From 332b493b0f9703a2a371f1d83e57c5ac2b9f2457 Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Tue, 20 Dec 1988 23:13:20 +0000
Subject: [PATCH] If combination has a `continuation-push', prevent that
 continuation from being pushed when the combination is constant folded in any
 way.

---
 v7/src/compiler/base/ctypes.scm  | 10 +++++++---
 v7/src/compiler/fgopt/sideff.scm | 15 +++------------
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/v7/src/compiler/base/ctypes.scm b/v7/src/compiler/base/ctypes.scm
index f445b1e97..544a6da7c 100644
--- a/v7/src/compiler/base/ctypes.scm
+++ b/v7/src/compiler/base/ctypes.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/base/ctypes.scm,v 4.8 1988/12/13 13:02:21 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/base/ctypes.scm,v 4.9 1988/12/20 23:13:08 cph Exp $
 
 Copyright (c) 1988 Massachusetts Institute of Technology
 
@@ -154,7 +154,11 @@ MIT in each case. |#
   (let ((continuation (combination/continuation combination)))
     (set-application-type! combination 'RETURN)
     (set-application-operator! combination continuation)
-    (set-application-operands! combination (list rvalue))))
+    (set-application-operands! combination (list rvalue)))
+  (let ((push (combination/continuation-push combination)))
+    (if (and push (rvalue-known-value (combination/continuation combination)))
+	(set-virtual-continuation/type! (virtual-return-operator push)
+					continuation-type/effect))))
 
 (define-integrable (make-return block continuation rvalue)
   (make-application 'RETURN block continuation (list rvalue) false))
@@ -164,7 +168,7 @@ MIT in each case. |#
 
 (define-integrable return/context application-context)
 (define-integrable return/operator application-operator)
-
+(define-integrable return/continuation-push application-continuation-push)
 (define-integrable (return/operand return)
   (car (application-operands return)))
 
diff --git a/v7/src/compiler/fgopt/sideff.scm b/v7/src/compiler/fgopt/sideff.scm
index 4e6472efe..3a711219c 100644
--- a/v7/src/compiler/fgopt/sideff.scm
+++ b/v7/src/compiler/fgopt/sideff.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/fgopt/sideff.scm,v 1.3 1988/12/13 18:21:52 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/fgopt/sideff.scm,v 1.4 1988/12/20 23:13:20 cph Exp $
 
 Copyright (c) 1988 Massachusetts Institute of Technology
 
@@ -317,7 +317,8 @@ MIT in each case. |#
 
 (define (analyze-combination! app)
   (define (simplify-combination! value)
-    (combination/trivial! app value)
+    (combination/constant! app
+			   (r/lvalue->rvalue (combination/context app) value))
     (enqueue-node! (block-procedure (application-block app))))
 
   (define (check value op-vals)
@@ -403,16 +404,6 @@ MIT in each case. |#
       (make-reference context r/lvalue false)
       r/lvalue))
 
-(define (combination/trivial! comb r/lvalue)
-  (let ((push (combination/continuation-push comb)))
-    (if (and push (rvalue-known-value (combination/continuation comb)))
-	(set-virtual-continuation/type!
-	 (virtual-return-operator push)
-	 continuation-type/effect)))
-  (combination/constant!
-   comb
-   (r/lvalue->rvalue (combination/context comb) r/lvalue)))
-
 (define (procedure/trivial! procedure kind)
   (let ((place (assq 'TRIVIAL (procedure-properties procedure))))
     (cond ((not place)
-- 
2.25.1