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Merge the optimizers for LET and LET* adding a new function for unregistering variables from discarded C1FORMs.

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This commit is contained in:
Juan Jose Garcia Ripoll 2010-05-13 00:24:27 +02:00
parent 124e0427ec
commit dbf16619eb
1 changed files with 18 additions and 7 deletions
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25
src/cmp/cmplet.lsp
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@ -43,14 +43,9 @@
(process-let-bindings let/let* bindings body)
;; Try eliminating unused variables, replace constant ones, etc.
(multiple-value-setq (vars forms)
(if (eq let/let* 'let*)
(optimize-c1let* vars forms body)
(c1let-optimize-read-only-vars 'let vars forms body)))
(c1let-optimize-read-only-vars vars forms body))
;; Verify that variables are referenced and assign final boxed / unboxed type
(mapc #'check-vref vars)
(unless (= (length vars) (length forms))
(break)
(error "foo"))
(let ((sp-change (some #'global-var-p vars)))
(make-c1form* let/let*
:sp-change sp-change
@ -101,7 +96,7 @@
(c1declare-specials specials)
(values vars forms (c1decl-body other-decls body)))))
(defun c1let-optimize-read-only-vars (let/let* all-vars all-forms body)
(defun c1let-optimize-read-only-vars (all-vars all-forms body)
(loop with base = (list body)
for vars on all-vars
for forms on (nconc all-forms (list body))
@ -110,6 +105,8 @@
for rest-vars = (cdr vars)
for rest-forms = (cdr forms)
for read-only-p = (and (null (var-set-nodes var))
(null (var-functions-reading var))
(null (var-functions-setting var))
(not (global-var-p var)))
when read-only-p
do (fix-read-only-variable-type var form rest-forms)
@ -136,6 +133,7 @@
(not (form-causes-side-effect form)))
(unless (var-ignorable var)
(cmpnote "Removing unused variable ~A" (var-name var)))
(delete-c1forms form)
t))
(defun c1let-optimize-out-variable (var form rest-vars rest-forms)
@ -485,6 +483,19 @@
(and (can-be-replaced var body)
(not (var-changed-in-form-list var forms))))
;; should check whether a form before var causes a side-effect
;; exactly one occurrence of var is present in forms
(defun delete-c1forms (form)
(flet ((eliminate-references (form)
(if (eq (c1form-name form) 'VAR)
(let ((var (c1form-arg 0 form)))
(when var
(decf (var-ref var))
(setf (var-ref var) (1- (var-ref var))
(var-read-nodes var)
(delete form (var-read-nodes var))))))))
(traverse-c1form-tree form #'eliminate-references)))
(defun nsubst-var (var form)
(when (var-set-nodes var)
(baboon "Cannot replace a variable that is to be changed"))