Author: Kai Luo Date: 2020-11-25T04:39:03Z New Revision: 8e6d92026c624386b85675a4664e2666225fcfac
URL: https://github.com/llvm/llvm-project/commit/8e6d92026c624386b85675a4664e2666225fcfac DIFF: https://github.com/llvm/llvm-project/commit/8e6d92026c624386b85675a4664e2666225fcfac.diff LOG: [DAG][PowerPC] Fix dropped `nsw` flag in `SimplifySetCC` by adding `doesNodeExist` helper `SimplifySetCC` invokes `getNodeIfExists` without passing `Flags` argument and `getNodeIfExists` uses a default `SDNodeFlags` to intersect the original flags, as a consequence, flags like `nsw` is dropped. Added a new helper function `doesNodeExist` to check if a node exists without modifying its flags. Reviewed By: #powerpc, nemanjai Differential Revision: https://reviews.llvm.org/D89938 Added: Modified: llvm/include/llvm/CodeGen/SelectionDAG.h llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll Removed: ################################################################################ diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h index 8966e7f51dd9..cbd2e8b043a0 100644 --- a/llvm/include/llvm/CodeGen/SelectionDAG.h +++ b/llvm/include/llvm/CodeGen/SelectionDAG.h @@ -1520,6 +1520,9 @@ class SelectionDAG { SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTList, ArrayRef<SDValue> Ops); + /// Check if a node exists without modifying its flags. + bool doesNodeExist(unsigned Opcode, SDVTList VTList, ArrayRef<SDValue> Ops); + /// Creates a SDDbgValue node. SDDbgValue *getDbgValue(DIVariable *Var, DIExpression *Expr, SDNode *N, unsigned R, bool IsIndirect, const DebugLoc &DL, diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 489651e987ac..eee80cc4bc70 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -8326,6 +8326,19 @@ SDNode *SelectionDAG::getNodeIfExists(unsigned Opcode, SDVTList VTList, return nullptr; } +/// doesNodeExist - Check if a node exists without modifying its flags. +bool SelectionDAG::doesNodeExist(unsigned Opcode, SDVTList VTList, + ArrayRef<SDValue> Ops) { + if (VTList.VTs[VTList.NumVTs - 1] != MVT::Glue) { + FoldingSetNodeID ID; + AddNodeIDNode(ID, Opcode, VTList, Ops); + void *IP = nullptr; + if (FindNodeOrInsertPos(ID, SDLoc(), IP)) + return true; + } + return false; +} + /// getDbgValue - Creates a SDDbgValue node. /// /// SDNode diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp index 1d51773dc2d8..93df88b3f6d7 100644 --- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -3476,8 +3476,8 @@ SDValue TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1, if (!isConstOrConstSplat(N0) && !isConstOrConstSplat(N1) && (DCI.isBeforeLegalizeOps() || isCondCodeLegal(SwappedCC, N0.getSimpleValueType())) && - DAG.getNodeIfExists(ISD::SUB, DAG.getVTList(OpVT), { N1, N0 } ) && - !DAG.getNodeIfExists(ISD::SUB, DAG.getVTList(OpVT), { N0, N1 } )) + DAG.doesNodeExist(ISD::SUB, DAG.getVTList(OpVT), {N1, N0}) && + !DAG.doesNodeExist(ISD::SUB, DAG.getVTList(OpVT), {N0, N1})) return DAG.getSetCC(dl, VT, N1, N0, SwappedCC); if (auto *N1C = isConstOrConstSplat(N1)) { diff --git a/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll b/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll index ee4697b874e2..3d89fea12216 100644 --- a/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll +++ b/llvm/test/CodeGen/PowerPC/setcc-sub-flag.ll @@ -10,7 +10,7 @@ define void @f(i64 %a, i64 %b) { ; CHECK: liveins: $x3, $x4 ; CHECK: [[COPY:%[0-9]+]]:g8rc = COPY $x4 ; CHECK: [[COPY1:%[0-9]+]]:g8rc = COPY $x3 - ; CHECK: [[SUBF8_:%[0-9]+]]:g8rc = SUBF8 [[COPY1]], [[COPY]] + ; CHECK: [[SUBF8_:%[0-9]+]]:g8rc = nsw SUBF8 [[COPY1]], [[COPY]] %c = sub nsw i64 %b, %a call void @foo(i64 %c) %d = icmp slt i64 %a, %b _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
