#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/PassManager.h"
-#include "llvm/IR/ValueHandle.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/BranchProbability.h"
void calculate(const Function &F, const LoopInfo &LI);
- /// Forget analysis results for the given basic block.
- void eraseBlock(const BasicBlock *BB);
-
private:
void operator=(const BranchProbabilityInfo &) = delete;
BranchProbabilityInfo(const BranchProbabilityInfo &) = delete;
// Since we allow duplicate edges from one basic block to another, we use
// a pair (PredBlock and an index in the successors) to specify an edge.
- typedef std::pair<AssertingVH<const BasicBlock>, unsigned> Edge;
+ typedef std::pair<const BasicBlock *, unsigned> Edge;
// Default weight value. Used when we don't have information about the edge.
// TODO: DEFAULT_WEIGHT makes sense during static predication, when none of
const char *Suffix);
void UpdateBlockFreqAndEdgeWeight(BasicBlock *PredBB, BasicBlock *BB,
BasicBlock *NewBB, BasicBlock *SuccBB);
-
- void dropBlockAnalysisResults(BasicBlock *BB);
};
} // end namespace llvm
class DIBuilder;
class DominatorTree;
class LazyValueInfo;
-class BranchProbabilityInfo;
template<typename T> class SmallVectorImpl;
/// Remove all blocks that can not be reached from the function's entry.
///
/// Returns true if any basic block was removed.
-/// \param F Target function
-/// \param LVI Will update this analysis if non null
-/// \param BPI Will update this analysis if non null
-bool removeUnreachableBlocks(Function &F, LazyValueInfo *LVI = nullptr,
- BranchProbabilityInfo *BPI = nullptr);
+bool removeUnreachableBlocks(Function &F, LazyValueInfo *LVI = nullptr);
/// Combine the metadata of two instructions so that K can replace J
///
return OS;
}
-void BranchProbabilityInfo::eraseBlock(const BasicBlock *BB) {
- for (auto I = Probs.begin(), E = Probs.end(); I != E; ++I) {
- auto Key = I->first;
- if (Key.first == BB)
- Probs.erase(Key);
- }
-}
-
void BranchProbabilityInfo::calculate(const Function &F, const LoopInfo &LI) {
DEBUG(dbgs() << "---- Branch Probability Info : " << F.getName()
<< " ----\n\n");
// back edges. This works for normal cases but not for unreachable blocks as
// they may have cycle with no back edge.
bool EverChanged = false;
- EverChanged |= removeUnreachableBlocks(F, LVI, BPI.get());
+ EverChanged |= removeUnreachableBlocks(F, LVI);
FindLoopHeaders(F);
DEBUG(dbgs() << " JT: Deleting dead block '" << BB->getName()
<< "' with terminator: " << *BB->getTerminator() << '\n');
LoopHeaders.erase(BB);
- dropBlockAnalysisResults(BB);
+ LVI->eraseBlock(BB);
DeleteDeadBlock(BB);
Changed = true;
continue;
// for a block even if it doesn't get erased. This isn't totally
// awesome, but it allows us to use AssertingVH to prevent nasty
// dangling pointer issues within LazyValueInfo.
- dropBlockAnalysisResults(BB);
+ LVI->eraseBlock(BB);
if (TryToSimplifyUncondBranchFromEmptyBlock(BB)) {
Changed = true;
// If we deleted BB and BB was the header of a loop, then the
if (LoopHeaders.erase(SinglePred))
LoopHeaders.insert(BB);
- dropBlockAnalysisResults(SinglePred);
+ LVI->eraseBlock(SinglePred);
MergeBasicBlockIntoOnlyPred(BB);
return true;
return false;
}
-
-/// dropBlockAnalysisResults - Inform relevant analyzes that BB is going to
-/// be removed. This is important in order to prevent dangling pointer problems.
-void JumpThreadingPass::dropBlockAnalysisResults(BasicBlock *BB) {
- LVI->eraseBlock(BB);
- if (BPI)
- BPI->eraseBlock(BB);
-}
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/MemoryBuiltins.h"
/// removeUnreachableBlocksFromFn - Remove blocks that are not reachable, even
/// if they are in a dead cycle. Return true if a change was made, false
/// otherwise.
-bool llvm::removeUnreachableBlocks(Function &F, LazyValueInfo *LVI,
- BranchProbabilityInfo *BPI) {
+bool llvm::removeUnreachableBlocks(Function &F, LazyValueInfo *LVI) {
SmallPtrSet<BasicBlock*, 16> Reachable;
bool Changed = markAliveBlocks(F, Reachable);
(*SI)->removePredecessor(&*BB);
if (LVI)
LVI->eraseBlock(&*BB);
- if (BPI)
- BPI->eraseBlock(&*BB);
BB->dropAllReferences();
}
+++ /dev/null
-; RUN: opt -S -jump-threading %s 2>&1 | FileCheck %s
-
-; Test that after removing basic block we had also removed it from BPI. If we
-; didn't there will be dangling pointer inside BPI. It can lead to a
-; miscalculation in the edge weight and possibly other problems.
-; Checks that we are not failing assertion inside AssettingVH
-
-; CHECK-NOT: An asserting value handle still pointed to this value
-
-define void @foo(i32 %n, i1 %cond) !prof !0 {
-; Record this block into BPI cache
-single-pred:
- br i1 %cond, label %entry, label %entry, !prof !{!"branch_weights", i32 1, i32 1}
-
-entry:
- ret void
-}
-
-!0 = !{!"function_entry_count", i64 1}
SMDiagnostic Err;
return parseAssemblyString(ModuleStrig, Err, C);
}
-
- void destroyBFI() {
- // Prevent AssertingVH from failing.
- BPI->releaseMemory();
- }
};
TEST_F(BlockFrequencyInfoTest, Basic) {
EXPECT_EQ(BFI.getBlockProfileCount(BB3).getValue(), UINT64_C(100));
EXPECT_EQ(BFI.getBlockProfileCount(BB1).getValue(), 100 * BB1Freq / BB0Freq);
EXPECT_EQ(BFI.getBlockProfileCount(BB2).getValue(), 100 * BB2Freq / BB0Freq);
-
- destroyBFI();
}
} // end anonymous namespace
OSDN Git Service
