The following output seems to be wrong:(format nil "~G" 1.0d0)                                                                                                      
"1.0    "

I expect it to be
"1.    "

For the formula in CLHS "22.3.3.3 Tilde G: General Floating-Point"
I arrive at q=0, n=1, d=1, dd=0 where dd stands for the number of decimals to print.