diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 25f2fc66b73..d564bda7987 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2800,7 +2800,12 @@ SDValue DAGCombiner::visitSUBSAT(SDNode *N) { if (N0.isUndef() || N1.isUndef()) return DAG.getConstant(0, DL, VT); - // TODO Constant Folding + if (DAG.isConstantIntBuildVectorOrConstantInt(N0) && + DAG.isConstantIntBuildVectorOrConstantInt(N1)) { + // fold (sub_sat c1, c2) -> c3 + return DAG.FoldConstantArithmetic(N->getOpcode(), DL, VT, N0.getNode(), + N1.getNode()); + } // fold (sub_sat x, 0) -> x if (isNullConstant(N1)) |
