Handle loops to as-yet unvisited places

1 files changed, 22 insertions, 8 deletions

diff --git a/deloopify.c b/deloopify.c
index 0a39784..5006604 100644
--- a/deloopify.c
+++ b/deloopify.c
@@ -16,7 +16,9 @@
 #include <string.h>
 
 /* length of sliding history of line beginnings */
-#define MAX_LOOP_LEN 30000
+#define MAX_LOOP_LEN 32768
+
+#define SIG_LEN 128
 
 bool loop_concluded(FILE *tracef, uint16_t loopendip)
 {
@@ -48,7 +50,8 @@ int main(int argc, char *argv[])
 {
 	FILE *tracef, *outf;
 	long inlineno = 0, outlineno = -1;
-	char sig[MAX_LOOP_LEN][100];
+	typedef char asig[SIG_LEN];
+	asig *sig;
 	char loopsig[] = "Loop";
 	bool borken = false;
 
@@ -64,7 +67,11 @@ int main(int argc, char *argv[])
 		exit(EXIT_FAILURE);
 	}
 
-	memset(sig, 0, sizeof(sig));
+	if (!(sig = calloc(MAX_LOOP_LEN, SIG_LEN))) {
+		printf("Signature table calloc failed\n");
+		exit(EXIT_FAILURE);
+	}
+
 	while (!feof(tracef)) {
 		char line[180];
 
@@ -132,8 +139,8 @@ int main(int argc, char *argv[])
 
 			int looplen = 1;
 			int bonus = 0;
-			for ( ; looplen < MAX_LOOP_LEN; looplen++) {
-				/* on our way back through the sliding sig list, retrive the
+			for ( ; looplen < MAX_LOOP_LEN && looplen < outlineno; looplen++) {
+				/* on our way back through the sliding sig list, retrieve the
 				 * uncontracted length of any previously compacted loops
 				 */
 				if (!strncmp(loopsig, sig[(outlineno - looplen) % MAX_LOOP_LEN], 4)) {
@@ -147,9 +154,14 @@ int main(int argc, char *argv[])
 					break;
 			}
 
-			if (looplen == MAX_LOOP_LEN) {	/* fail */
-				printf("Didn't find start of loop -- try increasing MAX_LOOP_LEN?\n");
-				exit(EXIT_FAILURE);
+			/* we don't bail out on these two cases, as loops to places we haven't yet visited do occur,
+			 * so just ignore this loop instr
+			 */
+			if (looplen == outlineno) /* didn't find start of loop and searched through complete history */
+				continue;
+			if (looplen == MAX_LOOP_LEN) { /* fail */
+				printf("Didn't find start of loop at line %ld in history -- try increasing MAX_LOOP_LEN?\n", inlineno);
+				continue;
 			}
 
 //fprintf(outf, "loop sig %s, startsig %s, found %s, looplen %d, bonus %d\n", sig[outlineno % MAX_LOOP_LEN], startsig, sig[(outlineno - looplen - 4) % MAX_LOOP_LEN], looplen, bonus);
@@ -200,5 +212,7 @@ next:
 		}
 	}
 
+	free(sig);
+
 	return 0;
 }