Add __bitcount*() to RTEMS <machine/types.h>

Use a dedicated header file <machine/_bitcount.h> to avoid cyclic header
dependencies in future changes.

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>

newlib/libc/sys/rtems/include/machine/_bitcount.h

@@ -0,0 +1,90 @@
+/*-
+ * Copyright (c) 2015 John Baldwin <jhb@FreeBSD.org>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _MACHINE__BITCOUNT_H
+#define	_MACHINE__BITCOUNT_H
+
+#ifdef __POPCNT__
+#define	__bitcount64(x)	__builtin_popcountll((__uint64_t)(x))
+#define	__bitcount32(x)	__builtin_popcountl((__uint32_t)(x))
+#define	__bitcount16(x)	__builtin_popcount((__uint16_t)(x))
+#define	__bitcountl(x)	__builtin_popcountl((unsigned long)(x))
+#define	__bitcount(x)	__builtin_popcount((unsigned int)(x))
+#else /* !__POPCNT__ */
+static __inline __uint16_t
+__bitcount16(__uint16_t _x)
+{
+	_x = (_x & 0x5555u) + ((_x & 0xaaaau) >> 1);
+	_x = (_x & 0x3333u) + ((_x & 0xccccu) >> 2);
+	_x = (_x + (_x >> 4)) & 0x0f0fu;
+	_x = (_x + (_x >> 8)) & 0x00ffu;
+	return (_x);
+}
+
+static __inline __uint32_t
+__bitcount32(__uint32_t _x)
+{
+	_x = (_x & 0x55555555u) + ((_x & 0xaaaaaaaau) >> 1);
+	_x = (_x & 0x33333333u) + ((_x & 0xccccccccu) >> 2);
+	_x = (_x + (_x >> 4)) & 0x0f0f0f0fu;
+	_x = (_x + (_x >> 8));
+	_x = (_x + (_x >> 16)) & 0x000000ffu;
+	return (_x);
+}
+
+static __inline __uint64_t
+__bitcount64(__uint64_t _x)
+{
+#if __SIZEOF_LONG__ == 8
+	_x = (_x & 0x5555555555555555u) + ((_x & 0xaaaaaaaaaaaaaaaau) >> 1);
+	_x = (_x & 0x3333333333333333u) + ((_x & 0xccccccccccccccccu) >> 2);
+	_x = (_x + (_x >> 4)) & 0x0f0f0f0f0f0f0f0fu;
+	_x = (_x + (_x >> 8));
+	_x = (_x + (_x >> 16));
+	_x = (_x + (_x >> 32)) & 0x000000ffu;
+	return (_x);
+#else
+	return (__bitcount32(_x >> 32) + __bitcount32(_x));
+#endif
+}
+
+#if __SIZEOF_LONG__ == 8
+#define	__bitcountl(x)	__bitcount64((unsigned long)(x))
+#else
+#define	__bitcountl(x)	__bitcount32((unsigned long)(x))
+#endif
+
+#if __SIZEOF_INT__ == 8
+#define	__bitcount(x)	__bitcount64((unsigned int)(x))
+#else
+#define	__bitcount(x)	__bitcount32((unsigned int)(x))
+#endif
+#endif /* __POPCNT__ */
+
+#endif /* _MACHINE__BITCOUNT_H */

newlib/libc/sys/rtems/include/machine/types.h

@@ -28,6 +28,8 @@
 #error "must be included via <sys/types.h>"
 #endif /* !_SYS_TYPES_H */
 
+#include <machine/_bitcount.h>
+
 #if __BSD_VISIBLE
 
 #ifndef _ACCMODE_T_DECLARED