RFR: 8251462: Remove legacy compilation policy [v4]

[Vladimir Kozlov]

On Fri, 22 Jan 2021 18:15:40 GMT, Igor Veresov <iveresov at openjdk.org> wrote:

>> src/hotspot/share/compiler/compilerDefinitions.cpp line 62:
>> 
>>> 60:       }
>>> 61:     } else if (strcmp(CompilationMode, "high-only") == 0) {
>>> 62:       if (!CompilerConfig::has_c2() && !CompilerConfig::is_jvmci_compiler()) {
>> 
>> Is using `!is_c2_or_jvmci_compiler_available()` better here? All flags should be processed at this point. And we could have some `TieredStopAtLevel` flags.
>> It looks like you have cross dependency between CompilerConfig and CompilationModeFlag which make using `is_c2_or_jvmci_compiler_available()` impossible here.
>
> Yes, there is an unfortunate cross dependency. It would probably work fine since ```_mode``` is initialized to ```NORMAL``` before parsing the flag. But I wanted to not use any function that would depend on the value of the ```_mode``` during parsing. It could create trouble in the future. I'll put more comments about that.

okay.

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PR: https://git.openjdk.java.net/jdk/pull/1985