diff options
| -rw-r--r-- | llvm/lib/Analysis/MemoryDependenceAnalysis.cpp | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp index 46f28fbca38..9de9d1af7c7 100644 --- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp +++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp @@ -979,6 +979,11 @@ MemDepResult MemoryDependenceResults::GetNonLocalInfoForBlock( Instruction *QueryInst, const MemoryLocation &Loc, bool isLoad, BasicBlock *BB, NonLocalDepInfo *Cache, unsigned NumSortedEntries) { + bool isInvariantLoad = false; + + if (LoadInst *LI = dyn_cast_or_null<LoadInst>(QueryInst)) + isInvariantLoad = LI->getMetadata(LLVMContext::MD_invariant_load); + // Do a binary search to see if we already have an entry for this block in // the cache set. If so, find it. NonLocalDepInfo::iterator Entry = std::upper_bound( @@ -990,6 +995,13 @@ MemDepResult MemoryDependenceResults::GetNonLocalInfoForBlock( if (Entry != Cache->begin() + NumSortedEntries && Entry->getBB() == BB) ExistingResult = &*Entry; + // Use cached result for invariant load only if there is no dependency for non + // invariant load. In this case invariant load can not have any dependency as + // well. + if (ExistingResult && isInvariantLoad && + !ExistingResult->getResult().isNonFuncLocal()) + ExistingResult = nullptr; + // If we have a cached entry, and it is non-dirty, use it as the value for // this dependency. if (ExistingResult && !ExistingResult->getResult().isDirty()) { @@ -1018,6 +1030,10 @@ MemDepResult MemoryDependenceResults::GetNonLocalInfoForBlock( MemDepResult Dep = getPointerDependencyFrom(Loc, isLoad, ScanPos, BB, QueryInst); + // Don't cache results for invariant load. + if (isInvariantLoad) + return Dep; + // If we had a dirty entry for the block, update it. Otherwise, just add // a new entry. if (ExistingResult) @@ -1454,7 +1470,6 @@ bool MemoryDependenceResults::getNonLocalPointerDepFromBB( if (SkipFirstBlock) return false; - bool foundBlock = false; for (NonLocalDepEntry &I : llvm::reverse(*Cache)) { if (I.getBB() != BB) continue; @@ -1462,14 +1477,12 @@ bool MemoryDependenceResults::getNonLocalPointerDepFromBB( assert((GotWorklistLimit || I.getResult().isNonLocal() || !DT.isReachableFromEntry(BB)) && "Should only be here with transparent block"); - foundBlock = true; I.setResult(MemDepResult::getUnknown()); - Result.push_back( - NonLocalDepResult(I.getBB(), I.getResult(), Pointer.getAddr())); break; } - (void)foundBlock; (void)GotWorklistLimit; - assert((foundBlock || GotWorklistLimit) && "Current block not in cache?"); + // Go ahead and report unknown dependence. + Result.push_back( + NonLocalDepResult(BB, MemDepResult::getUnknown(), Pointer.getAddr())); } // Okay, we're done now. If we added new values to the cache, re-sort it. |
