;;; ;;; Written by William Lott. ;;; (in-package "SB!VM") ;;;; Length (define-vop (length/list) (:translate length) (:args (object :scs (descriptor-reg) :target ptr)) (:arg-types list) (:temporary (:scs (descriptor-reg) :from (:argument 0)) ptr) (:temporary (:scs (non-descriptor-reg)) temp) (:temporary (:scs (any-reg) :type fixnum :to (:result 0) :target result) count) (:results (result :scs (any-reg descriptor-reg))) (:policy :fast-safe) (:vop-var vop) (:save-p :compute-only) (:generator 50 (let ((done (gen-label)) (loop (gen-label)) (not-list (generate-cerror-code vop object-not-list-error object))) (move ptr object) (move count zero-tn) (emit-label loop) (inst cmpw ptr null-tn) (inst beq done) (test-type ptr temp not-list t sb!vm:list-pointer-lowtag) (loadw ptr ptr sb!vm:cons-cdr-slot sb!vm:list-pointer-lowtag) (inst addi count count (fixnumize 1)) (test-type ptr temp loop nil sb!vm:list-pointer-lowtag) (cerror-call vop done object-not-list-error ptr) (emit-label done) (move result count)))) (define-static-fun length (object) :translate length)