xpress_compress.c: rename a few variables
authorEric Biggers <ebiggers3@gmail.com>
Sat, 19 Sep 2015 18:56:12 +0000 (13:56 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Sun, 27 Sep 2015 14:41:27 +0000 (09:41 -0500)
src/xpress_compress.c

index b57d0ea..bce0901 100644 (file)
@@ -394,11 +394,11 @@ xpress_write_item_list(struct xpress_output_bitstream *os,
                       struct xpress_optimum_node *optimum_nodes,
                       size_t count, const u32 codewords[], const u8 lens[])
 {
-       struct xpress_optimum_node *cur_optimum_ptr = optimum_nodes;
-       struct xpress_optimum_node *end_optimum_ptr = optimum_nodes + count;
+       struct xpress_optimum_node *cur_node = optimum_nodes;
+       struct xpress_optimum_node *end_node = optimum_nodes + count;
        do {
-               unsigned length = cur_optimum_ptr->item & OPTIMUM_LEN_MASK;
-               unsigned offset = cur_optimum_ptr->item >> OPTIMUM_OFFSET_SHIFT;
+               unsigned length = cur_node->item & OPTIMUM_LEN_MASK;
+               unsigned offset = cur_node->item >> OPTIMUM_OFFSET_SHIFT;
 
                if (length == 1) {
                        /* Literal  */
@@ -408,22 +408,22 @@ xpress_write_item_list(struct xpress_output_bitstream *os,
                } else {
                        /* Match  */
                        unsigned adjusted_len;
-                       unsigned offset_high_bit;
+                       unsigned log2_offset;
                        unsigned len_hdr;
                        unsigned sym;
 
                        adjusted_len = length - XPRESS_MIN_MATCH_LEN;
-                       offset_high_bit = fls32(offset);
+                       log2_offset = fls32(offset);
                        len_hdr = min(0xF, adjusted_len);
-                       sym = XPRESS_NUM_CHARS + ((offset_high_bit << 4) | len_hdr);
+                       sym = XPRESS_NUM_CHARS + ((log2_offset << 4) | len_hdr);
 
                        xpress_write_bits(os, codewords[sym], lens[sym]);
                        xpress_write_extra_length_bytes(os, adjusted_len);
-                       xpress_write_bits(os, offset - (1U << offset_high_bit),
-                                         offset_high_bit);
+                       xpress_write_bits(os, offset - (1U << log2_offset),
+                                         log2_offset);
                }
-               cur_optimum_ptr += length;
-       } while (cur_optimum_ptr != end_optimum_ptr);
+               cur_node += length;
+       } while (cur_node != end_node);
 }
 #endif /* SUPPORT_NEAR_OPTIMAL_PARSING */
 
@@ -501,16 +501,16 @@ xpress_record_match(struct xpress_compressor *c, unsigned length, unsigned offse
 {
        unsigned adjusted_len = length - XPRESS_MIN_MATCH_LEN;
        unsigned len_hdr = min(adjusted_len, 0xF);
-       unsigned offset_high_bit = fls32(offset);
-       unsigned sym = XPRESS_NUM_CHARS + ((offset_high_bit << 4) | len_hdr);
+       unsigned log2_offset = fls32(offset);
+       unsigned sym = XPRESS_NUM_CHARS + ((log2_offset << 4) | len_hdr);
 
        c->freqs[sym]++;
 
        return (struct xpress_item) {
                .data = (u64)sym |
                        ((u64)adjusted_len << 9) |
-                       ((u64)offset_high_bit << 25) |
-                       ((u64)(offset ^ (1U << offset_high_bit)) << 29),
+                       ((u64)log2_offset << 25) |
+                       ((u64)(offset ^ (1U << log2_offset)) << 29),
        };
 }
 
@@ -734,13 +734,13 @@ xpress_update_costs(struct xpress_compressor *c)
  */
 static void
 xpress_tally_item_list(struct xpress_compressor *c,
-                      struct xpress_optimum_node *end_optimum_ptr)
+                      struct xpress_optimum_node *end_node)
 {
-       struct xpress_optimum_node *cur_optimum_ptr = c->optimum_nodes;
+       struct xpress_optimum_node *cur_node = c->optimum_nodes;
 
        do {
-               unsigned length = cur_optimum_ptr->item & OPTIMUM_LEN_MASK;
-               unsigned offset = cur_optimum_ptr->item >> OPTIMUM_OFFSET_SHIFT;
+               unsigned length = cur_node->item & OPTIMUM_LEN_MASK;
+               unsigned offset = cur_node->item >> OPTIMUM_OFFSET_SHIFT;
 
                if (length == 1) {
                        /* Literal  */
@@ -750,19 +750,19 @@ xpress_tally_item_list(struct xpress_compressor *c,
                } else {
                        /* Match  */
                        unsigned adjusted_len;
-                       unsigned offset_high_bit;
+                       unsigned log2_offset;
                        unsigned len_hdr;
                        unsigned sym;
 
                        adjusted_len = length - XPRESS_MIN_MATCH_LEN;
-                       offset_high_bit = fls32(offset);
+                       log2_offset = fls32(offset);
                        len_hdr = min(0xF, adjusted_len);
-                       sym = XPRESS_NUM_CHARS + ((offset_high_bit << 4) | len_hdr);
+                       sym = XPRESS_NUM_CHARS + ((log2_offset << 4) | len_hdr);
 
                        c->freqs[sym]++;
                }
-               cur_optimum_ptr += length;
-       } while (cur_optimum_ptr != end_optimum_ptr);
+               cur_node += length;
+       } while (cur_node != end_node);
 }
 
 /*
@@ -781,10 +781,10 @@ static void
 xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
                          struct lz_match *end_cache_ptr)
 {
-       struct xpress_optimum_node *cur_optimum_ptr = c->optimum_nodes + in_nbytes;
+       struct xpress_optimum_node *cur_node = c->optimum_nodes + in_nbytes;
        struct lz_match *cache_ptr = end_cache_ptr;
 
-       cur_optimum_ptr->cost_to_end = 0;
+       cur_node->cost_to_end = 0;
        do {
                unsigned literal;
                u32 best_item;
@@ -793,7 +793,7 @@ xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
                struct lz_match *match;
                unsigned len;
 
-               cur_optimum_ptr--;
+               cur_node--;
                cache_ptr--;
 
                literal = cache_ptr->offset;
@@ -801,14 +801,14 @@ xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
                /* Consider coding a literal.  */
                best_item = ((u32)literal << OPTIMUM_OFFSET_SHIFT) | 1;
                best_cost_to_end = c->costs[literal] +
-                                  (cur_optimum_ptr + 1)->cost_to_end;
+                                  (cur_node + 1)->cost_to_end;
 
                num_matches = cache_ptr->length;
 
                if (num_matches == 0) {
                        /* No matches; the only choice is the literal.  */
-                       cur_optimum_ptr->cost_to_end = best_cost_to_end;
-                       cur_optimum_ptr->item = best_item;
+                       cur_node->cost_to_end = best_cost_to_end;
+                       cur_node->item = best_item;
                        continue;
                }
 
@@ -827,12 +827,12 @@ xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
                        /* All lengths are small.  Optimize accordingly.  */
                        do {
                                unsigned offset;
-                               unsigned offset_high_bit;
+                               unsigned log2_offset;
                                u32 offset_cost;
 
                                offset = match->offset;
-                               offset_high_bit = fls32(offset);
-                               offset_cost = offset_high_bit;
+                               log2_offset = fls32(offset);
+                               offset_cost = log2_offset;
                                do {
                                        unsigned len_hdr;
                                        unsigned sym;
@@ -840,10 +840,10 @@ xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
 
                                        len_hdr = len - XPRESS_MIN_MATCH_LEN;
                                        sym = XPRESS_NUM_CHARS +
-                                             ((offset_high_bit << 4) | len_hdr);
+                                             ((log2_offset << 4) | len_hdr);
                                        cost_to_end =
                                                offset_cost + c->costs[sym] +
-                                               (cur_optimum_ptr + len)->cost_to_end;
+                                               (cur_node + len)->cost_to_end;
                                        if (cost_to_end < best_cost_to_end) {
                                                best_cost_to_end = cost_to_end;
                                                best_item =
@@ -856,12 +856,12 @@ xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
                        /* Some lengths are big.  */
                        do {
                                unsigned offset;
-                               unsigned offset_high_bit;
+                               unsigned log2_offset;
                                u32 offset_cost;
 
                                offset = match->offset;
-                               offset_high_bit = fls32(offset);
-                               offset_cost = offset_high_bit;
+                               log2_offset = fls32(offset);
+                               offset_cost = log2_offset;
                                do {
                                        unsigned adjusted_len;
                                        unsigned len_hdr;
@@ -871,10 +871,10 @@ xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
                                        adjusted_len = len - XPRESS_MIN_MATCH_LEN;
                                        len_hdr = min(adjusted_len, 0xF);
                                        sym = XPRESS_NUM_CHARS +
-                                             ((offset_high_bit << 4) | len_hdr);
+                                             ((log2_offset << 4) | len_hdr);
                                        cost_to_end =
                                                offset_cost + c->costs[sym] +
-                                               (cur_optimum_ptr + len)->cost_to_end;
+                                               (cur_node + len)->cost_to_end;
                                        if (adjusted_len >= 0xF) {
                                                cost_to_end += 8;
                                                if (adjusted_len - 0xF >= 0xFF)
@@ -890,9 +890,9 @@ xpress_find_min_cost_path(struct xpress_compressor *c, size_t in_nbytes,
                        } while (++match != cache_ptr);
                }
                cache_ptr -= num_matches;
-               cur_optimum_ptr->cost_to_end = best_cost_to_end;
-               cur_optimum_ptr->item = best_item;
-       } while (cur_optimum_ptr != c->optimum_nodes);
+               cur_node->cost_to_end = best_cost_to_end;
+               cur_node->item = best_item;
+       } while (cur_node != c->optimum_nodes);
 }
 
 /*