RFR: 8332442: C2: refactor Mod cases in Compile::final_graph_reshaping_main_switch() [v2]

[Roland Westrelin]

On Tue, 10 Sep 2024 11:50:36 GMT, Roland Westrelin <roland at openjdk.org> wrote:

>> Kangcheng Xu has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   remove redundant arguments, test with -XX:-UseDivMod
>
> test/hotspot/jtreg/compiler/c2/TestDivModNodes.java line 47:
> 
>> 45:     @Arguments(values = {Argument.RANDOM_EACH, Argument.RANDOM_EACH})
>> 46:     @IR(counts = {IRNode.DIV_MOD_I, "1" }, applyIf = {"UseDivMod", "true"})
>> 47:     @IR(failOn = {IRNode.DIV_MOD_I}, applyIf = {"UseDivMod", "false"})
> 
> Rather than check that there's no `DivMod` node, you could check that there are the expected nodes (1 `Mul`, 1 `Sub`).

Actually, my comment is incorrect. Sorry for the confusion. The expected nodes are 1 `Div`, 1 `Mod` and no `Div`, no `Mod` when `UseDivMod` is true.

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PR Review Comment: https://git.openjdk.org/jdk/pull/20877#discussion_r1752154518