gzip: code shrink

function                                             old     new   delta
gzip_main                                            267     264      -3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/archival/gzip.c b/archival/gzip.c
index b08e60efd7bf2f34768b4a2553d6a1de24c0d545..3966a06b4255cee8d27f63574714a083f03f708e 100644 (file)
--- a/archival/gzip.c
+++ b/archival/gzip.c
@@ -259,7 +259,7 @@ enum {
 
 #if !ENABLE_FEATURE_GZIP_LEVELS
 
-       comp_level = 6,
+       comp_level_minus4 = 6 - 4,
        max_chain_length = 128,
 /* To speed up deflation, hash chains are never searched beyond this length.
  * A higher limit improves compression ratio but degrades the speed.
@@ -335,16 +335,16 @@ struct globals {
 #define head (G1.prev + WSIZE) /* hash head (see deflate.c) */
 
 #if ENABLE_FEATURE_GZIP_LEVELS
-       unsigned comp_level;
+       unsigned comp_level_minus4;     /* can be a byte */
        unsigned max_chain_length;
        unsigned max_lazy_match;
        unsigned good_match;
        unsigned nice_match;
-#define comp_level       (G1.comp_level)
-#define max_chain_length (G1.max_chain_length)
-#define max_lazy_match   (G1.max_lazy_match)
-#define good_match       (G1.good_match)
-#define nice_match       (G1.nice_match)
+#define comp_level_minus4 (G1.comp_level_minus4)
+#define max_chain_length  (G1.max_chain_length)
+#define max_lazy_match    (G1.max_lazy_match)
+#define good_match        (G1.good_match)
+#define nice_match        (G1.nice_match)
 #endif
 
 /* =========================================================================== */
@@ -2082,7 +2082,7 @@ static void zip(void)
        deflate_flags = 0x300; /* extra flags. OS id = 3 (Unix) */
 #if ENABLE_FEATURE_GZIP_LEVELS
        /* Note that comp_level < 4 do not exist in this version of gzip */
-       if (comp_level == 9) {
+       if (comp_level_minus4 == 9 - 4) {
                deflate_flags |= 0x02; /* SLOW flag */
        }
 #endif
@@ -2232,7 +2232,7 @@ int gzip_main(int argc UNUSED_PARAM, char **argv)
                opt = 1 << 5; /* default: 6 */
        opt = ffs(opt >> 4); /* Maps -1..-4 to [0], -5 to [1] ... -9 to [5] */
 
-       comp_level = opt + 4;
+       comp_level_minus4 = opt;
 
        max_chain_length = 1 << gzip_level_config[opt].chain_shift;
        good_match       = gzip_level_config[opt].good;