bechordal: Fully use the information provided by the borders to simplify assignment...

The live-ins are recorded in the borders, so not special case is necessary.

diff --git a/ir/be/bechordal.c b/ir/be/bechordal.c
index d2bfcae..41d319c 100644 (file)
--- a/ir/be/bechordal.c
+++ b/ir/be/bechordal.c
@@ -284,7 +284,6 @@ static void assign(ir_node *const block, void *const env_ptr)
 {
        be_chordal_env_t *const env  = (be_chordal_env_t*)env_ptr;
        struct list_head *const head = get_block_border_head(env, block);
-       be_lv_t          *const lv   = be_get_irg_liveness(env->irg);
 
        DBG((dbg, LEVEL_4, "Assigning colors for block %+F\n", block));
        DBG((dbg, LEVEL_4, "\tusedef chain for block\n"));
@@ -296,19 +295,6 @@ static void assign(ir_node *const block, void *const env_ptr)
        bitset_t *const available = bitset_alloca(env->allocatable_regs->size);
        bitset_copy(available, env->allocatable_regs);
 
-       /* Add initial defs for all values live in.
-        * Since their colors have already been assigned (The dominators were
-        * allocated before), we have to mark their colors as used also. */
-       be_lv_foreach_cls(lv, block, be_lv_state_in, env->cls, irn) {
-               arch_register_t const *const reg = arch_get_irn_register(irn);
-
-               assert(reg && "Node must have been assigned a register");
-               DBG((dbg, LEVEL_4, "%+F has reg %s\n", irn, reg->name));
-
-               /* Mark the color of the live in value as used. */
-               bitset_clear(available, reg->index);
-       }
-
        /* Mind that the sequence of defs from back to front defines a perfect
         * elimination order. So, coloring the definitions from first to last
         * will work. */
@@ -322,10 +308,14 @@ static void assign(ir_node *const block, void *const env_ptr)
                        arch_register_t const *const reg = arch_get_irn_register(irn);
                        assert(reg && "Register must have been assigned");
                        bitset_set(available, reg->index);
-               } else if (!be_is_live_in(lv, block, irn)) {
+               } else {
                        int                    col;
                        arch_register_t const *reg = arch_get_irn_register(irn);
+                       /* All live-ins must have a register assigned. (The dominators were
+                        * allocated before.) */
+                       assert(b->is_real || reg);
                        if (reg) {
+                               DBG((dbg, LEVEL_4, "%+F has reg %s\n", irn, reg->name));
                                col = reg->index;
                                assert(bitset_is_set(available, col) && "pre-colored register must be free");
                        } else {