diff options
| author | Thomas Köppe <tkoeppe-at-google.com@ffmpeg.org> | 2017-11-12 16:24:37 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2017-11-13 03:58:34 +0100 |
| commit | 43171a2a738f5114768d34a7278e56e5fde714bc (patch) | |
| tree | 1a62d32327c279e9303a50e55a13416f3e102923 /libavutil | |
| parent | 1828c549c3ecd45d54ff03aee784b00a41f0e69e (diff) | |
Fix missing used attribute for inline assembly variables
Variables used in inline assembly need to be marked with attribute((used)).
Static constants already were, via the define of DECLARE_ASM_CONST.
But DECLARE_ALIGNED does not add this attribute, and some of the variables
defined with it are const only used in inline assembly, and therefore
appeared dead. This change adds a macro DECLARE_ASM_ALIGNED that marks
variables as used.
This change makes FFMPEG work with Clang's ThinLTO.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavutil')
| -rw-r--r-- | libavutil/mem.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/libavutil/mem.h b/libavutil/mem.h index e5ca8299dc..9e344bd2c3 100644 --- a/libavutil/mem.h +++ b/libavutil/mem.h @@ -74,6 +74,19 @@ */ /** + * @def DECLARE_ASM_ALIGNED(n,t,v) + * Declare an aligned variable appropriate for use in inline assembly code. + * + * @code{.c} + * DECLARE_ASM_ALIGNED(16, uint64_t, pw_08) = UINT64_C(0x0008000800080008); + * @endcode + * + * @param n Minimum alignment in bytes + * @param t Type of the variable (or array element) + * @param v Name of the variable + */ + +/** * @def DECLARE_ASM_CONST(n,t,v) * Declare a static constant aligned variable appropriate for use in inline * assembly code. @@ -89,18 +102,22 @@ #if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 1110 || defined(__SUNPRO_C) #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v + #define DECLARE_ASM_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v #define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v #elif defined(__DJGPP__) #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (FFMIN(n, 16)))) v #define DECLARE_ASM_CONST(n,t,v) static const t av_used __attribute__ ((aligned (FFMIN(n, 16)))) v #elif defined(__GNUC__) || defined(__clang__) #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v + #define DECLARE_ASM_ALIGNED(n,t,v) t av_used __attribute__ ((aligned (n))) v #define DECLARE_ASM_CONST(n,t,v) static const t av_used __attribute__ ((aligned (n))) v #elif defined(_MSC_VER) #define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v + #define DECLARE_ASM_ALIGNED(n,t,v) __declspec(align(n)) t v #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v #else #define DECLARE_ALIGNED(n,t,v) t v + #define DECLARE_ASM_ALIGNED(n,t,v) t v #define DECLARE_ASM_CONST(n,t,v) static const t v #endif |