X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fir1final.lisp;h=4dd2925dd62fb755c9d86d8cb92e14d2e1472473;hb=c47519c9e63fd32a635943a84ec13d8a60d95f08;hp=d2888c5f79bf91522d141c9a34a1b5168a881802;hpb=57e21c4b62e8c1a1ee7ef59ed2abb0c864fb06bc;p=sbcl.git

diff --git a/src/compiler/ir1final.lisp b/src/compiler/ir1final.lisp
index d2888c5..4dd2925 100644
--- a/src/compiler/ir1final.lisp
+++ b/src/compiler/ir1final.lisp
@@ -115,6 +115,27 @@
 	    (setq atype (note-fun-use dest atype)))))
       (setf (info :function :assumed-type name) atype))))
 
+;;; Merge CASTs with preceding/following nodes.
+(defun ir1-merge-casts (component)
+  (do-blocks-backwards (block component)
+    (do-nodes-backwards (node lvar block)
+      (let ((dest (when lvar (lvar-dest lvar))))
+        (cond ((and (cast-p dest)
+                    (not (cast-type-check dest))
+                    (immediately-used-p lvar node))
+               (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))
+               (delete-filter node lvar (cast-value node))))))))
+
 ;;; Do miscellaneous things that we want to do once all optimization
 ;;; has been done:
 ;;;  -- Record the derived result type before the back-end trashes the
@@ -136,4 +157,7 @@
   (maphash (lambda (k v)
 	     (note-assumed-types component k v))
 	   *free-funs*)
+
+  (ir1-merge-casts component)
+
   (values))