Adding copies for arguments that occur multiple times constrained

diff --git a/ir/be/bechordal.c b/ir/be/bechordal.c
index dc6ea1a..bd36822 100644 (file)
--- a/ir/be/bechordal.c
+++ b/ir/be/bechordal.c
@@ -224,11 +224,31 @@ static ir_node *prepare_constr_insn(be_chordal_env_t *env, ir_node *irn)
        be_insn_t *insn      = chordal_scan_insn(env, irn);
        bitset_t *def_constr = bitset_alloca(env->cls->n_regs);
        bitset_t *tmp        = bitset_alloca(env->cls->n_regs);
-       int i;
+       ir_node *bl          = get_nodes_block(insn->irn);
+       int i, j;
 
        if(!insn->has_constraints)
                goto end;
 
+       /* insert copies for nodes that occur constrained more than once. */
+       for(i = insn->use_start; i < insn->n_ops; ++i) {
+               be_operand_t *op = &insn->ops[i];
+
+               if(op->has_constraints) {
+                       for(j = i + 1; j < insn->n_ops; ++j) {
+                               be_operand_t *a_op = &insn->ops[j];
+
+                               if(a_op->carrier == op->carrier && a_op->has_constraints) {
+                                       ir_node *copy = be_new_Copy(env->cls, env->irg, bl, op->carrier);
+
+                                       sched_add_before(insn->irn, copy);
+                                       set_irn_n(insn->irn, a_op->pos, copy);
+                                       DBG((env->dbg, LEVEL_3, "inserting multiple constr copy %+F for %+F pos %d\n", copy, insn->irn, a_op->pos));
+                               }
+                       }
+               }
+       }
+
        /* collect all registers occuring in out constraints. */
        for(i = 0; i < insn->use_start; ++i) {
                be_operand_t *op = &insn->ops[i];
@@ -253,8 +273,6 @@ static ir_node *prepare_constr_insn(be_chordal_env_t *env, ir_node *irn)
                        3) is constrained to a register occuring in out constraints.
                */
                if(op->has_constraints && values_interfere(env->lv, insn->irn, op->carrier) && bitset_popcnt(tmp) > 0) {
-                       ir_node *bl   = get_nodes_block(insn->irn);
-
                        /*
                                only create the copy if the operand is no copy.
                                this is necessary since the assure constraints phase inserts