Improve string_char_and_length speed

This tweak improved the CPU time performance of
‘make compile-always’ by about 1.7% on my platform.
* src/character.c (string_char): Remove; no longer used.
* src/character.h (string_char_and_length): Redo so that it
needn’t call string_char.  This helps the caller, which can now
become a leaf function.

1 files changed, 0 insertions, 45 deletions

diff --git a/src/character.c b/src/character.c
index edcec5f1c79..4902e564b1d 100644
--- a/src/character.c
+++ b/src/character.c
@@ -141,51 +141,6 @@ char_string (unsigned int c, unsigned char *p)
 }
 
 
-/* Return a character whose multibyte form is at P.  Set *LEN to the
-   byte length of the multibyte form.  */
-
-int
-string_char (const unsigned char *p, int *len)
-{
-  int c;
-  const unsigned char *saved_p = p;
-
-  if (*p < 0x80 || ! (*p & 0x20) || ! (*p & 0x10))
-    {
-      /* 1-, 2-, and 3-byte sequences can be handled by the macro.  */
-      c = string_char_advance (&p);
-    }
-  else if (! (*p & 0x08))
-    {
-      /* A 4-byte sequence of this form:
-         11110xxx 10xxxxxx 10xxxxxx 10xxxxxx  */
-      c = ((((p)[0] & 0x7) << 18)
-           | (((p)[1] & 0x3F) << 12)
-           | (((p)[2] & 0x3F) << 6)
-           | ((p)[3] & 0x3F));
-      p += 4;
-    }
-  else
-    {
-      /* A 5-byte sequence of this form:
-
-         111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
-
-         Note that the top 4 `x's are always 0, so shifting p[1] can
-         never exceed the maximum valid character codepoint. */
-      c = (/* (((p)[0] & 0x3) << 24) ... always 0, so no need to shift. */
-           (((p)[1] & 0x3F) << 18)
-           | (((p)[2] & 0x3F) << 12)
-           | (((p)[3] & 0x3F) << 6)
-           | ((p)[4] & 0x3F));
-      p += 5;
-    }
-
-  *len = p - saved_p;
-  return c;
-}
-
-
 /* Translate character C by translation table TABLE.  If no translation is
    found in TABLE, return the untranslated character.  If TABLE is a list,
    elements are char tables.  In that case, recursively translate C by all the