Stream: git-wasmtime

Topic: wasmtime / Issue #2682 Fix some `i128` shift-related bugs...

Wasmtime GitHub notifications bot (Feb 25 2021 at 09:24):

bjorn3 commented on Issue #2682:

[legion/src/internals/insert.rs:54] component_index = 0
[legion/src/internals/insert.rs:54] 1u128 << dbg!(component_index) = 18446744073709551617

It didn't help unfortunately.

Wasmtime GitHub notifications bot (Feb 25 2021 at 17:49):

cfallin commented on Issue #2682:

Ah, yes, you were right; I confused tmp2 for tmp3 (a classic mistake!) and failed to actually use any test vectors with differing lower and upper halves. Should be fixed now (and added a few more test cases). Thanks!

Wasmtime GitHub notifications bot (Feb 26 2021 at 23:12):

cfallin commented on Issue #2682:

I think this looks fine. (As an aside, why aren't we using SSE2's PSLLDQ/PSRLDQ instructions instead of these long sequences? I haven't looked at much of the i128 code but it would seem that moving upper and lower halves to XMMs and back might still be faster for one of these cases?)

Ah, the simple answer is that I don't know SSE well enough to reach for such instructions -- though it looks like they should work much more efficiently than these sequences! I'll go ahead and merge with your +1 for now so that we have correct results; but we can definitely improve this later. Thanks!

Last updated: Dec 23 2024 at 13:07 UTC