cosmopolitan/libc/intrin/xchg.internal.h
Justine Tunney fa20edc44d
Reduce header complexity
- Remove most __ASSEMBLER__ __LINKER__ ifdefs
- Rename libc/intrin/bits.h to libc/serialize.h
- Block pthread cancelation in fchmodat() polyfill
- Remove `clang-format off` statements in third_party
2023-11-28 14:39:42 -08:00

23 lines
677 B
C

#ifndef COSMOPOLITAN_LIBC_BITS_XCHG_H_
#define COSMOPOLITAN_LIBC_BITS_XCHG_H_
#include "libc/str/str.h"
/**
* Exchanges *MEMORY into *LOCALVAR.
*
* @return *MEMORY
* todo(jart): what's the point of this?
*/
#define xchg(MEMORY, LOCALVAR) \
({ \
autotype(MEMORY) Memory = (MEMORY); \
typeof(Memory) LocalVar = (LOCALVAR); \
typeof(*Memory) Temp; \
memcpy(&Temp, Memory, sizeof(Temp)); \
memcpy(Memory, LocalVar, sizeof(Temp)); \
memcpy(LocalVar, &Temp, sizeof(Temp)); \
Temp; \
})
#endif /* COSMOPOLITAN_LIBC_BITS_XCHG_H_ */