RFR: 8270459: Conflict inlining decisions by C1/C2 with the same CompileCommand [v2]

[Xin Liu]

On Fri, 16 Jul 2021 04:06:12 GMT, Jie Fu <jiefu at openjdk.org> wrote:

>> Maybe like this. it can cover 2 cases.
>> 
>> index 8464d22ef42..15e1f474227 100644
>> --- a/src/hotspot/share/compiler/compilerOracle.cpp
>> +++ b/src/hotspot/share/compiler/compilerOracle.cpp
>> @@ -348,7 +348,7 @@ static bool resolve_inlining_predicate(enum CompileCommand option, const methodH
>>    bool has_inline = CompilerOracle::has_option_value(method, CompileCommand::Inline, v1);
>>    bool has_dnotinline = CompilerOracle::has_option_value(method, CompileCommand::DontInline, v2);
>>    if (has_inline && has_dnotinline) {
>> -    if (v1 && v2) {
>> +    if (v1 == v2) {
>>        // Conflict options detected
>>        // Find the last one for that method and return the predicate accordingly
>>        // option_list lists options in reverse order. So the first option we find is the last which was specified.
>> @@ -358,7 +358,7 @@ static bool resolve_inlining_predicate(enum CompileCommand option, const methodH
>>          last_one = current->option();
>>          if (last_one == CompileCommand::Inline || last_one == CompileCommand::DontInline) {
>>            if (current->matches(method)) {
>> -            return last_one == option;
>> +            return last_one == option ? v1 : !v1;
>>            }
>>          }
>>          current = current->next();
>
>> if has_inline == true && has_dnotinline == true, but v1 == false && v2 == false, two options conflict, don't they?
> 
> I don't think they are conflict.
> 
> This is because
> 
> -XX:CompilerCommand=inline,foo,false     ==> doesn't mean to disallow the inline of foo
> -XX:CompilerCommand=dontinline,foo,false ==>  doesn't mean to force inline of foo
> 
> 
> So if `inline` and `dontinline` options are set to false, they actually have no effect to the compiler.
> Thanks.

make sense. I take back my comment.  those 2 options don't have any effect when they are false.

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PR: https://git.openjdk.java.net/jdk/pull/4780