Remove OCL21ToSPIRV pass

Since
KhronosGroup/SPIRV-LLVM-Translator@6ceea97
this pass only handles input files coming out OpenCL C++ 2.1, which
technically doesn't exists and therefore this should be a dead code.

Additionally: most of the pass functionality (except sub-group barrier
handling) is untested and duplicated in OCLToSPIRV pass.

Author: AlexeySachkov

llvm-spirv/include/LLVMSPIRVLib.h

@@ -52,7 +52,6 @@ namespace llvm {
 class PassRegistry;
 void initializeLLVMToSPIRVPass(PassRegistry &);
 void initializeOCLToSPIRVPass(PassRegistry &);
-void initializeOCL21ToSPIRVPass(PassRegistry &);
 void initializeOCLTypeToSPIRVPass(PassRegistry &);
 void initializeSPIRVLowerBoolPass(PassRegistry &);
 void initializeSPIRVLowerConstExprPass(PassRegistry &);
@@ -166,10 +165,6 @@ ModulePass *createLLVMToSPIRV(SPIRV::SPIRVModule *);
 /// functions.
 ModulePass *createOCLToSPIRV();
 
-/// Create a pass for translating OCL 2.1 builtin functions to SPIR-V builtin
-/// functions.
-ModulePass *createOCL21ToSPIRV();
-
 /// Create a pass for adapting OCL types for SPIRV.
 ModulePass *createOCLTypeToSPIRV();
 

llvm-spirv/lib/SPIRV/CMakeLists.txt

@@ -5,7 +5,6 @@ add_llvm_library(LLVMSPIRVLib
   Mangler/ManglingUtils.cpp
   Mangler/ParameterType.cpp
   OCLToSPIRV.cpp
-  OCL21ToSPIRV.cpp
   OCLTypeToSPIRV.cpp
   OCLUtil.cpp
   VectorComputeUtil.cpp

llvm-spirv/lib/SPIRV/OCL21ToSPIRV.cpp

@@ -3600,7 +3600,6 @@ void addPassesForSPIRV(legacy::PassManager &PassMgr,
   if (Opts.isSPIRVMemToRegEnabled())
     PassMgr.add(createPromoteMemoryToRegisterPass());
   PassMgr.add(createPreprocessMetadata());
-  PassMgr.add(createOCL21ToSPIRV());
   PassMgr.add(createSPIRVLowerSPIRBlocks());
   PassMgr.add(createOCLTypeToSPIRV());
   PassMgr.add(createSPIRVLowerOCLBlocks());