kc3-lang/libjpeg-turbo

2021-10-01T16:28:54

Build: Improve Neon capability detection - Use check_c_source_compiles() rather than check_symbol_exists() to detect the presence of vld1_s16_x3(), vld1_u16_x2(), and vld1q_u8_x4(). check_symbol_exists() is unreliable for detecting intrinsics, and in practice, it did not detect the presence of the aforementioned intrinsics in versions of GCC that support them. - Set DEFAULT_NEON_INTRINSICS=0 for GCC < 12, even if the aforementioned intrinsics are available. The AArch64 back end in GCC 10 and 11 supports the necessary intrinsics, but the GAS implementation is still faster when using those compilers. Fixes #547