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 /* 6 * Common definitions for all gcc versions go here. 7 */ 8 9 10 /* Optimization barrier */ 11 /* The "volatile" is due to gcc bugs */ 12 #define barrier() __asm__ __volatile__("": : :"memory") 13 14 /* This macro obfuscates arithmetic on a variable address so that gcc 15 shouldn't recognize the original var, and make assumptions about it */ 16 /* 17 * Versions of the ppc64 compiler before 4.1 had a bug where use of 18 * RELOC_HIDE could trash r30. The bug can be worked around by changing 19 * the inline assembly constraint from =g to =r, in this particular 20 * case either is valid. 21 */ 22 #define RELOC_HIDE(ptr, off) \ 23 ({ unsigned long __ptr; \ 24 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ 25 (typeof(ptr)) (__ptr + (off)); }) 26 27 /* &a[0] degrades to a pointer: a different type from an array */ 28 #define __must_be_array(a) \ 29 BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0]))) 30 31 #define inline inline __attribute__((always_inline)) 32 #define __inline__ __inline__ __attribute__((always_inline)) 33 #define __inline __inline __attribute__((always_inline)) 34 #define __deprecated __attribute__((deprecated)) 35 #define __packed __attribute__((packed)) 36 #define __weak __attribute__((weak)) 37 #define __naked __attribute__((naked)) 38 #define __noreturn __attribute__((noreturn)) 39 40 /* 41 * From the GCC manual: 42 * 43 * Many functions have no effects except the return value and their 44 * return value depends only on the parameters and/or global 45 * variables. Such a function can be subject to common subexpression 46 * elimination and loop optimization just as an arithmetic operator 47 * would be. 48 * [...] 49 */ 50 #define __pure __attribute__((pure)) 51 #define __aligned(x) __attribute__((aligned(x))) 52 #define __printf(a,b) __attribute__((format(printf,a,b))) 53 #define noinline __attribute__((noinline)) 54 #define __attribute_const__ __attribute__((__const__)) 55 #define __maybe_unused __attribute__((unused)) 56