0.8.6.28:

[sbcl.git] / src / compiler / float-tran.lisp

diff --git a/src/compiler/float-tran.lisp b/src/compiler/float-tran.lisp
index 49b9cc7..413ca99 100644 (file)
--- a/src/compiler/float-tran.lisp
+++ b/src/compiler/float-tran.lisp
@@ -906,17 +906,21 @@
        ((csubtypep y (specifier-type 'integer))
         ;; A real raised to an integer power is well-defined.
         (merged-interval-expt x y))
+       ;; A real raised to a non-integral power can be a float or a
+       ;; complex number.
+       ((or (csubtypep x (specifier-type '(rational 0)))
+            (csubtypep x (specifier-type '(float (0d0)))))
+        ;; But a positive real to any power is well-defined.
+        (merged-interval-expt x y))
+       ((and (csubtypep x (specifier-type 'rational))
+             (csubtypep x (specifier-type 'rational)))
+        ;; A rational to the power of a rational could be a rational
+        ;; or a possibly-complex single float
+        (specifier-type '(or rational single-float (complex single-float))))
        (t
-        ;; A real raised to a non-integral power can be a float or a
-        ;; complex number.
-        (cond ((or (csubtypep x (specifier-type '(rational 0)))
-                   (csubtypep x (specifier-type '(float (0d0)))))
-               ;; But a positive real to any power is well-defined.
-               (merged-interval-expt x y))
-              (t
-               ;; a real to some power. The result could be a real
-               ;; or a complex.
-               (float-or-complex-float-type (numeric-contagion x y)))))))
+        ;; a real to some power. The result could be a real or a
+        ;; complex.
+        (float-or-complex-float-type (numeric-contagion x y)))))
 
 (defoptimizer (expt derive-type) ((x y))
   (two-arg-derive-type x y #'expt-derive-type-aux #'expt))