Move MIPS-specific GPRel32Directive and EK_GPRel32BlockAddress from generic code to Mips/

MaskRay · MaskRay · commit 0c5d709301b2 · 2025-03-02T15:37:55.000-08:00
Follow-up to 6048629 gprel/gprel64 functions can now be moved from MCTargetStreamer to MipsTargetStreamer.
diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -896,8 +896,6 @@ class AsmPrinter : public MachineFunctionPass {
   void emitJumpTableImpl(const MachineJumpTableInfo &MJTI,
                          ArrayRef<unsigned> JumpTableIndices,
                          bool JTInDiffSection);
-  void emitJumpTableEntry(const MachineJumpTableInfo &MJTI,
-                          const MachineBasicBlock *MBB, unsigned uid) const;
 
   void emitJumpTableSizesSection(const MachineJumpTableInfo &MJTI,
                                  const Function &F) const;
@@ -911,11 +909,13 @@ class AsmPrinter : public MachineFunctionPass {
   GCMetadataPrinter *getOrCreateGCPrinter(GCStrategy &S);
   void emitGlobalIFunc(Module &M, const GlobalIFunc &GI);
 
-private:
   /// This method decides whether the specified basic block requires a label.
   bool shouldEmitLabelForBasicBlock(const MachineBasicBlock &MBB) const;
 
 protected:
+  virtual void emitJumpTableEntry(const MachineJumpTableInfo &MJTI,
+                                  const MachineBasicBlock *MBB,
+                                  unsigned uid) const;
   virtual void emitGlobalAlias(const Module &M, const GlobalAlias &GA);
   virtual bool shouldEmitWeakSwiftAsyncExtendedFramePointerFlags() const {
     return false;
diff --git a/llvm/include/llvm/MC/MCAsmInfo.h b/llvm/include/llvm/MC/MCAsmInfo.h
@@ -241,11 +241,6 @@ class MCAsmInfo {
   /// True if data directives support signed values
   bool SupportsSignedData = true;
 
-  /// If non-null, a directive that is used to emit a word which should be
-  /// relocated as a 32-bit GP-relative offset, e.g. .gpword on Mips or .gprel32
-  /// on Alpha.  Defaults to nullptr.
-  const char *GPRel32Directive = nullptr;
-
   /// This is true if this target uses "Sun Style" syntax for section switching
   /// ("#alloc,#write" etc) instead of the normal ELF syntax (,"a,w") in
   /// .section directives.  Defaults to false.
@@ -450,7 +445,6 @@ class MCAsmInfo {
   const char *getData32bitsDirective() const { return Data32bitsDirective; }
   const char *getData64bitsDirective() const { return Data64bitsDirective; }
   bool supportsSignedData() const { return SupportsSignedData; }
-  const char *getGPRel32Directive() const { return GPRel32Directive; }
 
   /// Targets can implement this method to specify a section to switch to if the
   /// translation unit doesn't have any trampolines that require an executable
diff --git a/llvm/include/llvm/MC/MCStreamer.h b/llvm/include/llvm/MC/MCStreamer.h
@@ -130,10 +130,6 @@ class MCTargetStreamer {
   virtual void emitConstantPools();
 
   virtual void finish();
-
-  // MIPS specific functions called by AsmPrinter.
-  virtual void emitGPRel32Value(const MCExpr *);
-  virtual void emitGPRel64Value(const MCExpr *);
 };
 
 // FIXME: declared here because it is used from
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -3029,6 +3029,9 @@ void AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo &MJTI,
   switch (MJTI.getEntryKind()) {
   case MachineJumpTableInfo::EK_Inline:
     llvm_unreachable("Cannot emit EK_Inline jump table entry");
+  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
+  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
+    llvm_unreachable("MIPS specific");
   case MachineJumpTableInfo::EK_Custom32:
     Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
         &MJTI, MBB, UID, OutContext);
@@ -3038,25 +3041,6 @@ void AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo &MJTI,
     //     .word LBB123
     Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
     break;
-  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
-    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
-    // with a relocation as gp-relative, e.g.:
-    //     .gprel32 LBB123
-    MCSymbol *MBBSym = MBB->getSymbol();
-    OutStreamer->getTargetStreamer()->emitGPRel32Value(
-        MCSymbolRefExpr::create(MBBSym, OutContext));
-    return;
-  }
-
-  case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
-    // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
-    // with a relocation as gp-relative, e.g.:
-    //     .gpdword LBB123
-    MCSymbol *MBBSym = MBB->getSymbol();
-    OutStreamer->getTargetStreamer()->emitGPRel64Value(
-        MCSymbolRefExpr::create(MBBSym, OutContext));
-    return;
-  }
 
   case MachineJumpTableInfo::EK_LabelDifference32:
   case MachineJumpTableInfo::EK_LabelDifference64: {
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -447,23 +447,12 @@ unsigned TargetLowering::getJumpTableEncoding() const {
   if (!isPositionIndependent())
     return MachineJumpTableInfo::EK_BlockAddress;
 
-  // In PIC mode, if the target supports a GPRel32 directive, use it.
-  if (getTargetMachine().getMCAsmInfo()->getGPRel32Directive() != nullptr)
-    return MachineJumpTableInfo::EK_GPRel32BlockAddress;
-
   // Otherwise, use a label difference.
   return MachineJumpTableInfo::EK_LabelDifference32;
 }
 
 SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
                                                  SelectionDAG &DAG) const {
-  // If our PIC model is GP relative, use the global offset table as the base.
-  unsigned JTEncoding = getJumpTableEncoding();
-
-  if ((JTEncoding == MachineJumpTableInfo::EK_GPRel64BlockAddress) ||
-      (JTEncoding == MachineJumpTableInfo::EK_GPRel32BlockAddress))
-    return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy(DAG.getDataLayout()));
-
   return Table;
 }
 
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
@@ -90,14 +90,6 @@ void MCTargetStreamer::emitRawBytes(StringRef Data) {
 
 void MCTargetStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
 
-void MCTargetStreamer::emitGPRel32Value(const MCExpr *) {
-  report_fatal_error("unsupported directive");
-}
-
-void MCTargetStreamer::emitGPRel64Value(const MCExpr *) {
-  report_fatal_error("unsupported directive");
-}
-
 MCStreamer::MCStreamer(MCContext &Ctx)
     : Context(Ctx), CurrentWinFrameInfo(nullptr),
       CurrentProcWinFrameInfoStartIndex(0) {
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCAsmInfo.cpp
@@ -39,7 +39,6 @@ MipsELFMCAsmInfo::MipsELFMCAsmInfo(const Triple &TheTriple,
   Data64bitsDirective         = "\t.8byte\t";
   CommentString               = "#";
   ZeroDirective               = "\t.space\t";
-  GPRel32Directive            = "\t.gpword\t";
   UseAssignmentForEHBegin = true;
   SupportsDebugInformation = true;
   ExceptionsType = ExceptionHandling::DwarfCFI;
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.h b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.h
@@ -24,8 +24,8 @@ class MipsTargetStreamer : public MCTargetStreamer {
 public:
   MipsTargetStreamer(MCStreamer &S);
 
-  void emitGPRel32Value(const MCExpr *) override;
-  void emitGPRel64Value(const MCExpr *) override;
+  virtual void emitGPRel32Value(const MCExpr *);
+  virtual void emitGPRel64Value(const MCExpr *);
   virtual void emitDTPRel32Value(const MCExpr *);
   virtual void emitDTPRel64Value(const MCExpr *);
   virtual void emitTPRel32Value(const MCExpr *);
diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
@@ -821,6 +821,29 @@ void MipsAsmPrinter::emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
   getTargetStreamer().emitDirectiveSetPop();
 }
 
+void MipsAsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo &MJTI,
+                                        const MachineBasicBlock *MBB,
+                                        unsigned uid) const {
+  MCSymbol *MBBSym = MBB->getSymbol();
+  switch (MJTI.getEntryKind()) {
+  case MachineJumpTableInfo::EK_BlockAddress:
+    OutStreamer->emitValue(MCSymbolRefExpr::create(MBBSym, OutContext),
+                           getDataLayout().getPointerSize());
+    break;
+  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
+    // Each entry is a GP-relative value targeting the block symbol.
+    getTargetStreamer().emitGPRel32Value(
+        MCSymbolRefExpr::create(MBBSym, OutContext));
+    break;
+  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
+    getTargetStreamer().emitGPRel64Value(
+        MCSymbolRefExpr::create(MBBSym, OutContext));
+    break;
+  default:
+    llvm_unreachable("");
+  }
+}
+
 void MipsAsmPrinter::EmitJal(const MCSubtargetInfo &STI, MCSymbol *Symbol) {
   MCInst I;
   I.setOpcode(Mips::JAL);
diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.h b/llvm/lib/Target/Mips/MipsAsmPrinter.h
@@ -85,6 +85,10 @@ class LLVM_LIBRARY_VISIBILITY MipsAsmPrinter : public AsmPrinter {
   void emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
                         const MCSubtargetInfo *EndInfo) const override;
 
+  void emitJumpTableEntry(const MachineJumpTableInfo &MJTI,
+                          const MachineBasicBlock *MBB,
+                          unsigned uid) const override;
+
   void EmitJal(const MCSubtargetInfo &STI, MCSymbol *Symbol);
 
   void EmitInstrReg(const MCSubtargetInfo &STI, unsigned Opcode, unsigned Reg);
diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -4475,12 +4475,18 @@ bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
 }
 
 unsigned MipsTargetLowering::getJumpTableEncoding() const {
-
-  // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
-  if (ABI.IsN64() && isPositionIndependent())
+  if (!isPositionIndependent())
+    return MachineJumpTableInfo::EK_BlockAddress;
+  if (ABI.IsN64())
     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
+  return MachineJumpTableInfo::EK_GPRel32BlockAddress;
+}
 
-  return TargetLowering::getJumpTableEncoding();
+SDValue MipsTargetLowering::getPICJumpTableRelocBase(SDValue Table,
+                                                     SelectionDAG &DAG) const {
+  if (!isPositionIndependent())
+    return Table;
+  return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy(DAG.getDataLayout()));
 }
 
 bool MipsTargetLowering::useSoftFloat() const {
diff --git a/llvm/lib/Target/Mips/MipsISelLowering.h b/llvm/lib/Target/Mips/MipsISelLowering.h
@@ -707,6 +707,8 @@ class TargetRegisterClass;
                       bool ForCodeSize) const override;
 
     unsigned getJumpTableEncoding() const override;
+    SDValue getPICJumpTableRelocBase(SDValue Table,
+                                     SelectionDAG &DAG) const override;
     bool useSoftFloat() const override;
 
     bool shouldInsertFencesForAtomic(const Instruction *I) const override {
