RFR: 8332689: RISC-V: Use load instead of trampolines [v12]

[Robbin Ehn]

On Mon, 17 Jun 2024 08:07:57 GMT, Fei Yang <fyang at openjdk.org> wrote:

>> Robbin Ehn has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 18 commits:
>> 
>>  - Review comments, removed dead code.
>>  - Merge branch 'master' into 8332689
>>  - Merge branch 'master' into 8332689
>>  - Merge branch 'master' into 8332689
>>  - Merge branch 'master' into 8332689
>>  - Merge branch 'master' into 8332689
>>  - Remove tmp file
>>  - Prepare for dynamic NativeCall size
>>  - Only allow one calling convetion, i.e. fixed sized
>>  - Merge branch 'master' into 8332689
>>  - ... and 8 more: https://git.openjdk.org/jdk/compare/cc64aeac...f1dd3e16
>
> src/hotspot/cpu/riscv/codeBuffer_riscv.cpp line 74:
> 
>> 72: 
>> 73:   assert(requests->number_of_entries() >= 1, "at least one");
>> 74:   const int total_requested_size = MacroAssembler::max_patchable_far_call_stub_size() * requests->number_of_entries();
> 
> I see mixed uses of bot `MacroAssembler::max_patchable_far_call_stub_size()` and `MacroAssembler::NativeShortCall::trampoline_size` in this function. As this is only used under `UseTrampolines`, seems more reasonable to use `MacroAssembler::NativeShortCall::trampoline_size`.

As you see in diff the mixing is pre-exsisting, I only changed names.

Fixed.

> src/hotspot/cpu/riscv/macroAssembler_riscv.cpp line 3932:
> 
>> 3930:     return instruction_size + MacroAssembler::NativeShortCall::trampoline_size;
>> 3931:   }
>> 3932:   return 2 * wordSize;
> 
> Seems to me that this should be `instruction_size + wordSize`? That is one possible nop for alignment and an address of size `wordSize`.

Yes, thanks.

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PR Review Comment: https://git.openjdk.org/jdk/pull/19453#discussion_r1647412264
PR Review Comment: https://git.openjdk.org/jdk/pull/19453#discussion_r1647410894