+ ;; The internal variables of a transform are not going to be
+ ;; interesting to the debugger, so there's no sense in
+ ;; suppressing the substitution of variables with only one use
+ ;; (the extra variables can slow down constraint propagation).
+ ;;
+ ;; This needs to be done before the WITH-IR1-ENVIRONMENT-FROM-NODE,
+ ;; so that it will bind *LEXENV* to the right environment.
+ (setf (combination-lexenv call)
+ (make-lexenv :default (combination-lexenv call)
+ :policy (process-optimize-decl
+ '(optimize
+ (preserve-single-use-debug-variables 0))
+ (lexenv-policy
+ (combination-lexenv call)))))