[LLVMdev] legalization of truncating stores in LegalizeDAG.cpp

[Duncan Sands]

Hi Akira,

On 01/06/12 02:27, Hatanaka, Akira wrote:
> In LegalizeDAG.cpp, truncating stores are custom-lowered in line 1314-1317:
>
> 1314         case TargetLowering::Custom:
> 1315           ReplaceNode(SDValue(Node, 0),
> 1316                       TLI.LowerOperation(SDValue(Node, 0), DAG));
> 1317           break;
>
> Is there a reason it doesn't check whether the SDValue returned from
> TargetLowering::LowerOperation is null before it replaces the original node with
> the returned node? The return value is checked everywhere else
> TLI.LowerOperation is called (line 937, for example).
>
>
> 937         Tmp1 = TLI.LowerOperation(Tmp3, DAG);
> 938         if (Tmp1.getNode()) {
> 939           Tmp3 = Tmp1;
> 940           Tmp4 = Tmp1.getValue(1);
> 941         }
> 942         break;

probably it's just an oversight, because no backend needed it.  LegalizeDAG is
unfortunately full of code like this.

Ciao, Duncan.