Avoid unnecessary byte position calculation for the gap movement.

Since all users of move_gap do CHAR_TO_BYTE for other purposes
anyway, all of them should use move_gap_both instead.
* lisp.h (move_gap): Remove prototype.
* insdel.c (move_gap): Remove.
(move_gap_both): Add eassert.
* editfns.c (Ftranspose_regions): Tweak to use move_gap_both.
* xml.c (parse_region): Likewise.

5 files changed, 28 insertions, 24 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index f0d875b2027..13a1f1a3858 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,14 @@
+2013-01-11  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Avoid unnecessary byte position calculation for the gap movement.
+        Since all users of move_gap do CHAR_TO_BYTE for other purposes
+        anyway, all of them should use move_gap_both instead.
+        * lisp.h (move_gap): Remove prototype.
+        * insdel.c (move_gap): Remove.
+        (move_gap_both): Add eassert.
+        * editfns.c (Ftranspose_regions): Tweak to use move_gap_both.
+        * xml.c (parse_region): Likewise.
+
 2013-01-11  Paul Eggert  <eggert@cs.ucla.edu>
 
         emacsclient -t should not suspend Emacs server (Bug#13387)
diff --git a/src/editfns.c b/src/editfns.c
index 26dfdac3ba8..64269bab8df 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -4522,7 +4522,7 @@ Transposing beyond buffer boundaries is an error.  */)
   (Lisp_Object startr1, Lisp_Object endr1, Lisp_Object startr2, Lisp_Object endr2, Lisp_Object leave_markers)
 {
   register ptrdiff_t start1, end1, start2, end2;
-  ptrdiff_t start1_byte, start2_byte, len1_byte, len2_byte;
+  ptrdiff_t start1_byte, start2_byte, len1_byte, len2_byte, end2_byte;
   ptrdiff_t gap, len1, len_mid, len2;
   unsigned char *start1_addr, *start2_addr, *temp;
 
@@ -4583,20 +4583,22 @@ Transposing beyond buffer boundaries is an error.  */)
      the gap the minimum distance to get it out of the way, and then
      deal with an unbroken array.  */
 
+  start1_byte = CHAR_TO_BYTE (start1);
+  end2_byte = CHAR_TO_BYTE (end2);
+
   /* Make sure the gap won't interfere, by moving it out of the text
      we will operate on.  */
   if (start1 < gap && gap < end2)
     {
       if (gap - start1 < end2 - gap)
-        move_gap (start1);
+        move_gap_both (start1, start1_byte);
       else
-        move_gap (end2);
+        move_gap_both (end2, end2_byte);
     }
 
-  start1_byte = CHAR_TO_BYTE (start1);
   start2_byte = CHAR_TO_BYTE (start2);
   len1_byte = CHAR_TO_BYTE (end1) - start1_byte;
-  len2_byte = CHAR_TO_BYTE (end2) - start2_byte;
+  len2_byte = end2_byte - start2_byte;
 
 #ifdef BYTE_COMBINING_DEBUG
   if (end1 == start2)
diff --git a/src/insdel.c b/src/insdel.c
index 905249d6714..c2a3cd42821 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -84,21 +84,14 @@ check_markers (void)
 
 #endif /* MARKER_DEBUG */
 
-/* Move gap to position CHARPOS.
-   Note that this can quit!  */
-
-void
-move_gap (ptrdiff_t charpos)
-{
-  move_gap_both (charpos, CHAR_TO_BYTE (charpos));
-}
-
 /* Move gap to byte position BYTEPOS, which is also char position CHARPOS.
    Note that this can quit!  */
 
 void
 move_gap_both (ptrdiff_t charpos, ptrdiff_t bytepos)
 {
+  eassert (charpos == BYTE_TO_CHAR (bytepos)
+           && bytepos == CHAR_TO_BYTE (charpos));
   if (bytepos < GPT_BYTE)
     gap_left (charpos, bytepos, 0);
   else if (bytepos > GPT_BYTE)
diff --git a/src/lisp.h b/src/lisp.h
index 3200127881b..22e0a188e4b 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2775,7 +2775,6 @@ extern void syms_of_image (void);
 
 /* Defined in insdel.c.  */
 extern Lisp_Object Qinhibit_modification_hooks;
-extern void move_gap (ptrdiff_t);
 extern void move_gap_both (ptrdiff_t, ptrdiff_t);
 extern _Noreturn void buffer_overflow (void);
 extern void make_gap (ptrdiff_t);
diff --git a/src/xml.c b/src/xml.c
index 5939c58a564..5a52b0c2a1e 100644
--- a/src/xml.c
+++ b/src/xml.c
@@ -180,8 +180,7 @@ parse_region (Lisp_Object start, Lisp_Object end, Lisp_Object base_url, int html
   xmlDoc *doc;
   Lisp_Object result = Qnil;
   const char *burl = "";
-  ptrdiff_t bytes;
-  ptrdiff_t istart, iend;
+  ptrdiff_t istart, iend, istart_byte, iend_byte;
 
   fn_xmlCheckVersion (LIBXML_VERSION);
 
@@ -189,9 +188,11 @@ parse_region (Lisp_Object start, Lisp_Object end, Lisp_Object base_url, int html
 
   istart = XINT (start);
   iend = XINT (end);
+  istart_byte = CHAR_TO_BYTE (istart);
+  iend_byte = CHAR_TO_BYTE (iend);
 
   if (istart < GPT && GPT < iend)
-    move_gap (iend);
+    move_gap_both (iend, iend_byte);
 
   if (! NILP (base_url))
     {
@@ -199,17 +200,15 @@ parse_region (Lisp_Object start, Lisp_Object end, Lisp_Object base_url, int html
       burl = SSDATA (base_url);
     }
 
-  bytes = CHAR_TO_BYTE (iend) - CHAR_TO_BYTE (istart);
-
   if (htmlp)
-    doc = fn_htmlReadMemory ((char *) BYTE_POS_ADDR (CHAR_TO_BYTE (istart)),
-                             bytes, burl, "utf-8",
+    doc = fn_htmlReadMemory ((char *) BYTE_POS_ADDR (istart_byte),
+                             iend_byte - istart_byte, burl, "utf-8",
                              HTML_PARSE_RECOVER|HTML_PARSE_NONET|
                              HTML_PARSE_NOWARNING|HTML_PARSE_NOERROR|
                              HTML_PARSE_NOBLANKS);
   else
-    doc = fn_xmlReadMemory ((char *) BYTE_POS_ADDR (CHAR_TO_BYTE (istart)),
-                            bytes, burl, "utf-8",
+    doc = fn_xmlReadMemory ((char *) BYTE_POS_ADDR (istart_byte),
+                            iend_byte - istart_byte, burl, "utf-8",
                             XML_PARSE_NONET|XML_PARSE_NOWARNING|
                             XML_PARSE_NOBLANKS |XML_PARSE_NOERROR);