strange real timings partly explained

[Matthew Fluet]

> > Also Matthew, are double pseudo-regs aligned mod8?  That seems easy to do.
>
> They should be.  The declaration for pseudo-regs (and globals) are of the
> form:
>
> 	double localdouble[d];				       		\
>
> in x86codegen.h.  gcc should be giving these the proper alignment.  I
> think I double checked the assembly for this once, and the alignment
> pseudo-op is there.

gcc generates the following pseudo-op for allocation:

	.comm	localdouble,0,8

saying that the symbol localdouble is of size 0 (well, fib needs no
float pseudo-regs) and aligned mod 8.