diff options
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 3e46e11..e2c7253 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -5382,6 +5382,9 @@ static bool programUndefinedIfUndefOrPoison(const Value *V, return false; } + // Limit number of instructions we look at, to avoid scanning through large + // blocks. The current limit is chosen arbitrarily. + unsigned ScanLimit = 32; BasicBlock::const_iterator End = BB->end(); if (!PoisonOnly) { @@ -5390,6 +5393,11 @@ static bool programUndefinedIfUndefOrPoison(const Value *V, // well-defined operands. for (auto &I : make_range(Begin, End)) { + if (isa<DbgInfoIntrinsic>(I)) + continue; + if (--ScanLimit == 0) + break; + SmallPtrSet<const Value *, 4> WellDefinedOps; getGuaranteedWellDefinedOps(&I, WellDefinedOps); for (auto *Op : WellDefinedOps) { @@ -5415,9 +5423,12 @@ static bool programUndefinedIfUndefOrPoison(const Value *V, for_each(V->users(), Propagate); Visited.insert(BB); - unsigned Iter = 0; - while (Iter++ < MaxAnalysisRecursionDepth) { + while (true) { for (auto &I : make_range(Begin, End)) { + if (isa<DbgInfoIntrinsic>(I)) + continue; + if (--ScanLimit == 0) + return false; if (mustTriggerUB(&I, YieldsPoison)) return true; if (!isGuaranteedToTransferExecutionToSuccessor(&I)) |