Remove dead code. Improve llvm_unreachable text. Simplify some control flow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150918 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/ScalarEvolutionExpressions.h

@@ -491,7 +491,6 @@ namespace llvm {
 
     RetVal visitCouldNotCompute(const SCEVCouldNotCompute *S) {
       llvm_unreachable("Invalid use of SCEVCouldNotCompute!");
-      return RetVal();
     }
   };
 }

lib/CodeGen/GCStrategy.cpp

@@ -112,7 +112,7 @@ bool GCStrategy::initializeCustomLowering(Module &M) { return false; }
 
 bool GCStrategy::performCustomLowering(Function &F) {
   dbgs() << "gc " << getName() << " must override performCustomLowering.\n";
-  llvm_unreachable(0);
+  llvm_unreachable("must override performCustomLowering");
 }
 
 

lib/CodeGen/StrongPHIElimination.cpp

@@ -228,7 +228,6 @@ static MachineOperand *findLastUse(MachineBasicBlock *MBB, unsigned Reg) {
         return &MO;
     }
   }
-  return NULL;
 }
 
 bool StrongPHIElimination::runOnMachineFunction(MachineFunction &MF) {

lib/ExecutionEngine/Interpreter/Execution.cpp

@@ -1235,7 +1235,7 @@ GenericValue Interpreter::getConstantExprValue (ConstantExpr *CE,
     break;
   default:
     dbgs() << "Unhandled ConstantExpr: " << *CE << "\n";
-    llvm_unreachable(0);
+    llvm_unreachable("Unhandled ConstantExpr");
   }
   return Dest;
 }

lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp

@@ -34,7 +34,6 @@ resolveRelocation(uint8_t *Address, uint64_t Value, bool isPCRel,
     return resolveARMRelocation((uintptr_t)Address, (uintptr_t)Value,
                                 isPCRel, Type, Size, Addend);
   }
-  llvm_unreachable("");
 }
 
 bool RuntimeDyldMachO::

lib/MC/MCDisassembler/EDDisassembler.cpp

@@ -104,27 +104,22 @@ EDDisassembler *EDDisassembler::getDisassembler(StringRef str,
   CPUKey key;
   key.Triple = str.str();
   key.Syntax = syntax;
-  
+
   EDDisassembler::DisassemblerMap_t::iterator i = sDisassemblers.find(key);
-    
+
   if (i != sDisassemblers.end()) {
     return i->second;  
   }
-  else {
+
-    EDDisassembler *sdd = new EDDisassembler(key);
+  EDDisassembler *sdd = new EDDisassembler(key);
-    if (!sdd->valid()) {
+  if (!sdd->valid()) {
-      delete sdd;
+    delete sdd;
-      return NULL;
+    return NULL;
-    }
-    
-    sDisassemblers[key] = sdd;
-    
-    return sdd;
   }
-  
+
-  return NULL;
+  sDisassemblers[key] = sdd;
-    
+
-  return getDisassembler(Triple(str).getArch(), syntax);
+  return sdd;
 }
 
 EDDisassembler::EDDisassembler(CPUKey &key) : 

lib/Support/CrashRecoveryContext.cpp

@@ -165,7 +165,6 @@ static LONG CALLBACK ExceptionHandler(PEXCEPTION_POINTERS ExceptionInfo)
   // Note that we don't actually get here because HandleCrash calls
   // longjmp, which means the HandleCrash function never returns.
   llvm_unreachable("Handled the crash, should have longjmp'ed out of here");
-  return EXCEPTION_CONTINUE_SEARCH;
 }
 
 // Because the Enable and Disable calls are static, it means that

lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp

@@ -673,7 +673,6 @@ void ARMInstPrinter::printMSRMaskOperand(const MCInst *MI, unsigned OpNum,
     case 8:  O << "nzcvq"; return;
     case 12: O << "nzcvqg"; return;
     }
-    llvm_unreachable("Unexpected mask value!");
   }
 
   if (SpecRegRBit)

lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp

@@ -155,7 +155,6 @@ static MCStreamer *createMCStreamer(const Target &T, StringRef TT,
 
   if (TheTriple.isOSWindows()) {
     llvm_unreachable("ARM does not support Windows COFF format");
-    return NULL;
   }
 
   return createELFStreamer(Ctx, MAB, OS, Emitter, RelaxAll, NoExecStack);

lib/Target/MBlaze/MCTargetDesc/MBlazeMCTargetDesc.cpp

@@ -83,12 +83,10 @@ static MCStreamer *createMCStreamer(const Target &T, StringRef TT,
 
   if (TheTriple.isOSDarwin()) {
     llvm_unreachable("MBlaze does not support Darwin MACH-O format");
-    return NULL;
   }
 
   if (TheTriple.isOSWindows()) {
     llvm_unreachable("MBlaze does not support Windows COFF format");
-    return NULL;
   }
 
   return createELFStreamer(Ctx, MAB, _OS, _Emitter, RelaxAll, NoExecStack);

lib/Target/Mips/MipsAsmPrinter.cpp

@@ -246,11 +246,8 @@ const char *MipsAsmPrinter::getCurrentABIString() const {
   case MipsSubtarget::N32:  return "abiN32";
   case MipsSubtarget::N64:  return "abi64";
   case MipsSubtarget::EABI: return "eabi32"; // TODO: handle eabi64
-  default: break;
+  default: llvm_unreachable("Unknown Mips ABI");;
   }
-
-  llvm_unreachable("Unknown Mips ABI");
-  return NULL;
 }
 
 void MipsAsmPrinter::EmitFunctionEntryLabel() {

lib/Target/PTX/PTXAsmPrinter.cpp

@@ -79,7 +79,6 @@ static const char *getStateSpaceName(unsigned addressSpace) {
   case PTXStateSpace::Parameter: return "param";
   case PTXStateSpace::Shared:    return "shared";
   }
-  return NULL;
 }
 
 static const char *getTypeName(Type* type) {

lib/Target/PTX/PTXRegisterInfo.cpp

@@ -31,44 +31,8 @@ PTXRegisterInfo::PTXRegisterInfo(PTXTargetMachine &TM,
   : PTXGenRegisterInfo(0), TII(tii) {
 }
 
-void PTXRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
+void PTXRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator /*II*/,
-                                          int SPAdj,
+                                          int /*SPAdj*/,
-                                          RegScavenger *RS) const {
+                                          RegScavenger * /*RS*/) const {
-  unsigned Index;
-  MachineInstr &MI = *II;
-  //MachineBasicBlock &MBB = *MI.getParent();
-  //DebugLoc dl = MI.getDebugLoc();
-  //MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo();
-
-  //unsigned Reg = MRI.createVirtualRegister(PTX::RegF32RegisterClass);
-
   llvm_unreachable("FrameIndex should have been previously eliminated!");
-
-  Index = 0;
-  while (!MI.getOperand(Index).isFI()) {
-    ++Index;
-    assert(Index < MI.getNumOperands() &&
-           "Instr does not have a FrameIndex operand!");
-  }
-
-  int FrameIndex = MI.getOperand(Index).getIndex();
-
-  DEBUG(dbgs() << "eliminateFrameIndex: " << MI);
-  DEBUG(dbgs() << "- SPAdj: " << SPAdj << "\n");
-  DEBUG(dbgs() << "- FrameIndex: " << FrameIndex << "\n");
-
-  //MachineInstr* MI2 = BuildMI(MBB, II, dl, TII.get(PTX::LOAD_LOCAL_F32))
-  //.addReg(Reg, RegState::Define).addImm(FrameIndex);
-  //if (MI2->findFirstPredOperandIdx() == -1) {
-  //  MI2->addOperand(MachineOperand::CreateReg(PTX::NoRegister, /*IsDef=*/false));
-  //  MI2->addOperand(MachineOperand::CreateImm(PTX::PRED_NORMAL));
-  //}
-  //MI2->dump();
-
-  //MachineOperand ESOp = MachineOperand::CreateES("__local__");
-
-  // This frame index is post stack slot re-use assignments
-  //MI.getOperand(Index).ChangeToRegister(Reg, false);
-  MI.getOperand(Index).ChangeToImmediate(FrameIndex);
-  //MI.getOperand(Index) = ESOp;
 }

lib/Target/Sparc/SparcISelDAGToDAG.cpp

@@ -176,7 +176,6 @@ SDNode *SparcDAGToDAGISel::Select(SDNode *N) {
                                          MulLHS, MulRHS);
     // The high part is in the Y register.
     return CurDAG->SelectNodeTo(N, SP::RDY, MVT::i32, SDValue(Mul, 1));
-    return NULL;
   }
   }
 

lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -1444,7 +1444,6 @@ processInstruction(MCInst &Inst,
     return true;
   }
   }
-  return false;
 }
 
 bool X86AsmParser::

lib/Target/X86/Disassembler/X86DisassemblerDecoder.c

@@ -82,11 +82,9 @@ static int modRMRequired(OpcodeType type,
     decision = &THREEBYTEA7_SYM;
     break;
   }
-  
+
   return decision->opcodeDecisions[insnContext].modRMDecisions[opcode].
     modrm_type != MODRM_ONEENTRY;
-  
-  return 0;
 }
 
 /*

lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -920,7 +920,6 @@ Instruction *WidenIV::CloneIVUser(NarrowIVDefUse DU) {
     }
     return WideBO;
   }
-  llvm_unreachable(0);
 }
 
 /// No-wrap operations can transfer sign extension of their result to their

lib/VMCore/Instructions.cpp

@@ -2559,9 +2559,8 @@ CastInst::getCastOpcode(
       assert(DestBits == SrcBits &&
              "Casting vector to floating point of different width");
       return BitCast;                             // same size, no-op cast
-    } else {
-      llvm_unreachable("Casting pointer or non-first class to float");
     }
+    llvm_unreachable("Casting pointer or non-first class to float");
   } else if (DestTy->isVectorTy()) {
     assert(DestBits == SrcBits &&
            "Illegal cast to vector (wrong type or size)");
@@ -2571,24 +2570,16 @@ CastInst::getCastOpcode(
       return BitCast;                               // ptr -> ptr
     } else if (SrcTy->isIntegerTy()) {
       return IntToPtr;                              // int -> ptr
-    } else {
-      llvm_unreachable("Casting pointer to other than pointer or int");
     }
+    llvm_unreachable("Casting pointer to other than pointer or int");
   } else if (DestTy->isX86_MMXTy()) {
     if (SrcTy->isVectorTy()) {
       assert(DestBits == SrcBits && "Casting vector of wrong width to X86_MMX");
       return BitCast;                               // 64-bit vector to MMX
-    } else {
-      llvm_unreachable("Illegal cast to X86_MMX");
     }
-  } else {
+    llvm_unreachable("Illegal cast to X86_MMX");
-    llvm_unreachable("Casting to type that is not first-class");
   }
-
+  llvm_unreachable("Casting to type that is not first-class");
-  // If we fall through to here we probably hit an assertion cast above
-  // and assertions are not turned on. Anything we return is an error, so
-  // BitCast is as good a choice as any.
-  return BitCast;
 }
 
 //===----------------------------------------------------------------------===//

tools/llvm-ld/llvm-ld.cpp

@@ -423,7 +423,7 @@ static void EmitShellScript(char **argv, Module *M) {
     PrintAndExit(ErrMsg, M);
 
   return;
-#endif
+#else
 
   // Output the script to start the program...
   std::string ErrorInfo;
@@ -469,6 +469,7 @@ static void EmitShellScript(char **argv, Module *M) {
   }
   Out2.os() << "    "  << BitcodeOutputFilename << " ${1+\"$@\"}\n";
   Out2.keep();
+#endif
 }
 
 // BuildLinkItems -- This function generates a LinkItemList for the LinkItems

utils/KillTheDoctor/KillTheDoctor.cpp

@@ -211,19 +211,6 @@ static error_code GetFileNameFromHandle(HANDLE FileHandle,
   }
 }
 
-static std::string QuoteProgramPathIfNeeded(StringRef Command) {
-  if (Command.find_first_of(' ') == StringRef::npos)
-    return Command;
-  else {
-    std::string ret;
-    ret.reserve(Command.size() + 3);
-    ret.push_back('"');
-    ret.append(Command.begin(), Command.end());
-    ret.push_back('"');
-    return ret;
-  }
-}
-
 /// @brief Find program using shell lookup rules.
 /// @param Program This is either an absolute path, relative path, or simple a
 ///        program name. Look in PATH for any programs that match. If no
@@ -269,39 +256,6 @@ static std::string FindProgram(const std::string &Program, error_code &ec) {
   return PathName;
 }
 
-static error_code EnableDebugPrivileges() {
-  HANDLE TokenHandle;
-  BOOL success = ::OpenProcessToken(::GetCurrentProcess(),
-                                    TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
-                                    &TokenHandle);
-  if (!success)
-    return windows_error(::GetLastError());
-
-  TokenScopedHandle Token(TokenHandle);
-  TOKEN_PRIVILEGES  TokenPrivileges;
-  LUID              LocallyUniqueID;
-
-  success = ::LookupPrivilegeValueA(NULL,
-                                    SE_DEBUG_NAME,
-                                    &LocallyUniqueID);
-  if (!success)
-    return windows_error(::GetLastError());
-
-  TokenPrivileges.PrivilegeCount = 1;
-  TokenPrivileges.Privileges[0].Luid = LocallyUniqueID;
-  TokenPrivileges.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
-
-  success = ::AdjustTokenPrivileges(Token,
-                                    FALSE,
-                                    &TokenPrivileges,
-                                    sizeof(TOKEN_PRIVILEGES),
-                                    NULL,
-                                    NULL);
-  // The value of success is basically useless. Either way we are just returning
-  // the value of ::GetLastError().
-  return windows_error(::GetLastError());
-}
-
 static StringRef ExceptionCodeToString(DWORD ExceptionCode) {
   switch(ExceptionCode) {
   case EXCEPTION_ACCESS_VIOLATION: return "EXCEPTION_ACCESS_VIOLATION";

utils/TableGen/X86DisassemblerTables.cpp

@@ -140,8 +140,6 @@ static inline const char* stringForContext(InstructionContext insnContext) {
   INSTRUCTION_CONTEXTS
 #undef ENUM_ENTRY
   }
-
-  return 0;
 }
 
 /// stringForOperandType - Like stringForContext, but for OperandTypes.