c-strcaseeq.h

/* c-strcaseeq.h: Optimized case-insensitive string comparison in C locale.
 * Copyright (C) 2001-2002, 2007, 2009-2012 Free Software Foundation, Inc.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/* Written by Bruno Haible <bruno@clisp.org>.  */

#include "c-strcase.h"
#include "c-ctype.h"

/* STRCASEEQ allows to optimize string comparison with a small literal string.
 *    STRCASEEQ (s, "UTF-8", 'U','T','F','-','8',0,0,0,0)
 * is semantically equivalent to
 *    c_strcasecmp (s, "UTF-8") == 0
 * just faster. */

/* Help GCC to generate good code for string comparisons with
 * immediate strings. */
#if defined (__GNUC__) && defined (__OPTIMIZE__) && !defined(__STRICT_ANSI__)

/* Case insensitive comparison of ASCII characters. */
# if C_CTYPE_ASCII
#  define CASEEQ(other,upper) \
     (c_isupper(upper) ? (((other) & ~0x20) == (upper)) : ((other) == (upper)))
# elif C_CTYPE_CONSECUTIVE_UPPERCASE && C_CTYPE_CONSECUTIVE_LOWERCASE
#  define CASEEQ(other,upper) \
     (c_isupper(upper) ? (((other) == (upper)) || ((other) == ((upper) - 'A' + 'a'))) : (other) == (upper))
# else
#  define CASEEQ(other,upper) \
     (c_toupper(other) == (upper))
# endif /* C_CTYPE_ASCII || (C_CTYPE_CONSECUTIVE_UPPERCASE && C_CTYPE_CONSECUTIVE_LOWERCASE) */

static inline int
strcaseeq9(const char *s1, const char *s2)
{
  return (c_strcasecmp((s1 + 9), (s2 + 9)) == 0);
}

static inline int
strcaseeq8(const char *s1, const char *s2, char s28)
{
  if (CASEEQ(s1[8], s28)) {
      if (s28 == 0) {
		  return 1;
      } else {
		  return strcaseeq9(s1, s2);
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq7(const char *s1, const char *s2, char s27, char s28)
{
  if (CASEEQ(s1[7], s27)) {
      if (s27 == 0) {
		  return 1;
      } else {
		  return strcaseeq8(s1, s2, s28);
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq6(const char *s1, const char *s2, char s26, char s27, char s28)
{
  if (CASEEQ(s1[6], s26)) {
      if (s26 == 0) {
		  return 1;
      } else {
		  return strcaseeq7(s1, s2, s27, s28);
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq5(const char *s1, const char *s2,
		   char s25, char s26, char s27, char s28)
{
  if (CASEEQ(s1[5], s25)) {
      if (s25 == 0) {
		  return 1;
      } else {
		  /* why is it that only once we get to this level that '-Winline'
		   * kicks in? */
		  return strcaseeq6(s1, s2, s26, s27, s28); /* just like the others */
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq4(const char *s1, const char *s2,
		   char s24, char s25, char s26, char s27, char s28)
{
  if (CASEEQ(s1[4], s24)) {
      if (s24 == 0) {
		  return 1;
      } else {
		  return strcaseeq5(s1, s2, s25, s26, s27, s28);
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq3(const char *s1, const char *s2,
		   char s23, char s24, char s25, char s26, char s27, char s28)
{
  if (CASEEQ(s1[3], s23)) {
      if (s23 == 0) {
		  return 1;
      } else {
		  return strcaseeq4(s1, s2, s24, s25, s26, s27, s28);
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq2(const char *s1, const char *s2,
		   char s22, char s23, char s24, char s25, char s26, char s27, char s28)
{
  if (CASEEQ(s1[2], s22)) {
      if (s22 == 0) {
		  return 1;
      } else {
		  return strcaseeq3(s1, s2, s23, s24, s25, s26, s27, s28);
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq1(const char *s1, const char *s2,
		   char s21, char s22, char s23, char s24,
		   char s25, char s26, char s27, char s28)
{
  if (CASEEQ(s1[1], s21)) {
      if (s21 == 0) {
		  return 1;
      } else {
		  return strcaseeq2(s1, s2, s22, s23, s24, s25, s26, s27, s28);
	  }
  } else {
	  return 0;
  }
}

static inline int
strcaseeq0(const char *s1, const char *s2,
		   char s20, char s21, char s22, char s23,
		   char s24, char s25, char s26, char s27, char s28)
{
  if (CASEEQ(s1[0], s20)) {
      if (s20 == 0) {
		  return 1;
      } else {
		  return strcaseeq1(s1, s2, s21, s22, s23, s24, s25, s26, s27, s28);
	  }
  } else {
	  return 0;
  }
}

# define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
   strcaseeq0(s1, s2, s20, s21, s22, s23, s24, s25, s26, s27, s28)

#else

# define STRCASEEQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
   (c_strcasecmp(s1, s2) == 0)

#endif /* __GNUC__ && __OPTIMIZE__ && !__STRICT_ANSI__ */

/* EOF */