scc

commit 975dc3570759c0609e8532e9dce4127d9216ac7b
parent 950cfce031fb38e6337e087c398dc4e7c5efc467
Author: Roberto E. Vargas Caballero <Roberto E. Vargas Caballero>
Date:   Mon, 25 Apr 2016 22:29:16 +0200

[cc2] Optimize jumps to jumps statements

In this case of statements we are wasting time jumping
to another jump. We can jump directly to the target jump.

Diffstat:
M
cc2/optm.c
 | 
10
++++++++++
M
cc2/parser.c
 | 
1
+

2 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/cc2/optm.c b/cc2/optm.c
@@ -5,5 +5,15 @@
 Node *
 optm(Node *np)
 {
+	Node *dst;
+
+	switch (np->op) {
+	case OJMP:
+	case OBRANCH:
+		dst = np->u.sym->u.stmt;
+		if (dst->op == OJMP)
+			np->u.sym = dst->u.sym;
+		break;
+	}
 	return np;
 }
diff --git a/cc2/parser.c b/cc2/parser.c
@@ -577,6 +577,7 @@ labeldcl(void)
 	np->op = ONOP;
 	sym = np->u.sym;
 	sym->kind = SLABEL;
+	sym->u.stmt = np;
 	np->label = sym;
 	addstmt(np);
 }