From 448651caebe2809d6a966e4cf38d87b04628ee24 Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Sat, 13 Dec 1986 17:04:26 +0000
Subject: [PATCH] Initial revision

---
 v7/src/compiler/back/asmmac.scm | 118 ++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 v7/src/compiler/back/asmmac.scm

diff --git a/v7/src/compiler/back/asmmac.scm b/v7/src/compiler/back/asmmac.scm
new file mode 100644
index 000000000..779ebb53c
--- /dev/null
+++ b/v7/src/compiler/back/asmmac.scm
@@ -0,0 +1,118 @@
+;;; -*-Scheme-*-
+;;;
+;;;	Copyright (c) 1986 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.
+;;;
+
+;;;; Assembler Syntax Macros
+
+(declare (usual-integrations))
+(using-syntax (access compiler-syntax-table compiler-package)
+
+(syntax-table-define assembler-syntax-table 'DEFINE-INSTRUCTION
+  (macro (keyword . rules)
+    `(ADD-INSTRUCTION!
+      ',keyword
+      ,(compile-database rules
+	 (lambda (pattern actions)
+	   (if (null? actions)
+	       (error "DEFINE-INSTRUCTION: Too few forms")
+	       (parse-word (car actions) (cdr actions))))))))
+
+(define (compile-database cases procedure)
+  `(LIST
+    ,@(map (lambda (case)
+	     (parse-rule (car case) (cdr case)
+	       (lambda (pattern names transformer qualifier actions)
+		 `(CONS ',pattern
+			,(rule-result-expression names
+						 transformer
+						 qualifier
+						 (procedure pattern
+							    actions))))))
+	   cases)))
+
+;;;; Group Optimization
+
+(define optimize-group-syntax
+  (let ()
+    (define (find-constant components)
+      (cond ((null? components)
+	     '())
+	    ((car-constant? components)
+	     (compact (car-constant-value components)
+		      (cdr components)))
+	    (else
+	     (cons (car components)
+		   (find-constant (cdr components))))))
+
+    (define (compact bit-string components)
+      (cond ((null? components)
+	     (cons (make-constant bit-string) '()))
+	    ((car-constant? components)
+	     (compact (bit-string-append (car-constant-value components)
+					 bit-string)
+		      (cdr components)))
+	    (else
+	     (cons (make-constant bit-string)
+		   (cons (car components)
+			 (find-constant (cdr components)))))))
+
+    (define-integrable (car-constant? expression)
+      (and (eq? (caar expression) 'QUOTE)
+	   (bit-string? (cadar expression))))
+
+    (define-integrable (car-constant-value constant)
+      (cadar constant))
+
+    (define-integrable (make-constant bit-string)
+      `',bit-string)
+
+    (lambda components
+      (let ((components (find-constant components)))
+	(cond ((null? components)
+	       (error "OPTIMIZE-GROUP-SYNTAX: No components in group!"))
+	      ((null? (cdr components))
+	       (car components))
+	      (else
+	       `(OPTIMIZE-GROUP ,@components)))))))
+
+;;; end USING-SYNTAX
+)
+
+;;; Edwin Variables:
+;;; Scheme Environment: (access lap-syntaxer-package compiler-package)
+;;; Scheme Syntax Table: (access compiler-syntax-table compiler-package)
+;;; End:
+	       `(OPTIMIZE-GROUP ,@components)))))))
\ No newline at end of file
-- 
2.25.1