X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fx86%2Finsts.lisp;fp=src%2Fcompiler%2Fx86%2Finsts.lisp;h=2479299db986c0742f49fbb2893a9672a3d6e020;hb=0e92abc181338bb9eec15eeb06f4b830ea54d746;hp=6ed33adc076b70e590c3ac17b00333112ffccdc6;hpb=c09f6c37a4b36901793d5a9ac7e99b5eeea83593;p=sbcl.git

diff --git a/src/compiler/x86/insts.lisp b/src/compiler/x86/insts.lisp
index 6ed33ad..2479299 100644
--- a/src/compiler/x86/insts.lisp
+++ b/src/compiler/x86/insts.lisp
@@ -2642,9 +2642,8 @@
 (define-instruction fxch (segment source)
   (:printer floating-point-fp ((op '(#b001 #b001))))
   (:emitter
-    (unless (and (tn-p source)
-                 (eq (sb-name (sc-sb (tn-sc source))) 'float-registers))
-      (cl:break))
+    (aver (and (tn-p source)
+               (eq (sb-name (sc-sb (tn-sc source))) 'float-registers)))
     (emit-byte segment #b11011001)
     (emit-fp-op segment source #b001)))