X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillbelady.c;h=c5e58b727dc4f628439b472e7fd9eed32e22ba14;hb=205396c4f4f5abe7abd6dc2350c8c398a7623afc;hp=b91c645f9f84faa9eebd5911834c70439c63e1c8;hpb=895edce679ee6434eb0c4f8b976e3f668bf2d48b;p=libfirm

diff --git a/ir/be/bespillbelady.c b/ir/be/bespillbelady.c
index b91c645f9..c5e58b727 100644
--- a/ir/be/bespillbelady.c
+++ b/ir/be/bespillbelady.c
@@ -9,14 +9,6 @@
 #include "config.h"
 #endif
 
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#endif
-
-#ifdef HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "obst.h"
 #include "set.h"
 #include "pset.h"
@@ -29,9 +21,10 @@
 #include "iredges_t.h"
 #include "ircons_t.h"
 #include "irprintf.h"
+#include "xmalloc.h"
 
 #include "beutil.h"
-#include "bearch.h"
+#include "bearch_t.h"
 #include "bespillbelady.h"
 #include "beuses_t.h"
 #include "besched_t.h"
@@ -673,13 +666,27 @@ next_value:
 	}
 }
 
-void be_spill_belady(be_irg_t *birg, const arch_register_class_t *cls) {
+/**
+ * Do spilling for a register class on a graph using the belady heuristic.
+ * In the transformed graph, the register pressure never exceeds the number
+ * of available registers.
+ *
+ * @param birg  The backend graph
+ * @param cls   The register class to spill
+ */
+static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *cls) {
 	be_spill_belady_spill_env(birg, cls, NULL);
 }
 
 void be_spill_belady_spill_env(be_irg_t *birg, const arch_register_class_t *cls, spill_env_t *spill_env) {
 	belady_env_t env;
 	ir_graph *irg = be_get_birg_irg(birg);
+	int n_regs;
+
+	/* some special classes contain only ignore regs, nothing to do then */
+	n_regs = cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
+	if(n_regs == 0)
+		return;
 
 	be_invalidate_liveness(birg);
 	be_assure_liveness(birg);
@@ -693,7 +700,7 @@ void be_spill_belady_spill_env(be_irg_t *birg, const arch_register_class_t *cls,
 	env.arch      = birg->main_env->arch_env;
 	env.cls       = cls;
 	env.lv        = be_get_birg_liveness(birg);
-	env.n_regs    = env.cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
+	env.n_regs    = n_regs;
 	env.ws        = new_workset(&env, &env.ob);
 	env.uses      = be_begin_uses(irg, env.lv);
 	env.loop_ana  = be_new_loop_pressure(birg);