Reduce usage of pointer element types (31).

This change replaces calls to getNonOpaquePtrEltTy with element type
information got through other means. This change is part of the effort
to support opaque pointers in newer LLVM versions.

Author: ViacheslavRb

IGC/Compiler/Optimizer/OpenCLPasses/GenericAddressResolution/GASPropagator.cpp

@@ -120,21 +120,21 @@ bool GASPropagator::visitBitCastInst(BitCastInst& I) {
     PointerType* SrcPtrTy = cast<PointerType>(TheVal->getType());
     PointerType* DstPtrTy = cast<PointerType>(I.getType());
 
+    BuilderType::InsertPointGuard Guard(IRB);
+    IRB.SetInsertPoint(I.getNextNode());
+    Value* Src = TheVal;
     if (!IGCLLVM::isOpaquePointerTy(SrcPtrTy)) {
-        BuilderType::InsertPointGuard Guard(IRB);
-        IRB.SetInsertPoint(I.getNextNode());
         // Push `addrspacecast` forward by replacing this `bitcast` on GAS with the
         // one on non-GAS followed by a new `addrspacecast` to GAS.
         Type* DstTy = IGCLLVM::getNonOpaquePtrEltTy(DstPtrTy);     // Legacy code: getNonOpaquePtrEltTy
         PointerType* TransPtrTy =
             PointerType::get(DstTy, SrcPtrTy->getAddressSpace());
-        Value* Src = TheVal;
         if (IGCLLVM::getNonOpaquePtrEltTy(SrcPtrTy) != DstTy)      // Legacy code: getNonOpaquePtrEltTy
             Src = IRB.CreateBitCast(Src, TransPtrTy);
-        Value* NewPtr = IRB.CreateAddrSpaceCast(Src, DstPtrTy);
-        I.replaceAllUsesWith(NewPtr);
-        I.eraseFromParent();
     }
+    Value* NewPtr = IRB.CreateAddrSpaceCast(Src, DstPtrTy);
+    I.replaceAllUsesWith(NewPtr);
+    I.eraseFromParent();
     return true;
 }
 

IGC/Compiler/Optimizer/OpenCLPasses/GenericAddressResolution/GASResolving.cpp

@@ -11,6 +11,7 @@ SPDX-License-Identifier: MIT
 #include "Compiler/CISACodeGen/ShaderCodeGen.hpp"
 #include "Compiler/InitializePasses.h"
 #include "llvmWrapper/IR/DerivedTypes.h"
+#include "llvmWrapper/IR/Argument.h"
 
 // Generic address space (GAS) pointer resolving is done in two steps:
 // 1) Find cast from non-GAS pointer to GAS pointer
@@ -266,7 +267,12 @@ bool GASResolving::checkGenericArguments(Function& F) const {
         if (auto Ty = dyn_cast<PointerType>(FT->getParamType(p))) {
             if (Ty->getAddressSpace() != ADDRESS_SPACE_GLOBAL)
                 continue;
-            auto PteeTy = IGCLLVM::getNonOpaquePtrEltTy(Ty);
+            auto PteeTy = IGCLLVM::getArgAttrEltTy(F.getArg(p));
+            if (PteeTy == nullptr && !IGCLLVM::isOpaquePointerTy(Ty))
+                PteeTy = IGCLLVM::getNonOpaquePtrEltTy(Ty);    // Legacy code: getNonOpaquePtrEltTy
+            if (PteeTy == nullptr)
+                // go to slow path
+                return true;
             if (auto PTy = dyn_cast<PointerType>(PteeTy)) {
                 if (PTy->getAddressSpace() == ADDRESS_SPACE_GENERIC)
                     return true;

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

@@ -37,6 +37,22 @@ inline void setParamByRefType([[maybe_unused]] llvm::Argument *arg, [[maybe_unus
 #endif
 }
 
+inline llvm::Type* getArgAttrEltTy(const llvm::Argument* Arg) {
+    llvm::AttributeSet ParamAttrs =
+        Arg->getParent()->getAttributes().getParamAttrs(Arg->getArgNo());
+    if (llvm::Type* ByValTy = ParamAttrs.getByValType())
+        return ByValTy;
+    if (llvm::Type* ByRefTy = ParamAttrs.getByRefType())
+        return ByRefTy;
+    if (llvm::Type* PreAllocTy = ParamAttrs.getPreallocatedType())
+        return PreAllocTy;
+    if (llvm::Type* InAllocaTy = ParamAttrs.getInAllocaType())
+        return InAllocaTy;
+    if (llvm::Type* SRetTy = ParamAttrs.getStructRetType())
+        return SRetTy;
+    return nullptr;
+}
+
 } // namespace IGCLLVM
 
 #endif // IGCLLVM_IR_ARGUMENT_H