This sections describes built-in functions related to read and write
instructions to access memory. These functions generate
membar instructions to flush the I/O load and stores where
appropriate, as described in Fujitsu’s manual described above.
unsigned char __builtin_read8 (void *data)unsigned short __builtin_read16 (void *data)unsigned long __builtin_read32 (void *data)unsigned long long __builtin_read64 (void *data)void __builtin_write8 (void *data, unsigned char datum)void __builtin_write16 (void *data, unsigned short datum)void __builtin_write32 (void *data, unsigned long datum)void __builtin_write64 (void *data, unsigned long long datum)