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[BPF] TableGen-erate SDNode descriptions #166499

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[BPF] TableGen-erate SDNode descriptions #166499

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6d78736
[BPF] TableGen-erate SDNode descriptions
s-barannikov Nov 15, 2024
8c927fc
clang-format
s-barannikov Nov 5, 2025
84fb333
Remove SDNPOutGlue on MEMCPY
s-barannikov Nov 6, 2025
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20 changes: 0 additions & 20 deletions llvm/lib/Target/BPF/BPFISelLowering.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -803,26 +803,6 @@ SDValue BPFTargetLowering::LowerJumpTable(SDValue Op, SelectionDAG &DAG) const {
return getAddr(N, DAG);
}

const char *BPFTargetLowering::getTargetNodeName(unsigned Opcode) const {
switch ((BPFISD::NodeType)Opcode) {
case BPFISD::FIRST_NUMBER:
break;
case BPFISD::RET_GLUE:
return "BPFISD::RET_GLUE";
case BPFISD::CALL:
return "BPFISD::CALL";
case BPFISD::SELECT_CC:
return "BPFISD::SELECT_CC";
case BPFISD::BR_CC:
return "BPFISD::BR_CC";
case BPFISD::Wrapper:
return "BPFISD::Wrapper";
case BPFISD::MEMCPY:
return "BPFISD::MEMCPY";
}
return nullptr;
}

static SDValue getTargetNode(ConstantPoolSDNode *N, const SDLoc &DL, EVT Ty,
SelectionDAG &DAG, unsigned Flags) {
return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
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14 changes: 0 additions & 14 deletions llvm/lib/Target/BPF/BPFISelLowering.h
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Expand Up @@ -20,17 +20,6 @@

namespace llvm {
class BPFSubtarget;
namespace BPFISD {
enum NodeType : unsigned {
FIRST_NUMBER = ISD::BUILTIN_OP_END,
RET_GLUE,
CALL,
SELECT_CC,
BR_CC,
Wrapper,
MEMCPY
};
}

class BPFTargetLowering : public TargetLowering {
public:
Expand All @@ -39,9 +28,6 @@ class BPFTargetLowering : public TargetLowering {
// Provide custom lowering hooks for some operations.
SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;

// This method returns the name of a target specific DAG node.
const char *getTargetNodeName(unsigned Opcode) const override;

// This method decides whether folding a constant offset
// with the given GlobalAddress is legal.
bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
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6 changes: 2 additions & 4 deletions llvm/lib/Target/BPF/BPFInstrInfo.td
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Expand Up @@ -41,14 +41,12 @@ def BPFcallseq_start: SDNode<"ISD::CALLSEQ_START", SDT_BPFCallSeqStart,
[SDNPHasChain, SDNPOutGlue]>;
def BPFcallseq_end : SDNode<"ISD::CALLSEQ_END", SDT_BPFCallSeqEnd,
[SDNPHasChain, SDNPOptInGlue, SDNPOutGlue]>;
def BPFbrcc : SDNode<"BPFISD::BR_CC", SDT_BPFBrCC,
[SDNPHasChain, SDNPOutGlue, SDNPInGlue]>;
def BPFbrcc : SDNode<"BPFISD::BR_CC", SDT_BPFBrCC, [SDNPHasChain]>;
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@eddyz87 eddyz87 Nov 5, 2025

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Could you please comment a bit on removing SDNPOutGlue, SDNPInGlue and SDNPInGlue below?

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@s-barannikov s-barannikov Nov 6, 2025

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Glue operands/results are used when there is a copy to/from a physical register that needs be scheduled right before / next to the node. This isn't the case for BR_CC, BPFTargetLowering::LowerBR_CC() creates it without glue operands/results:

  return DAG.getNode(BPFISD::BR_CC, DL, Op.getValueType(), Chain, LHS, RHS,
                     DAG.getConstant(CC, DL, LHS.getValueType()), Dest);

Removing these properties here is just syncing with C++ code to make SDNodeInfo::verifyNode() happy.

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@yonghong-song yonghong-song Nov 6, 2025

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Indeed, for BPFISD::BR_CC, we do not have in/out glue so it makes sense to remove it.


def BPFselectcc : SDNode<"BPFISD::SELECT_CC", SDT_BPFSelectCC>;
def BPFWrapper : SDNode<"BPFISD::Wrapper", SDT_BPFWrapper>;
def BPFmemcpy : SDNode<"BPFISD::MEMCPY", SDT_BPFMEMCPY,
[SDNPHasChain, SDNPInGlue, SDNPOutGlue,
SDNPMayStore, SDNPMayLoad]>;
[SDNPHasChain, SDNPMayStore, SDNPMayLoad]>;
def BPFIsLittleEndian : Predicate<"Subtarget->isLittleEndian()">;
def BPFIsBigEndian : Predicate<"!Subtarget->isLittleEndian()">;
def BPFHasALU32 : Predicate<"Subtarget->getHasAlu32()">;
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18 changes: 11 additions & 7 deletions llvm/lib/Target/BPF/BPFSelectionDAGInfo.cpp
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Expand Up @@ -10,12 +10,20 @@
//
//===----------------------------------------------------------------------===//

#include "BPFSelectionDAGInfo.h"
#include "BPFTargetMachine.h"
#include "llvm/CodeGen/SelectionDAG.h"

#define GET_SDNODE_DESC
#include "BPFGenSDNodeInfo.inc"

using namespace llvm;

#define DEBUG_TYPE "bpf-selectiondag-info"

BPFSelectionDAGInfo::BPFSelectionDAGInfo()
: SelectionDAGGenTargetInfo(BPFGenSDNodeInfo) {}

SDValue BPFSelectionDAGInfo::EmitTargetCodeForMemcpy(
SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
SDValue Size, Align Alignment, bool isVolatile, bool AlwaysInline,
Expand All @@ -31,11 +39,7 @@ SDValue BPFSelectionDAGInfo::EmitTargetCodeForMemcpy(
if (StoresNumEstimate > getCommonMaxStoresPerMemFunc())
return SDValue();

SDVTList VTs = DAG.getVTList(MVT::Other, MVT::Glue);

Dst = DAG.getNode(BPFISD::MEMCPY, dl, VTs, Chain, Dst, Src,
DAG.getConstant(CopyLen, dl, MVT::i64),
DAG.getConstant(Alignment.value(), dl, MVT::i64));

return Dst.getValue(0);
return DAG.getNode(BPFISD::MEMCPY, dl, MVT::Other, Chain, Dst, Src,
DAG.getConstant(CopyLen, dl, MVT::i64),
DAG.getConstant(Alignment.value(), dl, MVT::i64));
}
10 changes: 7 additions & 3 deletions llvm/lib/Target/BPF/BPFSelectionDAGInfo.h
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Expand Up @@ -15,10 +15,15 @@

#include "llvm/CodeGen/SelectionDAGTargetInfo.h"

#define GET_SDNODE_ENUM
#include "BPFGenSDNodeInfo.inc"

namespace llvm {

class BPFSelectionDAGInfo : public SelectionDAGTargetInfo {
class BPFSelectionDAGInfo : public SelectionDAGGenTargetInfo {
public:
BPFSelectionDAGInfo();

SDValue EmitTargetCodeForMemcpy(SelectionDAG &DAG, const SDLoc &dl,
SDValue Chain, SDValue Dst, SDValue Src,
SDValue Size, Align Alignment,
Expand All @@ -27,9 +32,8 @@ class BPFSelectionDAGInfo : public SelectionDAGTargetInfo {
MachinePointerInfo SrcPtrInfo) const override;

unsigned getCommonMaxStoresPerMemFunc() const { return 128; }

};

}
} // namespace llvm

#endif
1 change: 1 addition & 0 deletions llvm/lib/Target/BPF/CMakeLists.txt
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Expand Up @@ -10,6 +10,7 @@ tablegen(LLVM BPFGenDisassemblerTables.inc -gen-disassembler)
tablegen(LLVM BPFGenInstrInfo.inc -gen-instr-info)
tablegen(LLVM BPFGenMCCodeEmitter.inc -gen-emitter)
tablegen(LLVM BPFGenRegisterInfo.inc -gen-register-info)
tablegen(LLVM BPFGenSDNodeInfo.inc -gen-sd-node-info)
tablegen(LLVM BPFGenSubtargetInfo.inc -gen-subtarget)
tablegen(LLVM BPFGenGlobalISel.inc -gen-global-isel)
tablegen(LLVM BPFGenRegisterBank.inc -gen-register-bank)
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