diff --git a/src/x86/cg.c b/src/x86/cg.c
index 303b84d..0b978f1 100644
--- a/src/x86/cg.c
+++ b/src/x86/cg.c
@@ -640,13 +640,15 @@ static void callee_saved(AST *tlc, struct CalleeSavedState *state) {
 	bool ebxused = false, ediused = false, esiused = false;
 	
 	for(size_t v = 0; v < tlc->chunk.varCount; v++) {
-		if(is_reg_b(tlc->chunk.vars[v]->data.var.registerClass, tlc->chunk.vars[v]->data.var.color)) {
+		size_t resource = REG_CLASSES[tlc->chunk.vars[v]->data.var.registerClass].rs[tlc->chunk.vars[v]->data.var.color];
+		
+		if(resource & HWR_EBX) {
 			ebxused = true;
 		}
-		if(is_reg_di(tlc->chunk.vars[v]->data.var.registerClass, tlc->chunk.vars[v]->data.var.color)) {
+		if(resource & HWR_EDI) {
 			ediused = true;
 		}
-		if(is_reg_si(tlc->chunk.vars[v]->data.var.registerClass, tlc->chunk.vars[v]->data.var.color)) {
+		if(resource & HWR_ESI) {
 			esiused = true;
 		}
 	}