From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 5 Feb 2016 00:36:48 +0000 (-0800)
Subject: Prefer memcpy and memset to doing it by hand
X-Git-Tag: emacs-26.0.90~2737
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=605f9019b47764d5b46544e525fa46b375951b35;p=emacs.git

Prefer memcpy and memset to doing it by hand

* src/alloc.c (Fmake_vector):
* src/ccl.c (setup_ccl_program):
Use memset to clear array.
* src/alloc.c (Fvector, Fmake_byte_code):
* src/charset.c (Fdefine_charset_internal):
Use memcpy to copy array.
---

diff --git a/src/alloc.c b/src/alloc.c
index ca86a84b06d..031c78c07ca 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -3318,22 +3318,18 @@ allocate_buffer (void)
 DEFUN ("make-vector", Fmake_vector, Smake_vector, 2, 2, 0,
        doc: /* Return a newly created vector of length LENGTH, with each element being INIT.
 See also the function `vector'.  */)
-  (register Lisp_Object length, Lisp_Object init)
+  (Lisp_Object length, Lisp_Object init)
 {
-  Lisp_Object vector;
-  register ptrdiff_t sizei;
-  register ptrdiff_t i;
-  register struct Lisp_Vector *p;
-
   CHECK_NATNUM (length);
 
-  p = allocate_vector (XFASTINT (length));
-  sizei = XFASTINT (length);
-  for (i = 0; i < sizei; i++)
-    p->contents[i] = init;
+  struct Lisp_Vector *p = allocate_vector (XFASTINT (length));
+  if (XLI (init) == 0)
+    memset (p->contents, 0, XFASTINT (length) * sizeof p->contents[0]);
+  else
+    for (ptrdiff_t i = 0; i < XFASTINT (length); i++)
+      p->contents[i] = init;
 
-  XSETVECTOR (vector, p);
-  return vector;
+  return make_lisp_ptr (p, Lisp_Vectorlike);
 }
 
 DEFUN ("vector", Fvector, Svector, 0, MANY, 0,
@@ -3342,12 +3338,9 @@ Any number of arguments, even zero arguments, are allowed.
 usage: (vector &rest OBJECTS)  */)
   (ptrdiff_t nargs, Lisp_Object *args)
 {
-  ptrdiff_t i;
-  register Lisp_Object val = make_uninit_vector (nargs);
-  register struct Lisp_Vector *p = XVECTOR (val);
-
-  for (i = 0; i < nargs; i++)
-    p->contents[i] = args[i];
+  Lisp_Object val = make_uninit_vector (nargs);
+  struct Lisp_Vector *p = XVECTOR (val);
+  memcpy (p->contents, args, nargs * sizeof *args);
   return val;
 }
 
@@ -3386,9 +3379,8 @@ stack before executing the byte-code.
 usage: (make-byte-code ARGLIST BYTE-CODE CONSTANTS DEPTH &optional DOCSTRING INTERACTIVE-SPEC &rest ELEMENTS)  */)
   (ptrdiff_t nargs, Lisp_Object *args)
 {
-  ptrdiff_t i;
-  register Lisp_Object val = make_uninit_vector (nargs);
-  register struct Lisp_Vector *p = XVECTOR (val);
+  Lisp_Object val = make_uninit_vector (nargs);
+  struct Lisp_Vector *p = XVECTOR (val);
 
   /* We used to purecopy everything here, if purify-flag was set.  This worked
      OK for Emacs-23, but with Emacs-24's lexical binding code, it can be
@@ -3398,8 +3390,7 @@ usage: (make-byte-code ARGLIST BYTE-CODE CONSTANTS DEPTH &optional DOCSTRING INT
      just wasteful and other times plainly wrong (e.g. those free vars may want
      to be setcar'd).  */
 
-  for (i = 0; i < nargs; i++)
-    p->contents[i] = args[i];
+  memcpy (p->contents, args, nargs * sizeof *args);
   make_byte_code (p);
   XSETCOMPILED (val, p);
   return val;
diff --git a/src/ccl.c b/src/ccl.c
index 8cfd9b5c8ee..ef6cb9862b8 100644
--- a/src/ccl.c
+++ b/src/ccl.c
@@ -1908,8 +1908,6 @@ ccl_get_compiled_code (Lisp_Object ccl_prog, ptrdiff_t *idx)
 bool
 setup_ccl_program (struct ccl_program *ccl, Lisp_Object ccl_prog)
 {
-  int i;
-
   if (! NILP (ccl_prog))
     {
       struct Lisp_Vector *vp;
@@ -1931,8 +1929,7 @@ setup_ccl_program (struct ccl_program *ccl, Lisp_Object ccl_prog)
 	}
     }
   ccl->ic = CCL_HEADER_MAIN;
-  for (i = 0; i < 8; i++)
-    ccl->reg[i] = 0;
+  memset (ccl->reg, 0, sizeof ccl->reg);
   ccl->last_block = false;
   ccl->status = 0;
   ccl->stack_idx = 0;
diff --git a/src/charset.c b/src/charset.c
index 48e476813be..f911e9e5e0a 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -1050,8 +1050,8 @@ usage: (define-charset-internal ...)  */)
       /* Here, we just copy the parent's fast_map.  It's not accurate,
 	 but at least it works for quickly detecting which character
 	 DOESN'T belong to this charset.  */
-      for (i = 0; i < 190; i++)
-	charset.fast_map[i] = parent_charset->fast_map[i];
+      memcpy (charset.fast_map, parent_charset->fast_map,
+	      sizeof charset.fast_map);
 
       /* We also copy these for parents.  */
       charset.min_char = parent_charset->min_char;