1 files changed, 106 insertions, 0 deletions
diff --git a/cpukit/score/include/rtems/score/bitfield.h b/cpukit/score/include/rtems/score/bitfield.h
new file mode 100644
index 0000000000..43f8fd09c4
--- /dev/null
+++ b/cpukit/score/include/rtems/score/bitfield.h
@@ -0,0 +1,106 @@
+/**
+ *  @file  rtems/score/bitfield.h
+ *
+ *  This include file contains all bit field manipulation routines.
+ */
+
+/*
+ *  COPYRIGHT (c) 1989-2006.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#ifndef _RTEMS_SCORE_BITFIELD_H
+#define _RTEMS_SCORE_BITFIELD_H
+
+/**
+ *  @defgroup ScoreBitfield Bitfield Handler
+ *
+ *  This handler encapsulates functionality that is used to manipulate the
+ *  priority bitfields used to lookup which priority has the highest
+ *  priority ready to execute thread.
+ */
+/**@{*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if ( CPU_USE_GENERIC_BITFIELD_DATA == TRUE )
+
+/**
+ *  This table is used by the generic bitfield routines to perform
+ *  a highly optimized bit scan without the use of special CPU
+ *  instructions.
+ */
+#ifndef SCORE_INIT
+extern const unsigned char __log2table[256];
+#else
+const unsigned char __log2table[256] = {
+    7, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
+    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+#endif
+
+#endif
+
+/**
+ *  This routine returns the @a _bit_number of the first bit set
+ *  in the specified value.  The correspondence between @a _bit_number
+ *  and actual bit position is processor dependent.  The search for
+ *  the first bit set may run from most to least significant bit
+ *  or vice-versa.
+ *
+ *  @param[in] _value is the value to bit scan.
+ *  @param[in] _bit_number is the position of the first bit set.
+ *
+ *  @note This routine is used when the executing thread is removed
+ *  from the ready state and, as a result, its performance has a
+ *  significant impact on the performance of the executive as a whole.
+ *
+ *  @note This routine must be a macro because if a CPU specific version
+ *  is used it will most likely use inline assembly.
+ */
+#if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE )
+#define _Bitfield_Find_first_bit( _value, _bit_number ) \
+        _CPU_Bitfield_Find_first_bit( _value, _bit_number )
+#else
+#define _Bitfield_Find_first_bit( _value, _bit_number ) \
+  { \
+    register uint32_t   __value = (uint32_t) (_value); \
+    register const unsigned char *__p = __log2table; \
+    \
+    if ( __value < 0x100 ) \
+      (_bit_number) = (Priority_bit_map_Control)( __p[ __value ] + 8 );  \
+    else \
+      (_bit_number) = (Priority_bit_map_Control)( __p[ __value >> 8 ] ); \
+  }
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+
+#endif
+/* end of include file */