Stream: git-wasmtime

Topic: wasmtime / PR #11637 [Cranelift] fold shifts over bitwise...

Wasmtime GitHub notifications bot (Sep 08 2025 at 12:42):

bongjunj opened PR #11637 from bongjunj:fold-shifts-over-and to bytecodealliance:main:

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This adds (rule (simplify (ushr ty (band ty (ishl ty x y) z) y)) (band ty x (ushr ty z y))).

Wasmtime GitHub notifications bot (Sep 08 2025 at 12:42):

bongjunj requested abrown for a review on PR #11637.

Wasmtime GitHub notifications bot (Sep 08 2025 at 12:42):

bongjunj requested wasmtime-compiler-reviewers for a review on PR #11637.

Wasmtime GitHub notifications bot (Sep 08 2025 at 14:46):

github-actions[bot] commented on PR #11637:

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cc @cfallin, @fitzgen

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Wasmtime GitHub notifications bot (Sep 09 2025 at 17:29):

fitzgen submitted PR review:

Thanks!

We can do the equivalent with sshr as well, right? Would you be willing to do a follow up PR adding that rule?

Wasmtime GitHub notifications bot (Sep 10 2025 at 01:06):

bongjunj commented on PR #11637:

Thank you for the comment. I will add the rule in this PR.

Wasmtime GitHub notifications bot (Sep 10 2025 at 06:11):

bongjunj commented on PR #11637:

@fitzgen

The verifier rejects the sshr case.

Verification failed for <unnamed rule>, width 8
(simplify (sshr [ty|8] (band [ty|8] (ishl [ty|8] [x|#x01] [y|#x07]) [z|#x80]) [y|#x07]))
=>
(band [ty|8] [x|#x01] (sshr [ty|8] [z|#x80] [y|#x07]))

#xff => #x01

I've tried the other cases of ushr, sshr and sshr, ushr.
But this rule is correct only when band folds two ushrs.

Wasmtime GitHub notifications bot (Sep 10 2025 at 06:13):

bongjunj updated PR #11637.

Wasmtime GitHub notifications bot (Sep 10 2025 at 06:16):

bongjunj updated PR #11637.

Wasmtime GitHub notifications bot (Sep 10 2025 at 20:01):

fitzgen commented on PR #11637:

Thanks for checking!

Wasmtime GitHub notifications bot (Sep 10 2025 at 20:41):

fitzgen merged PR #11637.

Last updated: Dec 06 2025 at 06:05 UTC