[CodeGen][NFC] Add laneBitmask as new MachineOperand Type

vg0204 · vg0204 · commit 4c7f52d99974 · 2025-08-04T11:04:28.000Z
This patch adds a new MachineOperand type to represent the
laneBitmask as MO_LaneMask that can be used in the instructions
to represent the relevant information associated with the register
operands of the same such as liveness.
diff --git a/llvm/docs/MIRLangRef.rst b/llvm/docs/MIRLangRef.rst
@@ -819,6 +819,7 @@ For an int eq predicate ``ICMP_EQ``, the syntax is:
 .. TODO: Describe the syntax of the metadata machine operands, and the
    instructions debug location attribute.
 .. TODO: Describe the syntax of the register live out machine operands.
+.. TODO: Describe the syntax of the lanemask machine operands.
 .. TODO: Describe the syntax of the machine memory operands.
 
 Comments
diff --git a/llvm/include/llvm/CodeGen/MachineInstrBuilder.h b/llvm/include/llvm/CodeGen/MachineInstrBuilder.h
@@ -292,6 +292,11 @@ class MachineInstrBuilder {
     return *this;
   }
 
+  const MachineInstrBuilder &addLaneMask(LaneBitmask LaneMask) const {
+    MI->addOperand(*MF, MachineOperand::CreateLaneMask(LaneMask));
+    return *this;
+  }
+
   const MachineInstrBuilder &addSym(MCSymbol *Sym,
                                     unsigned char TargetFlags = 0) const {
     MI->addOperand(*MF, MachineOperand::CreateMCSymbol(Sym, TargetFlags));
diff --git a/llvm/include/llvm/CodeGen/MachineOperand.h b/llvm/include/llvm/CodeGen/MachineOperand.h
@@ -16,6 +16,7 @@
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/CodeGen/Register.h"
 #include "llvm/IR/Intrinsics.h"
+#include "llvm/MC/LaneBitmask.h"
 #include "llvm/Support/Compiler.h"
 #include <cassert>
 
@@ -69,7 +70,8 @@ class MachineOperand {
     MO_Predicate,         ///< Generic predicate for ISel
     MO_ShuffleMask,       ///< Other IR Constant for ISel (shuffle masks)
     MO_DbgInstrRef, ///< Integer indices referring to an instruction+operand
-    MO_Last = MO_DbgInstrRef
+    MO_LaneMask,    ///< Mask to represent active parts of registers
+    MO_Last = MO_LaneMask
   };
 
 private:
@@ -178,6 +180,7 @@ class MachineOperand {
     Intrinsic::ID IntrinsicID; // For MO_IntrinsicID.
     unsigned Pred;           // For MO_Predicate
     ArrayRef<int> ShuffleMask; // For MO_ShuffleMask
+    LaneBitmask LaneMask;      // For MO_LaneMask
 
     struct {                  // For MO_Register.
       // Register number is in SmallContents.RegNo.
@@ -360,6 +363,7 @@ class MachineOperand {
   bool isIntrinsicID() const { return OpKind == MO_IntrinsicID; }
   bool isPredicate() const { return OpKind == MO_Predicate; }
   bool isShuffleMask() const { return OpKind == MO_ShuffleMask; }
+  bool isLaneMask() const { return OpKind == MO_LaneMask; }
   //===--------------------------------------------------------------------===//
   // Accessors for Register Operands
   //===--------------------------------------------------------------------===//
@@ -624,6 +628,11 @@ class MachineOperand {
     return Contents.ShuffleMask;
   }
 
+  LaneBitmask getLaneMask() const {
+    assert(isLaneMask() && "Wrong MachineOperand accessor");
+    return Contents.LaneMask;
+  }
+
   /// Return the offset from the symbol in this operand. This always returns 0
   /// for ExternalSymbol operands.
   int64_t getOffset() const {
@@ -989,6 +998,12 @@ class MachineOperand {
     return Op;
   }
 
+  static MachineOperand CreateLaneMask(LaneBitmask LaneMask) {
+    MachineOperand Op(MachineOperand::MO_LaneMask);
+    Op.Contents.LaneMask = LaneMask;
+    return Op;
+  }
+
   friend class MachineInstr;
   friend class MachineRegisterInfo;
 
diff --git a/llvm/lib/CodeGen/MIRParser/MILexer.cpp b/llvm/lib/CodeGen/MIRParser/MILexer.cpp
@@ -266,6 +266,7 @@ static MIToken::TokenKind getIdentifierKind(StringRef Identifier) {
       .Case("constant-pool", MIToken::kw_constant_pool)
       .Case("call-entry", MIToken::kw_call_entry)
       .Case("custom", MIToken::kw_custom)
+      .Case("lanemask", MIToken::kw_lanemask)
       .Case("liveout", MIToken::kw_liveout)
       .Case("landing-pad", MIToken::kw_landing_pad)
       .Case("inlineasm-br-indirect-target",
diff --git a/llvm/lib/CodeGen/MIRParser/MILexer.h b/llvm/lib/CodeGen/MIRParser/MILexer.h
@@ -122,6 +122,7 @@ struct MIToken {
     kw_constant_pool,
     kw_call_entry,
     kw_custom,
+    kw_lanemask,
     kw_liveout,
     kw_landing_pad,
     kw_inlineasm_br_indirect_target,
diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -496,6 +496,7 @@ class MIParser {
   bool parseTargetIndexOperand(MachineOperand &Dest);
   bool parseDbgInstrRefOperand(MachineOperand &Dest);
   bool parseCustomRegisterMaskOperand(MachineOperand &Dest);
+  bool parseLaneMaskOperand(MachineOperand &Dest);
   bool parseLiveoutRegisterMaskOperand(MachineOperand &Dest);
   bool parseMachineOperand(const unsigned OpCode, const unsigned OpIdx,
                            MachineOperand &Dest,
@@ -2870,6 +2871,32 @@ bool MIParser::parseCustomRegisterMaskOperand(MachineOperand &Dest) {
   return false;
 }
 
+bool MIParser::parseLaneMaskOperand(MachineOperand &Dest) {
+  assert(Token.is(MIToken::kw_lanemask));
+
+  lex();
+  if (expectAndConsume(MIToken::lparen))
+    return error("expected syntax lanemask(...)");
+
+  LaneBitmask LaneMask = LaneBitmask::getAll();
+  // Parse lanemask.
+  if (Token.isNot(MIToken::IntegerLiteral) && Token.isNot(MIToken::HexLiteral))
+    return error("expected a lane mask");
+  static_assert(sizeof(LaneBitmask::Type) == sizeof(uint64_t),
+                "Use correct get-function for lane mask");
+  LaneBitmask::Type V;
+  if (getUint64(V))
+    return error("invalid lanemask value");
+  LaneMask = LaneBitmask(V);
+  lex();
+
+  if (expectAndConsume(MIToken::rparen))
+    return error("lanemask should be terminated by ')'.");
+
+  Dest = MachineOperand::CreateLaneMask(LaneMask);
+  return false;
+}
+
 bool MIParser::parseLiveoutRegisterMaskOperand(MachineOperand &Dest) {
   assert(Token.is(MIToken::kw_liveout));
   uint32_t *Mask = MF.allocateRegMask();
@@ -2970,6 +2997,8 @@ bool MIParser::parseMachineOperand(const unsigned OpCode, const unsigned OpIdx,
     return parseIntrinsicOperand(Dest);
   case MIToken::kw_target_index:
     return parseTargetIndexOperand(Dest);
+  case MIToken::kw_lanemask:
+    return parseLaneMaskOperand(Dest);
   case MIToken::kw_liveout:
     return parseLiveoutRegisterMaskOperand(Dest);
   case MIToken::kw_floatpred:
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -928,7 +928,8 @@ static void printMIOperand(raw_ostream &OS, MFPrintState &State,
   case MachineOperand::MO_Predicate:
   case MachineOperand::MO_BlockAddress:
   case MachineOperand::MO_DbgInstrRef:
-  case MachineOperand::MO_ShuffleMask: {
+  case MachineOperand::MO_ShuffleMask:
+  case MachineOperand::MO_LaneMask: {
     unsigned TiedOperandIdx = 0;
     if (ShouldPrintRegisterTies && Op.isReg() && Op.isTied() && !Op.isDef())
       TiedOperandIdx = Op.getParent()->findTiedOperandIdx(OpIdx);
diff --git a/llvm/lib/CodeGen/MIRVRegNamerUtils.cpp b/llvm/lib/CodeGen/MIRVRegNamerUtils.cpp
@@ -106,6 +106,7 @@ std::string VRegRenamer::getInstructionOpcodeHash(MachineInstr &MI) {
     case MachineOperand::MO_ExternalSymbol:
     case MachineOperand::MO_GlobalAddress:
     case MachineOperand::MO_BlockAddress:
+    case MachineOperand::MO_LaneMask:
     case MachineOperand::MO_RegisterMask:
     case MachineOperand::MO_RegisterLiveOut:
     case MachineOperand::MO_Metadata:
diff --git a/llvm/lib/CodeGen/MachineOperand.cpp b/llvm/lib/CodeGen/MachineOperand.cpp
@@ -380,6 +380,8 @@ bool MachineOperand::isIdenticalTo(const MachineOperand &Other) const {
     return getPredicate() == Other.getPredicate();
   case MachineOperand::MO_ShuffleMask:
     return getShuffleMask() == Other.getShuffleMask();
+  case MachineOperand::MO_LaneMask:
+    return getLaneMask() == Other.getLaneMask();
   }
   llvm_unreachable("Invalid machine operand type");
 }
@@ -445,6 +447,9 @@ hash_code llvm::hash_value(const MachineOperand &MO) {
     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getPredicate());
   case MachineOperand::MO_ShuffleMask:
     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getShuffleMask());
+  case MachineOperand::MO_LaneMask:
+    return hash_combine(MO.getType(), MO.getTargetFlags(),
+                        MO.getLaneMask().getAsInteger());
   }
   llvm_unreachable("Invalid machine operand type");
 }
@@ -1004,11 +1009,11 @@ void MachineOperand::print(raw_ostream &OS, ModuleSlotTracker &MST,
   }
   case MachineOperand::MO_Predicate: {
     auto Pred = static_cast<CmpInst::Predicate>(getPredicate());
-    OS << (CmpInst::isIntPredicate(Pred) ? "int" : "float") << "pred("
-       << Pred << ')';
+    OS << (CmpInst::isIntPredicate(Pred) ? "int" : "float") << "pred(" << Pred
+       << ')';
     break;
   }
-  case MachineOperand::MO_ShuffleMask:
+  case MachineOperand::MO_ShuffleMask: {
     OS << "shufflemask(";
     ArrayRef<int> Mask = getShuffleMask();
     StringRef Separator;
@@ -1023,6 +1028,14 @@ void MachineOperand::print(raw_ostream &OS, ModuleSlotTracker &MST,
     OS << ')';
     break;
   }
+  case MachineOperand::MO_LaneMask: {
+    OS << "lanemask(";
+    LaneBitmask LaneMask = getLaneMask();
+    OS << "0x" << PrintLaneMask(LaneMask);
+    OS << ')';
+    break;
+  }
+  }
 }
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
diff --git a/llvm/lib/CodeGen/MachineStableHash.cpp b/llvm/lib/CodeGen/MachineStableHash.cpp
@@ -164,6 +164,10 @@ stable_hash llvm::stableHashValue(const MachineOperand &MO) {
     return stable_hash_combine(MO.getType(), MO.getTargetFlags(),
                                stable_hash_name(SymbolName));
   }
+  case MachineOperand::MO_LaneMask: {
+    return stable_hash_combine(MO.getType(), MO.getTargetFlags(),
+                               MO.getLaneMask().getAsInteger());
+  }
   case MachineOperand::MO_CFIIndex:
     return stable_hash_combine(MO.getType(), MO.getTargetFlags(),
                                MO.getCFIIndex());
diff --git a/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp b/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
@@ -930,6 +930,7 @@ static bool IsAnAddressOperand(const MachineOperand &MO) {
     return true;
   case MachineOperand::MO_RegisterMask:
   case MachineOperand::MO_RegisterLiveOut:
+  case MachineOperand::MO_LaneMask:
     return false;
   case MachineOperand::MO_Metadata:
   case MachineOperand::MO_MCSymbol:
diff --git a/llvm/unittests/CodeGen/MachineOperandTest.cpp b/llvm/unittests/CodeGen/MachineOperandTest.cpp
@@ -288,6 +288,23 @@ TEST(MachineOperandTest, PrintGlobalAddress) {
   }
 }
 
+TEST(MachineOperandTest, PrintLaneMask) {
+  // Create a MachineOperand with a lanemask and print it.
+  LaneBitmask LaneMask = LaneBitmask(12);
+  MachineOperand MO = MachineOperand::CreateLaneMask(LaneMask);
+
+  // Checking some preconditions on the newly created
+  // MachineOperand.
+  ASSERT_TRUE(MO.isLaneMask());
+  ASSERT_TRUE(MO.getLaneMask() == LaneMask);
+
+  std::string str;
+  // Print a MachineOperand that is lanemask as in HEX representation.
+  raw_string_ostream OS(str);
+  MO.print(OS, /*TRI=*/nullptr);
+  ASSERT_TRUE(str == "lanemask(0x000000000000000C)");
+}
+
 TEST(MachineOperandTest, PrintRegisterLiveOut) {
   // Create a MachineOperand with a register live out list and print it.
   uint32_t Mask = 0;
