RFR: 8304915: Create jdk.internal.util.Architecture enum and apply [v4]

[Glavo]

On Wed, 5 Apr 2023 20:40:32 GMT, Roger Riggs <rriggs at openjdk.org> wrote:

>> src/java.base/share/classes/jdk/internal/foreign/CABI.java line 48:
>> 
>>> 46:         // might be running in a 32-bit VM on a 64-bit platform.
>>> 47:         // addressSize will be correctly 32
>>> 48:         if (Architecture.isX64() && ADDRESS_SIZE == 64) {
>> 
>> Is there a difference to Architecture.is64bit (I.e. is the later or the former runtime vs compiletime
>
> There should be no difference; I was hesitant to drop the ADDRESS_SIZE check without knowing more about the foreign api dependencies.  ADDRESS_SIZE is computed (I think) from `UNSAFE.ADDRESS_SIZE * 8`.
> But I can't think of how it can be different than the CPU_BITS that are defined when the JDK is built.

> Is there a difference to Architecture.is64bit (I.e. is the later or the former runtime vs compiletime

Theoretically, the two can be unrelated. Linux x32 ABI is a typical example of using 32-bit addresses on the x86-64 architecture.

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PR Review Comment: https://git.openjdk.org/jdk/pull/13357#discussion_r1159032441