RFR: 8349479: C2: when a Type node becomes dead, make CFG path that uses it unreachable [v2]

Thu Mar 20 08:11:09 UTC 2025

On Tue, 18 Mar 2025 14:48:22 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> * We should make sure that compilation speed is not significantly affected by doing this search on all dying `Type` nodes (maybe @robcasloz can give you some pointers here - he did some compilation time measurements before).

I measured C2 speed for this patch on top of jdk-25+14 vs jdk-25+14 using DaCapo23 on two different platforms and do not see any significant effect, see detailed results [here](https://github.com/user-attachments/files/19361310/C2-speed-jdk-25%2B14-vs-JDK-8349479.pdf).

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

PR Comment: https://git.openjdk.org/jdk/pull/23468#issuecomment-2739518268