[lworld] RFR: 8371357: [lworld] Remove EnableValhalla

[Stefan Karlsson]

On Tue, 25 Nov 2025 13:37:46 GMT, Paul Hübner <phubner at openjdk.org> wrote:

> Hi all,
> 
> This removes the `EnableValhalla` in favour of the `--enable-preview` flag. Concretely:
> * I've replaced most of the `EnableValhalla` checks with `Arguments::is_valhalla_enabled()`. 
> * Some checks were redundant and could be removed entirely.
> * I've made the `EnableValhalla` flag obsolete.
> * Some tests had to be updated.
> 
> This greatly changes the semantics of tests. I've refined some test groups to make it easier.
> 
> Testing: tiers 1-4.

Not a full review, but I think this looks good. If this is accepted you'll have to add includes of arguments.hpp to all places where you have added a call to `is_valhalla_enabled()`.

src/hotspot/share/runtime/arguments.cpp line 4005:

> 4003:     FLAG_SET_DEFAULT(BytecodeVerificationRemote, true);
> 4004:   }
> 4005:   if (!Arguments::is_valhalla_enabled() || (is_interpreter_only() && !CDSConfig::is_dumping_archive() && !UseSharedSpaces)) {

Can this be just:
Suggestion:

  if (!is_valhalla_enabled() || (is_interpreter_only() && !CDSConfig::is_dumping_archive() && !UseSharedSpaces)) {

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PR Review: https://git.openjdk.org/valhalla/pull/1759#pullrequestreview-3572302794
PR Review Comment: https://git.openjdk.org/valhalla/pull/1759#discussion_r2614606046