]>
Commit | Line | Data |
---|---|---|
95ffaba3 GR |
1 | #ifndef __LINUX_COMPILER_H |
2 | #error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead." | |
3 | #endif | |
4 | ||
5 | /* GCC 4.1.[01] miscompiles __weak */ | |
6 | #ifdef __KERNEL__ | |
fb8ffd7c | 7 | # if GCC_VERSION >= 40100 && GCC_VERSION <= 40101 |
95ffaba3 GR |
8 | # error Your version of gcc miscompiles the __weak directive |
9 | # endif | |
10 | #endif | |
11 | ||
12 | #define __used __attribute__((__used__)) | |
13 | #define __must_check __attribute__((warn_unused_result)) | |
14 | #define __compiler_offsetof(a,b) __builtin_offsetof(a,b) | |
95ffaba3 | 15 | |
fb8ffd7c MY |
16 | #if GCC_VERSION >= 40100 && GCC_VERSION < 40600 |
17 | # define __compiletime_object_size(obj) __builtin_object_size(obj, 0) | |
18 | #endif | |
95ffaba3 | 19 | |
fb8ffd7c | 20 | #if GCC_VERSION >= 40300 |
95ffaba3 GR |
21 | /* Mark functions as cold. gcc will assume any path leading to a call |
22 | to them will be unlikely. This means a lot of manual unlikely()s | |
23 | are unnecessary now for any paths leading to the usual suspects | |
24 | like BUG(), printk(), panic() etc. [but let's keep them for now for | |
25 | older compilers] | |
26 | ||
27 | Early snapshots of gcc 4.3 don't support this and we can't detect this | |
28 | in the preprocessor, but we can live with this because they're unreleased. | |
29 | Maketime probing would be overkill here. | |
30 | ||
31 | gcc also has a __attribute__((__hot__)) to move hot functions into | |
32 | a special section, but I don't see any sense in this right now in | |
33 | the kernel context */ | |
34 | #define __cold __attribute__((__cold__)) | |
35 | ||
fb8ffd7c | 36 | #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) |
95ffaba3 | 37 | |
fb8ffd7c MY |
38 | #ifndef __CHECKER__ |
39 | # define __compiletime_warning(message) __attribute__((warning(message))) | |
40 | # define __compiletime_error(message) __attribute__((error(message))) | |
41 | #endif /* __CHECKER__ */ | |
42 | #endif /* GCC_VERSION >= 40300 */ | |
43 | ||
44 | #if GCC_VERSION >= 40500 | |
95ffaba3 GR |
45 | /* |
46 | * Mark a position in code as unreachable. This can be used to | |
47 | * suppress control flow warnings after asm blocks that transfer | |
48 | * control elsewhere. | |
49 | * | |
50 | * Early snapshots of gcc 4.5 don't support this and we can't detect | |
51 | * this in the preprocessor, but we can live with this because they're | |
52 | * unreleased. Really, we need to have autoconf for the kernel. | |
53 | */ | |
54 | #define unreachable() __builtin_unreachable() | |
95ffaba3 | 55 | |
fb8ffd7c MY |
56 | /* Mark a function definition as prohibited from being cloned. */ |
57 | #define __noclone __attribute__((__noclone__)) | |
58 | ||
59 | #endif /* GCC_VERSION >= 40500 */ | |
60 | ||
61 | #if GCC_VERSION >= 40600 | |
62 | /* | |
63 | * Tell the optimizer that something else uses this function or variable. | |
64 | */ | |
65 | #define __visible __attribute__((externally_visible)) | |
95ffaba3 GR |
66 | #endif |
67 | ||
fb8ffd7c MY |
68 | /* |
69 | * GCC 'asm goto' miscompiles certain code sequences: | |
70 | * | |
71 | * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 | |
72 | * | |
73 | * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. | |
74 | * Fixed in GCC 4.8.2 and later versions. | |
75 | * | |
76 | * (asm goto is automatically volatile - the naming reflects this.) | |
77 | */ | |
78 | #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) | |
79 | ||
80 | #ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP | |
81 | #if GCC_VERSION >= 40400 | |
82 | #define __HAVE_BUILTIN_BSWAP32__ | |
83 | #define __HAVE_BUILTIN_BSWAP64__ | |
95ffaba3 | 84 | #endif |
fb8ffd7c MY |
85 | #if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600) |
86 | #define __HAVE_BUILTIN_BSWAP16__ | |
95ffaba3 | 87 | #endif |
fb8ffd7c | 88 | #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */ |