Address space struct design

Issue to discuss how to handle pointer address spaces.

spir-v has the concept of Storage Classes which are declared both on pointer types, as well as load/store instructions. We need to somehow carry through the correct pointer type and emit the correct metadata:

Some thoughts off the top of my head:

Conservative option: declare some intrinsic structs:

struct WorkgroupMemory<T> {
    #[spirv(workgroup_memory)]
    ptr: *mut T,
}
impl<T> WorkgroupMemory<T> {
    pub fn load(&self) -> T {
        spirv_intrinsic_load_workgroup_memory(self.ptr)
    }
}

Way-too-aggressive option: add syntax to Rust:

fn f(x: &workgroup u32);

It looks like we're going with a format similar to:

#[spirv(storage_class = "private")]
pub struct Private<T> {
    x: *mut T,
}

(where poking at x is an incredibly unsafe operation that requires knowledge of how the backend works, this will be in the spirv-std library, not user code)

So the question is, what do we call all these structs? do we copy the names directly from the spirv spec, or do we try to make something that's a little easier to type and understand?

the list of storage classes is here, I'd like to give rusty names to all of them.

rust-gpu/rustc_codegen_spirv/src/symbols.rs

Lines 19 to 38 in 9697c22

    
           ("uniform_constant", UniformConstant), 
        
           ("input", Input), 
        
           ("uniform", Uniform), 
        
           ("output", Output), 
        
           ("workgroup", Workgroup), 
        
           ("cross_workgroup", CrossWorkgroup), 
        
           ("private", Private), 
        
           ("function", Function), 
        
           ("generic", Generic), 
        
           ("push_constant", PushConstant), 
        
           ("atomic_counter", AtomicCounter), 
        
           ("image", Image), 
        
           ("storage_buffer", StorageBuffer), 
        
           ("callable_data_nv", CallableDataNV), 
        
           ("incoming_callable_data_nv", IncomingCallableDataNV), 
        
           ("ray_payload_nv", RayPayloadNV), 
        
           ("hit_attribute_nv", HitAttributeNV), 
        
           ("incoming_ray_payload_nv", IncomingRayPayloadNV), 
        
           ("shader_record_buffer_nv", ShaderRecordBufferNV), 
        
           ("physical_storage_buffer", PhysicalStorageBuffer),

Also, how do we load/store from them? If methods, what do we call the load/store methods?

This design issue has been open for a while, and no comments have been made, so closing this by assuming that the current design is what we want to go with.

Navigation Menu

Repository navigation

Address space struct design #23

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

	("uniform_constant", UniformConstant),
	("input", Input),
	("uniform", Uniform),
	("output", Output),
	("workgroup", Workgroup),
	("cross_workgroup", CrossWorkgroup),
	("private", Private),
	("function", Function),
	("generic", Generic),
	("push_constant", PushConstant),
	("atomic_counter", AtomicCounter),
	("image", Image),
	("storage_buffer", StorageBuffer),
	("callable_data_nv", CallableDataNV),
	("incoming_callable_data_nv", IncomingCallableDataNV),
	("ray_payload_nv", RayPayloadNV),
	("hit_attribute_nv", HitAttributeNV),
	("incoming_ray_payload_nv", IncomingRayPayloadNV),
	("shader_record_buffer_nv", ShaderRecordBufferNV),
	("physical_storage_buffer", PhysicalStorageBuffer),

Address space struct design #23

Description

Activity

khyperia commented on Sep 18, 2020

khyperia commented on Nov 12, 2020

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions