Vx

E6022

Error · Topology/Hardware

E6022 — An impl transfer lowering whose edge endpoints are not visible to a topology that declares the edge — the lowering would execute on a part that cannot address the spaces it moves bytes between, which the transfer contract's space-visibility constraint forbids.

What the compiler reports

E6022
cannot see

The fragments the test suite holds the compiler to. An ellipsis marks text the test does not constrain; the emitted message also carries a source location.

A program that triggers it

// The topology declares the edge but cannot see one of its endpoints: the
// lowering would run on a part that cannot address the space it fills.
Topology Dev {
  memory: Memory::L2,
  visible: [Memory::L2],
  transfer Memory::CPU_DRAM -> Memory::L2 : 10 GB/s,
  transfer Memory::L2 -> Memory::SMEM
}
impl Transfer<Memory::L2, Memory::SMEM> for Topology::Dev {
  fn move_tile(src: &Tensor<f32, [4]>, dst: &mut Tensor<f32, [4]>) -> i32 {
    raw::store(dst, 0, 1.0);
    raw::barrier();
    return 0;
  }
}
fn main() -> i32 {
  return 0;
}

From tests/middle_end/fail/raw_space_invisible.vx, which asserts this diagnostic on every commit.

Related

Topologies and memoryThe chapter covering the rule this code enforces. All diagnosticsEvery code the compiler can emit, grouped by stage. E6021A violation of the async/synchronization discipline in a lowering body: a destination read while an async_copy into it is still outstanding, a body that ends with copies no async_wait covers, or a lowering for a synchronizing edge whose body does not end with raw::barrier() (the seam obligation of hir/seam.rs: a relaxed publication makes a stale read reachable). E6023An impl transfer lowering whose declared tile shape is not the shape the transfer at hand actually moves. A lowering is selected by edge, so nothing else relates the two, and the raw:: primitives take their extents from the declaration: a smaller declaration copies part of the tile and leaves the rest uninitialised, a larger one stores past the end (observed as a SIGSEGV).