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

Wilco Dijkstra Wilco.Dijkstra@arm.com
Tue Sep 9 11:19:58 GMT 2025


Switch hppa to builtin atomics.

Passes buildmanyglibc, OK for commit?

---

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 */





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