Stream: git-wasmtime

Topic: wasmtime / PR #4729 x64: Lower bitcast, fabs, and fneg in...

Wasmtime GitHub notifications bot (Aug 17 2022 at 03:32):

elliottt opened PR #4729 from trevor/x64-bitcast-fabs-fneg to main:

This PR doesn't need to be reviewed until #4722 is merged

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Migrate the bitcast, fabs, and fneg instructions to ISLE
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Wasmtime GitHub notifications bot (Aug 17 2022 at 23:56):

cfallin created PR review comment:

I wonder, would it be better to use a VCodeConstant here to get the appropriate MSBs-only-in-each-lane value?

Wasmtime GitHub notifications bot (Aug 17 2022 at 23:56):

cfallin submitted PR review.

Wasmtime GitHub notifications bot (Aug 17 2022 at 23:56):

cfallin submitted PR review.

Wasmtime GitHub notifications bot (Aug 18 2022 at 20:05):

elliottt has marked PR #4729 as ready for review.

Wasmtime GitHub notifications bot (Aug 18 2022 at 20:05):

elliottt edited PR #4729 from trevor/x64-bitcast-fabs-fneg to main:

Migrate the bitcast, fabs, and fneg instructions to ISLE
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Wasmtime GitHub notifications bot (Aug 18 2022 at 20:07):

elliottt updated PR #4729 from trevor/x64-bitcast-fabs-fneg to main.

Wasmtime GitHub notifications bot (Aug 18 2022 at 20:09):

elliottt updated PR #4729 from trevor/x64-bitcast-fabs-fneg to main.

Wasmtime GitHub notifications bot (Aug 18 2022 at 21:37):

elliottt requested cfallin for a review on PR #4729.

Wasmtime GitHub notifications bot (Aug 18 2022 at 21:38):

elliottt submitted PR review.

Wasmtime GitHub notifications bot (Aug 18 2022 at 21:38):

elliottt created PR review comment:

Would that be a savings over the two instructions?

Wasmtime GitHub notifications bot (Aug 19 2022 at 00:58):

cfallin submitted PR review.

Wasmtime GitHub notifications bot (Aug 19 2022 at 00:58):

cfallin created PR review comment:

Possibly, though looking at xorps I see the basic SSE version is not reg, reg/mem but just reg, reg so it would still be a separate load; one load vs. dependent chain of two 1-cycle ops, the latter likely wins. Anyway it's an unimportant enough question that I don't care too much to investigate further :-)

Wasmtime GitHub notifications bot (Aug 19 2022 at 00:59):

cfallin submitted PR review.

Wasmtime GitHub notifications bot (Aug 19 2022 at 00:59):

cfallin merged PR #4729.

Last updated: Dec 23 2024 at 12:05 UTC