[riscv-port-jdk17u:riscv-port] RFR: 8294366: RISC-V: Partially mark out incompressible regions

[Xiaolin Zheng]

On Tue, 28 Mar 2023 11:37:57 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

>> One little difference: there is no `C2_MacroAssembler::emit_entry_barrier_stub` on JDK17.
>> 
>> Tested along with remaining patches, hotspot tier1~4 with fastdebug build.
>
> src/hotspot/cpu/riscv/assembler_riscv.hpp line 2119:
> 
>> 2117: //
>> 2118: //      CompressibleRegion cr(_masm);
>> 2119: //      __ add(...);       // this instruction will be compressed into 'c.and' when possible
> 
> Comments use `c.and`, but the example asm uses `add`, is this a typo?

Indeed typos, thanks for the catch. The `openjdk/jdk` repo also has these two typos. Not sure about the rule of backporting: should I fix it here and then file another patch on `openjdk/jdk`, or?

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PR Review Comment: https://git.openjdk.org/riscv-port-jdk17u/pull/28#discussion_r1150495499