[llvm] 768ccf6 - MCSymbolRefExpr: Remove HasSubsectionsViaSymbolsBit

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2025-04-06T14:11:01-07:00
New Revision: 768ccf69f3febe962e0d63dc87fbee31e59547a7

URL: https://github.com/llvm/llvm-project/commit/768ccf69f3febe962e0d63dc87fbee31e59547a7
DIFF: https://github.com/llvm/llvm-project/commit/768ccf69f3febe962e0d63dc87fbee31e59547a7.diff

LOG: MCSymbolRefExpr: Remove HasSubsectionsViaSymbolsBit

This information is only needed assembly time and we
can get it with Asm->getContext().getAsmInfo()->hasSubsectionsViaSymbols().

Added: 
    

Modified: 
    llvm/include/llvm/MC/MCExpr.h
    llvm/lib/MC/MCExpr.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/MC/MCExpr.h b/llvm/include/llvm/MC/MCExpr.h
index 3d9113e92485d..f6377aa492c58 100644
--- a/llvm/include/llvm/MC/MCExpr.h
+++ b/llvm/include/llvm/MC/MCExpr.h
@@ -217,20 +217,6 @@ class MCSymbolRefExpr : public MCExpr {
   /// The symbol being referenced.
   const MCSymbol *Symbol;
 
-  // Subclass data stores VariantKind in bits 0..15 and HasSubsectionsViaSymbols
-  // in bit 16.
-  static const unsigned VariantKindBits = 16;
-  static const unsigned VariantKindMask = (1 << VariantKindBits) - 1;
-
-  // FIXME: Remove this bit.
-  static const unsigned HasSubsectionsViaSymbolsBit = 1 << VariantKindBits;
-
-  static unsigned encodeSubclassData(VariantKind Kind,
-                                     bool HasSubsectionsViaSymbols) {
-    return (unsigned)Kind |
-           (HasSubsectionsViaSymbols ? HasSubsectionsViaSymbolsBit : 0);
-  }
-
   explicit MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
                            const MCAsmInfo *MAI, SMLoc Loc = SMLoc());
 
@@ -259,16 +245,8 @@ class MCSymbolRefExpr : public MCExpr {
   // Some targets encode the relocation specifier within SymA using
   // MCSymbolRefExpr::SubclassData, which is copied to MCValue::Specifier,
   // though this method is now deprecated.
-  VariantKind getKind() const {
-    return (VariantKind)(getSubclassData() & VariantKindMask);
-  }
-  uint16_t getSpecifier() const {
-    return (getSubclassData() & VariantKindMask);
-  }
-
-  bool hasSubsectionsViaSymbols() const {
-    return (getSubclassData() & HasSubsectionsViaSymbolsBit) != 0;
-  }
+  VariantKind getKind() const { return VariantKind(getSubclassData()); }
+  uint16_t getSpecifier() const { return getSubclassData(); }
 
   /// @}
 

diff  --git a/llvm/lib/MC/MCExpr.cpp b/llvm/lib/MC/MCExpr.cpp
index 9fbe395e294b8..4c159feea48f8 100644
--- a/llvm/lib/MC/MCExpr.cpp
+++ b/llvm/lib/MC/MCExpr.cpp
@@ -235,9 +235,7 @@ const MCConstantExpr *MCConstantExpr::create(int64_t Value, MCContext &Ctx,
 
 MCSymbolRefExpr::MCSymbolRefExpr(const MCSymbol *Symbol, VariantKind Kind,
                                  const MCAsmInfo *MAI, SMLoc Loc)
-    : MCExpr(MCExpr::SymbolRef, Loc,
-             encodeSubclassData(Kind, MAI->hasSubsectionsViaSymbols())),
-      Symbol(Symbol) {
+    : MCExpr(MCExpr::SymbolRef, Loc, Kind), Symbol(Symbol) {
   assert(Symbol);
 }
 
@@ -507,7 +505,8 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
     // Evaluate recursively if this is a variable.
     if (Sym.isVariable() && (Kind == MCSymbolRefExpr::VK_None || Layout) &&
         canExpand(Sym, InSet)) {
-      bool IsMachO = SRE->hasSubsectionsViaSymbols();
+      bool IsMachO =
+          Asm && Asm->getContext().getAsmInfo()->hasSubsectionsViaSymbols();
       if (Sym.getVariableValue()->evaluateAsRelocatableImpl(Res, Asm,
                                                             InSet || IsMachO)) {
         if (Kind != MCSymbolRefExpr::VK_None) {