[ust.git] / include / ust / processor.h

/* Copyright (C) 2009  Pierre-Marc Fournier
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#ifndef UST_PROCESSOR_H
#define UST_PROCESSOR_H

#define ____cacheline_aligned __attribute__((aligned(CAA_CACHE_LINE_SIZE)))

#ifdef __i386

static inline int fls(int x)
{
        int r;
        asm("bsrl %1,%0\n\t"
            "cmovzl %2,%0"
            : "=&r" (r) : "rm" (x), "rm" (-1));
        return r + 1;
}

#elif defined(__x86_64)

static inline int fls(int x)
{
        int r;
        asm("bsrl %1,%0\n\t"
            "cmovzl %2,%0"
            : "=&r" (r) : "rm" (x), "rm" (-1));
        return r + 1;
}

#elif defined(__PPC__)

static __inline__ int fls(unsigned int x)
{
        int lz;

        asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
        return 32 - lz;
}

#else /* arch-agnostic */

static __inline__ int fls(unsigned int x)
{
	int r = 32;

	if (!x)
		return 0;
	if (!(x & 0xFFFF0000U)) {
		x <<= 16;
		r -= 16;
	}
	if (!(x & 0xFF000000U)) {
		x <<= 8;
		r -= 8;
	}
	if (!(x & 0xF0000000U)) {
		x <<= 4;
		r -= 4;
	}
	if (!(x & 0xC0000000U)) {
		x <<= 2;
		r -= 2;
	}
	if (!(x & 0x80000000U)) {
		x <<= 1;
		r -= 1;
	}
	return r;
}

#endif

#endif /* UST_PROCESSOR_H */
Commit	Line	Data
	1	/* Copyright (C) 2009 Pierre-Marc Fournier
	2	*
	3	* This library is free software; you can redistribute it and/or
	4	* modify it under the terms of the GNU Lesser General Public
	5	* License as published by the Free Software Foundation; either
	6	* version 2.1 of the License, or (at your option) any later version.
	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 Free Software
	15	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	16	*/
	17
	18	#ifndef UST_PROCESSOR_H
	19	#define UST_PROCESSOR_H
	20
	21	#define ____cacheline_aligned __attribute__((aligned(CAA_CACHE_LINE_SIZE)))
	22
	23	#ifdef __i386
	24
	25	static inline int fls(int x)
	26	{
	27	int r;
	28	asm("bsrl %1,%0\n\t"
	29	"cmovzl %2,%0"
	30	: "=&r" (r) : "rm" (x), "rm" (-1));
	31	return r + 1;
	32	}
	33
	34	#elif defined(__x86_64)
	35
	36	static inline int fls(int x)
	37	{
	38	int r;
	39	asm("bsrl %1,%0\n\t"
	40	"cmovzl %2,%0"
	41	: "=&r" (r) : "rm" (x), "rm" (-1));
	42	return r + 1;
	43	}
	44
	45	#elif defined(__PPC__)
	46
	47	static __inline__ int fls(unsigned int x)
	48	{
	49	int lz;
	50
	51	asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
	52	return 32 - lz;
	53	}
	54
	55	#else /* arch-agnostic */
	56
	57	static __inline__ int fls(unsigned int x)
	58	{
	59	int r = 32;
	60
	61	if (!x)
	62	return 0;
	63	if (!(x & 0xFFFF0000U)) {
	64	x <<= 16;
	65	r -= 16;
	66	}
	67	if (!(x & 0xFF000000U)) {
	68	x <<= 8;
	69	r -= 8;
	70	}
	71	if (!(x & 0xF0000000U)) {
	72	x <<= 4;
	73	r -= 4;
	74	}
	75	if (!(x & 0xC0000000U)) {
	76	x <<= 2;
	77	r -= 2;
	78	}
	79	if (!(x & 0x80000000U)) {
	80	x <<= 1;
	81	r -= 1;
	82	}
	83	return r;
	84	}
	85
	86	#endif
	87
	88	#endif /* UST_PROCESSOR_H */