lzx_common: add constants for minimum aligned offset slot

[wimlib] / src / lzx_compress.c

diff --git a/src/lzx_compress.c b/src/lzx_compress.c
index fdbce434cf794d7ccd3881b39c70bcb61c6d454b..8aff56f4ba3340eadbf32efdff5593dd49ceef0a 100644 (file)
--- a/src/lzx_compress.c
+++ b/src/lzx_compress.c
@@ -889,7 +889,12 @@ lzx_write_sequences(struct lzx_output_bitstream *os, int block_type,
                    const struct lzx_codes *codes)
 {
        const struct lzx_sequence *seq = sequences;
-       u32 ones_if_aligned = 0 - (block_type == LZX_BLOCKTYPE_ALIGNED);
+       unsigned min_aligned_offset_slot;
+
+       if (block_type == LZX_BLOCKTYPE_ALIGNED)
+               min_aligned_offset_slot = LZX_MIN_ALIGNED_OFFSET_SLOT;
+       else
+               min_aligned_offset_slot = LZX_MAX_OFFSET_SLOTS;
 
        for (;;) {
                /* Output the next sequence.  */
@@ -1001,7 +1006,7 @@ lzx_write_sequences(struct lzx_output_bitstream *os, int block_type,
                 * there are at least extra 3 offset bits required.  All other
                 * extra offset bits are output verbatim.  */
 
-               if ((adjusted_offset & ones_if_aligned) >= 16) {
+               if (offset_slot >= min_aligned_offset_slot) {
 
                        lzx_add_bits(os, extra_bits >> LZX_NUM_ALIGNED_OFFSET_BITS,
                                     num_extra_bits - LZX_NUM_ALIGNED_OFFSET_BITS);
@@ -1422,7 +1427,7 @@ lzx_walk_item_list(struct lzx_compressor *c, u32 block_size, bool is_16_bit,
                /* Record a match. */
 
                /* Tally the aligned offset symbol if needed. */
-               if (adjusted_offset >= 16)
+               if (adjusted_offset >= LZX_MIN_ALIGNED_OFFSET + LZX_OFFSET_ADJUSTMENT)
                        c->freqs.aligned[adjusted_offset & LZX_ALIGNED_OFFSET_BITMASK]++;
 
                /* Record the adjusted length. */
@@ -1704,7 +1709,7 @@ lzx_find_min_cost_path(struct lzx_compressor * const restrict c,
                                u32 cost;
 
                        #if CONSIDER_ALIGNED_COSTS
-                               if (offset >= 16 - LZX_OFFSET_ADJUSTMENT)
+                               if (offset >= LZX_MIN_ALIGNED_OFFSET)
                                        base_cost += c->costs.aligned[adjusted_offset &
                                                                      LZX_ALIGNED_OFFSET_BITMASK];
                        #endif
@@ -1845,7 +1850,7 @@ lzx_compute_match_costs(struct lzx_compressor *c)
                unsigned i;
 
        #if CONSIDER_ALIGNED_COSTS
-               if (offset_slot >= 8)
+               if (offset_slot >= LZX_MIN_ALIGNED_OFFSET_SLOT)
                        extra_cost -= LZX_NUM_ALIGNED_OFFSET_BITS * BIT_COST;
        #endif