-;;;; Some other common SXHASH cases are defined as DEFTRANSFORMs in order to
-;;;; avoid having to do TYPECASE at runtime.
+;;; Some other common SXHASH cases are defined as DEFTRANSFORMs in
+;;; order to avoid having to do TYPECASE at runtime.
+;;;
+;;; We also take the opportunity to handle the cases of constant
+;;; strings, and of symbols whose names are known at compile time;
+;;; except that since SXHASH on the cross-compilation host is not in
+;;; general compatible with SXHASH on the target SBCL, we can't so
+;;; easily do this optimization in the cross-compiler, and SBCL itself
+;;; doesn't seem to need this optimization, so we don't try.