From a3aeee88aaf843de49e4815e4b2d61743e423441 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= Date: Wed, 26 Jan 2022 11:28:33 +0100 Subject: [PATCH] Minor `concat` tweaks * src/fns.c (concat): Do things in the right order for speed. (concat_strings): Initialise variable. --- src/fns.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/src/fns.c b/src/fns.c index 87237f3b5e4..16f1ebe4392 100644 --- a/src/fns.c +++ b/src/fns.c @@ -790,9 +790,8 @@ concat_strings (ptrdiff_t nargs, Lisp_Object *args) if (STRINGP (arg)) { - ptrdiff_t arg_len_byte; + ptrdiff_t arg_len_byte = SBYTES (arg); len = SCHARS (arg); - arg_len_byte = SBYTES (arg); if (STRING_MULTIBYTE (arg)) dest_multibyte = true; else @@ -986,15 +985,16 @@ concat (ptrdiff_t nargs, Lisp_Object *args, Lisp_Object last_tail, memory_full (SIZE_MAX); } + /* When the target is a list, return the tail directly if all other + arguments are empty. */ + if (!vector_target && result_len == 0) + return last_tail; + /* Create the output object. */ Lisp_Object result = vector_target ? make_nil_vector (result_len) : Fmake_list (make_fixnum (result_len), Qnil); - /* In `append', if all but last arg are nil, return last arg. */ - if (!vector_target && NILP (result)) - return last_tail; - /* Copy the contents of the args into the result. */ Lisp_Object tail = Qnil; ptrdiff_t toindex = 0; @@ -1022,14 +1022,12 @@ concat (ptrdiff_t nargs, Lisp_Object *args, Lisp_Object last_tail, /* Fetch next element of `arg' arg into `elt', or break if `arg' is exhausted. */ Lisp_Object elt; - if (NILP (arg)) - break; if (CONSP (arg)) { elt = XCAR (arg); arg = XCDR (arg); } - else if (argindex >= arglen) + else if (NILP (arg) || argindex >= arglen) break; else if (STRINGP (arg)) { -- 2.39.5