diff options
| -rw-r--r-- | lib/Transforms/Scalar/LICM.cpp | 8 | ||||
| -rw-r--r-- | test/Transforms/LICM/2007-09-17-PrompteValue.ll | 26 |
2 files changed, 34 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp index ac927da..6c5976a 100644 --- a/lib/Transforms/Scalar/LICM.cpp +++ b/lib/Transforms/Scalar/LICM.cpp @@ -791,6 +791,14 @@ void LICM::FindPromotableValuesInLoop( break; } + // If GEP base is NULL then the calculated address used by Store or + // Load instruction is invalid. Do not promote this value because + // it may expose load and store instruction that are covered by + // condition which may not yet folded. + if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) + if (isa<ConstantPointerNull>(GEP->getOperand(0))) + PointerOk = false; + if (PointerOk) { const Type *Ty = cast<PointerType>(V->getType())->getElementType(); AllocaInst *AI = new AllocaInst(Ty, 0, V->getName()+".tmp", FnStart); diff --git a/test/Transforms/LICM/2007-09-17-PrompteValue.ll b/test/Transforms/LICM/2007-09-17-PrompteValue.ll new file mode 100644 index 0000000..acbbabf --- /dev/null +++ b/test/Transforms/LICM/2007-09-17-PrompteValue.ll @@ -0,0 +1,26 @@ +; ModuleID = 'PR1657.bc' +; Do not promote getelementptr because it may exposes load from a null pointer +; and store from a null pointer which are covered by +; icmp eq %struct.decision* null, null condition. +; RUN: llvm-as < %s | opt -licm | llvm-dis | not grep promoted + %struct.decision = type { i8, %struct.decision* } + +define i32 @main() { +entry: + br label %blah.i + +blah.i: ; preds = %cond_true.i, %entry + %tmp3.i = icmp eq %struct.decision* null, null ; <i1> [#uses=1] + br i1 %tmp3.i, label %clear_modes.exit, label %cond_true.i + +cond_true.i: ; preds = %blah.i + %tmp1.i = getelementptr %struct.decision* null, i32 0, i32 0 ; <i8*> [#uses=1] + store i8 0, i8* %tmp1.i + br label %blah.i + +clear_modes.exit: ; preds = %blah.i + call void @exit( i32 0 ) + unreachable +} + +declare void @exit(i32) |