diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/LICM.cpp | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp index d42d4ff..935cd5d 100644 --- a/lib/Transforms/Scalar/LICM.cpp +++ b/lib/Transforms/Scalar/LICM.cpp @@ -372,7 +372,11 @@ bool LICM::canSinkOrHoistInst(Instruction &I) { return !pointerInvalidatedByLoop(LI->getOperand(0), Size, LI->getMetadata(LLVMContext::MD_tbaa)); } else if (CallInst *CI = dyn_cast<CallInst>(&I)) { - // Handle obvious cases efficiently. + // Don't sink or hoist dbg info; it's legal, but not useful. + if (isa<DbgInfoIntrinsic>(I)) + return false; + + // Handle simple cases by querying alias analysis. AliasAnalysis::ModRefBehavior Behavior = AA->getModRefBehavior(CI); if (Behavior == AliasAnalysis::DoesNotAccessMemory) return true; @@ -522,14 +526,7 @@ void LICM::sink(Instruction &I) { SSA.AddAvailableValue(ExitBlock, New); } - // If the instruction doesn't dominate any exit blocks, it must be dead. - if (NumInserted == 0) { - CurAST->deleteValue(&I); - if (!I.use_empty()) - I.replaceAllUsesWith(UndefValue::get(I.getType())); - I.eraseFromParent(); - return; - } + assert(NumInserted && "We shouldn't see dead instructions here!"); // Next, rewrite uses of the instruction, inserting PHI nodes as needed. for (Value::use_iterator UI = I.use_begin(), UE = I.use_end(); UI != UE; ) { |