It's probably bad form, but I've seen people set CC to name/path to compiler followed by switches, e.g.:

   export CC='gcc -march=native -O3'

or the like (usually because they want to keep the build tool's default CFLAGS, and setting CFLAGS causes them to be replaced, not supplemented).

basename seems to strip the leading path components, but if someone shoved in other switches, they aren't removed, so if they happen to have "icc" in them, this would still have issues. Perhaps a basename followed by splitting on whitespace and only keeping the first component? Not a configure expert, not sure what's possible.