[libfirm] / ir / be / beinsn.c

/*
 * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
 *
 * This file is part of libFirm.
 *
 * This file may be distributed and/or modified under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation and appearing in the file LICENSE.GPL included in the
 * packaging of this file.
 *
 * Licensees holding valid libFirm Professional Edition licenses may use
 * this file in accordance with the libFirm Commercial License.
 * Agreement provided with the Software.
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE.
 */

/**
 * @file
 * @brief       A data structure to treat nodes and node-proj collections uniformly.
 * @author      Sebastian Hack
 */
#include "config.h"

#include "irgraph_t.h"
#include "irmode_t.h"
#include "irnode_t.h"
#include "iredges.h"

#include "besched.h"
#include "beinsn_t.h"
#include "beirg.h"
#include "beabi.h"
#include "raw_bitset.h"

/**
 * Create a be_insn_t for an IR node.
 *
 * @param env      the insn construction environment
 * @param irn      the irn for which the be_insn should be build
 *
 * @return the be_insn for the IR node
 */
be_insn_t *be_scan_insn(const be_insn_env_t *env, ir_node *irn)
{
        struct obstack *obst = env->obst;
        be_operand_t o;
        int i, n;
        int pre_colored = 0;

        be_insn_t *insn = OALLOCZ(obst, be_insn_t);

        insn->irn       = irn;
        insn->next_insn = sched_next(irn);
        if (get_irn_mode(irn) == mode_T) {
                ir_node *p;

                /* This instruction might create more than one def. These are handled
                   by Proj's, find them. */
                foreach_out_edge(irn, edge) {
                        p = get_edge_src_irn(edge);

                        /* did not work if the result is a ProjT. This should NOT happen
                           in the backend, but check it for now. */
                        assert(get_irn_mode(p) != mode_T);

                        if (arch_irn_consider_in_reg_alloc(env->cls, p)) {
                                /* found a def: create a new operand */
                                o.req             = arch_get_irn_register_req(p);
                                o.carrier         = p;
                                o.irn             = irn;
                                o.pos             = -(get_Proj_proj(p) + 1);
                                o.partner         = NULL;
                                o.has_constraints = arch_register_req_is(o.req, limited) | (o.req->width > 1);
                                obstack_grow(obst, &o, sizeof(o));
                                insn->n_ops++;
                                insn->out_constraints |= o.has_constraints;
                                pre_colored += arch_get_irn_register(p) != NULL;
                        }
                }
        } else if (arch_irn_consider_in_reg_alloc(env->cls, irn)) {
                /* only one def, create one operand */
                o.req     = arch_get_irn_register_req(irn);
                o.carrier = irn;
                o.irn     = irn;
                o.pos     = -1;
                o.partner = NULL;
                o.has_constraints = arch_register_req_is(o.req, limited) | (o.req->width > 1);
                obstack_grow(obst, &o, sizeof(o));
                insn->n_ops++;
                insn->out_constraints |= o.has_constraints;
                pre_colored += arch_get_irn_register(irn) != NULL;
        }

        if (pre_colored > 0) {
                assert(pre_colored == insn->n_ops && "partly pre-colored nodes not supported");
                insn->pre_colored = 1;
        }
        insn->use_start   = insn->n_ops;

        /* now collect the uses for this node */
        for (i = 0, n = get_irn_arity(irn); i < n; ++i) {
                ir_node *op = get_irn_n(irn, i);

                if (arch_irn_consider_in_reg_alloc(env->cls, op)) {
                        /* found a register use, create an operand */
                        o.req     = arch_get_irn_register_req_in(irn, i);
                        o.carrier = op;
                        o.irn     = irn;
                        o.pos     = i;
                        o.partner = NULL;
                        o.has_constraints = arch_register_req_is(o.req, limited);
                        obstack_grow(obst, &o, sizeof(o));
                        insn->n_ops++;
                        insn->in_constraints |= o.has_constraints;
                }
        }

        insn->has_constraints = insn->in_constraints | insn->out_constraints;
        insn->ops = (be_operand_t*)obstack_finish(obst);

        /* Compute the admissible registers bitsets. */
        for (i = 0; i < insn->n_ops; ++i) {
                be_operand_t *op = &insn->ops[i];
                const arch_register_req_t   *req = op->req;
                const arch_register_class_t *cls = req->cls;
                arch_register_req_type_t    type = req->type;

                /* If there is no special requirement, we allow current class here */
                if (cls == NULL && req->type == arch_register_req_type_none) {
                        cls  = env->cls;
                        type = arch_register_req_type_normal;
                }

                assert(cls == env->cls);

                if (type & arch_register_req_type_limited) {
                        bitset_t *regs = bitset_obstack_alloc(obst, env->cls->n_regs);
                        rbitset_copy_to_bitset(req->limited, regs);
                        op->regs = regs;
                } else {
                        op->regs = env->allocatable_regs;
                }
        }

        return insn;
}