The original SSE instruction set has been available since the Pentium 3 (1999) and the Athlon XP (2001).
Does Wine have a particular reason to second-guess the compiler, or do we just think that their default is a bad choice?
AFAIU the default `-march` setting is chosen by the distro and it's usually a very conservative default. Not much "guessing" on their part in any case. Also, we do in fact have additional info that we can use, which is what the second patch does (we're also building 64-bit code -> CPU must support 64-bit mode -> we can use all the features baseline in x86-64 architectures, namely SSE and SSE2). My immediate interest for this MR is to be able to use SSE compiler intrinsics in dsound with default CFLAGS. FWIW, we're already force enabling `-mcx16` on x86_64, and that one is even put in x86_64_EXTRACFLAGS since, I assume, we really do require it. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/10953#note_140761