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| author | yalin wang <yalin.wang2010@gmail.com> | 2015-09-09 15:39:18 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-10 13:29:01 -0700 |
| commit | 8b235f2f16a472b8cfc10e8ef1286fcd3331e033 (patch) | |
| tree | 833e552d3da36089d23727f25b6e2b133d769eb3 | |
| parent | e4e29dc4841d21943bec1bc5378ab421d2320d83 (diff) | |
| download | linux-8b235f2f16a472b8cfc10e8ef1286fcd3331e033.tar.gz linux-8b235f2f16a472b8cfc10e8ef1286fcd3331e033.tar.bz2 linux-8b235f2f16a472b8cfc10e8ef1286fcd3331e033.zip | |
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>
| -rw-r--r-- | lib/zlib_deflate/deftree.c | 6 | ||||
| -rw-r--r-- | lib/zlib_deflate/defutil.h | 16 |
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) |