1.0.48.20: fix mv-call regression from 1.0.43.57

[sbcl.git] / src / compiler / ctype.lisp

diff --git a/src/compiler/ctype.lisp b/src/compiler/ctype.lisp
index 124b488..eddb7f1 100644 (file)
--- a/src/compiler/ctype.lisp
+++ b/src/compiler/ctype.lisp
@@ -864,13 +864,17 @@
     (if trusted
         (derive-node-type call returns)
         (let ((lvar (node-lvar call)))
-          ;; If the value is used in a non-tail position, and
-          ;; the lvar is a single-use, assert the type. Multiple use
-          ;; sites need to be elided because the assertion has to apply
-          ;; to all uses. Tail positions are elided because the assertion
-          ;; would lose cause us not the be in a tail-position anymore.
+          ;; If the value is used in a non-tail position, and the lvar
+          ;; is a single-use, assert the type. Multiple use sites need
+          ;; to be elided because the assertion has to apply to all
+          ;; uses. Tail positions are elided because the assertion
+          ;; would cause us not the be in a tail-position anymore. MV
+          ;; calls are elided because not only are the assertions of
+          ;; less use there, but they can cause the MV call conversion
+          ;; to cause astray.
           (when (and lvar
                      (not (return-p (lvar-dest lvar)))
+                     (not (mv-combination-p (lvar-dest lvar)))
                      (lvar-has-single-use-p lvar))
             (when (assert-lvar-type lvar returns policy)
               (reoptimize-lvar lvar)))))