X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fx86%2Fpred.lisp;h=e83f65f12c3e50f31dd55e22f2dad4a03e41fe5f;hb=e119a2f79cf36039a39996f5490934b4d927529a;hp=8153429badf674741dba5b23ca4a362a71e95de4;hpb=0d871fd7a98fc4af92a8b942a1154761466ad8c9;p=sbcl.git

diff --git a/src/compiler/x86/pred.lisp b/src/compiler/x86/pred.lisp
index 8153429..e83f65f 100644
--- a/src/compiler/x86/pred.lisp
+++ b/src/compiler/x86/pred.lisp
@@ -38,33 +38,16 @@
   (:policy :fast-safe)
   (:translate eq)
   (:generator 3
-    (cond
-     ((sc-is y immediate)
-      (let ((val (tn-value y)))
-        (etypecase val
-          (integer
-           (if (and (zerop val) (sc-is x any-reg descriptor-reg))
-               (inst test x x) ; smaller
-             (inst cmp x (fixnumize val))))
-          (symbol
-           (inst cmp x (+ nil-value (static-symbol-offset val))))
-          (character
-           (inst cmp x (logior (ash (char-code val) n-widetag-bits)
-                               character-widetag))))))
-     ((sc-is x immediate) ; and y not immediate
-      ;; Swap the order to fit the compare instruction.
-      (let ((val (tn-value x)))
-        (etypecase val
-          (integer
-           (if (and (zerop val) (sc-is y any-reg descriptor-reg))
-               (inst test y y) ; smaller
-             (inst cmp y (fixnumize val))))
-          (symbol
-           (inst cmp y (+ nil-value (static-symbol-offset val))))
-          (character
-           (inst cmp y (logior (ash (char-code val) n-widetag-bits)
-                               character-widetag))))))
-      (t
-       (inst cmp x y)))
+    (let ((x-val (encode-value-if-immediate x))
+          (y-val (encode-value-if-immediate y)))
+      (cond
+        ;; Shorter instruction sequences for these two cases.
+        ((and (eql 0 y-val) (sc-is x any-reg descriptor-reg)) (inst test x x))
+        ((and (eql 0 x-val) (sc-is y any-reg descriptor-reg)) (inst test y y))
+
+        ;; An encoded value (literal integer) has to be the second argument.
+        ((sc-is x immediate) (inst cmp y x-val))
+
+        (t (inst cmp x y-val))))
 
     (inst jmp (if not-p :ne :e) target)))