Stream: git-wasmtime

Topic: wasmtime / PR #4327 Implement lowered-then-lifted functions

Wasmtime GitHub notifications bot (Jun 27 2022 at 15:39):

alexcrichton opened PR #4327 from component-lower-then-lift to main:

This commit is a few features bundled into one, culminating in the
implementation of lowered-then-lifted functions for the component model.
It's probably not going to be used all that often but this is possible
within a valid component so Wasmtime needs to do something relatively
reasonable. The main things implemented in this commit are:

• Component instances are now assigned a RuntimeComponentInstanceIndex
  to differentiate each one. This will be used in the future to detect
  fusion (one instance lowering a function from another instance). For
  now it's used to allocate separate VMComponentFlags for each
  internal component instance.

• The CoreExport<FuncIndex> of lowered functions was changed to a
  CoreDef since technically a lowered function can use another lowered
  function as the callee. This ended up being not too difficult to plumb
  through as everything else was already in place.

• A need arose to compile host-to-wasm trampolines which weren't already
  present. Currently wasm in a component is always entered through a
  host-to-wasm trampoline but core wasm modules are the source of all
  the trampolines. In the case of a lowered-then-lifted function there
  may not actually be any core wasm modules, so component objects now
  contain necessary trampolines not otherwise provided by the core wasm
  objects. This feature required splitting a new function into the
  Compiler trait for creating a host-to-wasm trampoline. After doing
  this core wasm compilation was also updated to leverage this which
  further enabled compiling trampolines in parallel as opposed to the
  previous synchronous compilation.

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Wasmtime GitHub notifications bot (Jun 27 2022 at 15:39):

alexcrichton requested fitzgen for a review on PR #4327.

Wasmtime GitHub notifications bot (Jun 27 2022 at 18:34):

fitzgen submitted PR review.

Wasmtime GitHub notifications bot (Jun 27 2022 at 18:34):

fitzgen submitted PR review.

Wasmtime GitHub notifications bot (Jun 27 2022 at 18:34):

fitzgen created PR review comment:

//      flags: [VMComponentFlags; component.num_runtime_component_instances],

Wasmtime GitHub notifications bot (Jun 27 2022 at 18:34):

fitzgen created PR review comment:

better not to open code / bake in the assumption that the flags will always be one byte large, especially since we wrap them up in a VMComponentFlags data abstraction elsewhere:

            size(flags) = cmul(size_of_vm_component_flags(), ret.num_runtime_component_instances),

Wasmtime GitHub notifications bot (Jun 28 2022 at 14:59):

alexcrichton updated PR #4327 from component-lower-then-lift to main.

Wasmtime GitHub notifications bot (Jun 28 2022 at 14:59):

alexcrichton has enabled auto merge for PR #4327.

Wasmtime GitHub notifications bot (Jun 28 2022 at 15:25):

alexcrichton updated PR #4327 from component-lower-then-lift to main.

Wasmtime GitHub notifications bot (Jun 28 2022 at 17:20):

alexcrichton updated PR #4327 from component-lower-then-lift to main.

Wasmtime GitHub notifications bot (Jun 28 2022 at 18:14):

alexcrichton updated PR #4327 from component-lower-then-lift to main.

Wasmtime GitHub notifications bot (Jun 28 2022 at 18:16):

alexcrichton updated PR #4327 from component-lower-then-lift to main.

Wasmtime GitHub notifications bot (Jun 28 2022 at 18:50):

alexcrichton merged PR #4327.

Last updated: Oct 23 2024 at 20:03 UTC