[LLVM16] Removal of Reapply_hasSetOpaquePointersValue.patch

In order to reduce the amount of patches this PR moves
check whether pointers mode was already set from LLVM to IGC

More details in comments

(cherry picked from commit ff57226)

Author: bokrzesi

IGC/Compiler/CodeGenContext.cpp

@@ -312,11 +312,22 @@ LLVMContextWrapper::LLVMContextWrapper(bool createResourceDimTypes) : m_UserAddr
   // perform automatic conversion of builtin types which should be represented using TargetExtTy.
   // TODO: For transition purposes, consider introducing an IGC internal option to tweak typed/opaque pointers
   // with a precedence over the environment flag.
-  if (IGC::canOverwriteLLVMCtxPtrMode(basePtr)) {
-    bool enableOpaquePointers = AreOpaquePointersEnabled();
 
+  // TODO: Remove/Re-evaluate once fully moved to the LLVM 16 opaque ptrs.
+  // This WA_OpaquePointersCL flag is related to the same flag in LLVM itself
+  // We're using it here to have consistent behaviour.
+  // https://github.com/llvm/llvm-project/blob/release/16.x/llvm/lib/IR/LLVMContextImpl.cpp#L50
+  auto WA_OpaquePointersCL = cl::getRegisteredOptions()["opaque-pointers"];
+  if (WA_OpaquePointersCL && WA_OpaquePointersCL->getNumOccurrences() > 0) {
+    IGC_IsPointerModeAlreadySet = true;
+  }
+  
+  if (IGC::canOverwriteLLVMCtxPtrMode(basePtr, IGC_IsPointerModeAlreadySet)) {
+    bool enableOpaquePointers = AreOpaquePointersEnabled();
     IGCLLVM::setOpaquePointers(basePtr, enableOpaquePointers);
+    IGC_IsPointerModeAlreadySet = true;
   }
+  // TODO: end
 }
 
 void LLVMContextWrapper::AddRef() { refCount++; }

IGC/Compiler/CodeGenPublic.h

@@ -765,6 +765,11 @@ class LLVMContextWrapper : public llvm::LLVMContext {
   llvm::SmallVector<llvm::StructType *, 16> m_allLayoutStructTypes;
   void AddRef();
   void Release();
+
+  // TODO: Remove after switch to LLVM 16 opque pointers.
+  // In order to get rid of `Reapply_hasSetOpaquePointersValue.patch` patch, we're implementing
+  // check if pointer type was set in IGC.
+  bool IGC_IsPointerModeAlreadySet = false;
 };
 
 struct RoutingIndex {

IGC/WrapperLLVM/include/llvmWrapper/IR/LLVMContext.h

@@ -1,6 +1,6 @@
 /*========================== begin_copyright_notice ============================
 
-Copyright (C) 2024 Intel Corporation
+Copyright (C) 2025 Intel Corporation
 
 SPDX-License-Identifier: MIT
 
@@ -27,7 +27,7 @@ inline void setOpaquePointers(llvm::LLVMContext *Ctx, const bool Enable) {
 } // end namespace IGCLLVM
 
 namespace IGC {
-inline bool canOverwriteLLVMCtxPtrMode(llvm::LLVMContext *Ctx) {
+inline bool canOverwriteLLVMCtxPtrMode(llvm::LLVMContext *Ctx, bool IGC_IsPointerModeAlreadySet) {
   IGC_ASSERT_MESSAGE(Ctx, "Null LLVMContext pointer!");
 #if LLVM_VERSION_MAJOR < 14
   return false;
@@ -38,11 +38,16 @@ inline bool canOverwriteLLVMCtxPtrMode(llvm::LLVMContext *Ctx) {
   // override this when opaque pointers are force-enabled in experimental
   // mode.
   return Ctx->supportsTypedPointers();
-#elif LLVM_VERSION_MAJOR >= 15
+#elif LLVM_VERSION_MAJOR == 15
   // With LLVM 15-16, we should not trigger CL option evaluation, as the
   // OPs mode will then get set as a permanent default. The only
   // alternative is to use an API below, non-native for LLVM 16.
   return !Ctx->hasSetOpaquePointersValue();
+#elif LLVM_VERSION_MAJOR >= 16
+  // LLVM 16: we start removing switching between typed/opaque ptrs mode
+  // In order to prepare for full move to the opaque pointers.
+  // The first step is to get rid of .patches related to opaque pointers mode.
+  return !IGC_IsPointerModeAlreadySet;
 #endif // LLVM_VERSION_MAJOR
 }
 } // end namespace IGC