Updated rasm to 1.7

1 files changed, 137 insertions, 0 deletions

diff --git a/tools/rasm/ZX0-main/src/optimize.c b/tools/rasm/ZX0-main/src/optimize.c
new file mode 100644
index 0000000..263837c
--- /dev/null
+++ b/tools/rasm/ZX0-main/src/optimize.c
@@ -0,0 +1,137 @@
+/*
+ * (c) Copyright 2021 by Einar Saukas. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * The name of its author may not be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "zx0.h"
+
+#define MAX_SCALE 50
+
+int offset_ceiling(int index, int offset_limit) {
+    return index > offset_limit ? offset_limit : index < INITIAL_OFFSET ? INITIAL_OFFSET : index;
+}
+
+int elias_gamma_bits(int value) {
+    int bits = 1;
+    while (value >>= 1)
+        bits += 2;
+    return bits;
+}
+
+BLOCK* zx0_optimize(unsigned char *input_data, int input_size, int skip, int offset_limit) {
+    BLOCK **last_literal;
+    BLOCK **last_match;
+    BLOCK **optimal;
+    int* match_length;
+    int* best_length;
+    int best_length_size;
+    int bits;
+    int index;
+    int offset;
+    int length;
+    int bits2;
+    int dots = 2;
+    int max_offset = offset_ceiling(input_size-1, offset_limit);
+
+    /* allocate all main data structures at once */
+    last_literal = (BLOCK **)calloc(max_offset+1, sizeof(BLOCK *));
+    last_match = (BLOCK **)calloc(max_offset+1, sizeof(BLOCK *));
+    optimal = (BLOCK **)calloc(input_size, sizeof(BLOCK *));
+    match_length = (int *)calloc(max_offset+1, sizeof(int));
+    best_length = (int *)malloc(input_size*sizeof(int));
+    if (!last_literal || !last_match || !optimal || !match_length || !best_length) {
+         fprintf(stderr, "Error: Insufficient memory\n");
+         exit(1);
+    }
+    best_length[2] = 2;
+
+    /* start with fake block */
+    assign(&last_match[INITIAL_OFFSET], allocate(-1, skip-1, INITIAL_OFFSET, NULL));
+
+    printf("[");
+
+    /* process remaining bytes */
+    for (index = skip; index < input_size; index++) {
+        best_length_size = 2;
+        max_offset = offset_ceiling(index, offset_limit);
+        for (offset = 1; offset <= max_offset; offset++) {
+            if (index != skip && index >= offset && input_data[index] == input_data[index-offset]) {
+                /* copy from last offset */
+                if (last_literal[offset]) {
+                    length = index-last_literal[offset]->index;
+                    bits = last_literal[offset]->bits + 1 + elias_gamma_bits(length);
+                    assign(&last_match[offset], allocate(bits, index, offset, last_literal[offset]));
+                    if (!optimal[index] || optimal[index]->bits > bits)
+                        assign(&optimal[index], last_match[offset]);
+                }
+                /* copy from new offset */
+                if (++match_length[offset] > 1) {
+                    if (best_length_size < match_length[offset]) {
+                        bits = optimal[index-best_length[best_length_size]]->bits + elias_gamma_bits(best_length[best_length_size]-1);
+                        do {
+                            best_length_size++;
+                            bits2 = optimal[index-best_length_size]->bits + elias_gamma_bits(best_length_size-1);
+                            if (bits2 <= bits) {
+                                best_length[best_length_size] = best_length_size;
+                                bits = bits2;
+                            } else {
+                                best_length[best_length_size] = best_length[best_length_size-1];
+                            }
+                        } while(best_length_size < match_length[offset]);
+                    }
+                    length = best_length[match_length[offset]];
+                    bits = optimal[index-length]->bits + 8 + elias_gamma_bits((offset-1)/128+1) + elias_gamma_bits(length-1);
+                    if (!last_match[offset] || last_match[offset]->index != index || last_match[offset]->bits > bits) {
+                        assign(&last_match[offset], allocate(bits, index, offset, optimal[index-length]));
+                        if (!optimal[index] || optimal[index]->bits > bits)
+                            assign(&optimal[index], last_match[offset]);
+                    }
+                }
+            } else {
+                /* copy literals */
+                match_length[offset] = 0;
+                if (last_match[offset]) {
+                    length = index-last_match[offset]->index;
+                    bits = last_match[offset]->bits + 1 + elias_gamma_bits(length) + length*8;
+                    assign(&last_literal[offset], allocate(bits, index, 0, last_match[offset]));
+                    if (!optimal[index] || optimal[index]->bits > bits)
+                        assign(&optimal[index], last_literal[offset]);
+                }
+            }
+        }
+
+        /* indicate progress */
+        if (index*MAX_SCALE/input_size > dots) {
+            printf(".");
+            fflush(stdout);
+            dots++;
+        }
+    }
+
+    printf("]\n");
+
+    return optimal[input_size-1];
+}