From c6d2a26fac47eafc08f291dab78bbca3088f8ca2 Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Tue, 30 Jan 2018 17:39:57 +0100
Subject: gzip: code shrink (consolidate zeroing on reinit)
function old new delta
deflate - 938 +938
pack_gzip 1903 923 -980
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
archival/gzip.c | 125 +++++++++++++++++++++++++-------------------------------
1 file changed, 55 insertions(+), 70 deletions(-)
diff --git a/archival/gzip.c b/archival/gzip.c
index 2a5288cce..10eda7aa3 100644
--- a/archival/gzip.c
+++ b/archival/gzip.c
@@ -15,21 +15,6 @@
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-/* big objects in bss:
- * 00000020 b bl_count
- * 00000074 b base_length
- * 00000078 b base_dist
- * 00000078 b static_dtree
- * 0000009c b bl_tree
- * 000000f4 b dyn_dtree
- * 00000100 b length_code
- * 00000200 b dist_code
- * 0000023d b depth
- * 00000400 b flag_buf
- * 0000047a b heap
- * 00000480 b static_ltree
- * 000008f4 b dyn_ltree
- */
/* TODO: full support for -v for DESKTOP
* "/usr/bin/gzip -v a bogus aa" should say:
a: 85.1% -- replaced with a.gz
@@ -351,6 +336,44 @@ struct globals {
unsigned match_start; /* start of matching string */
unsigned lookahead; /* number of valid bytes ahead in window */
+/* number of input bytes */
+ ulg isize; /* only 32 bits stored in .gz file */
+
+/* bbox always use stdin/stdout */
+#define ifd STDIN_FILENO /* input file descriptor */
+#define ofd STDOUT_FILENO /* output file descriptor */
+
+#ifdef DEBUG
+ unsigned insize; /* valid bytes in l_buf */
+#endif
+ unsigned outcnt; /* bytes in output buffer */
+
+ smallint eofile; /* flag set at end of input file */
+
+/* ===========================================================================
+ * Local data used by the "bit string" routines.
+ */
+
+ unsigned short bi_buf;
+
+/* Output buffer. bits are inserted starting at the bottom (least significant
+ * bits).
+ */
+#undef BUF_SIZE
+#define BUF_SIZE (8 * sizeof(G1.bi_buf))
+
+/* Number of bits used within bi_buf. (bi_buf might be implemented on
+ * more than 16 bits on some systems.)
+ */
+ int bi_valid;
+
+#ifdef DEBUG
+ ulg bits_sent; /* bit length of the compressed data */
+#endif
+
+ /*uint32_t *crc_32_tab;*/
+ uint32_t crc; /* shift register contents */
+
/* ===========================================================================
*/
#define DECLARE(type, array, size) \
@@ -390,47 +413,6 @@ struct globals {
/* Heads of the hash chains or 0. */
/* DECLARE(Pos, head, 1<<HASH_BITS); */
#define head (G1.prev + WSIZE) /* hash head (see deflate.c) */
-
-/* number of input bytes */
- ulg isize; /* only 32 bits stored in .gz file */
-
-/* bbox always use stdin/stdout */
-#define ifd STDIN_FILENO /* input file descriptor */
-#define ofd STDOUT_FILENO /* output file descriptor */
-
-#ifdef DEBUG
- unsigned insize; /* valid bytes in l_buf */
-#endif
- unsigned outcnt; /* bytes in output buffer */
-
- smallint eofile; /* flag set at end of input file */
-
-/* ===========================================================================
- * Local data used by the "bit string" routines.
- */
-
- unsigned short bi_buf;
-
-/* Output buffer. bits are inserted starting at the bottom (least significant
- * bits).
- */
-
-#undef BUF_SIZE
-#define BUF_SIZE (8 * sizeof(G1.bi_buf))
-/* Number of bits used within bi_buf. (bi_buf might be implemented on
- * more than 16 bits on some systems.)
- */
-
- int bi_valid;
-
-/* Current input function. Set to mem_read for in-memory compression */
-
-#ifdef DEBUG
- ulg bits_sent; /* bit length of the compressed data */
-#endif
-
- /*uint32_t *crc_32_tab;*/
- uint32_t crc; /* shift register contents */
};
#define G1 (*(ptr_to_globals - 1))
@@ -1816,7 +1798,7 @@ do { \
head[G1.ins_h] = (s); \
} while (0)
-static ulg deflate(void)
+static NOINLINE ulg deflate(void)
{
IPos hash_head; /* head of hash chain */
IPos prev_match; /* previous match */
@@ -1927,10 +1909,10 @@ static ulg deflate(void)
*/
static void bi_init(void)
{
- G1.bi_buf = 0;
- G1.bi_valid = 0;
+ //G1.bi_buf = 0; // globals are zeroed in pack_gzip()
+ //G1.bi_valid = 0; // globals are zeroed in pack_gzip()
#ifdef DEBUG
- G1.bits_sent = 0L;
+ //G1.bits_sent = 0L; // globals are zeroed in pack_gzip()
#endif
}
@@ -1950,8 +1932,8 @@ static void lm_init(ush * flagsp)
*flagsp |= 2; /* FAST 4, SLOW 2 */
/* ??? reduce max_chain_length for binary files */
- G1.strstart = 0;
- G1.block_start = 0L;
+ //G1.strstart = 0; // globals are zeroed in pack_gzip()
+ //G1.block_start = 0L; // globals are zeroed in pack_gzip()
G1.lookahead = file_read(G1.window,
sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE);
@@ -1961,14 +1943,15 @@ static void lm_init(ush * flagsp)
G1.lookahead = 0;
return;
}
- G1.eofile = 0;
+ //G1.eofile = 0; // globals are zeroed in pack_gzip()
+
/* Make sure that we always have enough lookahead. This is important
* if input comes from a device such as a tty.
*/
while (G1.lookahead < MIN_LOOKAHEAD && !G1.eofile)
fill_window();
- G1.ins_h = 0;
+ //G1.ins_h = 0; // globals are zeroed in pack_gzip()
for (j = 0; j < MIN_MATCH - 1; j++)
UPDATE_HASH(G1.ins_h, G1.window[j]);
/* If lookahead < MIN_MATCH, ins_h is garbage, but this is
@@ -1990,7 +1973,7 @@ static void ct_init(void)
int code; /* code value */
int dist; /* distance index */
- G2.compressed_len = 0L;
+ //G2.compressed_len = 0L; // globals are zeroed in pack_gzip()
#ifdef NOT_NEEDED
if (G2.static_dtree[0].Len != 0)
@@ -2073,12 +2056,11 @@ static void ct_init(void)
* Deflate in to out.
* IN assertions: the input and output buffers are cleared.
*/
-
static void zip(void)
{
ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
- G1.outcnt = 0;
+ //G1.outcnt = 0; // globals are zeroed in pack_gzip()
/* Write the header to the gzip file. See algorithm.doc for the format */
/* magic header for gzip files: 1F 8B */
@@ -2111,12 +2093,15 @@ static void zip(void)
static
IF_DESKTOP(long long) int FAST_FUNC pack_gzip(transformer_state_t *xstate UNUSED_PARAM)
{
+ /* Reinit G1.xxx except pointers to allocated buffers */
+ memset(&G1, 0, offsetof(struct globals, l_buf));
+
/* Clear input and output buffers */
- G1.outcnt = 0;
+ //G1.outcnt = 0;
#ifdef DEBUG
- G1.insize = 0;
+ //G1.insize = 0;
#endif
- G1.isize = 0;
+ //G1.isize = 0;
/* Reinit G2.xxx */
memset(&G2, 0, sizeof(G2));
--
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