[WIP]

Author: michalpaszkowski

llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp

@@ -290,7 +290,6 @@ void SPIRVEmitIntrinsics::insertPtrCastInstr(Instruction *I) {
   Value *Pointer;
   Type *ExpectedElementType;
   unsigned OperandToReplace;
-  bool AllowCastingToChar = false;
 
   StoreInst *SI = dyn_cast<StoreInst>(I);
   if (SI && F->getCallingConv() == CallingConv::SPIR_KERNEL &&
@@ -308,7 +307,6 @@ void SPIRVEmitIntrinsics::insertPtrCastInstr(Instruction *I) {
     Pointer = Arg;
     ExpectedElementType = IntegerType::getInt8Ty(F->getContext());
     OperandToReplace = 0;
-    AllowCastingToChar = true;
   } else if (SI) {
     Pointer = SI->getPointerOperand();
     ExpectedElementType = SI->getValueOperand()->getType();
@@ -390,10 +388,20 @@ void SPIRVEmitIntrinsics::insertPtrCastInstr(Instruction *I) {
   }
 
   // Do not emit spv_ptrcast if it would cast to the default pointer element
-  // type (i8) of the same address space.
-  if (ExpectedElementType->isIntegerTy(8) && !AllowCastingToChar)
+  // type (i8) of the same address space. In case of OpenCL kernels, make sure
+  // i8 is the pointer element type defined for the given kernel argument.
+  if (ExpectedElementType->isIntegerTy(8) &&
+      F->getCallingConv() != CallingConv::SPIR_KERNEL)
     return;
 
+  Argument *Arg = dyn_cast<Argument>(Pointer);
+  if (ExpectedElementType->isIntegerTy(8) &&
+      F->getCallingConv() == CallingConv::SPIR_KERNEL && Arg) {
+    MDString *ArgType = getOCLKernelArgType(*Arg->getParent(), Arg->getArgNo());
+    if (ArgType && ArgType->getString().starts_with("uchar*"))
+      return;
+  }
+
   // If this would be the first spv_ptrcast, the pointer's defining instruction
   // requires spv_assign_ptr_type and does not already have one, do not emit
   // spv_ptrcast and emit spv_assign_ptr_type instead.