Make EXPT use double-precision throughout in more cases

[sbcl.git] / src / code / irrat.lisp

diff --git a/src/code/irrat.lisp b/src/code/irrat.lisp
index 93c957b..1c684ac 100644 (file)
--- a/src/code/irrat.lisp
+++ b/src/code/irrat.lisp
@@ -323,8 +323,12 @@
                                    (coerce (* pow (%cos y*pi))
                                            rtype)
                                    (coerce (* pow (%sin y*pi))
-                                           rtype)))))))))))))
-      (declare (inline real-expt))
+                                           rtype))))))))))))
+             (complex-expt (base power)
+               (if (and (zerop base) (plusp (realpart power)))
+                   (* base power)
+                   (exp (* power (log base))))))
+      (declare (inline real-expt complex-expt))
       (number-dispatch ((base number) (power number))
         (((foreach fixnum (or bignum ratio) (complex rational)) integer)
          (intexp base power))
@@ -338,19 +342,33 @@
          (real-expt base power 'double-float))
         ((double-float single-float)
          (real-expt base power 'double-float))
-        (((foreach (complex rational) (complex float)) rational)
+        ;; Handle (expt <complex> <rational>), except the case dealt with
+        ;; in the first clause above, (expt <(complex rational)> <integer>).
+        (((foreach (complex rational) (complex single-float)
+                   (complex double-float))
+          rational)
          (* (expt (abs base) power)
             (cis (* power (phase base)))))
-        (((foreach fixnum (or bignum ratio) single-float double-float)
-          complex)
-         (if (and (zerop base) (plusp (realpart power)))
-             (* base power)
-             (exp (* power (log base)))))
-        (((foreach (complex float) (complex rational))
+        ;; The next three clauses handle (expt <real> <complex>).
+        (((foreach fixnum (or bignum ratio) single-float)
+          (foreach (complex single-float) (complex rational)))
+         (complex-expt base power))
+        (((foreach fixnum (or bignum ratio) single-float)
+          (complex double-float))
+         (complex-expt (coerce base 'double-float) power))
+        ((double-float complex)
+         (complex-expt base power))
+        ;; The next three clauses handle (expt <complex> <float>) and
+        ;; (expt <complex> <complex>).
+        (((foreach (complex single-float) (complex rational))
+          (foreach (complex single-float) (complex rational) single-float))
+         (complex-expt base power))
+        (((foreach (complex single-float) (complex rational))
+          (foreach (complex double-float) double-float))
+         (complex-expt (coerce base '(complex double-float)) power))
+        (((complex double-float)
           (foreach complex double-float single-float))
-         (if (and (zerop base) (plusp (realpart power)))
-             (* base power)
-             (exp (* power (log base)))))))))
+         (complex-expt base power))))))
 
 ;;; FIXME: Maybe rename this so that it's clearer that it only works
 ;;; on integers?