Add two new cases of foldable expressions, to permit certain string

operations to be folded.

diff --git a/v7/src/compiler/rtlopt/rcompr.scm b/v7/src/compiler/rtlopt/rcompr.scm
index 78fb6f4c6e4d715f18db9918353361fd4f16365d..01bb695d70c6f2a042dece520f5f32da84d62be4 100644 (file)
--- a/v7/src/compiler/rtlopt/rcompr.scm
+++ b/v7/src/compiler/rtlopt/rcompr.scm
@@ -1,8 +1,8 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlopt/rcompr.scm,v 1.10 1990/01/18 22:47:38 cph Rel $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlopt/rcompr.scm,v 1.11 1991/03/21 09:42:38 cph Exp $
 
-Copyright (c) 1988, 1989, 1990 Massachusetts Institute of Technology
+Copyright (c) 1988-91 Massachusetts Institute of Technology
 
 This material was developed by the Scheme project at the Massachusetts
 Institute of Technology, Department of Electrical Engineering and
@@ -155,7 +155,8 @@ MIT in each case. |#
               (if (rinst-dead-register? next register)
                   (values next expression)
                   (loop (rinst-next next)))))
-           ((rtl:offset? expression)
+           ((or (rtl:offset? expression)
+                (rtl:byte-offset? expression))
             (search-stopping-at expression
               (lambda (rtl)
                 (or (and (rtl:assign? rtl)
@@ -163,6 +164,12 @@ MIT in each case. |#
                                 (rtl:assign-address rtl))
                                '(OFFSET POST-INCREMENT PRE-INCREMENT)))
                     (expression-clobbers-stack-pointer? rtl)))))
+           ((and (rtl:cons-pointer? expression)
+                 (rtl:machine-constant? (rtl:cons-pointer-type expression)))
+            (recursion rtl:cons-pointer-datum
+                       (lambda (datum)
+                         (rtl:make-cons-pointer (rtl:cons-pointer-type expression)
+                                                datum))))
            ((rtl:object->address? expression)
             (recursion rtl:object->address-expression
                        rtl:make-object->address))