diff options
Diffstat (limited to 'lib/Analysis/BasicAliasAnalysis.cpp')
-rw-r--r-- | lib/Analysis/BasicAliasAnalysis.cpp | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp index 3270f35ac4..57d320971d 100644 --- a/lib/Analysis/BasicAliasAnalysis.cpp +++ b/lib/Analysis/BasicAliasAnalysis.cpp @@ -63,12 +63,23 @@ static bool AddressMightEscape(const Value *V) { // callees could modify it. break; // next use case Instruction::Call: - // If the call is to a few known safe intrinsics, we know that it does - // not escape. - // TODO: Eventually just check the 'nocapture' attribute. - if (!isa<MemIntrinsic>(I)) - return true; - break; // next use + // If the argument to the call has the nocapture attribute, then the call + // may store or load to the pointer, but it cannot escape. + if (cast<CallInst>(I)->paramHasAttr(UI.getOperandNo(), + Attribute::NoCapture)) + continue; + + // FIXME: MemIntrinsics should have their operands marked nocapture! + if (isa<MemIntrinsic>(I)) + continue; // next use + return true; + case Instruction::Invoke: + // If the argument to the call has the nocapture attribute, then the call + // may store or load to the pointer, but it cannot escape. + if (cast<InvokeInst>(I)->paramHasAttr(UI.getOperandNo()-2, + Attribute::NoCapture)) + continue; + return true; default: return true; } |