https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90181
--- Comment #13 from Elliott M <ehem+gccbugs at m5p dot com> --- (In reply to Andrew Pinski from comment #12) > Actually this is NOT a gross mischaracterization of GCC's x86 inline-asm and Making the 6 registers most likely to be needed on x86 available as machine-specific constraints makes the spirit of this request available for x86. It doesn't /quite/ fully implement the request, but does cover 95% of use cases, for x86. Whereas for modern architectures it is unavailable. > not understanding that is misrepresenting the history of GCC's inline-asm > and how it just exposes internal details of GCC to the user. GCC's x86 > constraints are exactly this way because of instructions requirements (ISA > constraints) and all of these constraints are used internally too. The documented limitations of GCC's extended inline assembly language were most readily explained by it exposing GCC's internals. As such I had already guessed this was the case. Unfortunately these limitations makes it extremely painful to use for actual benefit. (I see why most cases use full assembly language .S files, instead of inline assembly language)
