[XFS] Undo bit ops cleanup mod due to regression on 32-bit powermac

platform.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30559a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/fs/xfs/xfs_bit.c b/fs/xfs/xfs_bit.c
index 48228848f5ae..fab0b6d5a41b 100644
--- a/fs/xfs/xfs_bit.c
+++ b/fs/xfs/xfs_bit.c
@@ -25,6 +25,109 @@
  * XFS bit manipulation routines, used in non-realtime code.
  */
 
+#ifndef HAVE_ARCH_HIGHBIT
+/*
+ * Index of high bit number in byte, -1 for none set, 0..7 otherwise.
+ */
+static const char xfs_highbit[256] = {
+       -1, 0, 1, 1, 2, 2, 2, 2,                 /* 00 .. 07 */
+        3, 3, 3, 3, 3, 3, 3, 3,                 /* 08 .. 0f */
+        4, 4, 4, 4, 4, 4, 4, 4,                 /* 10 .. 17 */
+        4, 4, 4, 4, 4, 4, 4, 4,                 /* 18 .. 1f */
+        5, 5, 5, 5, 5, 5, 5, 5,                 /* 20 .. 27 */
+        5, 5, 5, 5, 5, 5, 5, 5,                 /* 28 .. 2f */
+        5, 5, 5, 5, 5, 5, 5, 5,                 /* 30 .. 37 */
+        5, 5, 5, 5, 5, 5, 5, 5,                 /* 38 .. 3f */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 40 .. 47 */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 48 .. 4f */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 50 .. 57 */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 58 .. 5f */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 60 .. 67 */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 68 .. 6f */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 70 .. 77 */
+        6, 6, 6, 6, 6, 6, 6, 6,                 /* 78 .. 7f */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* 80 .. 87 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* 88 .. 8f */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* 90 .. 97 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* 98 .. 9f */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* a0 .. a7 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* a8 .. af */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* b0 .. b7 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* b8 .. bf */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* c0 .. c7 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* c8 .. cf */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* d0 .. d7 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* d8 .. df */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* e0 .. e7 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* e8 .. ef */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* f0 .. f7 */
+        7, 7, 7, 7, 7, 7, 7, 7,                 /* f8 .. ff */
+};
+#endif
+
+/*
+ * xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set.
+ */
+inline int
+xfs_highbit32(
+        __uint32_t      v)
+{
+#ifdef HAVE_ARCH_HIGHBIT
+        return highbit32(v);
+#else
+        int             i;
+
+        if (v & 0xffff0000)
+                if (v & 0xff000000)
+                        i = 24;
+                else
+                        i = 16;
+        else if (v & 0x0000ffff)
+                if (v & 0x0000ff00)
+                        i = 8;
+                else
+                        i = 0;
+        else
+                return -1;
+        return i + xfs_highbit[(v >> i) & 0xff];
+#endif
+}
+
+/*
+ * xfs_lowbit64: get low bit set out of 64-bit argument, -1 if none set.
+ */
+int
+xfs_lowbit64(
+        __uint64_t      v)
+{
+        __uint32_t      w = (__uint32_t)v;
+        int             n = 0;
+
+        if (w) {        /* lower bits */
+                n = ffs(w);
+        } else {        /* upper bits */
+                w = (__uint32_t)(v >> 32);
+                if (w && (n = ffs(w)))
+                        n += 32;
+        }
+        return n - 1;
+}
+
+/*
+ * xfs_highbit64: get high bit set out of 64-bit argument, -1 if none set.
+ */
+int
+xfs_highbit64(
+        __uint64_t      v)
+{
+        __uint32_t      h = (__uint32_t)(v >> 32);
+
+        if (h)
+                return xfs_highbit32(h) + 32;
+        return xfs_highbit32((__uint32_t)v);
+}
+
+
 /*
  * Return whether bitmap is empty.
  * Size is number of words in the bitmap, which is padded to word boundary