database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-04-25 21:42:33 +03:00
Code

Use more of gcc's __sync_fetch_and_xxx builtin functions for atomic ops.

Browse Source 
In addition to __sync_fetch_and_add, gcc offers __sync_fetch_and_sub,
__sync_fetch_and_and, and __sync_fetch_and_or, which correspond directly
to primitive atomic ops that we want.  Testing shows that in some cases
they generate better code than our generic implementations, so use them.

We've assumed that configure's test for __sync_val_compare_and_swap is
sufficient to allow assuming that __sync_fetch_and_add is available, so
make the same assumption for these functions.  Should that prove to be
wrong, we can add more configure tests.

Yura Sokolov, reviewed by Jesper Pedersen and myself

Discussion: https://postgr.es/m/7f65886daca545067f82bf2b463b218d@postgrespro.ru
This commit is contained in:
Tom Lane 2017-09-06 14:21:39 -04:00
parent e530be9685
commit e09db94c0a
1 changed files with 58 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
src/include/port/atomics/generic-gcc.h
View File

@ -176,6 +176,8 @@ pg_atomic_compare_exchange_u32_impl(volatile pg_atomic_uint32 *ptr,
}
#endif
/* if we have 32-bit __sync_val_compare_and_swap, assume we have these too: */
#if !defined(PG_HAVE_ATOMIC_FETCH_ADD_U32) && defined(HAVE_GCC__SYNC_INT32_CAS)
#define PG_HAVE_ATOMIC_FETCH_ADD_U32
static inline uint32
@ -185,6 +187,33 @@ pg_atomic_fetch_add_u32_impl(volatile pg_atomic_uint32 *ptr, int32 add_)
}
#endif
#if !defined(PG_HAVE_ATOMIC_FETCH_SUB_U32) && defined(HAVE_GCC__SYNC_INT32_CAS)
#define PG_HAVE_ATOMIC_FETCH_SUB_U32
static inline uint32
pg_atomic_fetch_sub_u32_impl(volatile pg_atomic_uint32 *ptr, int32 sub_)
{
return __sync_fetch_and_sub(&ptr->value, sub_);
}
#endif
#if !defined(PG_HAVE_ATOMIC_FETCH_AND_U32) && defined(HAVE_GCC__SYNC_INT32_CAS)
#define PG_HAVE_ATOMIC_FETCH_AND_U32
static inline uint32
pg_atomic_fetch_and_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 and_)
{
return __sync_fetch_and_and(&ptr->value, and_);
}
#endif
#if !defined(PG_HAVE_ATOMIC_FETCH_OR_U32) && defined(HAVE_GCC__SYNC_INT32_CAS)
#define PG_HAVE_ATOMIC_FETCH_OR_U32
static inline uint32
pg_atomic_fetch_or_u32_impl(volatile pg_atomic_uint32 *ptr, uint32 or_)
{
return __sync_fetch_and_or(&ptr->value, or_);
}
#endif
#if !defined(PG_DISABLE_64_BIT_ATOMICS)
@ -214,6 +243,8 @@ pg_atomic_compare_exchange_u64_impl(volatile pg_atomic_uint64 *ptr,
}
#endif
/* if we have 64-bit __sync_val_compare_and_swap, assume we have these too: */
#if !defined(PG_HAVE_ATOMIC_FETCH_ADD_U64) && defined(HAVE_GCC__SYNC_INT64_CAS)
#define PG_HAVE_ATOMIC_FETCH_ADD_U64
static inline uint64
@ -223,6 +254,33 @@ pg_atomic_fetch_add_u64_impl(volatile pg_atomic_uint64 *ptr, int64 add_)
}
#endif
#if !defined(PG_HAVE_ATOMIC_FETCH_SUB_U64) && defined(HAVE_GCC__SYNC_INT64_CAS)
#define PG_HAVE_ATOMIC_FETCH_SUB_U64
static inline uint64
pg_atomic_fetch_sub_u64_impl(volatile pg_atomic_uint64 *ptr, int64 sub_)
{
return __sync_fetch_and_sub(&ptr->value, sub_);
}
#endif
#if !defined(PG_HAVE_ATOMIC_FETCH_AND_U64) && defined(HAVE_GCC__SYNC_INT64_CAS)
#define PG_HAVE_ATOMIC_FETCH_AND_U64
static inline uint64
pg_atomic_fetch_and_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 and_)
{
return __sync_fetch_and_and(&ptr->value, and_);
}
#endif
#if !defined(PG_HAVE_ATOMIC_FETCH_OR_U64) && defined(HAVE_GCC__SYNC_INT64_CAS)
#define PG_HAVE_ATOMIC_FETCH_OR_U64
static inline uint64
pg_atomic_fetch_or_u64_impl(volatile pg_atomic_uint64 *ptr, uint64 or_)
{
return __sync_fetch_and_or(&ptr->value, or_);
}
#endif
#endif /* !defined(PG_DISABLE_64_BIT_ATOMICS) */
#endif /* defined(HAVE_ATOMICS) */