From: Taylor R Campbell <campbell@mumble.net>
Date: Thu, 10 Jan 2019 04:01:57 +0000 (+0000)
Subject: Disable constant-folding machine-dependent primitives in LIARC.
X-Git-Tag: mit-scheme-pucked-10.1.10~6^2~54
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=23713958b57766536a37f22507999fb582f6f136;p=mit-scheme.git

Disable constant-folding machine-dependent primitives in LIARC.

These are not valid across word size changes, but LIARC does not
expose compiler:cross-compiling?.
---

diff --git a/src/compiler/base/utils.scm b/src/compiler/base/utils.scm
index 13c54ed4a..d580de2d8 100644
--- a/src/compiler/base/utils.scm
+++ b/src/compiler/base/utils.scm
@@ -541,7 +541,11 @@ USA.
 
 (define (constant-foldable-primitive? operator)
   (and (memq operator function-primitives)
-       (not (and compiler:cross-compiling?
+       (not (and (or compiler:cross-compiling?
+		     ;; C back end never sets COMPILER:CROSS-COMPILING?
+		     ;; but it has a nonconstant SCHEME-OBJECT-WIDTH
+		     ;; which serves as a proxy.
+		     (not (number? scheme-object-width)))
 		 (memq operator machine-dependent-primitives)))))
 
 (define-integrable (side-effect-free-primitive? operator)