On Thu, Apr 30, 2020 at 12:58:32PM -0400, George Koehler wrote:
> On Wed, 29 Apr 2020 21:08:52 +0200 (CEST)
> Mark Kettenis <[email protected]> wrote:
>
> > Upstream fixed this issue as well. Apparently only ADDE can't be
> > legalized (because it is "special") but ADDCARRY can. Do ypu want to
> > adjust your diff based on that information?
> >
> > Either way, ok kettenis@
>
> This adjusted diff changes only ADDE and not ADDCARRY. I expect it to
> work as well as my previous diff (Tue 28 Apr) on PowerPC, because
> PowerPC doesn't use ADDCARRY.
>
> After I built macppc clang with the previous diff, I did a successful
> "make build" in /usr/src. I'm not doing another "make build" with
> this adjusted diff, but I will check that some other stuff builds.
Looks good to me. ok mortimer@
>
> Index: lib/CodeGen/SelectionDAG/DAGCombiner.cpp
> ===================================================================
> RCS file: /cvs/src/gnu/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp,v
> retrieving revision 1.1.1.8
> diff -u -p -r1.1.1.8 DAGCombiner.cpp
> --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp 23 Jun 2019 21:36:48 -0000
> 1.1.1.8
> +++ lib/CodeGen/SelectionDAG/DAGCombiner.cpp 30 Apr 2020 16:18:31 -0000
> @@ -9904,9 +9904,11 @@ SDValue DAGCombiner::visitTRUNCATE(SDNod
> // (trunc adde(X, Y, Carry)) -> (adde trunc(X), trunc(Y), Carry)
> // (trunc addcarry(X, Y, Carry)) -> (addcarry trunc(X), trunc(Y), Carry)
> // When the adde's carry is not used.
> + // Don't make an illegal adde: LegalizeDAG can't expand nor promote it.
> if ((N0.getOpcode() == ISD::ADDE || N0.getOpcode() == ISD::ADDCARRY) &&
> N0.hasOneUse() && !N0.getNode()->hasAnyUseOfValue(1) &&
> - (!LegalOperations || TLI.isOperationLegal(N0.getOpcode(), VT))) {
> + ((!LegalOperations && N0.getOpcode() == ISD::ADDCARRY) ||
> + TLI.isOperationLegal(N0.getOpcode(), VT))) {
> SDLoc SL(N);
> auto X = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(0));
> auto Y = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(1));
