From a98d0daac473737da720c20f49f6f5abf36b074b Mon Sep 17 00:00:00 2001
From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= <mattiase@acm.org>
Date: Tue, 7 Feb 2023 13:16:40 +0100
Subject: [PATCH] Remove unnecessary cons in lexical eval
* src/eval.c (list_of_t): New.
(Feval): Use list_of_t instead of consing every time.
(syms_of_eval): Set list_of_t to (t) and staticpro it.
---
src/eval.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/src/eval.c b/src/eval.c
index d42f7ffe894..e377e30c6fb 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -2348,6 +2348,8 @@ it defines a macro. */)
}
+static Lisp_Object list_of_t; /* Never-modified constant containing (t). */
+
DEFUN ("eval", Feval, Seval, 1, 2, 0,
doc: /* Evaluate FORM and return its value.
If LEXICAL is t, evaluate using lexical scoping.
@@ -2357,7 +2359,7 @@ alist mapping symbols to their value. */)
{
specpdl_ref count = SPECPDL_INDEX ();
specbind (Qinternal_interpreter_environment,
- CONSP (lexical) || NILP (lexical) ? lexical : list1 (Qt));
+ CONSP (lexical) || NILP (lexical) ? lexical : list_of_t);
return unbind_to (count, eval_sub (form));
}
@@ -4392,6 +4394,9 @@ alist of active lexical bindings. */);
Qcatch_all_memory_full
= Fmake_symbol (build_pure_c_string ("catch-all-memory-full"));
+ staticpro (&list_of_t);
+ list_of_t = list1 (Qt);
+
defsubr (&Sor);
defsubr (&Sand);
defsubr (&Sif);
--
2.39.5