postgresql/src/include/port/atomics/arch-arm.h

33 lines
930 B
C

/*-------------------------------------------------------------------------
*
* arch-arm.h
* Atomic operations considerations specific to ARM
*
* Portions Copyright (c) 2013-2023, PostgreSQL Global Development Group
*
* NOTES:
*
* src/include/port/atomics/arch-arm.h
*
*-------------------------------------------------------------------------
*/
/* intentionally no include guards, should only be included by atomics.h */
#ifndef INSIDE_ATOMICS_H
#error "should be included via atomics.h"
#endif
/*
* 64 bit atomics on ARM32 are implemented using kernel fallbacks and thus
* might be slow, so disable entirely. On ARM64 that problem doesn't exist.
*/
#if !defined(__aarch64__)
#define PG_DISABLE_64_BIT_ATOMICS
#else
/*
* Architecture Reference Manual for ARMv8 states aligned read/write to/from
* general purpose register is atomic.
*/
#define PG_HAVE_8BYTE_SINGLE_COPY_ATOMICITY
#endif /* __aarch64__ */