On Thursday, 16 December 2021 at 14:26:42 UTC, bachmeier wrote: > https://github.com/ibuclaw/importC/blob/main/src/keywords.c.in > #define __builtin_bswap16(x) ((u_int16_t) ((((x) >> 8) & 0xff) > | (((x) & 0xff) << 8))) Oh, my, that's bad. GCC __builtins don't generally evaluate more than once. And this could just be an inline function anyway.