OpSpecConstantOp for OpPtrCastToGeneric or OpGenericCastToPtr

[Spencer Fricke]

It is not possible to have OpSpecConstantOp for OpPtrCastToGeneric or OpGenericCastToPtr currently

Both OpPtrCastToGeneric or OpGenericCastToPtr must appear in a block so the following is invalid

%void = OpTypeVoid
%func = OpTypeFunction %void
%f32 = OpTypeFloat 32
%f32ptr_gen = OpTypePointer Generic %f32
%f32ptr_wg = OpTypePointer Workgroup %f32
%var_wg = OpVariable %f32ptr_wg Workgroup
// spirv-val error: PtrCastToGeneric must appear in a block
%ptr_gen = OpPtrCastToGeneric %f32ptr_gen %var_wg
%ptr_wg = OpGenericCastToPtr %f32ptr_wg %ptr_gen
%main = OpFunction %void None %func
%main_entry = OpLabel
OpReturn
OpFunctionEnd

but at the same time SpecConstantOp cant appear in a function declaration so the following is also invalid

%void = OpTypeVoid
%func = OpTypeFunction %void
%f32 = OpTypeFloat 32
%f32ptr_gen = OpTypePointer Generic %f32
%f32ptr_wg = OpTypePointer Workgroup %f32
%var_wg = OpVariable %f32ptr_wg Workgroup
%main = OpFunction %void None %func
%main_entry = OpLabel
// spirv-val error: SpecConstantOp cannot appear in a function declaration
%ptr_gen = OpSpecConstantOp %f32ptr_gen PtrCastToGeneric %var_wg
%ptr_wg = OpSpecConstantOp %f32ptr_wg GenericCastToPtr %ptr_gen
OpReturn
OpFunctionEnd

So I am not sure when it is possible to use something such asOpSpecConstantOp %_ PtrCastToGeneric

[Tobski]

%ptr_gen = OpSpecConstantOp %f32ptr_gen PtrCastToGeneric %var_wg

This line should appear outside the function definition. You use PtrCastToGeneric as an operand to OpSpecConstantOp which is defined outside of the the function.

[Marty Johnson]

Closing per discussion in SPIR WG - please reopen if needed