A macro used internally in the bitops.h file to identify the number of
leading zeros (__cntlz) was implemented incorrectly for Xtensa processors
that don't provide the 'nsa/nsau' instructions. As a result, the dependent
functions and macros (ffs, ffz, fls) were broken.
Signed-off-by: Chris Zankel <chris@zankel.net>
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2001 - 2007 Tensilica Inc.
*/
#ifndef _XTENSA_BITOPS_H
*/
#ifndef _XTENSA_BITOPS_H
-static __inline__ int __cntlz (unsigned long x)
+static inline unsigned long __cntlz (unsigned long x)
{
int lz;
asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
{
int lz;
asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
-#else
-
-static __inline__ int __cntlz (unsigned long x)
-{
- unsigned long sum, x1, x2, x4, x8, x16;
- x1 = x & 0xAAAAAAAA;
- x2 = x & 0xCCCCCCCC;
- x4 = x & 0xF0F0F0F0;
- x8 = x & 0xFF00FF00;
- x16 = x & 0xFFFF0000;
- sum = x2 ? 2 : 0;
- sum += (x16 != 0) * 16;
- sum += (x8 != 0) * 8;
- sum += (x4 != 0) * 4;
- sum += (x1 != 0);
-
- return sum;
-}
-
-#endif
-
/*
* ffz: Find first zero in word. Undefined if no zero exists.
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*/
/*
* ffz: Find first zero in word. Undefined if no zero exists.
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*/
-static __inline__ int ffz(unsigned long x)
+static inline int ffz(unsigned long x)
- if ((x = ~x) == 0)
- return 32;
- return __cntlz(x & -x);
+ return 31 - __cntlz(~x & -~x);
}
/*
* __ffs: Find first bit set in word. Return 0 for bit 0
*/
}
/*
* __ffs: Find first bit set in word. Return 0 for bit 0
*/
-static __inline__ int __ffs(unsigned long x)
+static inline int __ffs(unsigned long x)
- return __cntlz(x & -x);
+ return 31 - __cntlz(x & -x);
/*
* ffs: Find first bit set in word. This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
/*
* ffs: Find first bit set in word. This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
-static __inline__ int ffs(unsigned long x)
+static inline int ffs(unsigned long x)
- return __cntlz(x & -x) + 1;
+ return 32 - __cntlz(x & -x);
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static __inline__ int fls (unsigned int x)
+static inline int fls (unsigned int x)
+ return 32 - __cntlz(x);
+
+#else
+
+/* Use the generic implementation if we don't have the nsa/nsau instructions. */
+
+# include <asm-generic/bitops/ffs.h>
+# include <asm-generic/bitops/__ffs.h>
+# include <asm-generic/bitops/ffz.h>
+# include <asm-generic/bitops/fls.h>
+
+#endif
+
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/find.h>
#include <asm-generic/bitops/ext2-non-atomic.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/find.h>
#include <asm-generic/bitops/ext2-non-atomic.h>