1.0.19.7: refactor stack allocation decisions

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

diff --git a/src/compiler/x86/pred.lisp b/src/compiler/x86/pred.lisp
index fcfe65f..e83f65f 100644 (file)
--- a/src/compiler/x86/pred.lisp
+++ b/src/compiler/x86/pred.lisp
@@ -27,44 +27,27 @@
 ;;; not immediate data.
 (define-vop (if-eq)
   (:args (x :scs (any-reg descriptor-reg control-stack constant)
-           :load-if (not (and (sc-is x immediate)
-                              (sc-is y any-reg descriptor-reg
-                                     control-stack constant))))
-        (y :scs (any-reg descriptor-reg immediate)
-           :load-if (not (and (sc-is x any-reg descriptor-reg immediate)
-                              (sc-is y control-stack constant)))))
+            :load-if (not (and (sc-is x immediate)
+                               (sc-is y any-reg descriptor-reg
+                                      control-stack constant))))
+         (y :scs (any-reg descriptor-reg immediate)
+            :load-if (not (and (sc-is x any-reg descriptor-reg immediate)
+                               (sc-is y control-stack constant)))))
   (:conditional)
   (:info target not-p)
   (: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) type-bits)
-                              base-char-type))))))
-     ((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) type-bits)
-                              base-char-type))))))
-      (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)))