Integrated: 8344306: RISC-V: Add zicond

[Robbin Ehn]

On Tue, 26 Nov 2024 09:00:34 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

> Hi, please consider.
> 
> In cpu models we save ~1 cycle per removed branch.
> This patch removes ~0.1% of branches in generic C2 generated code.
> We should probably investigate if we can improve/add peephole optimization to remove more branches.
> 
> As the C1 cmov code is a bit tricky I left that as a followup.
> 
> I added gtests for the cmovs.
> (we should add coverage for more of masm in this gtest suit)
> Pro tip, invoke the gtestLauncher directly (you only need to build exploded):
> `gtestLauncher -jdk build/linux-riscv64-server-fastdebug/jdk/ --gtest_break_on_failure --gtest_filter="*RiscV*" -XX:+UnlockDiagnosticVMOptions -XX:+UseZicond -XX:ParallelGCThreads=1 -XX:ConcGCThreads=1 -XX:CICompilerCount=2`
> 
> Tested on Spacemit X60, gtests and tier1.
> 
> Thanks, Robbin

This pull request has now been integrated.

Changeset: edfe2854
Author:    Robbin Ehn <rehn at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/edfe28541a6ed94357f873aa69778c7eba707cbb
Stats:     345 lines in 10 files changed: 340 ins; 1 del; 4 mod

8344306: RISC-V: Add zicond

Reviewed-by: fyang, luhenry, mli

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PR: https://git.openjdk.org/jdk/pull/22386