add a new MachineJumpTableInfo::getJTISymbol method,

use it to implement the default TargetLowering::getPICJumpTableRelocBaseExpr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94523 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineJumpTableInfo.h

@@ -90,6 +90,12 @@ public:
   const std::vector<MachineJumpTableEntry> &getJumpTables() const {
     return JumpTables;
   }
+
+  /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
+  /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
+  /// normal 'L' label is returned.
+  MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx, 
+                         bool isLinkerPrivate = false) const;
   
   /// RemoveJumpTable - Mark the specific index as being dead.  This will
   /// prevent it from being emitted.

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -527,6 +527,8 @@ void AsmPrinter::EmitJumpTableInfo(MachineFunction &MF) {
     // the assembler and linker the extents of the jump table object.  The
     // second label is actually referenced by the code.
     if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
+      // FIXME: This doesn't have to have any specific name, just any randomly
+      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
       OutStreamer.EmitLabel(GetJTISymbol(i, true));
 
     OutStreamer.EmitLabel(GetJTISymbol(i));
@@ -1389,12 +1391,7 @@ MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
 
 /// GetJTISymbol - Return the symbol for the specified jump table entry.
 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
-  const char *Prefix = isLinkerPrivate ? MAI->getLinkerPrivateGlobalPrefix() :
-                                         MAI->getPrivateGlobalPrefix();
-  SmallString<60> Name;
-  raw_svector_ostream(Name) << Prefix << "JTI" << getFunctionNumber() << '_'
-    << JTID;
-  return OutContext.GetOrCreateSymbol(Name.str());
+  return MF->getJumpTableInfo()->getJTISymbol(JTID, OutContext,isLinkerPrivate);
 }
 
 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
@@ -1549,12 +1546,13 @@ void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
 /// specified MachineBasicBlock for a jumptable entry.
 void AsmPrinter::printPICJumpTableSetLabel(unsigned uid, 
                                            const MachineBasicBlock *MBB) const {
-  if (!MAI->getSetDirective())
-    return;
-  
+  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
+  const TargetLowering *TLI = TM.getTargetLowering();
   O << MAI->getSetDirective() << ' ' << MAI->getPrivateGlobalPrefix()
     << *GetJTSetSymbol(uid, MBB->getNumber()) << ','
-    << *MBB->getSymbol(OutContext) << '-' << *GetJTISymbol(uid) << '\n';
+    << *MBB->getSymbol(OutContext) << '-'
+    << *TLI->getPICJumpTableRelocBaseExpr(MJTI,uid,OutContext)
+    << '\n';
 }
 
 void AsmPrinter::printVisibility(MCSymbol *Sym, unsigned Visibility) const {

lib/CodeGen/MachineFunction.cpp

@@ -16,7 +16,6 @@
 #include "llvm/DerivedTypes.h"
 #include "llvm/Function.h"
 #include "llvm/Instructions.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/Config/config.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFunction.h"
@@ -26,12 +25,16 @@
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/Passes.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
 #include "llvm/Analysis/DebugInfo.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/GraphWriter.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
@@ -578,11 +581,29 @@ unsigned MachineJumpTableInfo::getJumpTableIndex(
   return JumpTables.size()-1;
 }
 
+/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
+/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
+/// normal 'L' label is returned.
+MCSymbol *MachineJumpTableInfo::getJTISymbol(unsigned JTI, MCContext &Ctx, 
+                                             bool isLinkerPrivate) const {
+  assert(JTI < JumpTables.size() && !JumpTables[JTI].MBBs.empty() &&
+         "Invalid JTI!");
+  const MachineFunction *MF = JumpTables[JTI].MBBs[0]->getParent();
+  const MCAsmInfo &MAI = *MF->getTarget().getMCAsmInfo();
+  
+  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
+                                         MAI.getPrivateGlobalPrefix();
+  SmallString<60> Name;
+  raw_svector_ostream(Name)
+    << Prefix << "JTI" << MF->getFunctionNumber() << '_' << JTI;
+  return Ctx.GetOrCreateSymbol(Name.str());
+}
+
+
 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
 /// the jump tables to branch to New instead.
-bool
-MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
-                                             MachineBasicBlock *New) {
+bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
+                                                  MachineBasicBlock *New) {
   assert(Old != New && "Not making a change?");
   bool MadeChange = false;
   for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
@@ -592,10 +613,9 @@ MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
 
 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
 /// the jump table to branch to New instead.
-bool
-MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
-                                            MachineBasicBlock *Old,
-                                            MachineBasicBlock *New) {
+bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
+                                                 MachineBasicBlock *Old,
+                                                 MachineBasicBlock *New) {
   assert(Old != New && "Not making a change?");
   bool MadeChange = false;
   MachineJumpTableEntry &JTE = JumpTables[Idx];

lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -13,6 +13,7 @@
 
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCExpr.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetMachine.h"
@@ -812,6 +813,7 @@ unsigned TargetLowering::getJumpTableEncoding() const {
 
 SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
                                                  SelectionDAG &DAG) const {
+  // FIXME: Eliminate usesGlobalOffsetTable() in favor of JTEntryKind.
   if (usesGlobalOffsetTable())
     return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy());
   return Table;
@@ -824,10 +826,10 @@ const MCExpr *
 TargetLowering::getPICJumpTableRelocBaseExpr(const MachineJumpTableInfo *MJTI,
                                              unsigned JTI,
                                              MCContext &Ctx) const {
-  assert(0 && "FIXME: IMPLEMENT ME");
+  // The normal PIC reloc base is the label at the start of the jump table.
+  return MCSymbolRefExpr::Create(MJTI->getJTISymbol(JTI, Ctx), Ctx);
 }
 
-
 bool
 TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
   // Assume that everything is safe in static mode.