From 731d348166792bb9846022a82f7712c7bcec8f30 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 27 Oct 2005 05:06:38 +0000 Subject: [PATCH] Add a simple xform that is useful for bitfield operations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24029 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 0ccd0383ea7..30c8d98405f 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -1103,7 +1103,16 @@ SDOperand DAGCombiner::visitOR(SDNode *N) { if (N01C) return DAG.getNode(ISD::OR, VT, N0.getOperand(0), DAG.getConstant(N1C->getValue()|N01C->getValue(), VT)); + } else if (N1C && N0.getOpcode() == ISD::AND && N0.Val->hasOneUse() && + isa(N0.getOperand(1))) { + // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2) + ConstantSDNode *C1 = cast(N0.getOperand(1)); + return DAG.getNode(ISD::AND, VT, DAG.getNode(ISD::OR, VT, N0.getOperand(0), + N1), + DAG.getConstant(N1C->getValue() | C1->getValue(), VT)); } + + // fold (or (setcc x), (setcc y)) -> (setcc (or x, y)) if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){ ISD::CondCode Op0 = cast(CC0)->get(); -- 2.34.1