RFR: 8349361: C2: RShiftL should support all applicable transformations that RShiftI does

[Tobias Hartmann]

On Tue, 4 Feb 2025 13:02:47 GMT, Roland Westrelin <roland at openjdk.org> wrote:

> This change refactors `RShiftI`/`RshiftL` `Ideal`, `Identity` and
> `Value` because the `int` and `long` versions are very similar and so
> there's no logic duplication. In the process, support for some extra
> transformations is added to `RShiftL`. I also added some new test
> cases.

Fails to build on Mac AArch64:


[2025-02-05T06:43:04,925Z] * For target hotspot_variant-server_libjvm_objs_mulnode.o:
[2025-02-05T06:43:04,925Z] [...]workspace/open/src/hotspot/share/opto/mulnode.cpp:1400:13: error: use of bitwise '&' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
[2025-02-05T06:43:04,925Z]      assert((checked_cast<jint>(lo) == lo_verify) & (checked_cast<jint>(hi) == hi_verify), "inconsistent");

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PR Comment: https://git.openjdk.org/jdk/pull/23438#issuecomment-2635828033