Subject: Re: [PATCH] `memql' does not work for bignums
From: Paul Eggert <[email-masked]>
To: Mattias Engdegård <[email-masked]>
Cc: [email-masked]
Date: Thu, 30 May 2019 15:01:19 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

Thanks for the bug report and fix. I installed it into master, followed 
by the attached performance tweaks.

From 24a58620cb8ce4aa11e2428d86e58911e7975aeb Mon Sep 17 00:00:00 2001
From: Paul Eggert <[email-masked]>
Date: Thu, 30 May 2019 14:57:21 -0700
Subject: [PATCH] Improve eq1/memql performance

* src/fns.c (Fmemql, Feql): Inline to tweak performance.
---
 src/fns.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/fns.c b/src/fns.c
index da830a9000..cb47b818f1 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -1521,7 +1521,7 @@ DEFUN ("elt", Felt, Selt, 2, 2, 0,
   EMACS_UINT word[WORDS_PER_DOUBLE];
 };
 
-/* Return true if X and Y are the same floating-point value.
+/* Return true if the floats X and Y have the same value.
    This looks at X's and Y's representation, since (unlike '==')
    it returns true if X and Y are the same NaN.  */
 static bool
@@ -1567,32 +1567,32 @@ DEFUN ("memql", Fmemql, Smemql, 2, 2, 0,
 The value is actually the tail of LIST whose car is ELT.  */)
   (Lisp_Object elt, Lisp_Object list)
 {
+  Lisp_Object tail = list;
+
   if (FLOATP (elt))
     {
-      Lisp_Object tail = list;
       FOR_EACH_TAIL (tail)
         {
           Lisp_Object tem = XCAR (tail);
           if (FLOATP (tem) && same_float (elt, tem))
             return tail;
         }
-      CHECK_LIST_END (tail, list);
-      return Qnil;
     }
   else if (BIGNUMP (elt))
     {
-      Lisp_Object tail = list;
       FOR_EACH_TAIL (tail)
         {
           Lisp_Object tem = XCAR (tail);
-          if (equal_no_quit (elt, tem))
+          if (BIGNUMP (tem)
+	      && mpz_cmp (XBIGNUM (elt)->value, XBIGNUM (tem)->value) == 0)
             return tail;
         }
-      CHECK_LIST_END (tail, list);
-      return Qnil;
     }
   else
     return Fmemq (elt, list);
+
+  CHECK_LIST_END (tail, list);
+  return Qnil;
 }
 
 DEFUN ("assq", Fassq, Sassq, 2, 2, 0,
@@ -2301,7 +2301,9 @@ DEFUN ("eql", Feql, Seql, 2, 2, 0,
   if (FLOATP (obj1))
     return FLOATP (obj2) && same_float (obj1, obj2) ? Qt : Qnil;
   else if (BIGNUMP (obj1))
-    return equal_no_quit (obj1, obj2) ? Qt : Qnil;
+    return ((BIGNUMP (obj2)
+	     && mpz_cmp (XBIGNUM (obj1)->value, XBIGNUM (obj2)->value) == 0)
+	    ? Qt : Qnil);
   else
     return EQ (obj1, obj2) ? Qt : Qnil;
 }
-- 
2.21.0