Hi,
As always thank you VERY much for taking the time to share your VAST
array of knowledge! I REALLY do appreciate it!!! (You to Jonathon)
On Wed, Mar 2, 2011 at 3:15 PM, Ian Lance Taylor <iant@xxxxxxxxxx> wrote:
> kevin diggs <diggskevin38@xxxxxxxxx> writes:
>
>> If a pre-processor macro, say __m68k__ is defined shouldn't it show up
>> in gcc -v? gcc version is 3.4.6.
>
> gcc -v does not list predefined preprocessor macros. You can see them
> by running "gcc -x c /dev/null -E -dM".
>
I am trying to figure out if I should apologize for being to stupid to
figure this out. In my defense and in this case I can't build the
documentation (gcc 3.4.6 on an old Quadra 700 (mc68040)). makeinfo or
some such thing is missing. I think it also wants perl. Like I have
enough disk space on this thing to install (or build) that.
Did this change when the pre-processor moved into cc1?
>> P.S.: Anyone point me to an example of how to use the 68k 'Q' constraint?
>
> In what sense? There are various examples in gcc/config/m68k/m68k.md,
> e.g., tst<mode>_cf.
>
I apologize for the vagueness. I am referring to usage in embedded asm.
asm volatile("fmoveml %%fpcr/%%fpsr,%0@\n"
:
:"a"(save)
);
Q is address register indirect. I thought I could write this:
fmoveml %%fpcr/%%fpsr,%0\n"
:
:"Q"(save)
The compiler pitched a major league hissy fit though:
fmoveml.c: In function `f':
fmoveml.c:14: error: impossible constraint in `asm'
Are some of these constraints meant to be used only in md files?
>> And while I'm here, anyway to see when an instruction causes an
>> unimplemented instruction trap (like fcos on a 68040)?
>
> I guess I don't understand the question.
>
> Ian
>
Using ktruss dltest will show lots of diagnostic stuff. If I
understand it, on a 68040 the fcos instruction has to implemented by a
trap of some sort. Is there any utility that I can see these happen
analogous to what ktruss does for system calls?
Thanks!
kevin
