1.0.5.6: compare-and-swap / instance-set-conditional refactoring

[sbcl.git] / src / compiler / x86 / macros.lisp

diff --git a/src/compiler/x86/macros.lisp b/src/compiler/x86/macros.lisp
index 9d6ce4a..10540ca 100644 (file)
--- a/src/compiler/x86/macros.lisp
+++ b/src/compiler/x86/macros.lisp
@@ -389,6 +389,42 @@
 \f
 ;;;; indexed references
 
+(defmacro define-full-compare-and-swap
+    (name type offset lowtag scs el-type &optional translate)
+  `(progn
+     (define-vop (,name)
+         ,@(when translate `((:translate ,translate)))
+       (:policy :fast-safe)
+       (:args (object :scs (descriptor-reg) :to :eval)
+              (index :scs (any-reg immediate unsigned-reg) :to :result)
+              (old-value :scs ,scs :target eax)
+              (new-value :scs ,scs))
+       (:arg-types ,type tagged-num ,el-type ,el-type)
+       (:temporary (:sc descriptor-reg :offset eax-offset
+                        :from (:argument 2) :to :result :target value)  eax)
+       (:results (value :scs ,scs))
+       (:result-types ,el-type)
+       (:generator 5
+         (move eax old-value)
+         #!+sb-thread
+         (inst lock)
+         (let ((ea (sc-case index
+                     (immediate
+                      (make-ea :dword :base object
+                               :disp (- (* (+ ,offset (tn-value index))
+                                           n-word-bytes)
+                                        ,lowtag)))
+                     (unsigned-reg
+                      (make-ea :dword :base object :index index :scale 4
+                               :disp (- (* ,offset n-word-bytes)
+                                        ,lowtag)))
+                     (t
+                      (make-ea :dword :base object :index index
+                               :disp (- (* ,offset n-word-bytes)
+                                        ,lowtag))))))
+           (inst cmpxchg ea new-value))
+         (move value eax)))))
+
 (defmacro define-full-reffer (name type offset lowtag scs el-type &optional translate)
   `(progn
      (define-vop (,name)