xfs: byteswap constants instead of variables

Micro-optimize various comparisms by always byteswapping the constant
instead of the variable, which allows to do the swap at compile instead
of runtime.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index db310f8fb76a..d04ea6a2dfaf 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -167,7 +167,7 @@ xfs_imap_to_bp(
 
                 dip = (xfs_dinode_t *)xfs_buf_offset(bp,
                                         (i << mp->m_sb.sb_inodelog));
-                di_ok = be16_to_cpu(dip->di_magic) == XFS_DINODE_MAGIC &&
+                di_ok = dip->di_magic == cpu_to_be16(XFS_DINODE_MAGIC) &&
                             XFS_DINODE_GOOD_VERSION(dip->di_version);
                 if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
                                                 XFS_ERRTAG_ITOBP_INOTOBP,
@@ -802,7 +802,7 @@ xfs_iread(
          * If we got something that isn't an inode it means someone
          * (nfs or dmi) has a stale handle.
          */
-        if (be16_to_cpu(dip->di_magic) != XFS_DINODE_MAGIC) {
+        if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC)) {
 #ifdef DEBUG
                 xfs_alert(mp,
                         "%s: dip->di_magic (0x%x) != XFS_DINODE_MAGIC (0x%x)",
@@ -1457,7 +1457,7 @@ xfs_iunlink(
         ASSERT(agi->agi_unlinked[bucket_index]);
         ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);
 
-        if (be32_to_cpu(agi->agi_unlinked[bucket_index]) != NULLAGINO) {
+        if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) {
                 /*
                  * There is already another inode in the bucket we need
                  * to add ourselves to.  Add us at the front of the list.
@@ -1468,8 +1468,7 @@ xfs_iunlink(
                 if (error)
                         return error;
 
-                ASSERT(be32_to_cpu(dip->di_next_unlinked) == NULLAGINO);
-                /* both on-disk, don't endian flip twice */
+                ASSERT(dip->di_next_unlinked == cpu_to_be32(NULLAGINO));
                 dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
                 offset = ip->i_imap.im_boffset +
                         offsetof(xfs_dinode_t, di_next_unlinked);
@@ -1534,7 +1533,7 @@ xfs_iunlink_remove(
         agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
         ASSERT(agino != 0);
         bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
-        ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != NULLAGINO);
+        ASSERT(agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO));
         ASSERT(agi->agi_unlinked[bucket_index]);
 
         if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
@@ -2659,7 +2658,7 @@ xfs_iflush_int(
          */
         xfs_synchronize_times(ip);
 
-        if (XFS_TEST_ERROR(be16_to_cpu(dip->di_magic) != XFS_DINODE_MAGIC,
+        if (XFS_TEST_ERROR(dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC),
                                mp, XFS_ERRTAG_IFLUSH_1, XFS_RANDOM_IFLUSH_1)) {
                 xfs_alert_tag(mp, XFS_PTAG_IFLUSH,
                         "%s: Bad inode %Lu magic number 0x%x, ptr 0x%p",