[PATCH 6/8] atomic: Switch hppa to builtin atomics

[Adhemerval Zanella Netto]

On 09/09/25 08:19, Wilco Dijkstra wrote:
> Switch hppa to builtin atomics.
> 
> Passes buildmanyglibc, OK for commit?

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> 
> ---
> 
> diff --git a/sysdeps/unix/sysv/linux/hppa/atomic-machine.h b/sysdeps/unix/sysv/linux/hppa/atomic-machine.h
> index 85b820ddd629e87b29a184ac66eb76e90968528a..0e2f6e441e027affa12aa94e909e5a48ec967ad3 100644
> --- a/sysdeps/unix/sysv/linux/hppa/atomic-machine.h
> +++ b/sysdeps/unix/sysv/linux/hppa/atomic-machine.h
> @@ -21,84 +21,9 @@
>  #define atomic_full_barrier() __sync_synchronize ()
>  
>  #define __HAVE_64B_ATOMICS 0
> -#define USE_ATOMIC_COMPILER_BUILTINS 0
> -
> -/* We use the compiler atomic load and store builtins as the generic
> -   defines are not atomic.  In particular, we need to use compare and
> -   exchange for stores as the implementation is synthesized.  */
> -void __atomic_link_error (void);
> -#define __atomic_check_size_ls(mem) \
> - if ((sizeof (*mem) != 1) && (sizeof (*mem) != 2) && sizeof (*mem) != 4)    \
> -   __atomic_link_error ();
> -
> -#define atomic_load_relaxed(mem) \
> - ({ __atomic_check_size_ls((mem));                                           \
> -    __atomic_load_n ((mem), __ATOMIC_RELAXED); })
> -#define atomic_load_acquire(mem) \
> - ({ __atomic_check_size_ls((mem));                                           \
> -    __atomic_load_n ((mem), __ATOMIC_ACQUIRE); })
> -
> -#define atomic_store_relaxed(mem, val) \
> - do {                                                                        \
> -   __atomic_check_size_ls((mem));                                            \
> -   __atomic_store_n ((mem), (val), __ATOMIC_RELAXED);                        \
> - } while (0)
> -#define atomic_store_release(mem, val) \
> - do {                                                                        \
> -   __atomic_check_size_ls((mem));                                            \
> -   __atomic_store_n ((mem), (val), __ATOMIC_RELEASE);                        \
> - } while (0)
> +#define USE_ATOMIC_COMPILER_BUILTINS 1
>  
>  /* XXX Is this actually correct?  */
>  #define ATOMIC_EXCHANGE_USES_CAS 1
>  
> -/* prev = *addr;
> -   if (prev == old)
> -     *addr = new;
> -   return prev; */
> -
> -/* Use the kernel atomic light weight syscalls on hppa.  */
> -#define _LWS "0xb0"
> -#define _LWS_CAS "0"
> -/* Note r31 is the link register.  */
> -#define _LWS_CLOBBER "r1", "r23", "r22", "r20", "r31", "memory"
> -/* String constant for -EAGAIN.  */
> -#define _ASM_EAGAIN "-11"
> -/* String constant for -EDEADLOCK.  */
> -#define _ASM_EDEADLOCK "-45"
> -
> -/* The only basic operation needed is compare and exchange.  The mem
> -   pointer must be word aligned.  We no longer loop on deadlock.  */
> -#define atomic_compare_and_exchange_val_acq(mem, newval, oldval)	\
> -  ({									\
> -     register long lws_errno asm("r21");				\
> -     register unsigned long lws_ret asm("r28");				\
> -     register unsigned long lws_mem asm("r26") = (unsigned long)(mem);	\
> -     register unsigned long lws_old asm("r25") = (unsigned long)(oldval);\
> -     register unsigned long lws_new asm("r24") = (unsigned long)(newval);\
> -     __asm__ __volatile__(						\
> -	"0:					\n\t"			\
> -	"ble	" _LWS "(%%sr2, %%r0)		\n\t"			\
> -	"ldi	" _LWS_CAS ", %%r20		\n\t"			\
> -	"cmpiclr,<> " _ASM_EAGAIN ", %%r21, %%r0\n\t"			\
> -	"b,n 0b					\n\t"			\
> -	"cmpclr,= %%r0, %%r21, %%r0		\n\t"			\
> -	"iitlbp %%r0,(%%sr0, %%r0)		\n\t"			\
> -	: "=r" (lws_ret), "=r" (lws_errno)				\
> -	: "r" (lws_mem), "r" (lws_old), "r" (lws_new)			\
> -	: _LWS_CLOBBER							\
> -     );									\
> -									\
> -     (__typeof (oldval)) lws_ret;					\
> -   })
> -
> -#define atomic_compare_and_exchange_bool_acq(mem, newval, oldval)	\
> -  ({									\
> -     __typeof__ (*mem) ret;						\
> -     ret = atomic_compare_and_exchange_val_acq(mem, newval, oldval);	\
> -     /* Return 1 if it was already acquired.  */			\
> -     (ret != oldval);							\
> -   })
> -
>  #endif
> -/* _ATOMIC_MACHINE_H */
> 
> 
>