Tune by using memchr and memrchr.

[bpt/emacs.git] / src / xdisp.c

diff --git a/src/xdisp.c b/src/xdisp.c
index 3b82de9..463f4f9 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1392,21 +1392,9 @@ pos_visible_p (struct window *w, ptrdiff_t charpos, int *x, int *y,
              Lisp_Object cpos = make_number (charpos);
              Lisp_Object spec = Fget_char_property (cpos, Qdisplay, Qnil);
              Lisp_Object string = string_from_display_spec (spec);
-             int newline_in_string = 0;
-
-             if (STRINGP (string))
-               {
-                 const char *s = SSDATA (string);
-                 const char *e = s + SBYTES (string);
-                 while (s < e)
-                   {
-                     if (*s++ == '\n')
-                       {
-                         newline_in_string = 1;
-                         break;
-                       }
-                   }
-               }
+             bool newline_in_string
+               = (STRINGP (string)
+                  && memchr (SDATA (string), '\n', SBYTES (string)));
              /* The tricky code below is needed because there's a
                 discrepancy between move_it_to and how we set cursor
                 when the display line ends in a newline from a
@@ -14759,7 +14747,7 @@ compute_window_start_on_continuation_line (struct window *w)
        SET_TEXT_POS (start_pos, ZV, ZV_BYTE);
 
       /* Find the start of the continued line.  This should be fast
-        because scan_buffer is fast (newline cache).  */
+        because find_newline is fast (newline cache).  */
       row = w->desired_matrix->rows + (WINDOW_WANTS_HEADER_LINE_P (w) ? 1 : 0);
       init_iterator (&it, w, CHARPOS (start_pos), BYTEPOS (start_pos),
                     row, DEFAULT_FACE_ID);
@@ -21626,31 +21614,36 @@ display_count_lines (ptrdiff_t start_byte,
          ceiling = min (limit_byte - 1, ceiling);
          ceiling_addr = BYTE_POS_ADDR (ceiling) + 1;
          base = (cursor = BYTE_POS_ADDR (start_byte));
-         while (1)
+
+         do
            {
              if (selective_display)
-               while (*cursor != '\n' && *cursor != 015 && ++cursor != ceiling_addr)
-                 ;
+               {
+                 while (*cursor != '\n' && *cursor != 015
+                        && ++cursor != ceiling_addr)
+                   continue;
+                 if (cursor == ceiling_addr)
+                   break;
+               }
              else
-               while (*cursor != '\n' && ++cursor != ceiling_addr)
-                 ;
+               {
+                 cursor = memchr (cursor, '\n', ceiling_addr - cursor);
+                 if (! cursor)
+                   break;
+               }
+
+             cursor++;
 
-             if (cursor != ceiling_addr)
+             if (--count == 0)
                {
-                 if (--count == 0)
-                   {
-                     start_byte += cursor - base + 1;
-                     *byte_pos_ptr = start_byte;
-                     return orig_count;
-                   }
-                 else
-                   if (++cursor == ceiling_addr)
-                     break;
+                 start_byte += cursor - base;
+                 *byte_pos_ptr = start_byte;
+                 return orig_count;
                }
-             else
-               break;
            }
-         start_byte += cursor - base;
+         while (cursor < ceiling_addr);
+
+         start_byte += ceiling_addr - base;
        }
     }
   else
@@ -21659,35 +21652,35 @@ display_count_lines (ptrdiff_t start_byte,
        {
          ceiling = BUFFER_FLOOR_OF (start_byte - 1);
          ceiling = max (limit_byte, ceiling);
-         ceiling_addr = BYTE_POS_ADDR (ceiling) - 1;
+         ceiling_addr = BYTE_POS_ADDR (ceiling);
          base = (cursor = BYTE_POS_ADDR (start_byte - 1) + 1);
          while (1)
            {
              if (selective_display)
-               while (--cursor != ceiling_addr
-                      && *cursor != '\n' && *cursor != 015)
-                 ;
+               {
+                 while (--cursor >= ceiling_addr
+                        && *cursor != '\n' && *cursor != 015)
+                   continue;
+                 if (cursor < ceiling_addr)
+                   break;
+               }
              else
-               while (--cursor != ceiling_addr && *cursor != '\n')
-                 ;
+               {
+                 cursor = memrchr (ceiling_addr, '\n', cursor - ceiling_addr);
+                 if (! cursor)
+                   break;
+               }
 
-             if (cursor != ceiling_addr)
+             if (++count == 0)
                {
-                 if (++count == 0)
-                   {
-                     start_byte += cursor - base + 1;
-                     *byte_pos_ptr = start_byte;
-                     /* When scanning backwards, we should
-                        not count the newline posterior to which we stop.  */
-                     return - orig_count - 1;
-                   }
+                 start_byte += cursor - base + 1;
+                 *byte_pos_ptr = start_byte;
+                 /* When scanning backwards, we should
+                    not count the newline posterior to which we stop.  */
+                 return - orig_count - 1;
                }
-             else
-               break;
            }
-         /* Here we add 1 to compensate for the last decrement
-            of CURSOR, which took it past the valid range.  */
-         start_byte += cursor - base + 1;
+         start_byte += ceiling_addr - base;
        }
     }