Commit a967aa27 authored by Simon Pilgrim's avatar Simon Pilgrim
Browse files

[DAGCombiner] ISD::SDIV/UDIV/SREM/UREM - use general SelectionDAG::FoldConstantArithmetic 

This handles all the constant splat / opaque testing for us.
parent d242aa24

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

+10 −12
Original line number Diff line number Diff line
@@ -3741,13 +3741,14 @@ SDValue DAGCombiner::visitSDIV(SDNode *N) { 
  SDLoc DL(N);















  // fold (sdiv c1, c2) -> c1/c2













  ConstantSDNode *N0C = isConstOrConstSplat(N0);















  ConstantSDNode *N1C = isConstOrConstSplat(N1);













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













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













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













    return C;



























  // fold (sdiv X, -1) -> 0-X















  if (N1C && N1C->isAllOnesValue())















    return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), N0);



























  // fold (sdiv X, MIN_SIGNED) -> select(X == MIN_SIGNED, 1, 0)















  if (N1C && N1C->getAPIntValue().isMinSignedValue())















    return DAG.getSelect(DL, VT, DAG.getSetCC(DL, CCVT, N0, N1, ISD::SETEQ),










@@ -3885,12 +3886,10 @@ SDValue DAGCombiner::visitUDIV(SDNode *N) {













  SDLoc DL(N);





























  // fold (udiv c1, c2) -> c1/c2













  ConstantSDNode *N0C = isConstOrConstSplat(N0);















  ConstantSDNode *N1C = isConstOrConstSplat(N1);













  if (N0C && N1C)













    if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::UDIV, DL, VT,













                                                    N0C, N1C))













      return Folded;













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













    return C;



























  // fold (udiv X, -1) -> select(X == -1, 1, 0)















  if (N1C && N1C->getAPIntValue().isAllOnesValue())















    return DAG.getSelect(DL, VT, DAG.getSetCC(DL, CCVT, N0, N1, ISD::SETEQ),










@@ -3983,11 +3982,10 @@ SDValue DAGCombiner::visitREM(SDNode *N) {













  SDLoc DL(N);





























  // fold (rem c1, c2) -> c1%c2













  ConstantSDNode *N0C = isConstOrConstSplat(N0);















  ConstantSDNode *N1C = isConstOrConstSplat(N1);













  if (N0C && N1C)













    if (SDValue Folded = DAG.FoldConstantArithmetic(Opcode, DL, VT, N0C, N1C))













      return Folded;













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













    return C;



























  // fold (urem X, -1) -> select(X == -1, 0, x)















  if (!isSigned && N1C && N1C->getAPIntValue().isAllOnesValue())















    return DAG.getSelect(DL, VT, DAG.getSetCC(DL, CCVT, N0, N1, ISD::SETEQ),