Fix overflow for coeff -32768 in function ADD_RES_SSE_16_32_8 with no performance drop.(SSE2/AVX/AVX2) ./checkasm --test=hevc_add_res --bench Mainline: - hevc_add_res.add_residual [OK] hevc_add_res_32x32_8_sse2: 127.5 hevc_add_res_32x32_8_avx: 127.0 hevc_add_res_32x32_8_avx2: 86.5 Add overflow test case: - hevc_add_res.add_residual [FAILED] After: - hevc_add_res.add_residual [OK] hevc_add_res_32x32_8_sse2: 126.8 hevc_add_res_32x32_8_avx: 128.3 hevc_add_res_32x32_8_avx2: 86.8 Signed-off-by: Xu Guangxin <guangxin.xu@intel.com> Signed-off-by: Linjie Fu <linjie.fu@intel.com> Signed-off-by: Anton Khirnov <anton@khirnov.net>