RFR: 8319451: PhaseIdealLoop::conditional_move is too conservative [v2]

[Quan Anh Mai]

On Thu, 9 Nov 2023 14:29:06 GMT, Claes Redestad <redestad at openjdk.org> wrote:

>> Quan Anh Mai has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
>> 
>>  - change freq to double
>>  - Merge branch 'master' into cmovethreshold
>>  - adjust threshold, add benchmark
>
> test/micro/org/openjdk/bench/vm/compiler/CMove.java line 40:
> 
>> 38: 
>> 39:     @Param({"3", "6", "10", "20", "30", "60", "100", "200", "300", "600"})
>> 40:     int freq;
> 
> That `freq` is expressed in "occurrences per thousand" was only obvious after reading the code - perhaps a probability between 0 and 1 (with the appropriate adjustment to `r.nextFloat() < freq` below) would be slightly more intuitive?
> Suggestion:
> 
>     @Param({"0.003", "0.006", "0.01", "0.02", "0.03", "0.06", "0.1", "0.2", "0.3", "0.6"})
>     float freq;

@cl4es You are right, I have fixed that.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16524#discussion_r1424279741