* fns.c (concat): Minor tuning based on overflow analysis.

This doesn't fix any bugs.  Use int to hold character, instead
of constantly refetching from Emacs object.  Use XFASTINT, not
XINT, for value known to be a character.  Don't bother comparing
a single byte to 0400, as it's always less.

diff --git a/src/ChangeLog b/src/ChangeLog
index 08b99fd1b79c3dbf45f057145859c504903762ce..f5b81cff88e868463faeca98fc14e8f242bfe23a 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,11 @@
 2011-06-13  Paul Eggert  <eggert@cs.ucla.edu>
 
+       * fns.c (concat): Minor tuning based on overflow analysis.
+       This doesn't fix any bugs.  Use int to hold character, instead
+       of constantly refetching from Emacs object.  Use XFASTINT, not
+       XINT, for value known to be a character.  Don't bother comparing
+       a single byte to 0400, as it's always less.
+
        * floatfns.c (Fexpt):
        * fileio.c (make_temp_name): Omit unnecessary cast to unsigned.
 

diff --git a/src/fns.c b/src/fns.c
index 250df728cab72d2bddeb6a03f450323f22d18722..b42e5f3b7c23054440222837f088740b0b90b2f5 100644 (file)
--- a/src/fns.c
+++ b/src/fns.c
@@ -504,6 +504,7 @@ concat (size_t nargs, Lisp_Object *args,
             as well as the number of characters.  */
          EMACS_INT i;
          Lisp_Object ch;
+         int c;
          EMACS_INT this_len_byte;
 
          if (VECTORP (this) || COMPILEDP (this))
@@ -511,9 +512,10 @@ concat (size_t nargs, Lisp_Object *args,
              {
                ch = AREF (this, i);
                CHECK_CHARACTER (ch);
-               this_len_byte = CHAR_BYTES (XINT (ch));
+               c = XFASTINT (ch);
+               this_len_byte = CHAR_BYTES (c);
                result_len_byte += this_len_byte;
-               if (! ASCII_CHAR_P (XINT (ch)) && ! CHAR_BYTE8_P (XINT (ch)))
+               if (! ASCII_CHAR_P (c) && ! CHAR_BYTE8_P (c))
                  some_multibyte = 1;
              }
          else if (BOOL_VECTOR_P (this) && XBOOL_VECTOR (this)->size > 0)
@@ -523,9 +525,10 @@ concat (size_t nargs, Lisp_Object *args,
              {
                ch = XCAR (this);
                CHECK_CHARACTER (ch);
-               this_len_byte = CHAR_BYTES (XINT (ch));
+               c = XFASTINT (ch);
+               this_len_byte = CHAR_BYTES (c);
                result_len_byte += this_len_byte;
-               if (! ASCII_CHAR_P (XINT (ch)) && ! CHAR_BYTE8_P (XINT (ch)))
+               if (! ASCII_CHAR_P (c) && ! CHAR_BYTE8_P (c))
                  some_multibyte = 1;
              }
          else if (STRINGP (this))
@@ -631,23 +634,16 @@ concat (size_t nargs, Lisp_Object *args,
              {
                int c;
                if (STRING_MULTIBYTE (this))
-                 {
-                   FETCH_STRING_CHAR_ADVANCE_NO_CHECK (c, this,
-                                                       thisindex,
-                                                       thisindex_byte);
-                   XSETFASTINT (elt, c);
-                 }
+                 FETCH_STRING_CHAR_ADVANCE_NO_CHECK (c, this,
+                                                     thisindex,
+                                                     thisindex_byte);
                else
                  {
-                   XSETFASTINT (elt, SREF (this, thisindex)); thisindex++;
-                   if (some_multibyte
-                       && !ASCII_CHAR_P (XINT (elt))
-                       && XINT (elt) < 0400)
-                     {
-                       c = BYTE8_TO_CHAR (XINT (elt));
-                       XSETINT (elt, c);
-                     }
+                   c = SREF (this, thisindex); thisindex++;
+                   if (some_multibyte && !ASCII_CHAR_P (c))
+                     c = BYTE8_TO_CHAR (c);
                  }
+               XSETFASTINT (elt, c);
              }
            else if (BOOL_VECTOR_P (this))
              {