On Thu, Mar 9, 2023 at 2:38 PM Mike Taylor <[email protected]> wrote:
> On 3/9/23 3:42 PM, Deepti Gandluri wrote: > > Quick note that I realized my title was accidentally cropped, it should > be: > > "Intent to Implement and Ship: WebAssembly Relaxed SIMD". > > On Wed, Mar 8, 2023 at 4:11 PM Deepti Gandluri <[email protected]> > wrote: > >> Contact emails [email protected], [email protected], >> [email protected] >> >> Explainer >> https://github.com/WebAssembly/relaxed-simd/blob/main/proposals/relaxed-simd/Overview.md >> >> Specification >> https://github.com/WebAssembly/relaxed-simd/tree/main/document >> >> Summary >> >> Relaxed SIMD extends the existing SIMD proposal to introduce vector >> instructions that relax the strict determinism constraints of portable SIMD >> to take better advantage of the underlying hardware. The operations >> introduced in this proposal take advantage of widely available instruction >> sets to accelerate compute workloads. >> >> Blink component Blink>JavaScript>WebAssembly >> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EJavaScript%3EWebAssembly> >> >> TAG review Not required as per: >> https://v8.dev/docs/feature-launch-process. This introduces an >> additional set of vector operations to WebAssembly, and makes no API >> changes. >> Risks >> >> >> Interoperability and Compatibility >> >> *Gecko*: In development, enabled in nightly >> >> *WebKit*: No signal as per request for position: >> mail-archive.com/[email protected]/msg30574.html >> > This should be updated to neutral, with concerns around potential compat > issues (it was manually moved to the new standards-position repo: > https://github.com/WebKit/standards-positions/issues/4#issuecomment-1170364495 > ). > Thanks for the pointer, I missed the issue being moved over. > >> *Web developers*: Strongly positive, Proposal in Phase 3 in the >> WebAssembly CG the proposal was incubated to address some of the >> developer/user requests from the previous SIMD proposal. >> >> *Other signals*: Proposal voted to a provisional phase 4 as per meeting >> notes in the February 14th CG meeting (notes: >> https://github.com/WebAssembly/meetings/blob/main/main/2023/CG-02-14.md). >> The feature has consensus in the CG, but the vote is provisional till the >> formal spec is up to date (Tracking issue: >> https://github.com/WebAssembly/relaxed-simd/issues/134, PRs also in >> flight). >> >> WebView application risks >> >> Does this intent deprecate or change behavior of existing APIs, such that >> it has potentially high risk for Android WebView-based applications? No >> >> >> Debuggability >> >> Supported instructions are enabled in Liftoff, and are visible to >> DevTools for debuggability. >> >> >> Will this feature be supported on all six Blink platforms (Windows, Mac, >> Linux, Chrome OS, Android, and Android WebView)? Yes >> >> Is this feature fully tested by web-platform-tests >> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> >> ? Not applicable, tested by WebAssembly spec tests >> >> Flag name V8: --wasm-relaxed-simd Chrome: >> Features::kWebAssemblyRelaxedSimd >> >> Requires code in //chrome? False >> >> Tracking bug https://bugs.chromium.org/p/v8/issues/detail?id=12284 >> >> Estimated milestones >> >> 114 >> >> Anticipated spec changes >> >> No anticipated spec changes, but some potential for compat issues based >> on hardware, more details in this Entropy.md >> <https://github.com/WebAssembly/relaxed-simd/blob/main/proposals/relaxed-simd/Entropy.md>, >> and the linked issues. >> > Thanks for the Entropy.md doc - it's incredibly helpful. > > For most of the exposed entropy, we already expose this via the User-Agent > string, or the Arch UA Client Hint. Can you say more about "Differences > between hardware that has native FMA support, and hardware that does not." > and "whether the Dot product extension is supported in the most optimal > codegen" - any idea what the distributions would look there there? > > As to compat, "code compiled for one browser works differently on a > different browser" - this sounds a little bit scary! Do we have any ideas > on how to minimize (I assume preventing isn't a reality) this outcome? > I re-posted this thread to fix the title, and have pasted+responded to this in the newer thread. Sorry for the churn! > Link to entry on the Chrome Platform Status >> https://chromestatus.com/feature/5082417973952512 >> > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CALi9WK_SOE5jAVCPydhY0Xn4S6P2rr_W9qhQhN5tA0Ew9vJEdg%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CALi9WK_SOE5jAVCPydhY0Xn4S6P2rr_W9qhQhN5tA0Ew9vJEdg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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