Stream: git-wasmtime

Topic: wasmtime / PR #5727 Cranelift DFG: make inst clone deep-c...

view this post on Zulip Wasmtime GitHub notifications bot (Feb 06 2023 at 22:36):

cfallin opened PR #5727 from fix-inst-clone to main:

When investigating #5716, I found that rematerialization of a call, in
addition to blowing up for other reasons, caused aliasing of the varargs
list (the EntityList in the ListPool), such that editing the args of
the second copy of the call instruction inadvertently updated the first
as well.

This PR modifies DataFlowGraph::clone_inst so that it always clones
the varargs list if present. This shouldn't have any functional impact
on Cranelift today, because we don't rematerialize any instructions with
varargs; but it's important to get it right to avoid a bug later!

(Stacked on top of #5726.)

view this post on Zulip Wasmtime GitHub notifications bot (Feb 06 2023 at 22:36):

cfallin requested elliottt for a review on PR #5727.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 06 2023 at 22:36):

cfallin requested fitzgen for a review on PR #5727.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 06 2023 at 22:36):

cfallin requested jameysharp for a review on PR #5727.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 06 2023 at 22:45):

cfallin updated PR #5727 from fix-inst-clone to main.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 06 2023 at 22:46):

cfallin edited PR #5727 from fix-inst-clone to main:

When investigating #5716, I found that rematerialization of a call, in
addition to blowing up for other reasons, caused aliasing of the varargs
list (the EntityList in the ListPool), such that editing the args of
the second copy of the call instruction inadvertently updated the first
as well.

This PR modifies DataFlowGraph::clone_inst so that it always clones
the varargs list if present. This shouldn't have any functional impact
on Cranelift today, because we don't rematerialize any instructions with
varargs; but it's important to get it right to avoid a bug later!

view this post on Zulip Wasmtime GitHub notifications bot (Feb 07 2023 at 00:40):

cfallin updated PR #5727 from fix-inst-clone to main.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 07 2023 at 00:50):

jameysharp submitted PR review.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 07 2023 at 01:00):

cfallin has enabled auto merge for PR #5727.

view this post on Zulip Wasmtime GitHub notifications bot (Feb 07 2023 at 01:21):

cfallin merged PR #5727.

Last updated: Dec 23 2024 at 12:05 UTC