Stream: git-wasmtime

Topic: wasmtime / PR #1769 Make vconst BxN match specification

view this post on Zulip Wasmtime GitHub notifications bot (May 27 2020 at 15:45):

teapotd opened PR #1769 from vconst-boolean-fix to master:

Cranelift IR docs for boolean types say:

Several larger boolean types are also defined, primarily to be used as SIMD element types. They can be stored in memory, and are represented as either all zero bits or all one bits.

According to Zulip conversation, this applies only to boolean vector types, and it matches the WASM SIMD spec:

The comparison operations all compare two vectors lane-wise, and produce a mask vector with the same number of lanes as the input interpretation where the bits in each lane are 0 for false and all ones for true.

The vconst.BxN instruction currently produces vector with values 0 or 1 instead of masks. This PR changes it to produce masks.

r? @abrown

view this post on Zulip Wasmtime GitHub notifications bot (May 27 2020 at 16:09):

abrown requested abrown for a review on PR #1769.

view this post on Zulip Wasmtime GitHub notifications bot (May 27 2020 at 16:24):

abrown submitted PR Review.

view this post on Zulip Wasmtime GitHub notifications bot (May 27 2020 at 16:37):

abrown merged PR #1769.

Last updated: Dec 23 2024 at 12:05 UTC