OpenJDK11u linux/riscv32 port work update

[曹贵]

Hello, I am Gui Cao from ISCAS (Institute of Software, Chinese Academy of Sciences). Recently we have finished porting of OpenJDK11U C2 JIT to Linux/riscv32 platform. Currently, this port only supports template interpreter and C2 JIT.  The mainline OpenJDK supports Linux/riscv64 platform, which won't run on the Linux/riscv32 platform because of the difference in register widths. So we need a new port of OpenJDK. This is OpenJDK11U port repository for Linux/riscv32[1]. We use qemu for development and testing the port on Linux/riscv32 platform. We can run benchmark workloads such as SPECjbb2015, SPECjbb2005, SPECjvm2008, etc. And we witnessed an obvious speedup with C2 JIT as compared with the template interpreter when tested with qemu, and these benchmarks can pass the test normally.

Of course the work will go on:
1. There are still some jtreg test failures, we will continue to investigate the issues.
2. We will sync with latest openjdk jdk11u repo[2] after after passing the jtreg tests.
3. Add more C2 intrinsic optimizations to make it run faster.
4. We need to test the functionality and performance on real hardware.

Let me know if you are interested in this project or have any suggestions.

Best regards,
Gui Cao

[1] https://github.com/openjdk-riscv/jdk11u
[2] https://github.com/openjdk/jdk11u