RFR: 8308850: Change JVM options with small ranges that get -Wconversion warnings to 32 bits [v7]

[Ioi Lam]

On Thu, 10 Aug 2023 16:59:00 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> src/hotspot/share/jvmci/jvmciCompilerToVMInit.cpp line 261:
>> 
>>> 259:   do_int_flag(AllocatePrefetchLines)                                       \
>>> 260:   do_int_flag(AllocatePrefetchStepSize)                                    \
>>> 261:   do_int_flag(AllocatePrefetchStyle)                                       \
>> 
>> Why is AllocatePrefetchInstr not changed? It seems to use 0-3 only.
>
> Looks like from the constraints, it's allowed to be max_intx on some platforms, so changing this would be a functional change.
> 
> JVMFlag::Error AllocatePrefetchInstrConstraintFunc(intx value, bool verbose) {
>   intx max_value = max_intx;
> #if defined(X86)
>   max_value = 3;
> #endif

OK, that sounds reasonable.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/15164#discussion_r1290492755