From cd558887d3b17f99ad86605003a1e7c0e689a863 Mon Sep 17 00:00:00 2001 From: Nirav Dave Date: Wed, 20 Jun 2018 15:36:29 +0000 Subject: [DAG] Fix and-mask folding when narrowing loads. Summary: Check that and masks are strictly smaller than implicit mask from narrowed load. Fixes PR37820. Reviewers: samparker, RKSimon, nemanjai Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D48335 llvm-svn: 335137 --- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'llvm/lib/CodeGen') diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 3d835266b90..ee767c0fd03 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -8688,8 +8688,9 @@ SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) { if (ShiftMask.isMask()) { EVT MaskedVT = EVT::getIntegerVT(*DAG.getContext(), ShiftMask.countTrailingOnes()); - // Recompute the type. - if (TLI.isLoadExtLegal(ExtType, N0.getValueType(), MaskedVT)) + // If the mask is smaller, recompute the type. + if ((ExtVT.getSizeInBits() > MaskedVT.getSizeInBits()) && + TLI.isLoadExtLegal(ExtType, N0.getValueType(), MaskedVT)) ExtVT = MaskedVT; } } -- cgit v1.2.3