compiler-gcc.h 2.0 KB

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  1. #ifndef __LINUX_COMPILER_H
  2. #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
  3. #endif
  4. /*
  5. * Common definitions for all gcc versions go here.
  6. */
  7. /* Optimization barrier */
  8. /* The "volatile" is due to gcc bugs */
  9. #define barrier() __asm__ __volatile__("": : :"memory")
  10. /* This macro obfuscates arithmetic on a variable address so that gcc
  11. shouldn't recognize the original var, and make assumptions about it */
  12. /*
  13. * Versions of the ppc64 compiler before 4.1 had a bug where use of
  14. * RELOC_HIDE could trash r30. The bug can be worked around by changing
  15. * the inline assembly constraint from =g to =r, in this particular
  16. * case either is valid.
  17. */
  18. #define RELOC_HIDE(ptr, off) \
  19. ({ unsigned long __ptr; \
  20. __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
  21. (typeof(ptr)) (__ptr + (off)); })
  22. /* &a[0] degrades to a pointer: a different type from an array */
  23. #define __must_be_array(a) \
  24. BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
  25. #define inline inline __attribute__((always_inline))
  26. #define __inline__ __inline__ __attribute__((always_inline))
  27. #define __inline __inline __attribute__((always_inline))
  28. #define __deprecated __attribute__((deprecated))
  29. #define __packed __attribute__((packed))
  30. #define __weak __attribute__((weak))
  31. #define __naked __attribute__((naked))
  32. #define __noreturn __attribute__((noreturn))
  33. /*
  34. * From the GCC manual:
  35. *
  36. * Many functions have no effects except the return value and their
  37. * return value depends only on the parameters and/or global
  38. * variables. Such a function can be subject to common subexpression
  39. * elimination and loop optimization just as an arithmetic operator
  40. * would be.
  41. * [...]
  42. */
  43. #define __pure __attribute__((pure))
  44. #define __aligned(x) __attribute__((aligned(x)))
  45. #define __printf(a,b) __attribute__((format(printf,a,b)))
  46. #define noinline __attribute__((noinline))
  47. #define __attribute_const__ __attribute__((__const__))
  48. #define __maybe_unused __attribute__((unused))