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Re: -m68020 -fnobitfields != -mcpu32 ?
>>>>> "Timothy" == Timothy Potter <timbo@moshpit.air.net.au> writes:
Timothy> Hello again everyone. I've nearly got my GNU RTEMS m68k
Timothy> system up and going. There is one little thing that has
Timothy> been niggling at me ever since I started.
Timothy> The Motorola CPU32 is nearly a 68020 lacking only the
Timothy> bitfield instructions and a couple of addressing modes
Timothy> (plus a couple of extra instructions). Gas takes an
Timothy> option of -mcpu32 but there is no such option for gcc.
Timothy> The closest I can come up with is -m68020 -fnobitfields.
Timothy> My question is will these options generate some illegal
Timothy> code which uses one of the unsupported 68020 addressing
Timothy> modes on a CPU32? Or is it all taken care of in the
Timothy> assembly phase. (I do have a -Wa,-m68360 flag passed to
Timothy> the assembler).
Timothy> I hope someone has the answer to this - you guys have
Timothy> answered all my questions so far!
Timothy> Thanks,
Timothy> Tim Potter.
Try telling gcc to output assembler source code, then assembling it
with the -m68020 -fnobitfields options. This should flag as errors
any place where the unsupported instructions occurred. I suspect this
will be relatively infrequent. You can either patch the assembler
code, of edit the C source to generate different instructions. I know
it kludgy, but its pragmatic.
--
-------- "And there came a writing to him from Elijah" [2Ch 21:12] --------
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