From: Paul Eggert <eggert@twinsun.com>
Date: Sat, 29 Aug 1998 17:57:22 +0000 (+0000)
Subject: (arith_driver, float_arith_driver): Compute (- x) by
X-Git-Tag: emacs-20.4~1801
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=e64981da92e01fad3d2299022892105768f0bd4c;p=emacs.git

(arith_driver, float_arith_driver): Compute (- x) by
using negation, not subtraction; this makes a difference with
IEEE floating point arithmetic (and also if integer arithmetic
is ones' complement or signed-magnitude!).
---

diff --git a/src/data.c b/src/data.c
index 9d3955dd3a9..cb04426edf6 100644
--- a/src/data.c
+++ b/src/data.c
@@ -2203,9 +2203,7 @@ arith_driver (code, nargs, args)
 	{
 	case Aadd: accum += next; break;
 	case Asub:
-	  if (!argnum && nargs != 1)
-	    next = - next;
-	  accum -= next;
+	  accum = argnum ? accum - next : nargs == 1 ? - next : next;
 	  break;
 	case Amult: accum *= next; break;
 	case Adiv:
@@ -2265,9 +2263,7 @@ float_arith_driver (accum, argnum, code, nargs, args)
 	  accum += next;
 	  break;
 	case Asub:
-	  if (!argnum && nargs != 1)
-	    next = - next;
-	  accum -= next;
+	  accum = argnum ? accum - next : nargs == 1 ? - next : next;
 	  break;
 	case Amult:
 	  accum *= next;