0.8.16.26:

[sbcl.git] / src / compiler / alpha / cell.lisp

diff --git a/src/compiler/alpha/cell.lisp b/src/compiler/alpha/cell.lisp
index 24bfb51..3220e7d 100644 (file)
--- a/src/compiler/alpha/cell.lisp
+++ b/src/compiler/alpha/cell.lisp
@@ -86,6 +86,20 @@
   (:variant symbol-value-slot other-pointer-lowtag)
   (:policy :fast)
   (:translate symbol-value))
+
+(define-vop (symbol-hash)
+  (:policy :fast-safe)
+  (:translate symbol-hash)
+  (:args (symbol :scs (descriptor-reg)))
+  (:results (res :scs (any-reg)))
+  (:result-types positive-fixnum)
+  (:generator 2
+    ;; The symbol-hash slot of NIL holds NIL because it is also the
+    ;; cdr slot, so we have to strip off the two low bits to make sure
+    ;; it is a fixnum.  The lowtag selection magic that is required to
+    ;; ensure this is explained in the comment in objdef.lisp
+    (loadw res symbol symbol-hash-slot other-pointer-lowtag)
+    (inst bic res #.(ash lowtag-mask -1) res)))
 \f
 ;;;; fdefinition (FDEFN) objects