Remove entry point wrapper (#3418)

After LLVM community changes we don't need to do it ourselves.

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@5458eb2511d6184

Author: vmaksimo

llvm-spirv/lib/SPIRV/LLVMToSPIRVDbgTran.cpp

@@ -1276,17 +1276,8 @@ SPIRVEntry *LLVMToSPIRVDbgTran::transDbgFunction(const DISubprogram *Func) {
     Ops[FunctionIdIdx] = getDebugInfoNoneId();
     for (const llvm::Function &F : M->functions()) {
       if (Func->describes(&F)) {
-        // Function definition of spir_kernel can have no "spir_kernel" calling
-        // convention because SPIRVRegularizeLLVMBase::addKernelEntryPoint pass
-        // could have turned it to spir_func. The "true" entry point is a
-        // wrapper kernel function, which can be found further in the module.
-        if (FuncDef) {
-          if (F.getCallingConv() == CallingConv::SPIR_KERNEL) {
-            IsEntryPointKernel = true;
-            break;
-          }
+        if (FuncDef)
           continue;
-        }
 
         SPIRVValue *SPIRVFunc = SPIRVWriter->getTranslatedValue(&F);
         assert(SPIRVFunc && "All function must be already translated");
@@ -1295,7 +1286,6 @@ SPIRVEntry *LLVMToSPIRVDbgTran::transDbgFunction(const DISubprogram *Func) {
         if (!isNonSemanticDebugInfo())
           break;
 
-        // Most likely unreachable because of Regularise LLVM pass
         if (F.getCallingConv() == CallingConv::SPIR_KERNEL) {
           IsEntryPointKernel = true;
           break;

llvm-spirv/lib/SPIRV/SPIRVReader.cpp

@@ -3474,25 +3474,6 @@ Function *SPIRVToLLVM::transFunction(SPIRVFunction *BF, unsigned AS) {
     return Loc->second;
 
   auto IsKernel = isKernel(BF);
-
-  if (IsKernel) {
-    // search for a previous function with the same name
-    // upgrade it to a kernel and drop this if it's found
-    for (auto &I : FuncMap) {
-      auto BFName = I.getFirst()->getName();
-      if (BF->getName() == BFName) {
-        auto *F = I.getSecond();
-        F->setCallingConv(CallingConv::SPIR_KERNEL);
-        F->setLinkage(GlobalValue::ExternalLinkage);
-        F->setDSOLocal(false);
-        F = cast<Function>(mapValue(BF, F));
-        mapFunction(BF, F);
-        transFunctionAttrs(BF, F);
-        return F;
-      }
-    }
-  }
-
   auto Linkage = IsKernel ? GlobalValue::ExternalLinkage : transLinkageType(BF);
   FunctionType *FT = cast<FunctionType>(transType(BF->getFunctionType()));
   std::string FuncName = BF->getName();

llvm-spirv/lib/SPIRV/SPIRVRegularizeLLVM.cpp

@@ -615,7 +615,6 @@ void prepareCacheControlsTranslation(Metadata *MD, Instruction *Inst) {
 /// Remove entities not representable by SPIR-V
 bool SPIRVRegularizeLLVMBase::regularize() {
   eraseUselessFunctions(M);
-  addKernelEntryPoint(M);
   expandSYCLTypeUsing(M);
   cleanupConversionToNonStdIntegers(M);
   replacePrivateConstGlobalsWithAllocas(M);
@@ -808,69 +807,6 @@ bool SPIRVRegularizeLLVMBase::regularize() {
   return true;
 }
 
-void SPIRVRegularizeLLVMBase::addKernelEntryPoint(Module *M) {
-  std::vector<Function *> Work;
-
-  // Get a list of all functions that have SPIR kernel calling conv
-  for (auto &F : *M) {
-    if (F.getCallingConv() == CallingConv::SPIR_KERNEL)
-      Work.push_back(&F);
-  }
-  for (auto &F : Work) {
-    // for declarations just make them into SPIR functions.
-    F->setCallingConv(CallingConv::SPIR_FUNC);
-    if (F->isDeclaration())
-      continue;
-
-    // Otherwise add a wrapper around the function to act as an entry point.
-    FunctionType *FType = F->getFunctionType();
-    std::string WrapName =
-        kSPIRVName::EntrypointPrefix + static_cast<std::string>(F->getName());
-    Function *WrapFn =
-        getOrCreateFunction(M, F->getReturnType(), FType->params(), WrapName);
-
-    auto *CallBB = BasicBlock::Create(M->getContext(), "", WrapFn);
-    IRBuilder<> Builder(CallBB);
-
-    Function::arg_iterator DestI = WrapFn->arg_begin();
-    for (const Argument &I : F->args()) {
-      DestI->setName(I.getName());
-      DestI++;
-    }
-    SmallVector<Value *, 1> Args;
-    for (Argument &I : WrapFn->args()) {
-      Args.emplace_back(&I);
-    }
-    auto *CI = CallInst::Create(F, ArrayRef<Value *>(Args), "", CallBB);
-    CI->setCallingConv(F->getCallingConv());
-    CI->setAttributes(F->getAttributes());
-
-    // copy over all the metadata (should it be removed from F?)
-    SmallVector<std::pair<unsigned, MDNode *>> MDs;
-    F->getAllMetadata(MDs);
-    WrapFn->setAttributes(F->getAttributes());
-    for (auto MD = MDs.begin(), End = MDs.end(); MD != End; ++MD) {
-      WrapFn->addMetadata(MD->first, *MD->second);
-    }
-    WrapFn->setCallingConv(CallingConv::SPIR_KERNEL);
-    WrapFn->setLinkage(llvm::GlobalValue::InternalLinkage);
-
-    Builder.CreateRet(F->getReturnType()->isVoidTy() ? nullptr : CI);
-
-    // Have to find the spir-v metadata for execution mode and transfer it to
-    // the wrapper.
-    if (auto NMD = SPIRVMDWalker(*M).getNamedMD(kSPIRVMD::ExecutionMode)) {
-      while (!NMD.atEnd()) {
-        Function *MDF = nullptr;
-        auto N = NMD.nextOp(); /* execution mode MDNode */
-        N.get(MDF);
-        if (MDF == F)
-          N.M->replaceOperandWith(0, ValueAsMetadata::get(WrapFn));
-      }
-    }
-  }
-}
-
 } // namespace SPIRV
 
 INITIALIZE_PASS(SPIRVRegularizeLLVMLegacy, "spvregular",

llvm-spirv/lib/SPIRV/SPIRVRegularizeLLVM.h

@@ -51,11 +51,6 @@ class SPIRVRegularizeLLVMBase {
   // Lower functions
   bool regularize();
 
-  // SPIR-V disallows functions being entrypoints and called
-  // LLVM doesn't. This adds a wrapper around the entry point
-  // that later SPIR-V writer renames.
-  void addKernelEntryPoint(Module *M);
-
   /// Some LLVM intrinsics that have no SPIR-V counterpart may be wrapped in
   /// @spirv.llvm_intrinsic_* function. During reverse translation from SPIR-V
   /// to LLVM IR we can detect this @spirv.llvm_intrinsic_* function and

llvm-spirv/lib/SPIRV/SPIRVWriter.cpp

@@ -954,19 +954,12 @@ SPIRVFunction *LLVMToSPIRVBase::transFunctionDecl(Function *F) {
       static_cast<SPIRVFunction *>(mapValue(F, BM->addFunction(BFT)));
   BF->setFunctionControlMask(transFunctionControlMask(F));
   if (F->hasName()) {
-    if (isKernel(F)) {
-      /* strip the prefix as the runtime will be looking for this name */
-      std::string Prefix = kSPIRVName::EntrypointPrefix;
-      std::string Name = F->getName().str();
-      BM->setName(BF, Name.substr(Prefix.size()));
-    } else {
-      if (isUniformGroupOperation(F))
-        BM->getErrorLog().checkError(
-            BM->isAllowedToUseExtension(
-                ExtensionID::SPV_KHR_uniform_group_instructions),
-            SPIRVEC_RequiresExtension, "SPV_KHR_uniform_group_instructions\n");
-      BM->setName(BF, F->getName().str());
-    }
+    if (isUniformGroupOperation(F))
+      BM->getErrorLog().checkError(
+          BM->isAllowedToUseExtension(
+              ExtensionID::SPV_KHR_uniform_group_instructions),
+          SPIRVEC_RequiresExtension, "SPV_KHR_uniform_group_instructions\n");
+    BM->setName(BF, F->getName().str());
   }
   if (!isKernel(F) && F->getLinkage() != GlobalValue::InternalLinkage)
     BF->setLinkageType(transLinkageType(F));
@@ -6268,7 +6261,7 @@ void LLVMToSPIRVBase::transFunction(Function *I) {
 
   if (isKernel(I)) {
     auto Interface = collectEntryPointInterfaces(BF, I);
-    BM->addEntryPoint(ExecutionModelKernel, BF->getId(), BF->getName(),
+    BM->addEntryPoint(ExecutionModelKernel, BF->getId(), I->getName().str(),
                       Interface);
   }
 }
@@ -6630,9 +6623,8 @@ bool LLVMToSPIRVBase::transMetadata() {
 // Work around to translate kernel_arg_type and kernel_arg_type_qual metadata
 static void transKernelArgTypeMD(SPIRVModule *BM, Function *F, MDNode *MD,
                                  std::string MDName) {
-  std::string Prefix = kSPIRVName::EntrypointPrefix;
-  std::string Name = F->getName().str().substr(Prefix.size());
-  std::string KernelArgTypesMDStr = std::string(MDName) + "." + Name + ".";
+  std::string KernelArgTypesMDStr =
+      std::string(MDName) + "." + F->getName().str() + ".";
   for (const auto &TyOp : MD->operands())
     KernelArgTypesMDStr += cast<MDString>(TyOp)->getString().str() + ",";
   BM->getString(KernelArgTypesMDStr);

llvm-spirv/test/AtomicCompareExchangeWeak.spvasm

@@ -11,7 +11,7 @@
                OpCapability Int8
           %1 = OpExtInstImport "OpenCL.std"
                OpMemoryModel Physical64 OpenCL
-               OpEntryPoint Kernel %19 "test_atomic_global"
+               OpEntryPoint Kernel %19 "entry_test_atomic_global"
                OpSource OpenCL_C 200000
                OpName %test_atomic_global "test_atomic_global"
                OpName %dst "dst"

llvm-spirv/test/DebugInfo/DebugInfoTypeVector.spvasm

@@ -22,7 +22,7 @@
           %1 = OpExtInstImport "OpenCL.std"
           %2 = OpExtInstImport "OpenCL.DebugInfo.100"
                OpMemoryModel Physical32 OpenCL
-               OpEntryPoint Kernel %23 "do_add_sub" %__spirv_BuiltInGlobalInvocationId
+               OpEntryPoint Kernel %23 "kernel" %__spirv_BuiltInGlobalInvocationId
          %27 = OpString "/app/<stdin>"
          %28 = OpString "//__CSK_MD5:df3c6ff4eef4b9de43419af39216b003"
          %31 = OpString "short4"

llvm-spirv/test/extensions/INTEL/SPV_INTEL_cache_controls/multiple-decoration-single-arg.ll

@@ -3,8 +3,8 @@
 ; RUN: llvm-spirv --spirv-ext=+SPV_INTEL_cache_controls %t.bc -o %t.spv
 ; RUN: llvm-spirv -r %t.spv --spirv-target-env=SPV-IR -o - | llvm-dis -o - | FileCheck %s --check-prefix=CHECK-LLVM
 
-; CHECK-SPIRV-DAG: Name [[#Func:]] "test"
-; CHECK-SPIRV-DAG: Name [[#FuncGEP:]] "test_gep"
+; CHECK-SPIRV-DAG: EntryPoint [[#]] [[#Func:]] "test"
+; CHECK-SPIRV-DAG: EntryPoint [[#]] [[#FuncGEP:]] "test_gep"
 ; CHECK-SPIRV-DAG: TypeInt [[#Int32:]] 32 0
 ; CHECK-SPIRV-DAG: Constant [[#Int32]] [[#Zero:]] 0
 ; CHECK-SPIRV-DAG: Decorate [[#GEP1:]] CacheControlLoadINTEL 1 1

llvm-spirv/test/extensions/INTEL/SPV_INTEL_fpga_argument_interfaces/sycl-kernel-arg-annotation.ll

@@ -52,7 +52,6 @@ entry:
 ; CHECK-SPIRV: Capability FPGAArgumentInterfacesINTEL
 ; CHECK-SPIRV: Extension "SPV_INTEL_fpga_argument_interfaces"
 ; CHECK-SPIRV: Extension "SPV_INTEL_fpga_buffer_location"
-; CHECK-SPIRV-DAG:  Name [[IDS:[0-9]+]] "_arg_p"
 ; CHECK-SPIRV-DAG:  Name [[ID:[0-9]+]] "_arg_p"
 ; CHECK-SPIRV:  Decorate [[ID]] Alignment 4
 ; CHECK-SPIRV:  Decorate [[ID]] MMHostInterfaceAddressWidthINTEL 32

llvm-spirv/test/extensions/INTEL/SPV_INTEL_function_pointers/CodeSectionINTEL/alias.ll

@@ -10,11 +10,10 @@ target triple = "spir64-unknown-unknown"
 ; when used since they can't be translated directly.
 
 ; CHECK-SPIRV-DAG: Name [[#FOO:]] "foo"
-; CHECK-SPIRV-DAG: Name [[#BAR:]] "bar"
+; CHECK-SPIRV-DAG: EntryPoint [[#]] [[#BAR:]] "bar"
 ; CHECK-SPIRV-DAG: Name [[#Y:]] "y"
 ; CHECK-SPIRV-DAG: Name [[#FOOPTR:]] "foo.alias"
 ; CHECK-SPIRV-DAG: Decorate [[#FOO]] LinkageAttributes "foo" Export
-; CHECK-SPIRV-DAG: Decorate [[#BAR]] LinkageAttributes "bar" Export
 ; CHECK-SPIRV-DAG: TypeInt [[#I32:]] 32 0
 ; CHECK-SPIRV-DAG: TypeInt [[#I64:]] 64 0
 ; CHECK-SPIRV-DAG: TypeFunction [[#FOO_TYPE:]] [[#I32]] [[#I32]]