Stream: git-wasmtime

Topic: wasmtime / PR #6565 cranelift: Remove the `fcvt_low_from_...

Wasmtime GitHub notifications bot (Jun 12 2023 at 20:30):

alexcrichton opened PR #6565 from alexcrichton:remove-fcvt-low-from-sint to bytecodealliance:main:

This commit removes this instruction since it's a combination of swiden_low plus fcvt_from_sint. This was used by the WebAssembly f64x2.convert_low_i32x4_s instruction previously but the corresponding unsigned variant of the instruction, f64x2.convert_low_i32x4_u, used a uwiden_low plus fcvt_from_uint combo. To help simplify Cranelift's instruction set and to make these two instructions mirrors of each other the Cranelift instruction is removed.

The s390x and AArch64 backend lowering rules for this instruction could simply be deleted as the previous combination of the swiden_low and fcvt_from_sint lowering rules produces the same code. The x64 backend moved its lowering to a special case of the fcvt_from_sint lowering.

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Wasmtime GitHub notifications bot (Jun 12 2023 at 20:30):

alexcrichton requested abrown for a review on PR #6565.

Wasmtime GitHub notifications bot (Jun 12 2023 at 20:30):

alexcrichton requested wasmtime-compiler-reviewers for a review on PR #6565.

Wasmtime GitHub notifications bot (Jun 12 2023 at 20:59):

alexcrichton updated PR #6565.

Wasmtime GitHub notifications bot (Jun 12 2023 at 21:15):

jameysharp submitted PR review:

It's always nice to get rid of CLIF instructions and this one looks to have been remarkably painless. Thank you!

Wasmtime GitHub notifications bot (Jun 13 2023 at 01:12):

alexcrichton merged PR #6565.

Last updated: Dec 06 2025 at 06:05 UTC