[lttv.git] / ltt / compiler.h

/* This file is part of the Linux Trace Toolkit trace reading library
 * Copyright (C) 2003-2004 Mathieu Desnoyers
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License Version 2.1 as published by the Free Software Foundation.
 *
 * This library 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 library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef COMPILER_H
#define COMPILER_H

/* Fast prediction if likely branches */
#define likely(x) __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)
 

/*
 * Check at compile time that something is of a particular type.
 * Always evaluates to 1 so you may use it easily in comparisons.
 */
#define typecheck(type,x) \
({  type __dummy; \
  typeof(x) __dummy2; \
  (void)(&__dummy == &__dummy2); \
  1; \
})

/* Deal with 32 wrap correctly */
#define guint32_after(a,b) \
  (typecheck(guint32, a) && \
   typecheck(guint32, b) && \
   ((gint32)(b) - (gint32)(a) < 0))
#define guint32_before(a,b)  guint32_after(b,a)

#define guint32_after_eq(a,b) \
  (typecheck(guint32, a) && \
   typecheck(guint32, b) && \
   ((gint32)(b) - (gint32)(a) <= 0))
#define guint32_before_eq(a,b)  guint32_after_eq(b,a)

#define __EXPORT __attribute__ ((visibility ("default")))

#endif //COMPILER_H
Commit	Line	Data
	1	/* This file is part of the Linux Trace Toolkit trace reading library
	2	* Copyright (C) 2003-2004 Mathieu Desnoyers
	3	*
	4	* This library is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU Lesser General Public
	6	* License Version 2.1 as published by the Free Software Foundation.
	7	*
	8	* This library is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* Lesser General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU Lesser General Public
	14	* License along with this library; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 02111-1307, USA.
	17	*/
	18
	19	#ifndef COMPILER_H
	20	#define COMPILER_H
	21
	22	/* Fast prediction if likely branches */
	23	#define likely(x) __builtin_expect(!!(x), 1)
	24	#define unlikely(x) __builtin_expect(!!(x), 0)
	25
	26
	27	/*
	28	* Check at compile time that something is of a particular type.
	29	* Always evaluates to 1 so you may use it easily in comparisons.
	30	*/
	31	#define typecheck(type,x) \
	32	({ type __dummy; \
	33	typeof(x) __dummy2; \
	34	(void)(&__dummy == &__dummy2); \
	35	1; \
	36	})
	37
	38	/* Deal with 32 wrap correctly */
	39	#define guint32_after(a,b) \
	40	(typecheck(guint32, a) && \
	41	typecheck(guint32, b) && \
	42	((gint32)(b) - (gint32)(a) < 0))
	43	#define guint32_before(a,b) guint32_after(b,a)
	44
	45	#define guint32_after_eq(a,b) \
	46	(typecheck(guint32, a) && \
	47	typecheck(guint32, b) && \
	48	((gint32)(b) - (gint32)(a) <= 0))
	49	#define guint32_before_eq(a,b) guint32_after_eq(b,a)
	50
	51	#define __EXPORT __attribute__ ((visibility ("default")))
	52
	53	#endif //COMPILER_H