Index: contrib/elftoolchain/addr2line/addr2line.c
===================================================================
--- contrib/elftoolchain/addr2line/addr2line.c
+++ contrib/elftoolchain/addr2line/addr2line.c
@@ -84,6 +84,8 @@
 static char unknown[] = { '?', '?', '\0' };
 static Dwarf_Addr section_base;
 static struct CU *culist;
+static Dwarf_Unsigned locache = ~0ULL, hicache = 0ULL;
+static Dwarf_Die last_die = NULL;
 
 #define	USAGE_MESSAGE	"\
 Usage: %s [options] hexaddress...\n\
@@ -403,8 +405,18 @@
 	cu = NULL;
 	die = NULL;
 
-	while ((ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
-	    &de)) ==  DW_DLV_OK) {
+
+	// using cache 
+	if (addr >= locache && addr < hicache) {
+		die = last_die;
+		goto status_ok;
+	} else if (last_die != NULL) {
+		// cache miss AND not new cu
+		goto next_cu;
+	}
+
+	while ((ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL, 
+		&de)) == DW_DLV_OK) {
 		die = NULL;
 		while (dwarf_siblingof(dbg, die, &ret_die, &de) == DW_DLV_OK) {
 			if (die != NULL)
@@ -420,6 +432,7 @@
 			if (tag == DW_TAG_compile_unit)
 				break;
 		}
+
 		if (ret_die == NULL) {
 			warnx("could not find DW_TAG_compile_unit die");
 			goto next_cu;
@@ -465,6 +478,13 @@
 		}
 
 	next_cu:
+		// if we got here, addr is not in this cu, clear cache
+		if (last_die != NULL) {
+			dwarf_dealloc(dbg, last_die, DW_DLA_DIE);
+			last_die = NULL;
+		}
+		locache = ~0ULL;
+		hicache = 0ULL;
 		if (die != NULL) {
 			dwarf_dealloc(dbg, die, DW_DLA_DIE);
 			die = NULL;
@@ -474,6 +494,12 @@
 	if (ret != DW_DLV_OK || die == NULL)
 		goto out;
 
+	locache = lopc;
+	hicache = hipc;
+	last_die = die;
+
+status_ok:
+	
 	switch (dwarf_srclines(die, &lbuf, &lcount, &de)) {
 	case DW_DLV_OK:
 		break;
@@ -573,20 +599,8 @@
 		print_inlines(cu, f->inlined_caller, f->call_file,
 		    f->call_line);
 
-	if (die != NULL)
+	if (die != NULL && (die != last_die))
 		dwarf_dealloc(dbg, die, DW_DLA_DIE);
-
-	/*
-	 * Reset internal CU pointer, so we will start from the first CU
-	 * next round.
-	 */
-	while (ret != DW_DLV_NO_ENTRY) {
-		if (ret == DW_DLV_ERROR)
-			errx(EXIT_FAILURE, "dwarf_next_cu_header: %s",
-			    dwarf_errmsg(de));
-		ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
-		    &de);
-	}
 }
 
 static void