Handle byval generic pointer in LegalizeFunctionSignatures

When generic pointer argument with `byval` attribute was legalized to
the actual argument passed by value, LegalizeFunctionSignatures wasn't
inserting addrspace cast back to generic addrspace when handling uses
of this argument.

(cherry picked from commit be0cfaa)

Author: aratajew

IGC/AdaptorCommon/LegalizeFunctionSignatures.cpp

@@ -400,6 +400,10 @@ void LegalizeFunctionSignatures::FixFunctionBody(Module& M)
                     NewArgIt->removeAttr(llvm::Attribute::ByVal);
                     Value* newArgPtr = builder.CreateAlloca(NewArgIt->getType());
                     StoreToStruct(builder, &*NewArgIt, newArgPtr);
+                    // cast back to original addrspace
+                    IGC_ASSERT(OldArgIt->getType()->getPointerAddressSpace() == ADDRESS_SPACE_GENERIC ||
+                               OldArgIt->getType()->getPointerAddressSpace() == ADDRESS_SPACE_PRIVATE);
+                    newArgPtr = builder.CreateAddrSpaceCast(newArgPtr, OldArgIt->getType());
                     VMap[&*OldArgIt] = newArgPtr;
                 }
                 else if (!isLegalSignatureType(M, OldArgIt->getType(), isStackCall))

IGC/Compiler/tests/LegalizeFunctionSignatures/generic-struct-by-val.ll

@@ -0,0 +1,57 @@
+;=========================== begin_copyright_notice ============================
+;
+; Copyright (C) 2023 Intel Corporation
+;
+; SPDX-License-Identifier: MIT
+;
+;============================ end_copyright_notice =============================
+;
+; RUN: igc_opt %s -S -o - --igc-legalize-function-signatures | FileCheck %s
+
+; ------------------------------------------------
+; LegalizeFunctionSignatures
+; ------------------------------------------------
+
+; The test checks if struct argument passed as generic pointer with byval attribute is correctly legalized
+
+%structtype = type { i32, i32 }
+
+define spir_kernel void @kernel() {
+; CHECK-LABEL: @kernel(
+; CHECK: [[AL:%.*]] = alloca %structtype
+; CHECK: [[TMP0:%.*]] = addrspacecast %structtype* [[AL]] to %structtype addrspace(4)*
+; CHECK: [[GEP0:%.*]] = getelementptr inbounds %structtype, %structtype addrspace(4)* [[TMP0]], i32 0, i32 0
+; CHECK: [[L0:%.*]] = load i32, i32 addrspace(4)* [[GEP0]]
+; CHECK: [[I0:%.*]] = insertvalue %structtype undef, i32 [[L0]], 0
+; CHECK: [[GEP1:%.*]] = getelementptr inbounds %structtype, %structtype addrspace(4)* [[TMP0]], i32 0, i32 1
+; CHECK: [[L1:%.*]] = load i32, i32 addrspace(4)* [[GEP1]]
+; CHECK: [[I1:%.*]] = insertvalue %structtype [[I0]], i32 [[L1]], 1
+; CHECK: call i32 @foo(%structtype [[I1]])
+; CHECK: ret void
+
+  %1 = alloca %structtype
+  %2 = addrspacecast %structtype* %1 to %structtype addrspace(4)*
+  call i32 @foo(%structtype addrspace(4)* byval(%structtype) %2)
+  ret void
+}
+
+define spir_func i32 @foo(%structtype addrspace(4)* byval(%structtype) %src) #0 {
+; CHECK-LABEL: define spir_func i32 @foo(%structtype %src)
+; CHECK: [[AL:%.*]] = alloca %structtype
+; CHECK: [[GEP0:%.*]] = getelementptr inbounds %structtype, %structtype* [[AL]], i32 0, i32 0
+; CHECK: [[E0:%.*]] = extractvalue %structtype %src, 0
+; CHECK: store i32 [[E0]], i32* [[GEP0]]
+; CHECK: [[GEP1:%.*]] = getelementptr inbounds %structtype, %structtype* [[AL]], i32 0, i32 1
+; CHECK: [[E1:%.*]] = extractvalue %structtype %src, 1
+; CHECK: store i32 [[E1]], i32* [[GEP1]]
+;
+; CHECK: [[ASC:%.*]] = addrspacecast %structtype* [[AL]] to %structtype addrspace(4)*
+; CHECK: [[GEP2:%.*]] = getelementptr inbounds %structtype, %structtype addrspace(4)* [[ASC]], i64 0, i32 1
+; CHECK: [[LOAD:%.*]] = load i32, i32 addrspace(4)* [[GEP2]]
+; CHECK: ret i32 [[LOAD]]
+  %1 = getelementptr inbounds %structtype, %structtype addrspace(4)* %src, i64 0, i32 1
+  %2 = load i32, i32 addrspace(4)* %1
+  ret i32 %2
+}
+
+attributes #0 = { "visaStackCall" }