Stream: git-wasmtime

Topic: wasmtime / PR #10839 x64: Update codegen of `XmmCmove` ps...

Wasmtime GitHub notifications bot (May 27 2025 at 15:48):

alexcrichton opened PR #10839 from alexcrichton:x64-new-xmm-cmove to bytecodealliance:main:

In #4317 this instruction was updated to handle 128-bit vectors in addition to the previous handling of 32/64-bit floats. Originally the pseudo-instruction used movs{s,d} to achieve its task and when adding 128-bit support I mistakenly switched both f32/f64 paths to using movsd instead of conditionally using movss for f32. In retrospect though it's probably best to use a full register move here instead of just a singular mov because movss and movsd preserve the upper bits of the register, needlessly creating a data dependency with the previous value in the register.

This commit updates this helper to using Inst::gen_move which already internally does this optimization of using movaps, a documented zero-latency instruction, for all xmm-style register movements.

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Wasmtime GitHub notifications bot (May 27 2025 at 15:48):

alexcrichton requested cfallin for a review on PR #10839.

Wasmtime GitHub notifications bot (May 27 2025 at 15:48):

alexcrichton requested wasmtime-compiler-reviewers for a review on PR #10839.

Wasmtime GitHub notifications bot (May 27 2025 at 15:48):

alexcrichton requested dicej for a review on PR #10839.

Wasmtime GitHub notifications bot (May 27 2025 at 15:48):

alexcrichton requested wasmtime-core-reviewers for a review on PR #10839.

Wasmtime GitHub notifications bot (May 27 2025 at 16:07):

cfallin submitted PR review.

Wasmtime GitHub notifications bot (May 27 2025 at 16:47):

cfallin merged PR #10839.

Last updated: Dec 06 2025 at 06:05 UTC