From: Tom Tromey <tom@tromey.com>
Date: Thu, 5 Jul 2018 19:17:36 +0000 (-0600)
Subject: Allow conversion of bignums to floats
X-Git-Tag: emacs-27.0.90~4598^2~29
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=872faabbd8cb0f5518777b2d4fe7de187f684a92;p=emacs.git

Allow conversion of bignums to floats

* src/floatfns.c (extract_float, Ffloat): Handle bignums.
* src/lisp.h (XFLOATINT): Handle bignums.
* test/src/floatfns-tests.el (bignum-to-float): New test.
---

diff --git a/src/floatfns.c b/src/floatfns.c
index 766044ba35c..bd3f2dec80a 100644
--- a/src/floatfns.c
+++ b/src/floatfns.c
@@ -67,7 +67,7 @@ CHECK_FLOAT (Lisp_Object x)
 double
 extract_float (Lisp_Object num)
 {
-  CHECK_FIXNUM_OR_FLOAT (num);
+  CHECK_NUMBER (num);
   return XFLOATINT (num);
 }
 
@@ -289,8 +289,10 @@ DEFUN ("float", Ffloat, Sfloat, 1, 1, 0,
        doc: /* Return the floating point number equal to ARG.  */)
   (register Lisp_Object arg)
 {
-  CHECK_FIXNUM_OR_FLOAT (arg);
+  CHECK_NUMBER (arg);
 
+  if (BIGNUMP (arg))
+    return make_float (mpz_get_d (XBIGNUM (arg)->value));
   if (FIXNUMP (arg))
     return make_float ((double) XINT (arg));
   else				/* give 'em the same float back */
diff --git a/src/lisp.h b/src/lisp.h
index be679320494..63b057073d0 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2919,6 +2919,8 @@ CHECK_FIXNAT (Lisp_Object x)
 INLINE double
 XFLOATINT (Lisp_Object n)
 {
+  if (BIGNUMP (n))
+    return mpz_get_d (XBIGNUM (n)->value);
   return FLOATP (n) ? XFLOAT_DATA (n) : XINT (n);
 }
 
diff --git a/test/src/floatfns-tests.el b/test/src/floatfns-tests.el
index cb173eea76d..c87445b6bd2 100644
--- a/test/src/floatfns-tests.el
+++ b/test/src/floatfns-tests.el
@@ -34,4 +34,8 @@
   (should-error (ftruncate 0) :type 'wrong-type-argument)
   (should-error (fround 0) :type 'wrong-type-argument))
 
+(ert-deftest bignum-to-float ()
+  (should (eql (float (+ most-positive-fixnum 1))
+               (+ (float most-positive-fixnum) 1))))
+
 (provide 'floatfns-tests)