1764367 - Stop using MachineState for Wasm stack maps

Status: RESOLVED FIXED

(Core :: JavaScript: WebAssembly, task, P3)

Description

[Jan de Mooij [:jandem]]

Wasm uses MachineState to store register offsets instead of a pointer to the register contents. We can replace this with a separate RegisterOffsets class, this is simpler and faster, gets rid of some reinterpret_casts, and lets us refactor MachineState in bug 1764366.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1764367 - Replace use of MachineState for stack maps with a RegisterOffsets class. r?rhunt!

The goal is to stop using MachineState for this, so that we can refactor MachineState
separately for the JS use cases.

This also has some other benefits: the new RegisterOffsets type is much smaller than
MachineState, because it doesn't store any information for floating-point registers
and it stores a 32-bit offset instead of a pointer. This also gets rid of some casts.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/363d45d9ebf1
Replace use of MachineState for stack maps with a RegisterOffsets class. r=rhunt

Comment 3

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/363d45d9ebf1