Commit 57b0d332 authored by Simon Pilgrim's avatar Simon Pilgrim
Browse files

[DAGCombiner] ISD::AND/OR/XOR - use general SelectionDAG::FoldConstantArithmetic 

This handles all the constant splat / opaque testing for us.
parent a967aa27

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

+16 −10
Original line number Diff line number Diff line
@@ -5165,17 +5165,19 @@ SDValue DAGCombiner::visitAND(SDNode *N) { 
  }















  // fold (and c1, c2) -> c1&c2













  ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);















  ConstantSDNode *N1C = isConstOrConstSplat(N1);













  if (N0C && N1C && !N1C->isOpaque())













    return DAG.FoldConstantArithmetic(ISD::AND, SDLoc(N), VT, N0C, N1C);













  if (SDValue C = DAG.FoldConstantArithmetic(ISD::AND, SDLoc(N), VT, {N0, N1}))













    return C;



























  // canonicalize constant to RHS















  if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&















      !DAG.isConstantIntBuildVectorOrConstantInt(N1))















    return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0);



























  // fold (and x, -1) -> x















  if (isAllOnesConstant(N1))















    return N0;



























  // if (and x, c) is known to be zero, return 0















  unsigned BitWidth = VT.getScalarSizeInBits();















  if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),










@@ -5866,17 +5868,19 @@ SDValue DAGCombiner::visitOR(SDNode *N) {













  }





























  // fold (or c1, c2) -> c1|c2













  ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);















  ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);













  if (N0C && N1C && !N1C->isOpaque())













    return DAG.FoldConstantArithmetic(ISD::OR, SDLoc(N), VT, N0C, N1C);













  if (SDValue C = DAG.FoldConstantArithmetic(ISD::OR, SDLoc(N), VT, {N0, N1}))













    return C;



























  // canonicalize constant to RHS















  if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&















     !DAG.isConstantIntBuildVectorOrConstantInt(N1))















    return DAG.getNode(ISD::OR, SDLoc(N), VT, N1, N0);



























  // fold (or x, 0) -> x















  if (isNullConstant(N1))















    return N0;



























  // fold (or x, -1) -> -1















  if (isAllOnesConstant(N1))















    return N1;










@@ -7021,20 +7025,22 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {













  SDLoc DL(N);















  if (N0.isUndef() && N1.isUndef())















    return DAG.getConstant(0, DL, VT);



























  // fold (xor x, undef) -> undef















  if (N0.isUndef())















    return N0;















  if (N1.isUndef())















    return N1;



























  // fold (xor c1, c2) -> c1^c2













  ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);













  ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);













  if (N0C && N1C)













    return DAG.FoldConstantArithmetic(ISD::XOR, DL, VT, N0C, N1C);













  if (SDValue C = DAG.FoldConstantArithmetic(ISD::XOR, DL, VT, {N0, N1}))













    return C;



























  // canonicalize constant to RHS















  if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&















     !DAG.isConstantIntBuildVectorOrConstantInt(N1))















    return DAG.getNode(ISD::XOR, DL, VT, N1, N0);



























  // fold (xor x, 0) -> x















  if (isNullConstant(N1))















    return N0;