Re: Why VAX Was the Ultimate CISC and Not RISC

Anton Ertl <anton@mips.complang.tuwien.ac.at> schrieb:

MarkC <usenet@em-ess-see-twenty-seven.me.uk> writes:

NetBSD still has a VAX port, so the sizes of pre-built packages from
there might be informative.

>
Thanks.  The NetBSD pkgsrc is not limited to NetBSD, and there is a
wide variety of prebuilt stuff there.  I took those that sound like
architecture names (and probably belong to NetBSD): aarch64 alpha
amd64 earmv7hf i386 m68k mips64eb mipsel powerpc sparc sparc64 vax
>
Unfortunately, they do not seem to port to RISC-V in any form yet, and
their earmv7hf port uses ARM A32, not T32.  So the NetBSD competition
is performed without entries for those two instruction set encodings
that showed the smallest code sizes on Debian.  Anyway, here are the
results:
>
  bash      grep       xz
  710838             42236 m68k
  748354   159304    40930 vax
  829077   176836    42840 amd64
  855400   164188          aarch64
  877284   186924    48032 sparc
  882847   187203    49866 i386
  898532   179844          earmv7hf
  962128   205776    54704 powerpc
 1004864   192256    53632 sparc64
 1025136             51160 mips64eb
 1147664   232688    63456 alpha
 1172692                   mipsel

Utilities are often compiled with a medium to high level of
optimizationo (like -O2), which can do loop unrolling, inlining
and function cloning, all of which can increase code size.
These decisions can also depend on the number of available register.

If your aim is small code size, it is better to compare output
compiled with -Os.