RFR: 8332268: C2: Add missing optimizations for UDivI/L and UModI/L and unify the shared logic with the signed nodes [v3]

[theoweidmannoracle]

On Mon, 25 Nov 2024 13:29:22 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

>> theoweidmannoracle has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Improve tests, remove edge case
>
> src/hotspot/share/opto/divnode.cpp line 1184:
> 
>> 1182: 
>> 1183:   if (con == 1) {
>> 1184:     return ConNode::make(TypeClass::ZERO);
> 
> This should be in `Value` instead.

This is analogous to code for ModI/LNode::Ideal. I'll file an RFE that this should be changed in all locations

> src/hotspot/share/opto/divnode.cpp line 1213:
> 
>> 1211:   }
>> 1212:   // X MOD X is 0
>> 1213:   if (mod->in(1) == mod->in(2)) {
> 
> `mod->in(1)->eqv_uncast(mod->in(2))`

This is analogous to code for ModI/LNode::Ideal.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22061#discussion_r1856682022
PR Review Comment: https://git.openjdk.org/jdk/pull/22061#discussion_r1856684659