lzx_write_match(): One-branch check for aligned offset case

diff --git a/src/lzx-compress.c b/src/lzx-compress.c
index 4c89b7d9768e1110b5e54f71580ba6ec0a592327..23d410b910b4193d1dcb5bd63af44a1e9dc1b725 100644 (file)
--- a/src/lzx-compress.c
+++ b/src/lzx-compress.c
@@ -659,9 +659,9 @@ lzx_make_huffman_codes(const struct lzx_freqs *freqs,
  *
  * @os:
  *     The bitstream to which to write the match.
  *
  * @os:
  *     The bitstream to which to write the match.

- * @block_type:
- *     The type of the LZX block (LZX_BLOCKTYPE_ALIGNED or
- *     LZX_BLOCKTYPE_VERBATIM)
+ * @ones_if_aligned
+ *     A mask of all ones if the block is of type LZX_BLOCKTYPE_ALIGNED,
+ *     otherwise 0.

  * @match:
  *     The match data.
  * @codes:
  * @match:
  *     The match data.
  * @codes:


@@ -669,7 +669,7 @@ lzx_make_huffman_codes(const struct lzx_freqs *freqs,
  *     and aligned offset Huffman codes for the current LZX compressed block.
  */
 static void
  *     and aligned offset Huffman codes for the current LZX compressed block.
  */
 static void

-lzx_write_match(struct lzx_output_bitstream *os, int block_type,
+lzx_write_match(struct lzx_output_bitstream *os, unsigned ones_if_aligned,

                struct lzx_item match, const struct lzx_codes *codes)
 {
        unsigned match_len_minus_2 = match.data & 0xff;
                struct lzx_item match, const struct lzx_codes *codes)
 {
        unsigned match_len_minus_2 = match.data & 0xff;


@@ -719,7 +719,7 @@ lzx_write_match(struct lzx_output_bitstream *os, int block_type,
 
        num_extra_bits = lzx_get_num_extra_bits(position_slot);
 
 
        num_extra_bits = lzx_get_num_extra_bits(position_slot);
 

-       if ((block_type == LZX_BLOCKTYPE_ALIGNED) && (num_extra_bits >= 3)) {
+       if ((num_extra_bits & ones_if_aligned) >= 3) {

 
                /* Aligned offset blocks: The low 3 bits of the position footer
                 * are Huffman-encoded using the aligned offset code.  The
 
                /* Aligned offset blocks: The low 3 bits of the position footer
                 * are Huffman-encoded using the aligned offset code.  The


@@ -948,12 +948,14 @@ lzx_write_items(struct lzx_output_bitstream *os, int block_type,
                const struct lzx_item items[], u32 num_items,
                const struct lzx_codes *codes)
 {
                const struct lzx_item items[], u32 num_items,
                const struct lzx_codes *codes)
 {

+       unsigned ones_if_aligned = 0U - (block_type == LZX_BLOCKTYPE_ALIGNED);
+

        for (u32 i = 0; i < num_items; i++) {
                /* The high bit of the 32-bit intermediate representation
                 * indicates whether the item is an actual LZ-style match (1) or
                 * a literal byte (0).  */
                if (items[i].data & 0x80000000)
        for (u32 i = 0; i < num_items; i++) {
                /* The high bit of the 32-bit intermediate representation
                 * indicates whether the item is an actual LZ-style match (1) or
                 * a literal byte (0).  */
                if (items[i].data & 0x80000000)

-                       lzx_write_match(os, block_type, items[i], codes);
+                       lzx_write_match(os, ones_if_aligned, items[i], codes);

                else
                        lzx_write_literal(os, items[i].data, codes);
        }
                else
                        lzx_write_literal(os, items[i].data, codes);
        }