[PATCH 3/8] atomic: Switch alpha to builtin atomics
Wilco Dijkstra
Wilco.Dijkstra@arm.com
Tue Sep 9 11:15:50 GMT 2025
Switch alpha to builtin atomics.
Passes buildmanyglibc, OK for commit?
---
diff --git a/sysdeps/alpha/atomic-machine.h b/sysdeps/alpha/atomic-machine.h
index 393176df08a3119fdbc41db2d09d932a6ca643d4..dcb3b56cc0e9b46c0abc8abc4727312f20f756b2 100644
--- a/sysdeps/alpha/atomic-machine.h
+++ b/sysdeps/alpha/atomic-machine.h
@@ -18,322 +18,11 @@
#include <stdint.h>
#define __HAVE_64B_ATOMICS 1
-#define USE_ATOMIC_COMPILER_BUILTINS 0
+#define USE_ATOMIC_COMPILER_BUILTINS 1
/* XXX Is this actually correct? */
#define ATOMIC_EXCHANGE_USES_CAS 1
-
-#define __MB " mb\n"
-
-
-/* Compare and exchange. For all of the "xxx" routines, we expect a
- "__prev" and a "__cmp" variable to be provided by the enclosing scope,
- in which values are returned. */
-
-#define __arch_compare_and_exchange_xxx_8_int(mem, new, old, mb1, mb2) \
-({ \
- unsigned long __tmp, __snew, __addr64; \
- __asm__ __volatile__ ( \
- mb1 \
- " andnot %[__addr8],7,%[__addr64]\n" \
- " insbl %[__new],%[__addr8],%[__snew]\n" \
- "1: ldq_l %[__tmp],0(%[__addr64])\n" \
- " extbl %[__tmp],%[__addr8],%[__prev]\n" \
- " cmpeq %[__prev],%[__old],%[__cmp]\n" \
- " beq %[__cmp],2f\n" \
- " mskbl %[__tmp],%[__addr8],%[__tmp]\n" \
- " or %[__snew],%[__tmp],%[__tmp]\n" \
- " stq_c %[__tmp],0(%[__addr64])\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- "2:" \
- : [__prev] "=&r" (__prev), \
- [__snew] "=&r" (__snew), \
- [__tmp] "=&r" (__tmp), \
- [__cmp] "=&r" (__cmp), \
- [__addr64] "=&r" (__addr64) \
- : [__addr8] "r" (mem), \
- [__old] "Ir" ((uint64_t)(uint8_t)(uint64_t)(old)), \
- [__new] "r" (new) \
- : "memory"); \
-})
-
-#define __arch_compare_and_exchange_xxx_16_int(mem, new, old, mb1, mb2) \
-({ \
- unsigned long __tmp, __snew, __addr64; \
- __asm__ __volatile__ ( \
- mb1 \
- " andnot %[__addr16],7,%[__addr64]\n" \
- " inswl %[__new],%[__addr16],%[__snew]\n" \
- "1: ldq_l %[__tmp],0(%[__addr64])\n" \
- " extwl %[__tmp],%[__addr16],%[__prev]\n" \
- " cmpeq %[__prev],%[__old],%[__cmp]\n" \
- " beq %[__cmp],2f\n" \
- " mskwl %[__tmp],%[__addr16],%[__tmp]\n" \
- " or %[__snew],%[__tmp],%[__tmp]\n" \
- " stq_c %[__tmp],0(%[__addr64])\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- "2:" \
- : [__prev] "=&r" (__prev), \
- [__snew] "=&r" (__snew), \
- [__tmp] "=&r" (__tmp), \
- [__cmp] "=&r" (__cmp), \
- [__addr64] "=&r" (__addr64) \
- : [__addr16] "r" (mem), \
- [__old] "Ir" ((uint64_t)(uint16_t)(uint64_t)(old)), \
- [__new] "r" (new) \
- : "memory"); \
-})
-
-#define __arch_compare_and_exchange_xxx_32_int(mem, new, old, mb1, mb2) \
-({ \
- __asm__ __volatile__ ( \
- mb1 \
- "1: ldl_l %[__prev],%[__mem]\n" \
- " cmpeq %[__prev],%[__old],%[__cmp]\n" \
- " beq %[__cmp],2f\n" \
- " mov %[__new],%[__cmp]\n" \
- " stl_c %[__cmp],%[__mem]\n" \
- " beq %[__cmp],1b\n" \
- mb2 \
- "2:" \
- : [__prev] "=&r" (__prev), \
- [__cmp] "=&r" (__cmp) \
- : [__mem] "m" (*(mem)), \
- [__old] "Ir" ((uint64_t)(int32_t)(uint64_t)(old)), \
- [__new] "Ir" (new) \
- : "memory"); \
-})
-
-#define __arch_compare_and_exchange_xxx_64_int(mem, new, old, mb1, mb2) \
-({ \
- __asm__ __volatile__ ( \
- mb1 \
- "1: ldq_l %[__prev],%[__mem]\n" \
- " cmpeq %[__prev],%[__old],%[__cmp]\n" \
- " beq %[__cmp],2f\n" \
- " mov %[__new],%[__cmp]\n" \
- " stq_c %[__cmp],%[__mem]\n" \
- " beq %[__cmp],1b\n" \
- mb2 \
- "2:" \
- : [__prev] "=&r" (__prev), \
- [__cmp] "=&r" (__cmp) \
- : [__mem] "m" (*(mem)), \
- [__old] "Ir" ((uint64_t)(old)), \
- [__new] "Ir" (new) \
- : "memory"); \
-})
-
-/* For all "bool" routines, we return FALSE if exchange successful. */
-
-#define __arch_compare_and_exchange_bool_8_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_8_int(mem, new, old, mb1, mb2); \
- !__cmp; })
-
-#define __arch_compare_and_exchange_bool_16_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_16_int(mem, new, old, mb1, mb2); \
- !__cmp; })
-
-#define __arch_compare_and_exchange_bool_32_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_32_int(mem, new, old, mb1, mb2); \
- !__cmp; })
-
-#define __arch_compare_and_exchange_bool_64_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_64_int(mem, new, old, mb1, mb2); \
- !__cmp; })
-
-/* For all "val" routines, return the old value whether exchange
- successful or not. */
-
-#define __arch_compare_and_exchange_val_8_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_8_int(mem, new, old, mb1, mb2); \
- (typeof (*mem))__prev; })
-
-#define __arch_compare_and_exchange_val_16_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_16_int(mem, new, old, mb1, mb2); \
- (typeof (*mem))__prev; })
-
-#define __arch_compare_and_exchange_val_32_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_32_int(mem, new, old, mb1, mb2); \
- (typeof (*mem))__prev; })
-
-#define __arch_compare_and_exchange_val_64_int(mem, new, old, mb1, mb2) \
-({ unsigned long __prev; int __cmp; \
- __arch_compare_and_exchange_xxx_64_int(mem, new, old, mb1, mb2); \
- (typeof (*mem))__prev; })
-
-/* Compare and exchange with "acquire" semantics, ie barrier after. */
-
-#define atomic_compare_and_exchange_bool_acq(mem, new, old) \
- __atomic_bool_bysize (__arch_compare_and_exchange_bool, int, \
- mem, new, old, "", __MB)
-
-#define atomic_compare_and_exchange_val_acq(mem, new, old) \
- __atomic_val_bysize (__arch_compare_and_exchange_val, int, \
- mem, new, old, "", __MB)
-
-/* Compare and exchange with "release" semantics, ie barrier before. */
-
-#define atomic_compare_and_exchange_val_rel(mem, new, old) \
- __atomic_val_bysize (__arch_compare_and_exchange_val, int, \
- mem, new, old, __MB, "")
-
-
-/* Atomically store value and return the previous value. */
-
-#define __arch_exchange_8_int(mem, value, mb1, mb2) \
-({ \
- unsigned long __tmp, __addr64, __sval; __typeof(*mem) __ret; \
- __asm__ __volatile__ ( \
- mb1 \
- " andnot %[__addr8],7,%[__addr64]\n" \
- " insbl %[__value],%[__addr8],%[__sval]\n" \
- "1: ldq_l %[__tmp],0(%[__addr64])\n" \
- " extbl %[__tmp],%[__addr8],%[__ret]\n" \
- " mskbl %[__tmp],%[__addr8],%[__tmp]\n" \
- " or %[__sval],%[__tmp],%[__tmp]\n" \
- " stq_c %[__tmp],0(%[__addr64])\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- : [__ret] "=&r" (__ret), \
- [__sval] "=&r" (__sval), \
- [__tmp] "=&r" (__tmp), \
- [__addr64] "=&r" (__addr64) \
- : [__addr8] "r" (mem), \
- [__value] "r" (value) \
- : "memory"); \
- __ret; })
-
-#define __arch_exchange_16_int(mem, value, mb1, mb2) \
-({ \
- unsigned long __tmp, __addr64, __sval; __typeof(*mem) __ret; \
- __asm__ __volatile__ ( \
- mb1 \
- " andnot %[__addr16],7,%[__addr64]\n" \
- " inswl %[__value],%[__addr16],%[__sval]\n" \
- "1: ldq_l %[__tmp],0(%[__addr64])\n" \
- " extwl %[__tmp],%[__addr16],%[__ret]\n" \
- " mskwl %[__tmp],%[__addr16],%[__tmp]\n" \
- " or %[__sval],%[__tmp],%[__tmp]\n" \
- " stq_c %[__tmp],0(%[__addr64])\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- : [__ret] "=&r" (__ret), \
- [__sval] "=&r" (__sval), \
- [__tmp] "=&r" (__tmp), \
- [__addr64] "=&r" (__addr64) \
- : [__addr16] "r" (mem), \
- [__value] "r" (value) \
- : "memory"); \
- __ret; })
-
-#define __arch_exchange_32_int(mem, value, mb1, mb2) \
-({ \
- signed int __tmp; __typeof(*mem) __ret; \
- __asm__ __volatile__ ( \
- mb1 \
- "1: ldl_l %[__ret],%[__mem]\n" \
- " mov %[__val],%[__tmp]\n" \
- " stl_c %[__tmp],%[__mem]\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- : [__ret] "=&r" (__ret), \
- [__tmp] "=&r" (__tmp) \
- : [__mem] "m" (*(mem)), \
- [__val] "Ir" (value) \
- : "memory"); \
- __ret; })
-
-#define __arch_exchange_64_int(mem, value, mb1, mb2) \
-({ \
- unsigned long __tmp; __typeof(*mem) __ret; \
- __asm__ __volatile__ ( \
- mb1 \
- "1: ldq_l %[__ret],%[__mem]\n" \
- " mov %[__val],%[__tmp]\n" \
- " stq_c %[__tmp],%[__mem]\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- : [__ret] "=&r" (__ret), \
- [__tmp] "=&r" (__tmp) \
- : [__mem] "m" (*(mem)), \
- [__val] "Ir" (value) \
- : "memory"); \
- __ret; })
-
-#define atomic_exchange_acq(mem, value) \
- __atomic_val_bysize (__arch_exchange, int, mem, value, "", __MB)
-
-#define atomic_exchange_rel(mem, value) \
- __atomic_val_bysize (__arch_exchange, int, mem, value, __MB, "")
-
-
-/* Atomically add value and return the previous (unincremented) value. */
-
-#define __arch_exchange_and_add_8_int(mem, value, mb1, mb2) \
- ({ __builtin_trap (); 0; })
-
-#define __arch_exchange_and_add_16_int(mem, value, mb1, mb2) \
- ({ __builtin_trap (); 0; })
-
-#define __arch_exchange_and_add_32_int(mem, value, mb1, mb2) \
-({ \
- signed int __tmp; __typeof(*mem) __ret; \
- __asm__ __volatile__ ( \
- mb1 \
- "1: ldl_l %[__ret],%[__mem]\n" \
- " addl %[__ret],%[__val],%[__tmp]\n" \
- " stl_c %[__tmp],%[__mem]\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- : [__ret] "=&r" (__ret), \
- [__tmp] "=&r" (__tmp) \
- : [__mem] "m" (*(mem)), \
- [__val] "Ir" ((signed int)(value)) \
- : "memory"); \
- __ret; })
-
-#define __arch_exchange_and_add_64_int(mem, value, mb1, mb2) \
-({ \
- unsigned long __tmp; __typeof(*mem) __ret; \
- __asm__ __volatile__ ( \
- mb1 \
- "1: ldq_l %[__ret],%[__mem]\n" \
- " addq %[__ret],%[__val],%[__tmp]\n" \
- " stq_c %[__tmp],%[__mem]\n" \
- " beq %[__tmp],1b\n" \
- mb2 \
- : [__ret] "=&r" (__ret), \
- [__tmp] "=&r" (__tmp) \
- : [__mem] "m" (*(mem)), \
- [__val] "Ir" ((unsigned long)(value)) \
- : "memory"); \
- __ret; })
-
-/* ??? Barrier semantics for atomic_exchange_and_add appear to be
- undefined. Use full barrier for now, as that's safe. */
-#define atomic_exchange_and_add(mem, value) \
- __atomic_val_bysize (__arch_exchange_and_add, int, mem, value, __MB, __MB)
-
-
-/* ??? Blah, I'm lazy. Implement these later. Can do better than the
- compare-and-exchange loop provided by generic code.
-
-#define atomic_decrement_if_positive(mem)
-#define atomic_bit_test_set(mem, bit)
-
-*/
-
#define atomic_full_barrier() __asm ("mb" : : : "memory");
#define atomic_read_barrier() __asm ("mb" : : : "memory");
#define atomic_write_barrier() __asm ("wmb" : : : "memory");
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