBasicBlock::pred_iterator PI = (*BCI)->pred_begin(),
- PE = (*BCI)->pred_end();
- PI != PE; ++PI) {
- if (BlockToChain[*PI] == &Chain)
+ for (MachineBasicBlock *ChainBB : Chain) {
+ assert(BlockToChain[ChainBB] == &Chain);
+ for (MachineBasicBlock *Pred : ChainBB->predecessors()) {
+ if (BlockToChain[Pred] == &Chain)
continue;
++Chain.LoopPredecessors;
}
// Crash at the end so we get all of the debugging output first.
bool BadFunc = false;
FunctionBlockSetType FunctionBlockSet;
- for (MachineFunction::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
- FunctionBlockSet.insert(FI);
+ for (MachineBasicBlock &MBB : F)
+ FunctionBlockSet.insert(&MBB);
- for (BlockChain::iterator BCI = FunctionChain.begin(),
- BCE = FunctionChain.end();
- BCI != BCE; ++BCI)
- if (!FunctionBlockSet.erase(*BCI)) {
+ for (MachineBasicBlock *ChainBB : FunctionChain)
+ if (!FunctionBlockSet.erase(ChainBB)) {
BadFunc = true;
dbgs() << "Function chain contains a block not in the function!\n"
- << " Bad block: " << getBlockName(*BCI) << "\n";
+ << " Bad block: " << getBlockName(ChainBB) << "\n";
}
if (!FunctionBlockSet.empty()) {
BadFunc = true;
- for (FunctionBlockSetType::iterator FBI = FunctionBlockSet.begin(),
- FBE = FunctionBlockSet.end();
- FBI != FBE; ++FBI)
+ for (MachineBasicBlock *RemainingBB : FunctionBlockSet)
dbgs() << "Function contains blocks never placed into a chain!\n"
- << " Bad block: " << getBlockName(*FBI) << "\n";
+ << " Bad block: " << getBlockName(RemainingBB) << "\n";
}
assert(!BadFunc && "Detected problems with the block placement.");
});
// Splice the blocks into place.
MachineFunction::iterator InsertPos = F.begin();
- for (BlockChain::iterator BI = FunctionChain.begin(),
- BE = FunctionChain.end();
- BI != BE; ++BI) {
- DEBUG(dbgs() << (BI == FunctionChain.begin() ? "Placing chain "
- : " ... ")
- << getBlockName(*BI) << "\n");
- if (InsertPos != MachineFunction::iterator(*BI))
- F.splice(InsertPos, *BI);
+ for (MachineBasicBlock *ChainBB : FunctionChain) {
+ DEBUG(dbgs() << (ChainBB == *FunctionChain.begin() ? "Placing chain "
+ : " ... ")
+ << getBlockName(ChainBB) << "\n");
+ if (InsertPos != MachineFunction::iterator(ChainBB))
+ F.splice(InsertPos, ChainBB);
else
++InsertPos;
// Update the terminator of the previous block.
- if (BI == FunctionChain.begin())
+ if (ChainBB == *FunctionChain.begin())
continue;
- MachineBasicBlock *PrevBB = std::prev(MachineFunction::iterator(*BI));
+ MachineBasicBlock *PrevBB = &*std::prev(MachineFunction::iterator(ChainBB));
// FIXME: It would be awesome of updateTerminator would just return rather
// than assert when the branch cannot be analyzed in order to remove this
// is mistakenly pointing to "*BI".
//
bool needUpdateBr = true;
- if (!Cond.empty() && (!FBB || FBB == *BI)) {
+ if (!Cond.empty() && (!FBB || FBB == ChainBB)) {
PrevBB->updateTerminator();
needUpdateBr = false;
Cond.clear();
// exclusively on the loop info here so that we can align backedges in
// unnatural CFGs and backedges that were introduced purely because of the
// loop rotations done during this layout pass.
+ // FIXME: Use Function::optForSize().
if (F.getFunction()->hasFnAttribute(Attribute::OptimizeForSize))
return;
if (FunctionChain.begin() == FunctionChain.end())
return; // Empty chain.
const BranchProbability ColdProb(1, 5); // 20%
- BlockFrequency EntryFreq = MBFI->getBlockFreq(F.begin());
+ BlockFrequency EntryFreq = MBFI->getBlockFreq(&F.front());
BlockFrequency WeightedEntryFreq = EntryFreq * ColdProb;
- for (BlockChain::iterator BI = std::next(FunctionChain.begin()),
- BE = FunctionChain.end();
- BI != BE; ++BI) {
+ for (MachineBasicBlock *ChainBB : FunctionChain) {
+ if (ChainBB == *FunctionChain.begin())
+ continue;
+
// Don't align non-looping basic blocks. These are unlikely to execute
// enough times to matter in practice. Note that we'll still handle
// unnatural CFGs inside of a natural outer loop (the common case) and
// rotated loops.
- MachineLoop *L = MLI->getLoopFor(*BI);
+ MachineLoop *L = MLI->getLoopFor(ChainBB);
if (!L)
continue;
// If the block is cold relative to the function entry don't waste space
// aligning it.
- BlockFrequency Freq = MBFI->getBlockFreq(*BI);
+ BlockFrequency Freq = MBFI->getBlockFreq(ChainBB);
if (Freq < WeightedEntryFreq)
continue;
// Check for the existence of a non-layout predecessor which would benefit
// from aligning this block.
- MachineBasicBlock *LayoutPred = *std::prev(BI);
+ MachineBasicBlock *LayoutPred =
+ &*std::prev(MachineFunction::iterator(ChainBB));
// Force alignment if all the predecessors are jumps. We already checked
// that the block isn't cold above.
- if (!LayoutPred->isSuccessor(*BI)) {
- (*BI)->setAlignment(Align);
+ if (!LayoutPred->isSuccessor(ChainBB)) {
+ ChainBB->setAlignment(Align);
continue;
}
// cold relative to the block. When this is true, other predecessors make up
// all of the hot entries into the block and thus alignment is likely to be
// important.
- BranchProbability LayoutProb = MBPI->getEdgeProbability(LayoutPred, *BI);
+ BranchProbability LayoutProb =
+ MBPI->getEdgeProbability(LayoutPred, ChainBB);
BlockFrequency LayoutEdgeFreq = MBFI->getBlockFreq(LayoutPred) * LayoutProb;
if (LayoutEdgeFreq <= (Freq * ColdProb))
- (*BI)->setAlignment(Align);
+ ChainBB->setAlignment(Align);
}
}
if (AlignAllBlock)
// Align all of the blocks in the function to a specific alignment.
- for (MachineFunction::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
- FI->setAlignment(AlignAllBlock);
+ for (MachineBasicBlock &MBB : F)
+ MBB.setAlignment(AlignAllBlock);
// We always return true as we have no way to track whether the final order
// differs from the original order.
MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
MBFI = &getAnalysis<MachineBlockFrequencyInfo>();
- for (MachineFunction::iterator I = F.begin(), E = F.end(); I != E; ++I) {
- BlockFrequency BlockFreq = MBFI->getBlockFreq(I);
+ for (MachineBasicBlock &MBB : F) {
+ BlockFrequency BlockFreq = MBFI->getBlockFreq(&MBB);
Statistic &NumBranches =
- (I->succ_size() > 1) ? NumCondBranches : NumUncondBranches;
+ (MBB.succ_size() > 1) ? NumCondBranches : NumUncondBranches;
Statistic &BranchTakenFreq =
- (I->succ_size() > 1) ? CondBranchTakenFreq : UncondBranchTakenFreq;
- for (MachineBasicBlock::succ_iterator SI = I->succ_begin(),
- SE = I->succ_end();
- SI != SE; ++SI) {
+ (MBB.succ_size() > 1) ? CondBranchTakenFreq : UncondBranchTakenFreq;
+ for (MachineBasicBlock *Succ : MBB.successors()) {
// Skip if this successor is a fallthrough.
- if (I->isLayoutSuccessor(*SI))
+ if (MBB.isLayoutSuccessor(Succ))
continue;
- BlockFrequency EdgeFreq = BlockFreq * MBPI->getEdgeProbability(I, *SI);
+ BlockFrequency EdgeFreq =
+ BlockFreq * MBPI->getEdgeProbability(&MBB, Succ);
++NumBranches;
BranchTakenFreq += EdgeFreq.getFrequency();
}
return false;
}
-
projects / oota-llvm.git / blobdiff