Stream: git-wasmtime

Topic: wasmtime / PR #5196 [RFC] Support big- and little-endian ...

Wasmtime GitHub notifications bot (Nov 04 2022 at 12:03):

uweigand opened PR #5196 from bitcast-lanes to main:

Add a MemFlags operand to the bitcast instruction, where only the big and little flags are accepted. These define the lane order to be used when casting between types of different lane counts.

Update all users to pass an appropriate MemFlags argument.

Implement lane swaps where necessary in the s390x back-end.

This is the final part necessary to fix
https://github.com/bytecodealliance/wasmtime/issues/4566.

CC @cfallin

This is still a RFC because of the following questions:

• Should we enforce that a byte order flag must be explicitly specified if the types differ in lane count? (This would be easily doable in the verifier.)
• There was some discussion in the issue whether or not the MemFlags API is the right choice. It seems that way to me, since it makes the semantics easy to specific, and is simple to implement based on the already existing MemFlags infrastructure. If you prefer some other implementation, please let me know - I'd be happy to change this.

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Wasmtime GitHub notifications bot (Nov 04 2022 at 12:20):

uweigand updated PR #5196 from bitcast-lanes to main.

Wasmtime GitHub notifications bot (Nov 04 2022 at 20:43):

cfallin submitted PR review.

Wasmtime GitHub notifications bot (Nov 04 2022 at 20:43):

cfallin submitted PR review.

Wasmtime GitHub notifications bot (Nov 04 2022 at 20:43):

cfallin created PR review comment:

s/using/both using/, just for clarity (other possibilities here include storing with one MemFlags and loading with another, which isn't what we're emulating but someone might imagine this instead)

Wasmtime GitHub notifications bot (Nov 05 2022 at 11:44):

uweigand updated PR #5196 from bitcast-lanes to main.

Last updated: Nov 22 2024 at 17:03 UTC