Don't double label BBs.

	If we've already got a BB with a specific label, don't add
	that label again.

	Fixes #28

1 files changed, 4 insertions, 2 deletions

diff --git a/mi/cfg.c b/mi/cfg.c
index f5c6961..12ecc75 100644
--- a/mi/cfg.c
+++ b/mi/cfg.c
@@ -29,8 +29,10 @@ static Bb *mkbb(Cfg *cfg)
 
 static void strlabel(Cfg *cfg, char *lbl, Bb *bb)
 {
-	htput(cfg->lblmap, lbl, bb);
-	lappend(&bb->lbls, &bb->nlbls, lbl);
+	if (htget(cfg->lblmap, lbl) != bb) {
+		htput(cfg->lblmap, lbl, bb);
+		lappend(&bb->lbls, &bb->nlbls, lbl);
+	}
 }
 
 static void label(Cfg *cfg, Node *lbl, Bb *bb)