--- /dev/null
+#| -*-Scheme-*-
+
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/machines/mips/lapopt.scm,v 1.1 1991/07/25 02:42:11 cph Exp $
+
+Copyright (c) 1991 Massachusetts Institute of Technology
+
+This material was developed by the Scheme project at the Massachusetts
+Institute of Technology, Department of Electrical Engineering and
+Computer Science. Permission to copy this software, to redistribute
+it, and to use it for any purpose is granted, subject to the following
+restrictions and understandings.
+
+1. Any copy made of this software must include this copyright notice
+in full.
+
+2. Users of this software agree to make their best efforts (a) to
+return to the MIT Scheme project any improvements or extensions that
+they make, so that these may be included in future releases; and (b)
+to inform MIT of noteworthy uses of this software.
+
+3. All materials developed as a consequence of the use of this
+software shall duly acknowledge such use, in accordance with the usual
+standards of acknowledging credit in academic research.
+
+4. MIT has made no warrantee or representation that the operation of
+this software will be error-free, and MIT is under no obligation to
+provide any services, by way of maintenance, update, or otherwise.
+
+5. In conjunction with products arising from the use of this material,
+there shall be no use of the name of the Massachusetts Institute of
+Technology nor of any adaptation thereof in any advertising,
+promotional, or sales literature without prior written consent from
+MIT in each case. |#
+
+;;;; LAP Optimizer for MIPS.
+
+(declare (usual-integrations))
+\f
+(define (optimize-linear-lap instructions)
+ ;; Find occurrences of LW/LBU/LWC1 followed by NOP, and delete the
+ ;; NOP if the instruction following it has no reference to the
+ ;; target register of the load.
+
+ ;; **** This is pretty fragile. ****
+ (letrec
+ ((find-load
+ (lambda (instructions)
+ (cond ((null? instructions) '())
+ ((and (pair? (car instructions))
+ (or (eq? 'LW (caar instructions))
+ (eq? 'LBU (caar instructions))
+ (eq? 'LWC1 (caar instructions))))
+ instructions)
+ (else (find-load (cdr instructions))))))
+ (get-next
+ (lambda (instructions)
+ (let ((instructions (cdr instructions)))
+ (cond ((null? instructions) '())
+ ((or (not (pair? (car instructions)))
+ (eq? 'LABEL (caar instructions))
+ (eq? 'COMMENT (caar instructions)))
+ (get-next instructions))
+ (else instructions)))))
+ (refers-to-register?
+ (lambda (instruction register)
+ (let loop ((x instruction))
+ (if (pair? x)
+ (or (loop (car x))
+ (loop (cdr x)))
+ (eqv? register x))))))
+ (let loop ((instructions instructions))
+ (let ((first (find-load instructions)))
+ (if (not (null? first))
+ (let ((second (get-next first)))
+ (if (not (null? second))
+ (let ((third (get-next second)))
+ (if (not (null? third))
+ (if (and (equal? '(NOP) (car second))
+ ;; This is a crude way to test for a
+ ;; reference to the target register
+ ;; -- it will sometimes incorrectly
+ ;; say that there is a reference, but
+ ;; it will never incorrectly say that
+ ;; there is no reference.
+ (not (refers-to-register? (car third)
+ (cadar first)))
+ (or (not (and (eq? 'LWC1 (caar first))
+ (odd? (cadar first))))
+ (not (refers-to-register?
+ (car third)
+ (- (cadar first) 1)))))
+ (begin
+ (let loop ((this (cdr first)) (prev first))
+ (if (eq? second this)
+ (set-cdr! prev (cdr this))
+ (loop (cdr this) this)))
+ (loop (if (equal? '(NOP) (car third))
+ first
+ third)))
+ (loop second))))))))))
+ instructions)
\ No newline at end of file
--- /dev/null
+#| -*-Scheme-*-
+
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/machines/spectrum/lapopt.scm,v 1.1 1991/07/25 02:41:53 cph Exp $
+
+Copyright (c) 1991 Massachusetts Institute of Technology
+
+This material was developed by the Scheme project at the Massachusetts
+Institute of Technology, Department of Electrical Engineering and
+Computer Science. Permission to copy this software, to redistribute
+it, and to use it for any purpose is granted, subject to the following
+restrictions and understandings.
+
+1. Any copy made of this software must include this copyright notice
+in full.
+
+2. Users of this software agree to make their best efforts (a) to
+return to the MIT Scheme project any improvements or extensions that
+they make, so that these may be included in future releases; and (b)
+to inform MIT of noteworthy uses of this software.
+
+3. All materials developed as a consequence of the use of this
+software shall duly acknowledge such use, in accordance with the usual
+standards of acknowledging credit in academic research.
+
+4. MIT has made no warrantee or representation that the operation of
+this software will be error-free, and MIT is under no obligation to
+provide any services, by way of maintenance, update, or otherwise.
+
+5. In conjunction with products arising from the use of this material,
+there shall be no use of the name of the Massachusetts Institute of
+Technology nor of any adaptation thereof in any advertising,
+promotional, or sales literature without prior written consent from
+MIT in each case. |#
+
+;;;; LAP Optimizer for HP Precision Archtecture.
+
+(declare (usual-integrations))
+
+(define (optimize-linear-lap instructions)
+ instructions)
\ No newline at end of file
--- /dev/null
+#| -*-Scheme-*-
+
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/machines/vax/lapopt.scm,v 1.1 1991/07/25 02:41:27 cph Exp $
+
+Copyright (c) 1991 Massachusetts Institute of Technology
+
+This material was developed by the Scheme project at the Massachusetts
+Institute of Technology, Department of Electrical Engineering and
+Computer Science. Permission to copy this software, to redistribute
+it, and to use it for any purpose is granted, subject to the following
+restrictions and understandings.
+
+1. Any copy made of this software must include this copyright notice
+in full.
+
+2. Users of this software agree to make their best efforts (a) to
+return to the MIT Scheme project any improvements or extensions that
+they make, so that these may be included in future releases; and (b)
+to inform MIT of noteworthy uses of this software.
+
+3. All materials developed as a consequence of the use of this
+software shall duly acknowledge such use, in accordance with the usual
+standards of acknowledging credit in academic research.
+
+4. MIT has made no warrantee or representation that the operation of
+this software will be error-free, and MIT is under no obligation to
+provide any services, by way of maintenance, update, or otherwise.
+
+5. In conjunction with products arising from the use of this material,
+there shall be no use of the name of the Massachusetts Institute of
+Technology nor of any adaptation thereof in any advertising,
+promotional, or sales literature without prior written consent from
+MIT in each case. |#
+
+;;;; LAP Optimizer for VAX.
+
+(declare (usual-integrations))
+
+(define (optimize-linear-lap instructions)
+ instructions)
\ No newline at end of file
projects / mit-scheme.git / commitdiff