[llvm-commits] [llvm] r78615 - in /llvm/trunk/lib: CodeGen/SelectionDAG/DAGCombiner.cpp Target/ARM/ARMISelDAGToDAG.cpp

[Evan Cheng]

Thanks. But there are a couple of places in DAG combiner that create  
fpconst nodes. Can you make sure they do the proper checks first?

Evan

On Aug 10, 2009, at 4:15 PM, Dan Gohman wrote:

> Author: djg
> Date: Mon Aug 10 18:15:10 2009
> New Revision: 78615
>
> URL: http://llvm.org/viewvc/llvm-project?rev=78615&view=rev
> Log:
> Fix a bug where DAGCombine was producing an illegal ConstantFP
> node after legalize, and remove the workaround code from the
> ARM backend.
>
> Modified:
>    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
>    llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp
>
> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=78615&r1=78614&r2=78615&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
> +++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Aug 10  
> 18:15:10 2009
> @@ -3721,7 +3721,18 @@
>   // If the input is a constant, let getNode fold it.
>   if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
>     SDValue Res = DAG.getNode(ISD::BIT_CONVERT, N->getDebugLoc(),  
> VT, N0);
> -    if (Res.getNode() != N) return Res;
> +    if (Res.getNode() != N) {
> +      if (!LegalOperations ||
> +          TLI.isOperationLegal(Res.getNode()->getOpcode(), VT))
> +        return Res;
> +
> +      // Folding it resulted in an illegal node, and it's too late to
> +      // do that. Clean up the old node and forego the  
> transformation.
> +      // Ideally this won't happen very often, because instcombine
> +      // and the earlier dagcombine runs (where illegal nodes are
> +      // permitted) should have folded most of them already.
> +      DAG.DeleteNode(Res.getNode());
> +    }
>   }
>
>   // (conv (conv x, t1), t2) -> (conv x, t2)
>
> Modified: llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp?rev=78615&r1=78614&r2=78615&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp Mon Aug 10  
> 18:15:10 2009
> @@ -988,24 +988,6 @@
>     // Other cases are autogenerated.
>     break;
>   }
> -  case ISD::ConstantFP: {
> -    ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(N);
> -    EVT VT = CFP->getValueType(0);
> -    ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP- 
> >getConstantFPValue());
> -    SDValue CPIdx = CurDAG->getTargetConstantPool(LLVMC,  
> TLI.getPointerTy());
> -    SDNode *ResNode;
> -    SDValue Ops[] = {
> -      CPIdx,
> -      CurDAG->getTargetConstant(0, EVT::i32),
> -      getAL(CurDAG),
> -      CurDAG->getRegister(0, EVT::i32),
> -      CurDAG->getEntryNode()
> -    };
> -    unsigned Opc = (VT == EVT::f32) ? ARM::FLDS : ARM::FLDD;
> -    ResNode=CurDAG->getTargetNode(Opc, dl, VT, EVT::Other, Ops, 5);
> -    ReplaceUses(Op, SDValue(ResNode, 0));
> -    return NULL;
> -  }
>   case ISD::FrameIndex: {
>     // Selects to ADDri FI, 0 which in turn will become ADDri SP, imm.
>     int FI = cast<FrameIndexSDNode>(N)->getIndex();
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits