Integrated: 8337780: RISC-V: C2: Change C calling convention for sp to NS

[Feilong Jiang]

On Sat, 3 Aug 2024 16:17:53 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

> Hi, please review this patch that changes the C calling convention for sp to NS as sp is always saved and restored by the prolog/epilog code..
> This could reduce the frame size by 16 bytes for those C2 runtime stubs [1] as we do not have to save sp on the method entry.
> 
> I also checked the calling convention type for sp on other platforms (AArch64, PPC, x86, x64, S390), and they are all treated as NS.
> 
> 
> Testing:
> - [x] tier1~3 & hotspot:tier4 with release build
> 
> 1: https://github.com/openjdk/jdk/blob/367e0a65561f95aad61b40930d5f46843fee3444/src/hotspot/share/opto/runtime.cpp#L147-L167

This pull request has now been integrated.

Changeset: 53db937d
Author:    Feilong Jiang <fjiang at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/53db937dd0766695906dc20c1dbbd3228c02fe1e
Stats:     2 lines in 1 file changed: 0 ins; 0 del; 2 mod

8337780: RISC-V: C2: Change C calling convention for sp to NS

Reviewed-by: fyang, rehn

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PR: https://git.openjdk.org/jdk/pull/20449