[libfirm] / ir / be / ia32 / bearch_ia32.c

/**
 * This is the main ia32 firm backend driver.
 * @author Christian Wuerdig
 * $Id$
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif

#ifdef HAVE_ALLOCA_H
#include <alloca.h>
#endif

#ifdef WITH_LIBCORE
#include <libcore/lc_opts.h>
#include <libcore/lc_opts_enum.h>
#endif /* WITH_LIBCORE */

#include "pseudo_irg.h"
#include "irgwalk.h"
#include "irprog.h"
#include "irprintf.h"
#include "iredges_t.h"
#include "ircons.h"
#include "irgmod.h"
#include "irgopt.h"
#include "irbitset.h"
#include "pdeq.h"
#include "debug.h"

#include "../beabi.h"                 /* the general register allocator interface */
#include "../benode_t.h"
#include "../belower.h"
#include "../besched_t.h"
#include "../be.h"
#include "bearch_ia32_t.h"

#include "ia32_new_nodes.h"           /* ia32 nodes interface */
#include "gen_ia32_regalloc_if.h"     /* the generated interface (register type and class defenitions) */
#include "ia32_gen_decls.h"           /* interface declaration emitter */
#include "ia32_transform.h"
#include "ia32_emitter.h"
#include "ia32_map_regs.h"
#include "ia32_optimize.h"
#include "ia32_x87.h"
#include "ia32_dbg_stat.h"
#include "ia32_finish.h"
#include "ia32_util.h"

#define DEBUG_MODULE "firm.be.ia32.isa"

/* TODO: ugly */
static set *cur_reg_set = NULL;

#undef is_Start
#define is_Start(irn) (get_irn_opcode(irn) == iro_Start)

/* Creates the unique per irg GP NoReg node. */
ir_node *ia32_new_NoReg_gp(ia32_code_gen_t *cg) {
        return be_abi_get_callee_save_irn(cg->birg->abi, &ia32_gp_regs[REG_GP_NOREG]);
}

/* Creates the unique per irg FP NoReg node. */
ir_node *ia32_new_NoReg_fp(ia32_code_gen_t *cg) {
        return be_abi_get_callee_save_irn(cg->birg->abi,
                USE_SSE2(cg) ? &ia32_xmm_regs[REG_XMM_NOREG] : &ia32_vfp_regs[REG_VFP_NOREG]);
}

/**************************************************
 *                         _ _              _  __
 *                        | | |            (_)/ _|
 *  _ __ ___  __ _    __ _| | | ___   ___   _| |_
 * | '__/ _ \/ _` |  / _` | | |/ _ \ / __| | |  _|
 * | | |  __/ (_| | | (_| | | | (_) | (__  | | |
 * |_|  \___|\__, |  \__,_|_|_|\___/ \___| |_|_|
 *            __/ |
 *           |___/
 **************************************************/

static ir_node *my_skip_proj(const ir_node *n) {
        while (is_Proj(n))
                n = get_Proj_pred(n);
        return (ir_node *)n;
}


/**
 * Return register requirements for an ia32 node.
 * If the node returns a tuple (mode_T) then the proj's
 * will be asked for this information.
 */
static const arch_register_req_t *ia32_get_irn_reg_req(const void *self, arch_register_req_t *req, const ir_node *irn, int pos) {
        const ia32_irn_ops_t      *ops = self;
        const ia32_register_req_t *irn_req;
        long                       node_pos = pos == -1 ? 0 : pos;
        ir_mode                   *mode     = is_Block(irn) ? NULL : get_irn_mode(irn);
        FIRM_DBG_REGISTER(firm_dbg_module_t *mod, DEBUG_MODULE);

        if (is_Block(irn) || mode == mode_M || mode == mode_X) {
                DBG((mod, LEVEL_1, "ignoring Block, mode_M, mode_X node %+F\n", irn));
                return NULL;
        }

        if (mode == mode_T && pos < 0) {
                DBG((mod, LEVEL_1, "ignoring request OUT requirements for node %+F\n", irn));
                return NULL;
        }

        DBG((mod, LEVEL_1, "get requirements at pos %d for %+F ... ", pos, irn));

        if (is_Proj(irn)) {
                if (pos == -1) {
                        node_pos = ia32_translate_proj_pos(irn);
                }
                else {
                        node_pos = pos;
                }

                irn = my_skip_proj(irn);

                DB((mod, LEVEL_1, "skipping Proj, going to %+F at pos %d ... ", irn, node_pos));
        }

        if (is_ia32_irn(irn)) {
                if (pos >= 0) {
                        irn_req = get_ia32_in_req(irn, pos);
                }
                else {
                        irn_req = get_ia32_out_req(irn, node_pos);
                }

                DB((mod, LEVEL_1, "returning reqs for %+F at pos %d\n", irn, pos));

                memcpy(req, &(irn_req->req), sizeof(*req));

                if (arch_register_req_is(&(irn_req->req), should_be_same)) {
                        assert(irn_req->same_pos >= 0 && "should be same constraint for in -> out NYI");
                        req->other_same = get_irn_n(irn, irn_req->same_pos);
                }

                if (arch_register_req_is(&(irn_req->req), should_be_different)) {
                        assert(irn_req->different_pos >= 0 && "should be different constraint for in -> out NYI");
                        req->other_different = get_irn_n(irn, irn_req->different_pos);
                }
        }
        else {
                /* treat Unknowns like Const with default requirements */
                if (is_Unknown(irn)) {
                        DB((mod, LEVEL_1, "returning UKNWN reqs for %+F\n", irn));
                        if (mode_is_float(mode)) {
                                if (USE_SSE2(ops->cg))
                                        memcpy(req, &(ia32_default_req_ia32_xmm_xmm_UKNWN), sizeof(*req));
                                else
                                        memcpy(req, &(ia32_default_req_ia32_vfp_vfp_UKNWN), sizeof(*req));
                        }
                        else if (mode_is_int(mode) || mode_is_reference(mode))
                                memcpy(req, &(ia32_default_req_ia32_gp_gp_UKNWN), sizeof(*req));
                        else if (mode == mode_T || mode == mode_M) {
                                DBG((mod, LEVEL_1, "ignoring Unknown node %+F\n", irn));
                                return NULL;
                        }
                        else
                                assert(0 && "unsupported Unknown-Mode");
                }
                else {
                        DB((mod, LEVEL_1, "returning NULL for %+F (not ia32)\n", irn));
                        req = NULL;
                }
        }

        return req;
}

static void ia32_set_irn_reg(const void *self, ir_node *irn, const arch_register_t *reg) {
        int                   pos = 0;
        const ia32_irn_ops_t *ops = self;

        if (get_irn_mode(irn) == mode_X) {
                return;
        }

        DBG((ops->cg->mod, LEVEL_1, "ia32 assigned register %s to node %+F\n", reg->name, irn));

        if (is_Proj(irn)) {
                pos = ia32_translate_proj_pos(irn);
                irn = my_skip_proj(irn);
        }

        if (is_ia32_irn(irn)) {
                const arch_register_t **slots;

                slots      = get_ia32_slots(irn);
                slots[pos] = reg;
        }
        else {
                ia32_set_firm_reg(irn, reg, cur_reg_set);
        }
}

static const arch_register_t *ia32_get_irn_reg(const void *self, const ir_node *irn) {
        int pos = 0;
        const arch_register_t *reg = NULL;

        if (is_Proj(irn)) {

                if (get_irn_mode(irn) == mode_X) {
                        return NULL;
                }

                pos = ia32_translate_proj_pos(irn);
                irn = my_skip_proj(irn);
        }

        if (is_ia32_irn(irn)) {
                const arch_register_t **slots;
                slots = get_ia32_slots(irn);
                reg   = slots[pos];
        }
        else {
                reg = ia32_get_firm_reg(irn, cur_reg_set);
        }

        return reg;
}

static arch_irn_class_t ia32_classify(const void *self, const ir_node *irn) {
        arch_irn_class_t classification = arch_irn_class_normal;

        irn = my_skip_proj(irn);

        if (is_cfop(irn))
                classification |= arch_irn_class_branch;

        if (! is_ia32_irn(irn))
                return classification & ~arch_irn_class_normal;

        if (is_ia32_Cnst(irn))
                classification |= arch_irn_class_const;

        if (is_ia32_Ld(irn))
                classification |= arch_irn_class_load;

        if (is_ia32_St(irn) || is_ia32_Store8Bit(irn))
                classification |= arch_irn_class_store;

        if (is_ia32_got_reload(irn))
                classification |= arch_irn_class_reload;

        return classification;
}

static arch_irn_flags_t ia32_get_flags(const void *self, const ir_node *irn) {
        irn = my_skip_proj(irn);
        if (is_ia32_irn(irn))
                return get_ia32_flags(irn);
        else {
                if (is_Unknown(irn))
                        return arch_irn_flags_ignore;
                return 0;
        }
}

static entity *ia32_get_frame_entity(const void *self, const ir_node *irn) {
        return is_ia32_irn(irn) ? get_ia32_frame_ent(irn) : NULL;
}

static void ia32_set_stack_bias(const void *self, ir_node *irn, int bias) {
        char buf[64];
        const ia32_irn_ops_t *ops = self;

        if (get_ia32_frame_ent(irn)) {
                ia32_am_flavour_t am_flav = get_ia32_am_flavour(irn);

                DBG((ops->cg->mod, LEVEL_1, "stack biased %+F with %d\n", irn, bias));
                snprintf(buf, sizeof(buf), "%d", bias);

                if (get_ia32_op_type(irn) == ia32_Normal) {
                        set_ia32_cnst(irn, buf);
                }
                else {
                        add_ia32_am_offs(irn, buf);
                        am_flav |= ia32_O;
                        set_ia32_am_flavour(irn, am_flav);
                }
        }
}

typedef struct {
        be_abi_call_flags_bits_t flags;
        const arch_isa_t *isa;
        const arch_env_t *aenv;
        ir_graph *irg;
} ia32_abi_env_t;

static void *ia32_abi_init(const be_abi_call_t *call, const arch_env_t *aenv, ir_graph *irg)
{
        ia32_abi_env_t *env    = xmalloc(sizeof(env[0]));
        be_abi_call_flags_t fl = be_abi_call_get_flags(call);
        env->flags = fl.bits;
        env->irg   = irg;
        env->aenv  = aenv;
        env->isa   = aenv->isa;
        return env;
}

/**
 * Put all registers which are saved by the prologue/epilogue in a set.
 *
 * @param self  The callback object.
 * @param s     The result set.
 */
static void ia32_abi_dont_save_regs(void *self, pset *s)
{
        ia32_abi_env_t *env = self;
        if(env->flags.try_omit_fp)
                pset_insert_ptr(s, env->isa->bp);
}

/**
 * Generate the routine prologue.
 *
 * @param self    The callback object.
 * @param mem     A pointer to the mem node. Update this if you define new memory.
 * @param reg_map A map mapping all callee_save/ignore/parameter registers to their defining nodes.
 *
 * @return        The register which shall be used as a stack frame base.
 *
 * All nodes which define registers in @p reg_map must keep @p reg_map current.
 */
static const arch_register_t *ia32_abi_prologue(void *self, ir_node **mem, pmap *reg_map)
{
        ia32_abi_env_t *env              = self;

        if (!env->flags.try_omit_fp) {
                ir_node *bl          = get_irg_start_block(env->irg);
                ir_node *curr_sp     = be_abi_reg_map_get(reg_map, env->isa->sp);
                ir_node *curr_bp     = be_abi_reg_map_get(reg_map, env->isa->bp);
                ir_node *push;

                /* push ebp */
                push    = new_rd_ia32_Push(NULL, env->irg, bl, curr_sp, curr_bp, *mem);
                curr_sp = new_r_Proj(env->irg, bl, push, get_irn_mode(curr_sp), pn_ia32_Push_stack);
                *mem    = new_r_Proj(env->irg, bl, push, mode_M, pn_ia32_Push_M);

                /* the push must have SP out register */
                arch_set_irn_register(env->aenv, curr_sp, env->isa->sp);
                set_ia32_flags(push, arch_irn_flags_ignore);

                /* move esp to ebp */
                curr_bp  = be_new_Copy(env->isa->bp->reg_class, env->irg, bl, curr_sp);
                be_set_constr_single_reg(curr_bp, BE_OUT_POS(0), env->isa->bp);
                arch_set_irn_register(env->aenv, curr_bp, env->isa->bp);
                be_node_set_flags(curr_bp, BE_OUT_POS(0), arch_irn_flags_ignore);

                /* beware: the copy must be done before any other sp use */
                curr_sp = be_new_CopyKeep_single(env->isa->sp->reg_class, env->irg, bl, curr_sp, curr_bp, get_irn_mode(curr_sp));
                be_set_constr_single_reg(curr_sp, BE_OUT_POS(0), env->isa->sp);
                arch_set_irn_register(env->aenv, curr_sp, env->isa->sp);
                be_node_set_flags(curr_sp, BE_OUT_POS(0), arch_irn_flags_ignore);

                be_abi_reg_map_set(reg_map, env->isa->sp, curr_sp);
                be_abi_reg_map_set(reg_map, env->isa->bp, curr_bp);

                return env->isa->bp;
        }

        return env->isa->sp;
}

/**
 * Generate the routine epilogue.
 * @param self    The callback object.
 * @param bl      The block for the epilog
 * @param mem     A pointer to the mem node. Update this if you define new memory.
 * @param reg_map A map mapping all callee_save/ignore/parameter registers to their defining nodes.
 * @return        The register which shall be used as a stack frame base.
 *
 * All nodes which define registers in @p reg_map must keep @p reg_map current.
 */
static void ia32_abi_epilogue(void *self, ir_node *bl, ir_node **mem, pmap *reg_map)
{
        ia32_abi_env_t *env  = self;
        ir_node *curr_sp     = be_abi_reg_map_get(reg_map, env->isa->sp);
        ir_node *curr_bp     = be_abi_reg_map_get(reg_map, env->isa->bp);

        if (env->flags.try_omit_fp) {
                /* simply remove the stack frame here */
                curr_sp = be_new_IncSP(env->isa->sp, env->irg, bl, curr_sp, *mem, BE_STACK_FRAME_SIZE, be_stack_dir_shrink);
        }
        else {
                const ia32_isa_t *isa = (ia32_isa_t *)env->isa;
                ir_mode *mode_bp = env->isa->bp->reg_class->mode;

                /* gcc always emits a leave at the end of a routine */
                if (1 || ARCH_AMD(isa->opt_arch)) {
                        ir_node *leave;

                        /* leave */
                        leave = new_rd_ia32_Leave(NULL, env->irg, bl, curr_sp, *mem);
                        set_ia32_flags(leave, arch_irn_flags_ignore);
                        curr_bp = new_r_Proj(current_ir_graph, bl, leave, mode_bp, pn_ia32_Leave_frame);
                        curr_sp = new_r_Proj(current_ir_graph, bl, leave, get_irn_mode(curr_sp), pn_ia32_Leave_stack);
                        *mem    = new_r_Proj(current_ir_graph, bl, leave, mode_M, pn_ia32_Leave_M);
                }
                else {
                        ir_node *pop;

                        /* copy ebp to esp */
                        curr_sp = be_new_SetSP(env->isa->sp, env->irg, bl, curr_sp, curr_bp, *mem);

                        /* pop ebp */
                        pop = new_rd_ia32_Pop(NULL, env->irg, bl, curr_sp, *mem);
                        set_ia32_flags(pop, arch_irn_flags_ignore);
                        curr_bp = new_r_Proj(current_ir_graph, bl, pop, mode_bp, pn_ia32_Pop_res);
                        curr_sp = new_r_Proj(current_ir_graph, bl, pop, get_irn_mode(curr_sp), pn_ia32_Pop_stack);
                        *mem    = new_r_Proj(current_ir_graph, bl, pop, mode_M, pn_ia32_Pop_M);
                }
                arch_set_irn_register(env->aenv, curr_sp, env->isa->sp);
                arch_set_irn_register(env->aenv, curr_bp, env->isa->bp);
        }

        be_abi_reg_map_set(reg_map, env->isa->sp, curr_sp);
        be_abi_reg_map_set(reg_map, env->isa->bp, curr_bp);
}

/**
 * Produces the type which sits between the stack args and the locals on the stack.
 * it will contain the return address and space to store the old base pointer.
 * @return The Firm type modeling the ABI between type.
 */
static ir_type *ia32_abi_get_between_type(void *self)
{
#define IDENT(s) new_id_from_chars(s, sizeof(s)-1)
        static ir_type *omit_fp_between_type = NULL;
        static ir_type *between_type         = NULL;

        ia32_abi_env_t *env = self;

        if ( !between_type) {
                entity *old_bp_ent;
                entity *ret_addr_ent;
                entity *omit_fp_ret_addr_ent;

                ir_type *old_bp_type   = new_type_primitive(IDENT("bp"), mode_P);
                ir_type *ret_addr_type = new_type_primitive(IDENT("return_addr"), mode_P);

                between_type           = new_type_struct(IDENT("ia32_between_type"));
                old_bp_ent             = new_entity(between_type, IDENT("old_bp"), old_bp_type);
                ret_addr_ent           = new_entity(between_type, IDENT("ret_addr"), ret_addr_type);

                set_entity_offset_bytes(old_bp_ent, 0);
                set_entity_offset_bytes(ret_addr_ent, get_type_size_bytes(old_bp_type));
                set_type_size_bytes(between_type, get_type_size_bytes(old_bp_type) + get_type_size_bytes(ret_addr_type));
                set_type_state(between_type, layout_fixed);

                omit_fp_between_type = new_type_struct(IDENT("ia32_between_type_omit_fp"));
                omit_fp_ret_addr_ent = new_entity(omit_fp_between_type, IDENT("ret_addr"), ret_addr_type);

                set_entity_offset_bytes(omit_fp_ret_addr_ent, 0);
                set_type_size_bytes(omit_fp_between_type, get_type_size_bytes(ret_addr_type));
                set_type_state(omit_fp_between_type, layout_fixed);
        }

        return env->flags.try_omit_fp ? omit_fp_between_type : between_type;
#undef IDENT
}

/**
 * Get the estimated cycle count for @p irn.
 *
 * @param self The this pointer.
 * @param irn  The node.
 *
 * @return     The estimated cycle count for this operation
 */
static int ia32_get_op_estimated_cost(const void *self, const ir_node *irn)
{
        int cost;

        if(is_Proj(irn))
          return 0;

        switch (get_ia32_irn_opcode(irn)) {
        case iro_ia32_xDiv:
        case iro_ia32_DivMod:
                cost = 8;
                break;

        case iro_ia32_xLoad:
        case iro_ia32_l_Load:
        case iro_ia32_Load:
                cost = 25;
                break;

        case iro_ia32_Push:
        case iro_ia32_Pop:
                cost = 5;
                break;

        case iro_ia32_xStore:
        case iro_ia32_l_Store:
        case iro_ia32_Store:
        case iro_ia32_Store8Bit:
                cost = 50;
                break;

        case iro_ia32_MulS:
        case iro_ia32_Mul:
        case iro_ia32_Mulh:
        case iro_ia32_xMul:
        case iro_ia32_l_MulS:
        case iro_ia32_l_Mul:
                cost = 2;
                break;

        default:
                cost = 1;
        }

        return cost;
}

/**
 * Returns the inverse operation if @p irn, recalculating the argument at position @p i.
 *
 * @param irn       The original operation
 * @param i         Index of the argument we want the inverse operation to yield
 * @param inverse   struct to be filled with the resulting inverse op
 * @param obstack   The obstack to use for allocation of the returned nodes array
 * @return          The inverse operation or NULL if operation invertible
 */
static arch_inverse_t *ia32_get_inverse(const void *self, const ir_node *irn, int i, arch_inverse_t *inverse, struct obstack *obst) {
        ir_graph *irg;
        ir_mode  *mode;
        ir_node  *block, *noreg, *nomem;
        int      pnc;

        /* we cannot invert non-ia32 irns */
        if (! is_ia32_irn(irn))
                return NULL;

        /* operand must always be a real operand (not base, index or mem) */
        if (i != 2 && i != 3)
                return NULL;

        /* we don't invert address mode operations */
        if (get_ia32_op_type(irn) != ia32_Normal)
                return NULL;

        irg   = get_irn_irg(irn);
        block = get_nodes_block(irn);
        mode  = get_ia32_res_mode(irn);
        noreg = get_irn_n(irn, 0);
        nomem = new_r_NoMem(irg);

        /* initialize structure */
        inverse->nodes = obstack_alloc(obst, 2 * sizeof(inverse->nodes[0]));
        inverse->costs = 0;
        inverse->n     = 2;

        switch (get_ia32_irn_opcode(irn)) {
                case iro_ia32_Add:
                        if (get_ia32_immop_type(irn) == ia32_ImmConst) {
                                /* we have an add with a const here */
                                /* invers == add with negated const */
                                inverse->nodes[0] = new_rd_ia32_Add(NULL, irg, block, noreg, noreg, get_irn_n(irn, i), noreg, nomem);
                                pnc               = pn_ia32_Add_res;
                                inverse->costs   += 1;
                                copy_ia32_Immop_attr(inverse->nodes[0], (ir_node *)irn);
                                set_ia32_Immop_tarval(inverse->nodes[0], tarval_neg(get_ia32_Immop_tarval(irn)));
                                set_ia32_commutative(inverse->nodes[0]);
                        }
                        else if (get_ia32_immop_type(irn) == ia32_ImmSymConst) {
                                /* we have an add with a symconst here */
                                /* invers == sub with const */
                                inverse->nodes[0] = new_rd_ia32_Sub(NULL, irg, block, noreg, noreg, get_irn_n(irn, i), noreg, nomem);
                                pnc               = pn_ia32_Sub_res;
                                inverse->costs   += 2;
                                copy_ia32_Immop_attr(inverse->nodes[0], (ir_node *)irn);
                        }
                        else {
                                /* normal add: inverse == sub */
                                ir_node *proj = ia32_get_res_proj(irn);
                                assert(proj);

                                inverse->nodes[0] = new_rd_ia32_Sub(NULL, irg, block, noreg, noreg, proj, get_irn_n(irn, i ^ 1), nomem);
                                pnc               = pn_ia32_Sub_res;
                                inverse->costs   += 2;
                        }
                        break;
                case iro_ia32_Sub:
                        if (get_ia32_immop_type(irn) != ia32_ImmNone) {
                                /* we have a sub with a const/symconst here */
                                /* invers == add with this const */
                                inverse->nodes[0] = new_rd_ia32_Add(NULL, irg, block, noreg, noreg, get_irn_n(irn, i), noreg, nomem);
                                pnc               = pn_ia32_Add_res;
                                inverse->costs   += (get_ia32_immop_type(irn) == ia32_ImmSymConst) ? 5 : 1;
                                copy_ia32_Immop_attr(inverse->nodes[0], (ir_node *)irn);
                        }
                        else {
                                /* normal sub */
                                ir_node *proj = ia32_get_res_proj(irn);
                                assert(proj);

                                if (i == 2) {
                                        inverse->nodes[0] = new_rd_ia32_Add(NULL, irg, block, noreg, noreg, proj, get_irn_n(irn, 3), nomem);
                                }
                                else {
                                        inverse->nodes[0] = new_rd_ia32_Sub(NULL, irg, block, noreg, noreg, get_irn_n(irn, 2), proj, nomem);
                                }
                                pnc             = pn_ia32_Sub_res;
                                inverse->costs += 1;
                        }
                        break;
                case iro_ia32_Eor:
                        if (get_ia32_immop_type(irn) != ia32_ImmNone) {
                                /* xor with const: inverse = xor */
                                inverse->nodes[0] = new_rd_ia32_Eor(NULL, irg, block, noreg, noreg, get_irn_n(irn, i), noreg, nomem);
                                pnc               = pn_ia32_Eor_res;
                                inverse->costs   += (get_ia32_immop_type(irn) == ia32_ImmSymConst) ? 5 : 1;
                                copy_ia32_Immop_attr(inverse->nodes[0], (ir_node *)irn);
                        }
                        else {
                                /* normal xor */
                                inverse->nodes[0] = new_rd_ia32_Eor(NULL, irg, block, noreg, noreg, (ir_node *)irn, get_irn_n(irn, i), nomem);
                                pnc               = pn_ia32_Eor_res;
                                inverse->costs   += 1;
                        }
                        break;
                case iro_ia32_Not: {
                        ir_node *proj = ia32_get_res_proj(irn);
                        assert(proj);

                        inverse->nodes[0] = new_rd_ia32_Not(NULL, irg, block, noreg, noreg, proj, nomem);
                        pnc = pn_ia32_Not_res;
                        inverse->costs   += 1;
                        break;
                }
                case iro_ia32_Minus: {
                        ir_node *proj = ia32_get_res_proj(irn);
                        assert(proj);

                        inverse->nodes[0] = new_rd_ia32_Minus(NULL, irg, block, noreg, noreg, proj, nomem);
                        pnc               = pn_ia32_Minus_res;
                        inverse->costs   += 1;
                        break;
                }
                default:
                        /* inverse operation not supported */
                        return NULL;
        }

        set_ia32_res_mode(inverse->nodes[0], mode);
        inverse->nodes[1] = new_r_Proj(irg, block, inverse->nodes[0], mode, pnc);

        return inverse;
}

/**
 * Check if irn can load it's operand at position i from memory (source addressmode).
 * @param self   Pointer to irn ops itself
 * @param irn    The irn to be checked
 * @param i      The operands position
 * @return Non-Zero if operand can be loaded
 */
static int ia32_possible_memory_operand(const void *self, const ir_node *irn, unsigned int i) {
        if (! is_ia32_irn(irn)                            ||  /* must be an ia32 irn */
                get_irn_arity(irn) != 5                       ||  /* must be a binary operation */
                get_ia32_op_type(irn) != ia32_Normal          ||  /* must not already be a addressmode irn */
                ! (get_ia32_am_support(irn) & ia32_am_Source) ||  /* must be capable of source addressmode */
        (i != 2 && i != 3)                            ||  /* a "real" operand position must be requested */
                (i == 2 && ! is_ia32_commutative(irn))        ||  /* if first operand requested irn must be commutative */
                is_ia32_use_frame(irn))                           /* must not already use frame */
                return 0;

        return 1;
}

static void ia32_perform_memory_operand(const void *self, ir_node *irn, ir_node *reload, unsigned int i) {
        assert(ia32_possible_memory_operand(self, irn, i) && "Cannot perform memory operand change");
        assert(get_nodes_block(reload) == get_nodes_block(irn) && "Reload must be in same block as irn.");

        if (get_irn_n_edges(reload) > 1)
                return;

        if (i == 2) {
                ir_node *tmp = get_irn_n(irn, 3);
                set_irn_n(irn, 3, get_irn_n(irn, 2));
                set_irn_n(irn, 2, tmp);
        }

        set_ia32_am_support(irn, ia32_am_Source);
        set_ia32_op_type(irn, ia32_AddrModeS);
        set_ia32_am_flavour(irn, ia32_B);
        set_ia32_ls_mode(irn, get_irn_mode(reload));
        set_ia32_frame_ent(irn, be_get_frame_entity(reload));
        set_ia32_use_frame(irn);
        set_ia32_got_reload(irn);

        set_irn_n(irn, 0, be_get_Reload_frame(reload));
        set_irn_n(irn, 4, be_get_Reload_mem(reload));

        /*
                Input at position one is index register, which is NoReg.
                We would need cg object to get a real noreg, but we cannot
                access it from here.
         */
        set_irn_n(irn, 3, get_irn_n(irn, 1));

        DBG_OPT_AM_S(reload, irn);
}

static const be_abi_callbacks_t ia32_abi_callbacks = {
        ia32_abi_init,
        free,
        ia32_abi_get_between_type,
        ia32_abi_dont_save_regs,
        ia32_abi_prologue,
        ia32_abi_epilogue,
};

/* fill register allocator interface */

static const arch_irn_ops_if_t ia32_irn_ops_if = {
        ia32_get_irn_reg_req,
        ia32_set_irn_reg,
        ia32_get_irn_reg,
        ia32_classify,
        ia32_get_flags,
        ia32_get_frame_entity,
        ia32_set_stack_bias,
        ia32_get_inverse,
        ia32_get_op_estimated_cost,
        ia32_possible_memory_operand,
        ia32_perform_memory_operand,
};

ia32_irn_ops_t ia32_irn_ops = {
        &ia32_irn_ops_if,
        NULL
};



/**************************************************
 *                _                         _  __
 *               | |                       (_)/ _|
 *   ___ ___   __| | ___  __ _  ___ _ __    _| |_
 *  / __/ _ \ / _` |/ _ \/ _` |/ _ \ '_ \  | |  _|
 * | (_| (_) | (_| |  __/ (_| |  __/ | | | | | |
 *  \___\___/ \__,_|\___|\__, |\___|_| |_| |_|_|
 *                        __/ |
 *                       |___/
 **************************************************/

/**
 * Transforms the standard firm graph into
 * an ia32 firm graph
 */
static void ia32_prepare_graph(void *self) {
        ia32_code_gen_t *cg = self;
        dom_front_info_t *dom;
        DEBUG_ONLY(firm_dbg_module_t *old_mod = cg->mod;)

        FIRM_DBG_REGISTER(cg->mod, "firm.be.ia32.transform");

        /* 1st: transform constants and psi condition trees */
        ia32_pre_transform_phase(cg);

        /* 2nd: transform all remaining nodes */
        ia32_register_transformers();
        dom = be_compute_dominance_frontiers(cg->irg);
        irg_walk_blkwise_graph(cg->irg, NULL, ia32_transform_node, cg);
        be_free_dominance_frontiers(dom);

        if (cg->dump)
                be_dump(cg->irg, "-transformed", dump_ir_block_graph_sched);

        /* 3rd: optimize address mode */
        FIRM_DBG_REGISTER(cg->mod, "firm.be.ia32.am");
        ia32_optimize_addressmode(cg);

        if (cg->dump)
                be_dump(cg->irg, "-am", dump_ir_block_graph_sched);

        DEBUG_ONLY(cg->mod = old_mod;)
}

/**
 * Dummy functions for hooks we don't need but which must be filled.
 */
static void ia32_before_sched(void *self) {
}

static void remove_unused_nodes(ir_node *irn, bitset_t *already_visited) {
        int i;
        ir_mode *mode;
        ir_node *mem_proj;

        if (is_Block(irn))
                return;

        mode = get_irn_mode(irn);

        /* check if we already saw this node or the node has more than one user */
        if (bitset_contains_irn(already_visited, irn) || get_irn_n_edges(irn) > 1)
                return;

        /* mark irn visited */
        bitset_add_irn(already_visited, irn);

        /* non-Tuple nodes with one user: ok, return */
        if (get_irn_n_edges(irn) >= 1 && mode != mode_T)
                return;

        /* tuple node has one user which is not the mem proj-> ok */
        if (mode == mode_T && get_irn_n_edges(irn) == 1) {
                mem_proj = ia32_get_proj_for_mode(irn, mode_M);
                if (! mem_proj)
                        return;
        }

        for (i = get_irn_arity(irn) - 1; i >= 0; i--) {
                ir_node *pred = get_irn_n(irn, i);

                /* do not follow memory edges or we will accidentally remove stores */
                if (is_Proj(pred) && get_irn_mode(pred) == mode_M)
                        continue;

                set_irn_n(irn, i, new_Bad());

                /*
                        The current node is about to be removed: if the predecessor
                        has only this node as user, it need to be removed as well.
                */
                if (get_irn_n_edges(pred) <= 1)
                        remove_unused_nodes(pred, already_visited);
        }

        if (sched_is_scheduled(irn))
                sched_remove(irn);
}

static void remove_unused_loads_walker(ir_node *irn, void *env) {
        bitset_t *already_visited = env;
        if (is_ia32_Ld(irn) && ! bitset_contains_irn(already_visited, irn))
                remove_unused_nodes(irn, env);
}

/**
 * Called before the register allocator.
 * Calculate a block schedule here. We need it for the x87
 * simulator and the emitter.
 */
static void ia32_before_ra(void *self) {
        ia32_code_gen_t *cg              = self;
        bitset_t        *already_visited = bitset_irg_malloc(cg->irg);

        cg->blk_sched = sched_create_block_schedule(cg->irg);

        /*
                Handle special case:
                There are sometimes unused loads, only pinned by memory.
                We need to remove those Loads and all other nodes which won't be used
                after removing the Load from schedule.
        */
        irg_walk_graph(cg->irg, remove_unused_loads_walker, NULL, already_visited);
        bitset_free(already_visited);
}


/**
 * Transforms a be node into a Load.
 */
static void transform_to_Load(ia32_transform_env_t *env) {
        ir_node *irn         = env->irn;
        entity  *ent         = be_get_frame_entity(irn);
        ir_mode *mode        = env->mode;
        ir_node *noreg       = ia32_new_NoReg_gp(env->cg);
        ir_node *nomem       = new_rd_NoMem(env->irg);
        ir_node *sched_point = NULL;
        ir_node *ptr         = get_irn_n(irn, 0);
        ir_node *mem         = be_is_Reload(irn) ? get_irn_n(irn, 1) : nomem;
        ir_node *new_op, *proj;
        const arch_register_t *reg;

        if (sched_is_scheduled(irn)) {
                sched_point = sched_prev(irn);
        }

        if (mode_is_float(mode)) {
                if (USE_SSE2(env->cg))
                        new_op = new_rd_ia32_xLoad(env->dbg, env->irg, env->block, ptr, noreg, mem);
                else
                        new_op = new_rd_ia32_vfld(env->dbg, env->irg, env->block, ptr, noreg, mem);
        }
        else {
                new_op = new_rd_ia32_Load(env->dbg, env->irg, env->block, ptr, noreg, mem);
        }

        set_ia32_am_support(new_op, ia32_am_Source);
        set_ia32_op_type(new_op, ia32_AddrModeS);
        set_ia32_am_flavour(new_op, ia32_B);
        set_ia32_ls_mode(new_op, mode);
        set_ia32_frame_ent(new_op, ent);
        set_ia32_use_frame(new_op);

        DBG_OPT_RELOAD2LD(irn, new_op);

        proj = new_rd_Proj(env->dbg, env->irg, env->block, new_op, mode, pn_Load_res);

        if (sched_point) {
                sched_add_after(sched_point, new_op);
                sched_add_after(new_op, proj);

                sched_remove(irn);
        }

        /* copy the register from the old node to the new Load */
        reg = arch_get_irn_register(env->cg->arch_env, irn);
        arch_set_irn_register(env->cg->arch_env, new_op, reg);

        SET_IA32_ORIG_NODE(new_op, ia32_get_old_node_name(env->cg, irn));

        exchange(irn, proj);
}

/**
 * Transforms a be node into a Store.
 */
static void transform_to_Store(ia32_transform_env_t *env) {
        ir_node *irn   = env->irn;
        entity  *ent   = be_get_frame_entity(irn);
        ir_mode *mode  = env->mode;
        ir_node *noreg = ia32_new_NoReg_gp(env->cg);
        ir_node *nomem = new_rd_NoMem(env->irg);
        ir_node *ptr   = get_irn_n(irn, 0);
        ir_node *val   = get_irn_n(irn, 1);
        ir_node *new_op, *proj;
        ir_node *sched_point = NULL;

        if (sched_is_scheduled(irn)) {
                sched_point = sched_prev(irn);
        }

        if (mode_is_float(mode)) {
                if (USE_SSE2(env->cg))
                        new_op = new_rd_ia32_xStore(env->dbg, env->irg, env->block, ptr, noreg, val, nomem);
                else
                        new_op = new_rd_ia32_vfst(env->dbg, env->irg, env->block, ptr, noreg, val, nomem);
        }
        else if (get_mode_size_bits(mode) == 8) {
                new_op = new_rd_ia32_Store8Bit(env->dbg, env->irg, env->block, ptr, noreg, val, nomem);
        }
        else {
                new_op = new_rd_ia32_Store(env->dbg, env->irg, env->block, ptr, noreg, val, nomem);
        }

        set_ia32_am_support(new_op, ia32_am_Dest);
        set_ia32_op_type(new_op, ia32_AddrModeD);
        set_ia32_am_flavour(new_op, ia32_B);
        set_ia32_ls_mode(new_op, mode);
        set_ia32_frame_ent(new_op, ent);
        set_ia32_use_frame(new_op);

        DBG_OPT_SPILL2ST(irn, new_op);

        proj = new_rd_Proj(env->dbg, env->irg, env->block, new_op, mode_M, pn_ia32_Store_M);

        if (sched_point) {
                sched_add_after(sched_point, new_op);
                sched_remove(irn);
        }

        SET_IA32_ORIG_NODE(new_op, ia32_get_old_node_name(env->cg, irn));

        exchange(irn, proj);
}

static ir_node *create_push(ia32_transform_env_t *env, ir_node *schedpoint, ir_node *sp, ir_node *mem, entity *ent, const char *offset) {
        ir_node *noreg = ia32_new_NoReg_gp(env->cg);

        ir_node *push = new_rd_ia32_Push(env->dbg, env->irg, env->block, sp, noreg, mem);

        set_ia32_frame_ent(push, ent);
        set_ia32_use_frame(push);
        set_ia32_op_type(push, ia32_AddrModeS);
        set_ia32_am_flavour(push, ia32_B);
        set_ia32_ls_mode(push, mode_Is);
        if(offset != NULL)
                add_ia32_am_offs(push, offset);

        sched_add_before(schedpoint, push);
        return push;
}

static ir_node *create_pop(ia32_transform_env_t *env, ir_node *schedpoint, ir_node *sp, entity *ent, const char *offset) {
        ir_node *pop = new_rd_ia32_Pop(env->dbg, env->irg, env->block, sp, new_NoMem());

        set_ia32_frame_ent(pop, ent);
        set_ia32_use_frame(pop);
        set_ia32_op_type(pop, ia32_AddrModeD);
        set_ia32_am_flavour(pop, ia32_B);
        set_ia32_ls_mode(pop, mode_Is);
        if(offset != NULL)
                add_ia32_am_offs(pop, offset);

        sched_add_before(schedpoint, pop);

        return pop;
}

static ir_node* create_spproj(ia32_transform_env_t *env, ir_node *pred, ir_node *schedpoint, const ir_node *oldsp) {
        ir_mode *spmode = get_irn_mode(oldsp);
        const arch_register_t *spreg = arch_get_irn_register(env->cg->arch_env, oldsp);
        ir_node *sp;

        sp = new_rd_Proj(env->dbg, env->irg, env->block, pred, spmode, 0);
        arch_set_irn_register(env->cg->arch_env, sp, spreg);
        sched_add_before(schedpoint, sp);

        return sp;
}

static void transform_MemPerm(ia32_transform_env_t *env) {
        /*
         * Transform memperm, currently we do this the ugly way and produce
         * push/pop into/from memory cascades. This is possible without using
         * any registers.
         */
        ir_node *node = env->irn;
        int i, arity;
        ir_node *sp = get_irn_n(node, 0);
        const ir_edge_t *edge;
        const ir_edge_t *next;
        ir_node **pops;

        arity = be_get_MemPerm_entity_arity(node);
        pops = alloca(arity * sizeof(pops[0]));

        // create pushs
        for(i = 0; i < arity; ++i) {
                entity *ent = be_get_MemPerm_in_entity(node, i);
                ir_type *enttype = get_entity_type(ent);
                int entbits = get_type_size_bits(enttype);
                ir_node *mem = get_irn_n(node, i + 1);
                ir_node *push;

                assert( (entbits == 32 || entbits == 64) && "spillslot on x86 should be 32 or 64 bit");

                push = create_push(env, node, sp, mem, ent, NULL);
                sp = create_spproj(env, push, node, sp);
                if(entbits == 64) {
                        // add another push after the first one
                        push = create_push(env, node, sp, mem, ent, "4");
                        sp = create_spproj(env, push, node, sp);
                }

                set_irn_n(node, i, new_Bad());
        }

        // create pops
        for(i = arity - 1; i >= 0; --i) {
                entity *ent = be_get_MemPerm_out_entity(node, i);
                ir_type *enttype = get_entity_type(ent);
                int entbits = get_type_size_bits(enttype);

                ir_node *pop;

                assert( (entbits == 32 || entbits == 64) && "spillslot on x86 should be 32 or 64 bit");

                pop = create_pop(env, node, sp, ent, NULL);
                if(entbits == 64) {
                        // add another pop after the first one
                        sp = create_spproj(env, pop, node, sp);
                        pop = create_pop(env, node, sp, ent, "4");
                }
                if(i != 0) {
                        sp = create_spproj(env, pop, node, sp);
                }

                pops[i] = pop;
        }

        // exchange memprojs
        foreach_out_edge_safe(node, edge, next) {
                ir_node *proj = get_edge_src_irn(edge);
                int p = get_Proj_proj(proj);

                assert(p < arity);

                set_Proj_pred(proj, pops[p]);
                set_Proj_proj(proj, 3);
        }

        sched_remove(node);
}

/**
 * Fix the mode of Spill/Reload
 */
static ir_mode *fix_spill_mode(ia32_code_gen_t *cg, ir_mode *mode)
{
        if (mode_is_float(mode)) {
                if (USE_SSE2(cg))
                        mode = mode_D;
                else
                        mode = mode_E;
        }
        else
                mode = mode_Is;
        return mode;
}

/**
 * Block-Walker: Calls the transform functions Spill and Reload.
 */
static void ia32_after_ra_walker(ir_node *block, void *env) {
        ir_node *node, *prev;
        ia32_code_gen_t *cg = env;
        ia32_transform_env_t tenv;

        tenv.block = block;
        tenv.irg   = current_ir_graph;
        tenv.cg    = cg;
        DEBUG_ONLY(tenv.mod = cg->mod;)

        /* beware: the schedule is changed here */
        for (node = sched_last(block); !sched_is_begin(node); node = prev) {
                prev = sched_prev(node);
                if (be_is_Reload(node)) {
                        /* we always reload the whole register  */
                        tenv.dbg  = get_irn_dbg_info(node);
                        tenv.irn  = node;
                        tenv.mode = fix_spill_mode(cg, get_irn_mode(node));
                        transform_to_Load(&tenv);
                }
                else if (be_is_Spill(node)) {
                        ir_node *spillval = get_irn_n(node, be_pos_Spill_val);
                        /* we always spill the whole register  */
                        tenv.dbg  = get_irn_dbg_info(node);
                        tenv.irn  = node;
                        tenv.mode = fix_spill_mode(cg, get_irn_mode(spillval));
                        transform_to_Store(&tenv);
                }
                else if(be_is_MemPerm(node)) {
                        tenv.dbg = get_irn_dbg_info(node);
                        tenv.irn = node;
                        transform_MemPerm(&tenv);
                }
        }
}

/**
 * We transform Spill and Reload here. This needs to be done before
 * stack biasing otherwise we would miss the corrected offset for these nodes.
 *
 * If x87 instruction should be emitted, run the x87 simulator and patch
 * the virtual instructions. This must obviously be done after register allocation.
 */
static void ia32_after_ra(void *self) {
        ia32_code_gen_t *cg = self;

        irg_block_walk_graph(cg->irg, NULL, ia32_after_ra_walker, self);

        /* if we do x87 code generation, rewrite all the virtual instructions and registers */
        if (cg->used_fp == fp_x87 || cg->force_sim) {
                x87_simulate_graph(cg->arch_env, cg->irg, cg->blk_sched);
        }
}

/**
 * Last touchups for the graph before emit
 */
static void ia32_finish(void *self) {
        ia32_code_gen_t *cg = self;
        ir_graph        *irg = cg->irg;

        ia32_finish_irg(irg, cg);
}

/**
 * Emits the code, closes the output file and frees
 * the code generator interface.
 */
static void ia32_codegen(void *self) {
        ia32_code_gen_t *cg = self;
        ir_graph        *irg = cg->irg;

        ia32_gen_routine(cg->isa->out, irg, cg);

        cur_reg_set = NULL;

        /* remove it from the isa */
        cg->isa->cg = NULL;

        /* de-allocate code generator */
        del_set(cg->reg_set);
        free(self);
}

static void *ia32_cg_init(const be_irg_t *birg);

static const arch_code_generator_if_t ia32_code_gen_if = {
        ia32_cg_init,
        NULL,                /* before abi introduce hook */
        ia32_prepare_graph,
        ia32_before_sched,   /* before scheduling hook */
        ia32_before_ra,      /* before register allocation hook */
        ia32_after_ra,       /* after register allocation hook */
        ia32_finish,         /* called before codegen */
        ia32_codegen         /* emit && done */
};

/**
 * Initializes a IA32 code generator.
 */
static void *ia32_cg_init(const be_irg_t *birg) {
        ia32_isa_t      *isa = (ia32_isa_t *)birg->main_env->arch_env->isa;
        ia32_code_gen_t *cg  = xcalloc(1, sizeof(*cg));

        cg->impl      = &ia32_code_gen_if;
        cg->irg       = birg->irg;
        cg->reg_set   = new_set(ia32_cmp_irn_reg_assoc, 1024);
        cg->arch_env  = birg->main_env->arch_env;
        cg->isa       = isa;
        cg->birg      = birg;
        cg->blk_sched = NULL;
        cg->fp_to_gp  = NULL;
        cg->gp_to_fp  = NULL;
        cg->fp_kind   = isa->fp_kind;
        cg->used_fp   = fp_none;
        cg->dump      = (birg->main_env->options->dump_flags & DUMP_BE) ? 1 : 0;

        FIRM_DBG_REGISTER(cg->mod, "firm.be.ia32.cg");

        /* copy optimizations from isa for easier access */
        cg->opt      = isa->opt;
        cg->arch     = isa->arch;
        cg->opt_arch = isa->opt_arch;

        /* enter it */
        isa->cg = cg;

#ifndef NDEBUG
        if (isa->name_obst_size) {
                //printf("freed %d bytes from name obst\n", isa->name_obst_size);
                isa->name_obst_size = 0;
                obstack_free(isa->name_obst, NULL);
                obstack_init(isa->name_obst);
        }
#endif /* NDEBUG */

        cur_reg_set = cg->reg_set;

        ia32_irn_ops.cg = cg;

        return (arch_code_generator_t *)cg;
}



/*****************************************************************
 *  ____             _                  _   _____  _____
 * |  _ \           | |                | | |_   _|/ ____|  /\
 * | |_) | __ _  ___| | _____ _ __   __| |   | | | (___   /  \
 * |  _ < / _` |/ __| |/ / _ \ '_ \ / _` |   | |  \___ \ / /\ \
 * | |_) | (_| | (__|   <  __/ | | | (_| |  _| |_ ____) / ____ \
 * |____/ \__,_|\___|_|\_\___|_| |_|\__,_| |_____|_____/_/    \_\
 *
 *****************************************************************/

/**
 * Set output modes for GCC
 */
static const tarval_mode_info mo_integer = {
        TVO_DECIMAL,
        NULL,
        NULL,
};

/*
* set the tarval output mode to C-semantics
*/
static void set_tarval_output_modes(void)
{
        set_tarval_mode_output_option(get_modeLs(), &mo_integer);
        set_tarval_mode_output_option(get_modeLu(), &mo_integer);
        set_tarval_mode_output_option(get_modeIs(), &mo_integer);
        set_tarval_mode_output_option(get_modeIu(), &mo_integer);
        set_tarval_mode_output_option(get_modeHs(), &mo_integer);
        set_tarval_mode_output_option(get_modeHu(), &mo_integer);
        set_tarval_mode_output_option(get_modeBs(), &mo_integer);
        set_tarval_mode_output_option(get_modeBu(), &mo_integer);
        set_tarval_mode_output_option(get_modeC(),  &mo_integer);
        set_tarval_mode_output_option(get_modeU(),  &mo_integer);
        set_tarval_mode_output_option(get_modeIu(), &mo_integer);
}


/**
 * The template that generates a new ISA object.
 * Note that this template can be changed by command line
 * arguments.
 */
static ia32_isa_t ia32_isa_template = {
        {
                &ia32_isa_if,            /* isa interface implementation */
                &ia32_gp_regs[REG_ESP],  /* stack pointer register */
                &ia32_gp_regs[REG_EBP],  /* base pointer register */
                -1,                      /* stack direction */
        },
        NULL,                    /* 16bit register names */
        NULL,                    /* 8bit register names */
        NULL,                    /* types */
        NULL,                    /* tv_ents */
        (0                 |
        IA32_OPT_INCDEC    |     /* optimize add 1, sub 1 into inc/dec               default: on  */
        IA32_OPT_DOAM      |     /* optimize address mode                            default: on  */
        IA32_OPT_LEA       |     /* optimize for LEAs                                default: on  */
        IA32_OPT_PLACECNST |     /* place constants immediately before instructions, default: on  */
        IA32_OPT_IMMOPS    |     /* operations can use immediates,                   default: on  */
        IA32_OPT_EXTBB),         /* use extended basic block scheduling,             default: on  */
        arch_pentium_4,          /* instruction architecture */
        arch_pentium_4,          /* optimize for architecture */
        fp_sse2,                 /* use sse2 unit */
        NULL,                    /* current code generator */
#ifndef NDEBUG
        NULL,                    /* name obstack */
        0                        /* name obst size */
#endif
};

/**
 * Initializes the backend ISA.
 */
static void *ia32_init(FILE *file_handle) {
        static int inited = 0;
        ia32_isa_t *isa;

        if (inited)
                return NULL;

        set_tarval_output_modes();

        isa = xmalloc(sizeof(*isa));
        memcpy(isa, &ia32_isa_template, sizeof(*isa));

        ia32_register_init(isa);
        ia32_create_opcodes();

        if ((ARCH_INTEL(isa->arch) && isa->arch < arch_pentium_4) ||
            (ARCH_AMD(isa->arch) && isa->arch < arch_athlon))
                /* no SSE2 for these cpu's */
                isa->fp_kind = fp_x87;

        if (ARCH_INTEL(isa->opt_arch) && isa->opt_arch >= arch_pentium_4) {
                /* Pentium 4 don't like inc and dec instructions */
                isa->opt &= ~IA32_OPT_INCDEC;
        }

        isa->regs_16bit = pmap_create();
        isa->regs_8bit  = pmap_create();
        isa->types      = pmap_create();
        isa->tv_ent     = pmap_create();
        isa->out        = file_handle;

        ia32_build_16bit_reg_map(isa->regs_16bit);
        ia32_build_8bit_reg_map(isa->regs_8bit);

        /* patch register names of x87 registers */
        if (USE_x87(isa)) {
                ia32_st_regs[0].name = "st";
                ia32_st_regs[1].name = "st(1)";
                ia32_st_regs[2].name = "st(2)";
                ia32_st_regs[3].name = "st(3)";
                ia32_st_regs[4].name = "st(4)";
                ia32_st_regs[5].name = "st(5)";
                ia32_st_regs[6].name = "st(6)";
                ia32_st_regs[7].name = "st(7)";
        }

#ifndef NDEBUG
        isa->name_obst = xmalloc(sizeof(*isa->name_obst));
        obstack_init(isa->name_obst);
        isa->name_obst_size = 0;
#endif /* NDEBUG */

        ia32_handle_intrinsics();
        ia32_switch_section(NULL, NO_SECTION);
        fprintf(isa->out, "\t.intel_syntax\n");

        inited = 1;

        return isa;
}



/**
 * Closes the output file and frees the ISA structure.
 */
static void ia32_done(void *self) {
        ia32_isa_t *isa = self;

        /* emit now all global declarations */
        ia32_gen_decls(isa->out);

        pmap_destroy(isa->regs_16bit);
        pmap_destroy(isa->regs_8bit);
        pmap_destroy(isa->tv_ent);
        pmap_destroy(isa->types);

#ifndef NDEBUG
        //printf("name obst size = %d bytes\n", isa->name_obst_size);
        obstack_free(isa->name_obst, NULL);
#endif /* NDEBUG */

        free(self);
}


/**
 * Return the number of register classes for this architecture.
 * We report always these:
 *  - the general purpose registers
 *  - the SSE floating point register set
 *  - the virtual floating point registers
 */
static int ia32_get_n_reg_class(const void *self) {
        return 3;
}

/**
 * Return the register class for index i.
 */
static const arch_register_class_t *ia32_get_reg_class(const void *self, int i) {
        assert(i >= 0 && i < 3 && "Invalid ia32 register class requested.");
        if (i == 0)
                return &ia32_reg_classes[CLASS_ia32_gp];
        else if (i == 1)
                return &ia32_reg_classes[CLASS_ia32_xmm];
        else
                return &ia32_reg_classes[CLASS_ia32_vfp];
}

/**
 * Get the register class which shall be used to store a value of a given mode.
 * @param self The this pointer.
 * @param mode The mode in question.
 * @return A register class which can hold values of the given mode.
 */
const arch_register_class_t *ia32_get_reg_class_for_mode(const void *self, const ir_mode *mode) {
        const ia32_isa_t *isa = self;
        if (mode_is_float(mode)) {
                return USE_SSE2(isa) ? &ia32_reg_classes[CLASS_ia32_xmm] : &ia32_reg_classes[CLASS_ia32_vfp];
        }
        else
                return &ia32_reg_classes[CLASS_ia32_gp];
}

/**
 * Get the ABI restrictions for procedure calls.
 * @param self        The this pointer.
 * @param method_type The type of the method (procedure) in question.
 * @param abi         The abi object to be modified
 */
static void ia32_get_call_abi(const void *self, ir_type *method_type, be_abi_call_t *abi) {
        const ia32_isa_t *isa = self;
        ir_type  *tp;
        ir_mode  *mode;
        unsigned  cc        = get_method_calling_convention(method_type);
        int       n         = get_method_n_params(method_type);
        int       biggest_n = -1;
        int       stack_idx = 0;
        int       i, ignore_1, ignore_2;
        ir_mode **modes;
        const arch_register_t *reg;
        be_abi_call_flags_t call_flags = be_abi_call_get_flags(abi);

        unsigned use_push = !IS_P6_ARCH(isa->opt_arch);

        /* set abi flags for calls */
        call_flags.bits.left_to_right         = 0;  /* always last arg first on stack */
        call_flags.bits.store_args_sequential = use_push;
        /* call_flags.bits.try_omit_fp                 not changed: can handle both settings */
        call_flags.bits.fp_free               = 0;  /* the frame pointer is fixed in IA32 */
        call_flags.bits.call_has_imm          = 1;  /* IA32 calls can have immediate address */

        /* set stack parameter passing style */
        be_abi_call_set_flags(abi, call_flags, &ia32_abi_callbacks);

        /* collect the mode for each type */
        modes = alloca(n * sizeof(modes[0]));

        for (i = 0; i < n; i++) {
                tp       = get_method_param_type(method_type, i);
                modes[i] = get_type_mode(tp);
        }

        /* set register parameters  */
        if (cc & cc_reg_param) {
                /* determine the number of parameters passed via registers */
                biggest_n = ia32_get_n_regparam_class(n, modes, &ignore_1, &ignore_2);

                /* loop over all parameters and set the register requirements */
                for (i = 0; i <= biggest_n; i++) {
                        reg = ia32_get_RegParam_reg(n, modes, i, cc);
                        assert(reg && "kaputt");
                        be_abi_call_param_reg(abi, i, reg);
                }

                stack_idx = i;
        }


        /* set stack parameters */
        for (i = stack_idx; i < n; i++) {
                be_abi_call_param_stack(abi, i, 1, 0, 0);
        }


        /* set return registers */
        n = get_method_n_ress(method_type);

        assert(n <= 2 && "more than two results not supported");

        /* In case of 64bit returns, we will have two 32bit values */
        if (n == 2) {
                tp   = get_method_res_type(method_type, 0);
                mode = get_type_mode(tp);

                assert(!mode_is_float(mode) && "two FP results not supported");

                tp   = get_method_res_type(method_type, 1);
                mode = get_type_mode(tp);

                assert(!mode_is_float(mode) && "two FP results not supported");

                be_abi_call_res_reg(abi, 0, &ia32_gp_regs[REG_EAX]);
                be_abi_call_res_reg(abi, 1, &ia32_gp_regs[REG_EDX]);
        }
        else if (n == 1) {
                const arch_register_t *reg;

                tp   = get_method_res_type(method_type, 0);
                assert(is_atomic_type(tp));
                mode = get_type_mode(tp);

                reg = mode_is_float(mode) ?
                        (USE_SSE2(isa) ? &ia32_xmm_regs[REG_XMM0] : &ia32_vfp_regs[REG_VF0]) :
                        &ia32_gp_regs[REG_EAX];

                be_abi_call_res_reg(abi, 0, reg);
        }
}


static const void *ia32_get_irn_ops(const arch_irn_handler_t *self, const ir_node *irn) {
        return &ia32_irn_ops;
}

const arch_irn_handler_t ia32_irn_handler = {
        ia32_get_irn_ops
};

const arch_irn_handler_t *ia32_get_irn_handler(const void *self) {
        return &ia32_irn_handler;
}

int ia32_to_appear_in_schedule(void *block_env, const ir_node *irn) {
        return is_ia32_irn(irn) ? 1 : -1;
}

/**
 * Initializes the code generator interface.
 */
static const arch_code_generator_if_t *ia32_get_code_generator_if(void *self) {
        return &ia32_code_gen_if;
}

list_sched_selector_t ia32_sched_selector;

/**
 * Returns the reg_pressure scheduler with to_appear_in_schedule() overloaded
 */
static const list_sched_selector_t *ia32_get_list_sched_selector(const void *self) {
//      memcpy(&ia32_sched_selector, reg_pressure_selector, sizeof(list_sched_selector_t));
        memcpy(&ia32_sched_selector, trivial_selector, sizeof(list_sched_selector_t));
        ia32_sched_selector.to_appear_in_schedule = ia32_to_appear_in_schedule;
        return &ia32_sched_selector;
}

/**
 * Returns the necessary byte alignment for storing a register of given class.
 */
static int ia32_get_reg_class_alignment(const void *self, const arch_register_class_t *cls) {
        ir_mode *mode = arch_register_class_mode(cls);
        int bytes     = get_mode_size_bytes(mode);

        if (mode_is_float(mode) && bytes > 8)
                return 16;
        return bytes;
}

static ia32_intrinsic_env_t intrinsic_env = { NULL, NULL };

/**
 * Returns the libFirm configuration parameter for this backend.
 */
static const backend_params *ia32_get_libfirm_params(void) {
        static const arch_dep_params_t ad = {
                1, /* also use subs */
                4, /* maximum shifts */
                31, /* maximum shift amount */

                1, /* allow Mulhs */
                1, /* allow Mulus */
                32  /* Mulh allowed up to 32 bit */
        };
        static backend_params p = {
                NULL,  /* no additional opcodes */
                NULL,  /* will be set later */
                1,     /* need dword lowering */
                ia32_create_intrinsic_fkt,
                &intrinsic_env,  /* context for ia32_create_intrinsic_fkt */
        };

        p.dep_param = &ad;
        return &p;
}
#ifdef WITH_LIBCORE

/* instruction set architectures. */
static const lc_opt_enum_int_items_t arch_items[] = {
        { "386",        arch_i386, },
        { "486",        arch_i486, },
        { "pentium",    arch_pentium, },
        { "586",        arch_pentium, },
        { "pentiumpro", arch_pentium_pro, },
        { "686",        arch_pentium_pro, },
        { "pentiummmx", arch_pentium_mmx, },
        { "pentium2",   arch_pentium_2, },
        { "p2",         arch_pentium_2, },
        { "pentium3",   arch_pentium_3, },
        { "p3",         arch_pentium_3, },
        { "pentium4",   arch_pentium_4, },
        { "p4",         arch_pentium_4, },
        { "pentiumm",   arch_pentium_m, },
        { "pm",         arch_pentium_m, },
        { "core",       arch_core, },
        { "k6",         arch_k6, },
        { "athlon",     arch_athlon, },
        { "athlon64",   arch_athlon_64, },
        { "opteron",    arch_opteron, },
        { NULL,         0 }
};

static lc_opt_enum_int_var_t arch_var = {
        &ia32_isa_template.arch, arch_items
};

static lc_opt_enum_int_var_t opt_arch_var = {
        &ia32_isa_template.opt_arch, arch_items
};

static const lc_opt_enum_int_items_t fp_unit_items[] = {
        { "x87" ,    fp_x87 },
        { "sse2",    fp_sse2 },
        { NULL,      0 }
};

static lc_opt_enum_int_var_t fp_unit_var = {
        &ia32_isa_template.fp_kind, fp_unit_items
};

static const lc_opt_enum_int_items_t gas_items[] = {
        { "linux",   ASM_LINUX_GAS },
        { "mingw",   ASM_MINGW_GAS },
        { NULL,      0 }
};

static lc_opt_enum_int_var_t gas_var = {
        (int *)&asm_flavour, gas_items
};

static const lc_opt_table_entry_t ia32_options[] = {
        LC_OPT_ENT_ENUM_INT("arch",      "select the instruction architecture", &arch_var),
        LC_OPT_ENT_ENUM_INT("opt",       "optimize for instruction architecture", &opt_arch_var),
        LC_OPT_ENT_ENUM_INT("fpunit",    "select the floating point unit", &fp_unit_var),
        LC_OPT_ENT_NEGBIT("noaddrmode",  "do not use address mode", &ia32_isa_template.opt, IA32_OPT_DOAM),
        LC_OPT_ENT_NEGBIT("nolea",       "do not optimize for LEAs", &ia32_isa_template.opt, IA32_OPT_LEA),
        LC_OPT_ENT_NEGBIT("noplacecnst", "do not place constants", &ia32_isa_template.opt, IA32_OPT_PLACECNST),
        LC_OPT_ENT_NEGBIT("noimmop",     "no operations with immediates", &ia32_isa_template.opt, IA32_OPT_IMMOPS),
        LC_OPT_ENT_NEGBIT("noextbb",     "do not use extended basic block scheduling", &ia32_isa_template.opt, IA32_OPT_EXTBB),
        LC_OPT_ENT_ENUM_INT("gasmode",   "set the GAS compatibility mode", &gas_var),
        { NULL }
};

/**
 * Register command line options for the ia32 backend.
 *
 * Options so far:
 *
 * ia32-arch=arch    create instruction for arch
 * ia32-opt=arch     optimize for run on arch
 * ia32-fpunit=unit  select floating point unit (x87 or SSE2)
 * ia32-incdec       optimize for inc/dec
 * ia32-noaddrmode   do not use address mode
 * ia32-nolea        do not optimize for LEAs
 * ia32-noplacecnst  do not place constants,
 * ia32-noimmop      no operations with immediates
 * ia32-noextbb      do not use extended basic block scheduling
 * ia32-gasmode      set the GAS compatibility mode
 */
static void ia32_register_options(lc_opt_entry_t *ent)
{
        lc_opt_entry_t *be_grp_ia32 = lc_opt_get_grp(ent, "ia32");
        lc_opt_add_table(be_grp_ia32, ia32_options);
}
#endif /* WITH_LIBCORE */

const arch_isa_if_t ia32_isa_if = {
        ia32_init,
        ia32_done,
        ia32_get_n_reg_class,
        ia32_get_reg_class,
        ia32_get_reg_class_for_mode,
        ia32_get_call_abi,
        ia32_get_irn_handler,
        ia32_get_code_generator_if,
        ia32_get_list_sched_selector,
        ia32_get_reg_class_alignment,
        ia32_get_libfirm_params,
#ifdef WITH_LIBCORE
        ia32_register_options
#endif
};