Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6

[pandora-kernel.git] / include / asm-frv / bitops.h

diff --git a/include/asm-frv/bitops.h b/include/asm-frv/bitops.h
index 1f70d47..f8560ed 100644 (file)
--- a/include/asm-frv/bitops.h
+++ b/include/asm-frv/bitops.h
@@ -256,6 +256,50 @@ int __ffs(unsigned long x)
        return 31 - bit;
 }
 
+/*
+ * special slimline version of fls() for calculating ilog2_u32()
+ * - note: no protection against n == 0
+ */
+#define ARCH_HAS_ILOG2_U32
+static inline __attribute__((const))
+int __ilog2_u32(u32 n)
+{
+       int bit;
+       asm("scan %1,gr0,%0" : "=r"(bit) : "r"(n));
+       return 31 - bit;
+}
+
+/*
+ * special slimline version of fls64() for calculating ilog2_u64()
+ * - note: no protection against n == 0
+ */
+#define ARCH_HAS_ILOG2_U64
+static inline __attribute__((const))
+int __ilog2_u64(u64 n)
+{
+       union {
+               u64 ll;
+               struct { u32 h, l; };
+       } _;
+       int bit, x, y;
+
+       _.ll = n;
+
+       asm("   subcc           %3,gr0,gr0,icc0         \n"
+           "   ckeq            icc0,cc4                \n"
+           "   cscan.p         %3,gr0,%0       ,cc4,0  \n"
+           "   setlos          #63,%1                  \n"
+           "   cscan.p         %4,gr0,%0       ,cc4,1  \n"
+           "   setlos          #31,%2                  \n"
+           "   csub.p          %1,%0,%0        ,cc4,0  \n"
+           "   csub            %2,%0,%0        ,cc4,1  \n"
+           : "=&r"(bit), "=r"(x), "=r"(y)
+           : "0r"(_.h), "r"(_.l)
+           : "icc0", "cc4"
+           );
+       return bit;
+}
+
 #include <asm-generic/bitops/sched.h>
 #include <asm-generic/bitops/hweight.h>