From 6ddb9a89d7bcb998f687f8314b7530aa83871608 Mon Sep 17 00:00:00 2001 From: Dale Curtis Date: Fri, 1 May 2020 10:20:43 -0700 Subject: [PATCH 2/2] Use gcc/clang builtins for av_sat_(add|sub)_64_c if available. Signed-off-by: Dale Curtis --- libavutil/common.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/libavutil/common.h b/libavutil/common.h index e926e7cb02..1fcbfbc03a 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -299,11 +299,16 @@ static av_always_inline int av_sat_dsub32_c(int a, int b) * @return sum with signed saturation */ static int64_t av_sat_add64_c(int64_t a, int64_t b) { +#if AV_GCC_VERSION_AT_LEAST(5,0) || defined(__clang__) + int64_t tmp; + return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN); +#else if (b >= 0 && a >= INT64_MAX - b) return INT64_MAX; if (b <= 0 && a <= INT64_MIN - b) return INT64_MIN; return a + b; +#endif } /** @@ -314,11 +319,16 @@ static int64_t av_sat_add64_c(int64_t a, int64_t b) { * @return difference with signed saturation */ static int64_t av_sat_sub64_c(int64_t a, int64_t b) { +#if AV_GCC_VERSION_AT_LEAST(5,0) || defined(__clang__) + int64_t tmp; + return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN); +#else if (b <= 0 && a >= INT64_MAX + b) { return INT64_MAX; if (b >= 0 && a <= INT64_MIN + b) { return INT64_MIN; return a - b; +#endif } /** -- 2.24.1.windows.2