X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fir1final.lisp;h=4dd2925dd62fb755c9d86d8cb92e14d2e1472473;hb=c47519c9e63fd32a635943a84ec13d8a60d95f08;hp=c78d83a49fba024337960adc6d457806c4df0d6d;hpb=61c18727668ff0c3263a3d363e609d4522d545cc;p=sbcl.git

diff --git a/src/compiler/ir1final.lisp b/src/compiler/ir1final.lisp
index c78d83a..4dd2925 100644
--- a/src/compiler/ir1final.lisp
+++ b/src/compiler/ir1final.lisp
@@ -123,7 +123,14 @@
         (cond ((and (cast-p dest)
                     (not (cast-type-check dest))
                     (immediately-used-p lvar node))
-               (derive-node-type node (cast-asserted-type dest)))
+               (when (values-types-equal-or-intersect
+                      (node-derived-type node)
+                      (cast-asserted-type dest))
+                 ;; FIXME: We do not perform pathwise CAST->type-error
+                 ;; conversion, and type errors can later cause
+                 ;; backend failures. On the other hand, this version
+                 ;; produces less efficient code.
+                 (derive-node-type node (cast-asserted-type dest))))
               ((and (cast-p node)
                     (eq (cast-type-check node) :external))
                (aver (basic-combination-p dest))