Volatile Loads/Stores

core/src/ptr/mod.rs で報告されている intrinsics::volatile_store の呼び出しから始め、Rust-GPU が volatile load と store を SPIR-V にどのように lowering しているかを追跡します。その経路を issue で言及されている SPIR-V Memory Operands と比較します。完了とは、報告されている MemFlags(VOLATILE) エラーなしで、要求された volatile 操作がサポートされることです。

I'm trying to use volatile loads and stores like so:

#[inline(always)]
pub fn get_item(&self, offset: u32) -> T {
    unsafe {
        let ptr = self
            .items
            .get_unchecked(((self.start_ticket + offset) % self.max_capacity) as usize);
        core::ptr::read_volatile(ptr)
    }
}

#[inline(always)]
pub fn set_item(&mut self, offset: u32, item: T) {
    unsafe {
        let ptr = self
            .items
            .get_unchecked_mut(((self.start_ticket + offset) % self.max_capacity) as usize);
        core::ptr::write_volatile(ptr, item);
    }
}

But when compiling I get an error saying this is not supported yet.

error: store_with_flags is not supported yet: MemFlags(VOLATILE)
      --> /home/peyton/.rustup/toolchains/nightly-2025-06-30-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:2180:9
       |
  2180 |         intrinsics::volatile_store(dst, src);
       |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

It would be very useful to be able to specify this in loads. It seems like its possible in SPIRV using Memory Operands is there any way to do this currently?

System Info

• SPIR-V: SPIRV-Tools v2025.4 v2025.4-0-g7f2d9ee9
  Targets:
  SPIR-V 1.0
  SPIR-V 1.1
  SPIR-V 1.2
  SPIR-V 1.3
  SPIR-V 1.4
  SPIR-V 1.5
  SPIR-V 1.6
  SPIR-V 1.2 (under OpenCL 2.2 Full Profile semantics)
  SPIR-V 1.0 (under Vulkan 1.0 semantics)
  SPIR-V 1.3 (under Vulkan 1.1 semantics)
  SPIR-V 1.4 (under Vulkan 1.1 semantics)
  SPIR-V 1.5 (under Vulkan 1.2 semantics)
  SPIR-V 1.6 (under Vulkan 1.3 semantics) SPIR-V 1.6 (under Vulkan 1.4 semantics)