internal compiler error

[BPetersen@Handspring.com]

Any idea why we'd be getting the below error with the below code?  It is
pretty interesting -- I'm getting an internal compiler error.  The code is
attempting to calculate the space needed to copy the preceding function into
RAM by subtracting its function pointer from the one preceding it.  

If you change the pointers to: 

	volatile Ptr p1;
	volatile Ptr p2;

then everything works fine.  The arithmetic is very straightforward, and it
didn't reproduce in the very simplest case.  

bob

------------------------------------------------------------------
void Func2 ()
{
	Ptr p1;
	Ptr p2;

	// Allocate a block large enough to hold the above procedure.
	p1 = (Ptr) Func1; 
	p2 = (Ptr) Func2; 
	size = p2 - p1; 

... 

}  // line 356


------------------------------------------------------------------
Error: 

../Src/file.c: In function `Func2':
file.c (356): internal error--insn does not satisfy its constraints:
(insn 86 19 87 (set (reg/v:SI 3 %d3)
        (plus:SI (pc)
            (symbol_ref/v:SI ("Func2")))) 42 {movsi+1} (nil)
    (nil))