Remove more unused utility functions; NFC (#2294)

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@01d7586

Author: svenvh

llvm-spirv/lib/SPIRV/SPIRVInternal.h

@@ -717,12 +717,6 @@ void makeVector(Instruction *InsPos, std::vector<Value *> &Ops,
 /// Get size_t type.
 IntegerType *getSizetType(Module *M);
 
-/// Get void(void) function type.
-Type *getVoidFuncType(Module *M);
-
-/// Get void(void) function pointer type.
-Type *getVoidFuncPtrType(Module *M, unsigned AddrSpace = 0);
-
 /// Get a 64 bit integer constant.
 ConstantInt *getInt64(Module *M, int64_t Value);
 
@@ -779,10 +773,6 @@ std::set<std::string> getNamedMDAsStringSet(Module *M,
 /// Get SPIR-V language by SPIR-V metadata spirv.Source
 std::tuple<unsigned, unsigned, std::string> getSPIRVSource(Module *M);
 
-/// Get postfix for given decoration.
-/// The returned postfix does not include "_" at the beginning.
-std::string getPostfix(Decoration Dec, unsigned Value = 0);
-
 /// Get postfix _R{ReturnType} for return type
 /// The returned postfix does not includ "_" at the beginning
 std::string getPostfixForReturnType(CallInst *CI, bool IsSigned = false);
@@ -813,10 +803,6 @@ std::string getSPIRVTypeName(StringRef BaseTyName, StringRef Postfixes = "");
 /// Checks if given type name is either ConstantSampler or ConsantPipeStorage.
 bool isSPIRVConstantName(StringRef TyName);
 
-/// Get the sampled type name used in postfix of image type in SPIR-V
-/// friendly LLVM IR.
-std::string getSPIRVImageSampledTypeName(SPIRVType *Ty);
-
 /// Get LLVM type for sampled type of SPIR-V image type by postfix.
 Type *getLLVMTypeForSPIRVImageSampledTypePostfix(StringRef Postfix,
                                                  LLVMContext &Ctx);
@@ -848,8 +834,6 @@ bool eraseUselessFunctions(Module *M);
 /// Erase a function if it is declaration, has internal linkage and has no use.
 bool eraseIfNoUse(Function *F);
 
-void eraseIfNoUse(Value *V);
-
 // Check if a mangled type name is unsigned
 bool isMangledTypeUnsigned(char Mangled);
 
@@ -1005,8 +989,6 @@ bool postProcessBuiltinsReturningStruct(Module *M, bool IsCpp = false);
 
 bool postProcessBuiltinsWithArrayArguments(Module *M, bool IsCpp = false);
 
-template <typename T>
-MetadataAsValue *map2MDString(LLVMContext &C, SPIRVValue *V);
 } // namespace SPIRV
 
 #endif // SPIRV_SPIRVINTERNAL_H

llvm-spirv/lib/SPIRV/SPIRVUtil.cpp

@@ -373,18 +373,6 @@ SPIRVValue *addDecorations(SPIRVValue *Target,
   return Target;
 }
 
-std::string getPostfix(Decoration Dec, unsigned Value) {
-  switch (Dec) {
-  default:
-    llvm_unreachable("not implemented");
-    return "unknown";
-  case spv::DecorationSaturatedConversion:
-    return kSPIRVPostfix::Sat;
-  case spv::DecorationFPRoundingMode:
-    return rmap<std::string>(static_cast<SPIRVFPRoundingModeKind>(Value));
-  }
-}
-
 std::string getPostfixForReturnType(CallInst *CI, bool IsSigned) {
   return getPostfixForReturnType(CI->getType(), IsSigned);
 }
@@ -1024,14 +1012,6 @@ IntegerType *getSizetType(Module *M) {
                                 M->getDataLayout().getPointerSizeInBits(0));
 }
 
-Type *getVoidFuncType(Module *M) {
-  return FunctionType::get(Type::getVoidTy(M->getContext()), false);
-}
-
-Type *getVoidFuncPtrType(Module *M, unsigned AddrSpace) {
-  return PointerType::get(getVoidFuncType(M), AddrSpace);
-}
-
 ConstantInt *getInt64(Module *M, int64_t Value) {
   return ConstantInt::getSigned(Type::getInt64Ty(M->getContext()), Value);
 }
@@ -1505,35 +1485,6 @@ bool isSPIRVConstantName(StringRef TyName) {
   return false;
 }
 
-std::string getSPIRVImageSampledTypeName(SPIRVType *Ty) {
-  switch (Ty->getOpCode()) {
-  case OpTypeVoid:
-    return kSPIRVImageSampledTypeName::Void;
-  case OpTypeInt:
-    if (Ty->getIntegerBitWidth() == 32) {
-      if (static_cast<SPIRVTypeInt *>(Ty)->isSigned())
-        return kSPIRVImageSampledTypeName::Int;
-      else
-        return kSPIRVImageSampledTypeName::UInt;
-    }
-    break;
-  case OpTypeFloat:
-    switch (Ty->getFloatBitWidth()) {
-    case 16:
-      return kSPIRVImageSampledTypeName::Half;
-    case 32:
-      return kSPIRVImageSampledTypeName::Float;
-    default:
-      break;
-    }
-    break;
-  default:
-    break;
-  }
-  llvm_unreachable("Invalid sampled type for image");
-  return std::string();
-}
-
 // ToDo: Find a way to represent uint sampled type in LLVM, maybe an
 //      opaque type.
 Type *getLLVMTypeForSPIRVImageSampledTypePostfix(StringRef Postfix,
@@ -1649,20 +1600,6 @@ bool eraseIfNoUse(Function *F) {
   return Changed;
 }
 
-void eraseIfNoUse(Value *V) {
-  if (!V->use_empty())
-    return;
-  if (Constant *C = dyn_cast<Constant>(V)) {
-    C->destroyConstant();
-    return;
-  }
-  if (Instruction *I = dyn_cast<Instruction>(V)) {
-    if (!I->mayHaveSideEffects())
-      I->eraseFromParent();
-  }
-  eraseIfNoUse(dyn_cast<Function>(V));
-}
-
 bool eraseUselessFunctions(Module *M) {
   bool Changed = false;
   for (auto I = M->begin(), E = M->end(); I != E;)
@@ -2540,13 +2477,4 @@ std::string getSPIRVFriendlyIRFunctionName(const std::string &UniqName,
   return mangleBuiltin(UniqName, ArgTys, &MangleInfo);
 }
 
-template <typename T>
-MetadataAsValue *map2MDString(LLVMContext &C, SPIRVValue *V) {
-  if (V->getOpCode() != OpConstant)
-    return nullptr;
-  uint64_t Const = static_cast<SPIRVConstant *>(V)->getZExtIntValue();
-  std::string Str = SPIRVMap<T, std::string>::map(static_cast<T>(Const));
-  return MetadataAsValue::get(C, MDString::get(C, Str));
-}
-
 } // namespace SPIRV