Re: portable proxy collector test...

On 12/9/2024 2:22 AM, aph@littlepinkcloud.invalid wrote:

Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:

>

Which compiler did you choose.? armv8?? Try ARM64.
>
The newer arms have new atomics
cas and atomic fetch ops.
>
LDREX/STREX is the older load store reserved.
On the newer stuff it's ldxr/stxr not ldrex/strex.

>
Well, for a ARM64 gcc 14.2.0 a relaxed fetch_add I get
__aarch64_ldadd8_acq_rel in the asm.

 For gcc 13.2.1 -O2 -march=armv8.1-a I see a mixture of acq/rel and
relaxed. Are you sure you're looking at the right one?
 Andrew.

Ahhh! So, when I use -O2 -march=armv8.1-a, I get:
https://godbolt.org/z/KrGvodb51
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main:
         sub     sp, sp, #16
         mov     x0, 123
         mov     x1, 1
         str     x0, [sp, 8]
         add     x0, sp, 8
         ldadd   x1, x1, [x0]
         add     sp, sp, 16
         mov     w0, 0
         ret
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:^)