Need help with -m68060 switch on egcs-1.1b
Wed Dec 2 07:33:00 GMT 1998

On Wed, 2 Dec 1998, Jyrki O Saarinen wrote:

> > > >   mulul %d3,%d1,%d0
> > > >   fdmulx %fp4,%fp3
> gcc emitted mulu.l dx,dy,dz for int-int multiply which is a bug
> IMHO. egcs doesn't do this for any CPU. 060 shouldn't have
> problems with floating point multiplies, the problematic
> area is trig etc. which for libFPSP can be used. 060 is 
> better than 040 in the aspect that it support fintrz for
> float to integer casts while 040 doesn't.

You might be surprised.  At one point the hppa port also did some integer
multiplication or division with the FPU.  This is an issue with RTEMS
since normally you can specify on a per task basis whether or not the FPU
context is saved/restored.  When the compiler surprises you, weird things
happen. :)

I agree that this is undesirable behavior on an embedded system and should
be reported.  

So this is a bug in gcc 2.x, not in egcs, right?

Joel Sherrill                    Director of Research & Development                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
   Support Available             (256) 722-9985

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