[MIT-Scheme-devel] new microcode with C back end

[Taylor R Campbell]

The C back end on PowerPC fails to compile early on with the new
microcode, due to the absence of a PC_ZERO_BITS macro in confshared.h.
It seems that the definition was moved from the cmpauxmd/*.h files to
confshared.h, but without any definition for the C back end, or
PowerPC.  On the PowerPC it ought to be 2, but the C back end formerly
automatically computed the value for whatever platform it ran on; is
there any reason that it no longer does so in the new microcode?  (It
is too late tonight for me to understand the relevant code.)