lzop: remove method checks which are always true/false

function                                             old     new   delta
do_lzo_compress                                      232     224      -8
lzo_compress                                         531     488     -43
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-51)             Total: -51 bytes

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

1 files changed, 22 insertions, 15 deletions

diff --git a/archival/lzop.c b/archival/lzop.c
index b6a3cca09..8f604254c 100644
--- a/archival/lzop.c
+++ b/archival/lzop.c
@@ -641,12 +641,20 @@ static NOINLINE int lzo_compress(const header_t *h)
         uint32_t d_crc32 = CRC32_INIT_VALUE;
         uint8_t *wrk_mem = NULL;
 
+        /* Only these methods are possible, see lzo_set_method():
+         * -1:    M_LZO1X_1_15
+         * -2..6: M_LZO1X_1
+         * -7..9: M_LZO1X_999 if ENABLE_LZOP_COMPR_HIGH
+         */
         if (h->method == M_LZO1X_1)
                 wrk_mem = xzalloc(LZO1X_1_MEM_COMPRESS);
-        else if (h->method == M_LZO1X_1_15)
-                wrk_mem = xzalloc(LZO1X_1_15_MEM_COMPRESS);
-        else if (h->method == M_LZO1X_999)
+        else /* check only if it's not the only possibility */
+                IF_LZOP_COMPR_HIGH(if (h->method == M_LZO1X_1_15))
+                        wrk_mem = xzalloc(LZO1X_1_15_MEM_COMPRESS);
+#if ENABLE_LZOP_COMPR_HIGH
+        else /* must be h->method == M_LZO1X_999 */
                 wrk_mem = xzalloc(LZO1X_999_MEM_COMPRESS);
+#endif
 
         for (;;) {
                 unsigned src_len, dst_len;
@@ -675,16 +683,13 @@ static NOINLINE int lzo_compress(const header_t *h)
                 /* compress */
                 if (h->method == M_LZO1X_1)
                         r = lzo1x_1_compress(b1, src_len, b2, &dst_len, wrk_mem);
-                else if (h->method == M_LZO1X_1_15)
+                else IF_LZOP_COMPR_HIGH(if (h->method == M_LZO1X_1_15))
                         r = lzo1x_1_15_compress(b1, src_len, b2, &dst_len, wrk_mem);
 #if ENABLE_LZOP_COMPR_HIGH
-                else if (h->method == M_LZO1X_999)
+                else /* must be h->method == M_LZO1X_999 */
                         r = lzo1x_999_compress_level(b1, src_len, b2, &dst_len,
                                                 wrk_mem, h->level);
 #endif
-                else
-                        bb_error_msg_and_die("internal error");
-
                 if (r != 0) /* not LZO_E_OK */
                         bb_error_msg_and_die("%s: %s", "internal error", "compression");
 
@@ -1025,25 +1030,27 @@ static int read_header(header_t *h)
 /**********************************************************************/
 static void lzo_set_method(header_t *h)
 {
-        int level = 1;
+        smallint level;
+
+        /* levels 2..6 or none (defaults to level 3) */
+        h->method = M_LZO1X_1;
+        level = 5; /* levels 2-6 are actually the same */
 
         if (option_mask32 & OPT_1) {
                 h->method = M_LZO1X_1_15;
-        } else if (option_mask32 & OPT_789) {
+                level = 1;
+        }
+        if (option_mask32 & OPT_789) {
 #if ENABLE_LZOP_COMPR_HIGH
                 h->method = M_LZO1X_999;
+                level = 9;
                 if (option_mask32 & OPT_7)
                         level = 7;
                 else if (option_mask32 & OPT_8)
                         level = 8;
-                else
-                        level = 9;
 #else
                 bb_error_msg_and_die("high compression not compiled in");
 #endif
-        } else { /* levels 2..6 or none (defaults to level 3) */
-                h->method = M_LZO1X_1;
-                level = 5; /* levels 2-6 are actually the same */
         }
 
         h->level = level;