RFR: 8310844: [AArch64] C1 compilation fails because monitor offset in OSR buffer is too large for immediate [v2]

[Tobias Hartmann]

On Thu, 4 Jan 2024 14:08:51 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> Tobias Hartmann has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Adjusted according to review
>
> src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp line 289:
> 
>> 287:       __ ldr(r19, Address(OSR_buf, slot_offset + 1*BytesPerWord));
>> 288:       __ str(r19, frame_map()->address_for_monitor_object(i));
>> 289:     }
> 
> The macro assembler automagically fuses `ldr` pairs. It'd be better to fix this with:
> 
> 
> --- a/src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp
> +++ b/src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp
> @@ -282,7 +282,8 @@ void LIR_Assembler::osr_entry() {
>          __ bind(L);
>        }
>  #endif
> -      __ ldp(r19, r20, Address(OSR_buf, slot_offset));
> +      __ ldr(r19, Address(OSR_buf, slot_offset));
> +      __ ldr(r20, Address(OSR_buf, slot_offset + BytesPerWord));
>        __ str(r19, frame_map()->address_for_monitor_lock(i));
>        __ str(r20, frame_map()->address_for_monitor_object(i));
>      }

Thanks for the review. I adjusted the fix accordingly.

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PR Review Comment: https://git.openjdk.org/jdk/pull/17266#discussion_r1441798599