diff options
Diffstat (limited to 'lib/Analysis/ScalarEvolutionExpander.cpp')
| -rw-r--r-- | lib/Analysis/ScalarEvolutionExpander.cpp | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp index 999fd55c86..34724709b0 100644 --- a/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/lib/Analysis/ScalarEvolutionExpander.cpp @@ -53,10 +53,9 @@ Value *SCEVExpander::InsertNoopCastOfTo(Value *V, const Type *Ty) { return CE->getOperand(0); } - // FIXME: keep track of the cast instruction. if (Constant *C = dyn_cast<Constant>(V)) return ConstantExpr::getCast(Op, C, Ty); - + if (Argument *A = dyn_cast<Argument>(V)) { // Check to see if there is already a cast! for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); @@ -317,13 +316,17 @@ static void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, } } -/// expandAddToGEP - Expand a SCEVAddExpr with a pointer type into a GEP -/// instead of using ptrtoint+arithmetic+inttoptr. This helps -/// BasicAliasAnalysis and other passes analyze the result. +/// expandAddToGEP - Expand an addition expression with a pointer type into +/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps +/// BasicAliasAnalysis and other passes analyze the result. See the rules +/// for getelementptr vs. inttoptr in +/// http://llvm.org/docs/LangRef.html#pointeraliasing +/// for details. /// -/// Design note: This depends on ScalarEvolution not recognizing inttoptr -/// and ptrtoint operators, as they may introduce pointer arithmetic -/// which may not be safely converted into getelementptr. +/// Design note: The correctness of using getelmeentptr here depends on +/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as +/// they may introduce pointer arithmetic which may not be safely converted +/// into getelementptr. /// /// Design note: It might seem desirable for this function to be more /// loop-aware. If some of the indices are loop-invariant while others |