Subject: Re: MACHINE_ARCH on mips
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Todd Vierling <>
List: tech-toolchain
Date: 07/25/1998 15:33:18
On Sat, 25 Jul 1998, Jonathan Stone wrote:

: I dont know either.  I honeslty dont see -le vs -be as that much
: different from 64 vs 32.  Todd says they're the same ${MACHINE_ARCH},
: even tho' strictly they aren't always supersets.  (pedantically,
: m68020 to 040 isn't a superset:

It's not a direct superset, but the default output of the m68k compilers is
MC68020 code, and all m68k kernels can emulate the rest of the unimplemented
68020 insns.  You can change the compiler output with an option, but you're
guaranteed what the default is, and that the default code will run on a
system of the same MACHINE_ARCH.

: Plus if you really want native 64-bit binaries, they arent going to
: run on a v8 sparc. So by that definition, sparc64 should be a seperate
: ${MACHINE_ARCH}. yes?

We don't have that yet.  As I said, if sparc64 goes to a full 64-bit
userland, it should change the MACHINE_ARCH, because its default toolchain
output is no longer compatible with sparc.

: Even worse is the option (which someone comes up with every 6 months)
: to use 32-bit ints and pointers, but to set the FPU into 64-bit mode.
: That doubles the number of FP registers and may increase memory
: bandwidth.   Is that yet another kind of ${MACHINE_ARCH}?

Only if it's changing the _default_ output of the toolchain to something not
compatible with other machines in the MACHINE_ARCH.  Command line switches,
as said before, don't count.

-- Todd Vierling (Personal; Bus.