RFR: 8309978: [x64] Fix useless padding [v2]

[Christian Hagedorn]

On Wed, 14 Jun 2023 16:34:54 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> test/hotspot/jtreg/compiler/c2/irTests/TestPadding.java line 50:
>> 
>>> 48:             test(i);
>>> 49:             tpf.b1++; // to take both branches in test()
>>> 50:         }
>> 
>> `test_runner()` will be invoked 2000 times (default warm-up) before the explicit compilation request of `test()` by the IR framework. So, this loop will run 2000 * 11000 times. Do you need that many iterations or can the loop be removed such that we only have 2000 warm-up iterations? I.e. something like:
>> 
>>     @Run(test = "test")
>>     public static void test_runner() {
>>         tpf = new TestPadding();
>>         test(42);
>>         tpf.b1++; // to take both branches in test()
>> 
>>     }
>> 
>> If you need more iterations, you could still specify `@Warmup(12345)` at `test_runner()` to get more profiling in before compilation of `test()`.
>
> Thank you, Christian. I updated the test as you suggested and verified that generated code for `test()` stay the same with 2000 default iterations.

That looks good to me, thanks for the update!

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

PR Review Comment: https://git.openjdk.org/jdk/pull/14461#discussion_r1230479457