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authoryalin wang <yalin.wang2010@gmail.com>2015-09-09 15:39:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-10 13:29:01 -0700
commit8b235f2f16a472b8cfc10e8ef1286fcd3331e033 (patch)
tree833e552d3da36089d23727f25b6e2b133d769eb3 /lib
parente4e29dc4841d21943bec1bc5378ab421d2320d83 (diff)
downloadlinux-linaro-stable-8b235f2f16a472b8cfc10e8ef1286fcd3331e033.tar.gz
zlib_deflate/deftree: remove bi_reverse()
Remove bi_reverse() and use generic bitrev32() instead - it should have better performance on some platforms. Signed-off-by: yalin wang <yalin.wang2010@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/zlib_deflate/deftree.c6
-rw-r--r--lib/zlib_deflate/defutil.h16
2 files changed, 3 insertions, 19 deletions
diff --git a/lib/zlib_deflate/deftree.c b/lib/zlib_deflate/deftree.c
index ddf348299f24..9b1756b12743 100644
--- a/lib/zlib_deflate/deftree.c
+++ b/lib/zlib_deflate/deftree.c
@@ -35,6 +35,7 @@
/* #include "deflate.h" */
#include <linux/zutil.h>
+#include <linux/bitrev.h>
#include "defutil.h"
#ifdef DEBUG_ZLIB
@@ -146,7 +147,6 @@ static void send_all_trees (deflate_state *s, int lcodes, int dcodes,
static void compress_block (deflate_state *s, ct_data *ltree,
ct_data *dtree);
static void set_data_type (deflate_state *s);
-static unsigned bi_reverse (unsigned value, int length);
static void bi_windup (deflate_state *s);
static void bi_flush (deflate_state *s);
static void copy_block (deflate_state *s, char *buf, unsigned len,
@@ -284,7 +284,7 @@ static void tr_static_init(void)
/* The static distance tree is trivial: */
for (n = 0; n < D_CODES; n++) {
static_dtree[n].Len = 5;
- static_dtree[n].Code = bi_reverse((unsigned)n, 5);
+ static_dtree[n].Code = bitrev32((u32)n) >> (32 - 5);
}
static_init_done = 1;
}
@@ -520,7 +520,7 @@ static void gen_codes(
int len = tree[n].Len;
if (len == 0) continue;
/* Now reverse the bits */
- tree[n].Code = bi_reverse(next_code[len]++, len);
+ tree[n].Code = bitrev32((u32)(next_code[len]++)) >> (32 - len);
Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
diff --git a/lib/zlib_deflate/defutil.h b/lib/zlib_deflate/defutil.h
index b640b6402e99..a8c370897c9f 100644
--- a/lib/zlib_deflate/defutil.h
+++ b/lib/zlib_deflate/defutil.h
@@ -293,22 +293,6 @@ void zlib_tr_stored_type_only (deflate_state *);
}
/* ===========================================================================
- * Reverse the first len bits of a code, using straightforward code (a faster
- * method would use a table)
- * IN assertion: 1 <= len <= 15
- */
-static inline unsigned bi_reverse(unsigned code, /* the value to invert */
- int len) /* its bit length */
-{
- register unsigned res = 0;
- do {
- res |= code & 1;
- code >>= 1, res <<= 1;
- } while (--len > 0);
- return res >> 1;
-}
-
-/* ===========================================================================
* Flush the bit buffer, keeping at most 7 bits in it.
*/
static inline void bi_flush(deflate_state *s)