cosmopolitan/libc/bits/segmentation.h

24 lines
783 B
C

#ifndef COSMOPOLITAN_LIBC_BITS_SEGMENTATION_H_
#define COSMOPOLITAN_LIBC_BITS_SEGMENTATION_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
/**
* Reads scalar from memory, offset by segment.
*
* @return *(MEM) relative to segment
* @see arch_prctl()
* @see pushpop()
*/
#define fs(MEM) __peek("fs", MEM)
#define gs(MEM) __peek("gs", MEM)
#define __peek(SEGMENT, ADDRESS) \
({ \
typeof(*(ADDRESS)) Pk; \
asm("mov\t%%" SEGMENT ":%1,%0" : "=r"(Pk) : "m"(*(ADDRESS))); \
Pk; \
})
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_BITS_SEGMENTATION_H_ */