diff options
Diffstat (limited to 'lib/Analysis/CaptureTracking.cpp')
| -rw-r--r-- | lib/Analysis/CaptureTracking.cpp | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/lib/Analysis/CaptureTracking.cpp b/lib/Analysis/CaptureTracking.cpp index a7292706dfa88..79fab1be44139 100644 --- a/lib/Analysis/CaptureTracking.cpp +++ b/lib/Analysis/CaptureTracking.cpp @@ -146,8 +146,14 @@ void llvm::PointerMayBeCaptured(const Value *V, CaptureTracker *Tracker) { case Instruction::PHI: case Instruction::Select: // The original value is not captured via this if the new value isn't. + Count = 0; for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE; ++UI) { + // If there are lots of uses, conservatively say that the value + // is captured to avoid taking too much compile time. + if (Count++ >= Threshold) + return Tracker->tooManyUses(); + Use *U = &UI.getUse(); if (Visited.insert(U)) if (Tracker->shouldExplore(U)) @@ -158,10 +164,10 @@ void llvm::PointerMayBeCaptured(const Value *V, CaptureTracker *Tracker) { // Don't count comparisons of a no-alias return value against null as // captures. This allows us to ignore comparisons of malloc results // with null, for example. - if (isNoAliasCall(V->stripPointerCasts())) - if (ConstantPointerNull *CPN = - dyn_cast<ConstantPointerNull>(I->getOperand(1))) - if (CPN->getType()->getAddressSpace() == 0) + if (ConstantPointerNull *CPN = + dyn_cast<ConstantPointerNull>(I->getOperand(1))) + if (CPN->getType()->getAddressSpace() == 0) + if (isNoAliasCall(V->stripPointerCasts())) break; // Otherwise, be conservative. There are crazy ways to capture pointers // using comparisons. |