add special constant to represent VA_START-address in a parameter_entity
[libfirm] / ir / lower / lower_mode_b.c
index b96072f..6a381be 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2011 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
  */
 
 /**
- * @file        lowers operations with mode_b. The result is a graph which
+ * @file
+ * @brief       lowers operations with mode_b. The result is a graph which
  *              might still contains some convs from/to mode_b, but no
  *              operations are performed on them anymore, they are just there
  *              so modes match. A backend can safely skip all mode_b convs.
  * @author      Matthias Braun, Christoph Mallon
  * @version     $Id$
+ *
+ * After this pass the following should hold:
+ *   - The only inputs with mode_b are for the Cond node or the
+ *     Sel input of a Mux node.
+ *   - The only nodes producing mode_b are: Proj(Cmp) and ConvB(X) (where X
+ *     is some mode that can be converted to the lowered mode).
+ *     ConvB will usually be implemented by a comparison with 0 producing some
+ *     flags in the backends. It's debatable whether ConvB(X) is a good idea.
+ *     Maybe we should rather introduce a Test node.
+ * All other former uses should be converted to manipulations with an integer
+ * mode that was specified in the pass configuration.
  */
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
 
 #include <stdlib.h>
+#include <stdbool.h>
 
 #include "irnode_t.h"
 #include "ircons_t.h"
+#include "irflag.h"
 #include "irgwalk.h"
 #include "irtools.h"
 #include "iredges.h"
 #include "iropt_t.h"
+#include "irgmod.h"
 #include "tv.h"
 #include "error.h"
 #include "lowering.h"
 #include "pdeq.h"
+#include "irpass_t.h"
+#include "util.h"
+#include "array.h"
 
-static lower_mode_b_config_t  config;
-static ir_type               *lowered_type  = NULL;
-static pdeq                  *lowered_nodes = NULL;
+static const lower_mode_b_config_t *config;
+static ir_type                     *lowered_type;
+static ir_node                    **lowered_nodes;
+static ir_node                    **check_later;
 
 /**
  * Removes a node if its out-edge count has reached 0.
@@ -52,96 +69,98 @@ static pdeq                  *lowered_nodes = NULL;
  */
 static void maybe_kill_node(ir_node *node)
 {
-       ir_graph *irg;
-       int       i, arity;
-
-       if(get_irn_n_edges(node) != 0)
+       if (get_irn_n_edges(node) != 0)
                return;
 
-       irg = get_irn_irg(node);
-
-       assert(!is_Bad(node));
-
-       arity = get_irn_arity(node);
-       for (i = 0; i < arity; ++i) {
-               set_irn_n(node, i, new_Bad());
-       }
-       set_nodes_block(node, new_Bad());
-
-       edges_node_deleted(node, irg);
+       kill_node(node);
 }
 
 static ir_node *create_not(dbg_info *dbgi, ir_node *node)
 {
-       ir_graph *irg    = current_ir_graph;
-       ir_node  *block  = get_nodes_block(node);
-       ir_mode  *mode   = config.lowered_mode;
-       tarval   *tv_one = get_tarval_one(mode);
-       ir_node  *one    = new_d_Const(dbgi, mode, tv_one);
+       ir_node   *block  = get_nodes_block(node);
+       ir_mode   *mode   = config->lowered_mode;
+       ir_tarval *tv_one = get_mode_one(mode);
+       ir_graph  *irg    = get_irn_irg(node);
+       ir_node   *one    = new_rd_Const(dbgi, irg, tv_one);
 
-       return new_rd_Eor(dbgi, irg, block, node, one, mode);
+       return new_rd_Eor(dbgi, block, node, one, mode);
 }
 
 static ir_node *create_convb(ir_node *node)
 {
-       ir_graph *irg   = current_ir_graph;
        ir_node  *block = get_nodes_block(node);
-       ir_node  *conv  = new_rd_Conv(NULL, irg, block, node, mode_b);
+       ir_node  *conv  = new_rd_Conv(NULL, block, node, mode_b);
 
        return conv;
 }
 
 static ir_type *create_lowered_type(void)
 {
-       if(lowered_type == NULL) {
-               lowered_type = new_type_primitive(new_id_from_str("__lowered_mode_b"),
-                                                 config.lowered_mode);
+       if (lowered_type == NULL) {
+               lowered_type = new_type_primitive(config->lowered_mode);
        }
        return lowered_type;
 }
 
-/**
- * creates a "set" node that produces a 0 or 1 based on a Cmp result
- */
-static ir_node *create_set(ir_node *node)
+ir_node *ir_create_mux_set(ir_node *cond, ir_mode *dest_mode)
 {
-       ir_graph *irg     = current_ir_graph;
-       dbg_info *dbgi    = get_irn_dbg_info(node);
-       ir_mode  *mode    = config.lowered_set_mode;
-       tarval   *tv_one  = get_tarval_one(mode);
-       ir_node  *one     = new_d_Const(dbgi, mode, tv_one);
-       ir_node  *block   = get_nodes_block(node);
-       tarval   *tv_zero = get_tarval_null(mode);
-       ir_node  *zero    = new_d_Const(dbgi, mode, tv_zero);
-
-       ir_node *vals[2]  = { one, zero };
-       ir_node *set      = new_rd_Psi(dbgi, irg, block, 1, &node, vals, mode);
-
-       if(mode != config.lowered_mode) {
-               set = new_r_Conv(irg, block, set, config.lowered_mode);
-       }
-
+       ir_graph  *irg     = get_irn_irg(cond);
+       ir_node   *block   = get_nodes_block(cond);
+       ir_tarval *tv_one  = get_mode_one(dest_mode);
+       ir_node   *one     = new_r_Const(irg, tv_one);
+       ir_tarval *tv_zero = get_mode_null(dest_mode);
+       ir_node   *zero    = new_r_Const(irg, tv_zero);
+       ir_node   *set     = new_r_Mux(block, cond, zero, one, dest_mode);
        return set;
 }
 
+ir_node *ir_create_cond_set(ir_node *cond_value, ir_mode *dest_mode)
+{
+       ir_node  *lower_block = part_block_edges(cond_value);
+       ir_node  *upper_block = get_nodes_block(cond_value);
+       ir_graph *irg         = get_irn_irg(cond_value);
+       ir_node  *cond        = new_r_Cond(upper_block, cond_value);
+       ir_node  *proj_true   = new_r_Proj(cond, mode_X, pn_Cond_true);
+       ir_node  *proj_false  = new_r_Proj(cond, mode_X, pn_Cond_false);
+       ir_node  *in_true[1]  = { proj_true };
+       ir_node  *in_false[1] = { proj_false };
+       ir_node  *true_block  = new_r_Block(irg, ARRAY_SIZE(in_true), in_true);
+       ir_node  *false_block = new_r_Block(irg, ARRAY_SIZE(in_false),in_false);
+       ir_node  *true_jmp    = new_r_Jmp(true_block);
+       ir_node  *false_jmp   = new_r_Jmp(false_block);
+       ir_node  *lower_in[2] = { true_jmp, false_jmp };
+       ir_node  *one         = new_r_Const(irg, get_mode_one(dest_mode));
+       ir_node  *zero        = new_r_Const(irg, get_mode_null(dest_mode));
+       ir_node  *phi_in[2]   = { one, zero };
+       ir_node  *phi;
+
+       set_irn_in(lower_block, ARRAY_SIZE(lower_in), lower_in);
+       phi = new_r_Phi(lower_block, ARRAY_SIZE(phi_in), phi_in, dest_mode);
+
+       /* make sure we do visit the cond_value later... */
+       ARR_APP1(ir_node*, check_later, cond_value);
+
+       return phi;
+}
+
 static void adjust_method_type(ir_type *method_type)
 {
-       int i;
-       int n_params;
-       int n_res;
+       size_t i;
+       size_t n_params;
+       size_t n_res;
 
        n_params = get_method_n_params(method_type);
-       for(i = 0; i < n_params; ++i) {
+       for (i = 0; i < n_params; ++i) {
                ir_type *param = get_method_param_type(method_type, i);
-               if(get_type_mode(param) == mode_b) {
+               if (get_type_mode(param) == mode_b) {
                        set_method_param_type(method_type, i, create_lowered_type());
                }
        }
 
        n_res = get_method_n_ress(method_type);
-       for(i = 0; i < n_res; ++i) {
+       for (i = 0; i < n_res; ++i) {
                ir_type *res_type = get_method_res_type(method_type, i);
-               if(get_type_mode(res_type) == mode_b) {
+               if (get_type_mode(res_type) == mode_b) {
                        set_method_res_type(method_type, i, create_lowered_type());
                }
        }
@@ -149,276 +168,298 @@ static void adjust_method_type(ir_type *method_type)
 
 static ir_node *lower_node(ir_node *node)
 {
-       ir_graph *irg   = current_ir_graph;
        dbg_info *dbgi  = get_irn_dbg_info(node);
-       ir_op    *op    = get_irn_op(node);
        ir_node  *block = get_nodes_block(node);
-       ir_mode *mode   = config.lowered_mode;
-       ir_node  *res;
-
-       assert(get_irn_mode(node) == mode_b);
+       ir_mode  *mode  = config->lowered_mode;
+       ir_node  *res   = (ir_node*)get_irn_link(node);
+       ir_graph *irg;
 
-       res = get_irn_link(node);
-       if(res != NULL)
+       if (res != NULL)
                return res;
 
-       /* TODO: be robust against phi-loops... */
-       if(op == op_Phi) {
+       node = skip_Tuple(node);
+
+       assert(get_irn_mode(node) == mode_b);
+
+       irg = get_irn_irg(node);
+       switch (get_irn_opcode(node)) {
+       case iro_Phi: {
                int       i, arity;
                ir_node **in;
-               ir_node  *unknown, *new_phi;
+               ir_node  *dummy;
+               ir_node  *new_phi;
 
                arity = get_irn_arity(node);
-               in    = alloca(arity * sizeof(in[0]));
-               unknown = new_Unknown(config.lowered_mode);
-               for(i = 0; i < arity; ++i) {
-                       in[i] = unknown;
+               in    = ALLOCAN(ir_node*, arity);
+               dummy = new_r_Dummy(irg, mode);
+               for (i = 0; i < arity; ++i) {
+                       in[i] = dummy;
                }
-               new_phi = new_r_Phi(irg, block, arity, in, config.lowered_mode);
+               new_phi = new_r_Phi(block, arity, in, mode);
+               /* FIXME This does not correctly break cycles: The Phi might not be the
+                * first in the recursion, so the caller(s) are some yet un-lowered
+                * nodes and this Phi might have them (indirectly) as operands, so they
+                * would be replaced twice. */
                set_irn_link(node, new_phi);
-               pdeq_putr(lowered_nodes, node);
+               ARR_APP1(ir_node*, lowered_nodes, node);
 
-               for(i = 0; i < arity; ++i) {
-                       ir_node *in     = get_irn_n(node, i);
-                       ir_node *low_in = lower_node(in);
+               for (i = 0; i < arity; ++i) {
+                       ir_node *in         = get_irn_n(node, i);
+                       ir_node *lowered_in = is_Bad(in) ? in : lower_node(in);
 
-                       set_irn_n(new_phi, i, low_in);
+                       set_irn_n(new_phi, i, lowered_in);
                }
 
                return new_phi;
        }
 
-       if(op == op_And || op == op_Or || op == op_Eor) {
-               int i, arity;
-               ir_node *copy = exact_copy(node);
-
-               arity = get_irn_arity(node);
-               for(i = 0; i < arity; ++i) {
-                       ir_node *in     = get_irn_n(node, i);
-                       ir_node *low_in = lower_node(in);
-
-                       set_irn_n(copy, i, low_in);
-               }
-               set_irn_mode(copy, config.lowered_mode);
-
-               set_irn_link(node, copy);
-               pdeq_putr(lowered_nodes, node);
-               return copy;
+       case iro_And: {
+               ir_node *lowered_left  = lower_node(get_And_left(node));
+               ir_node *lowered_right = lower_node(get_And_right(node));
+               res = new_rd_And(dbgi, block, lowered_left, lowered_right, mode);
+               break;
+       }
+       case iro_Or: {
+               ir_node *lowered_left  = lower_node(get_Or_left(node));
+               ir_node *lowered_right = lower_node(get_Or_right(node));
+               res = new_rd_Or(dbgi, block, lowered_left, lowered_right, mode);
+               break;
        }
-       if(op == op_Not) {
+       case iro_Eor: {
+               ir_node *lowered_left  = lower_node(get_Eor_left(node));
+               ir_node *lowered_right = lower_node(get_Eor_right(node));
+               res = new_rd_Eor(dbgi, block, lowered_left, lowered_right, mode);
+               break;
+       }
+
+       case iro_Not: {
                ir_node *op     = get_Not_op(node);
                ir_node *low_op = lower_node(op);
 
                res = create_not(dbgi, low_op);
-               set_irn_link(node, res);
-               pdeq_putr(lowered_nodes, node);
-               return res;
+               break;
        }
-       if(op == op_Psi) {
-               ir_node *cond        = get_Psi_cond(node, 0);
+
+       case iro_Mux: {
+               ir_node *cond        = get_Mux_sel(node);
                ir_node *low_cond    = lower_node(cond);
-               ir_node *v_true      = get_Psi_val(node, 0);
+               ir_node *v_true      = get_Mux_true(node);
                ir_node *low_v_true  = lower_node(v_true);
-               ir_node *v_false     = get_Psi_default(node);
+               ir_node *v_false     = get_Mux_false(node);
                ir_node *low_v_false = lower_node(v_false);
 
-               ir_node *and0     = new_rd_And(dbgi, irg, block, low_cond, low_v_true,
-                                              mode);
-
+               ir_node *and0     = new_rd_And(dbgi, block, low_cond, low_v_true, mode);
                ir_node *not_cond = create_not(dbgi, low_cond);
+               ir_node *and1     = new_rd_And(dbgi, block, not_cond, low_v_false, mode);
+               res = new_rd_Or(dbgi, block, and0, and1, mode);
+               break;
+       }
 
-               ir_node *and1     = new_rd_And(dbgi, irg, block, not_cond, low_v_false,
-                                              mode);
-
-               ir_node *or       = new_rd_Or(dbgi, irg, block, and0, and1,
-                                             mode);
+       case iro_Conv: {
+               ir_node   *pred     = get_Conv_op(node);
+               ir_mode   *mode     = get_irn_mode(pred);
+               ir_tarval *tv_zeroc = get_mode_null(mode);
+               ir_node   *zero_cmp = new_rd_Const(dbgi, irg, tv_zeroc);
 
-               set_irn_link(node, or);
-               pdeq_putr(lowered_nodes, node);
-               return or;
-       }
-       if(op == op_Conv) {
-               ir_node *pred     = get_Conv_op(node);
-               ir_mode *mode     = get_irn_mode(pred);
-               tarval  *tv_zeroc = get_tarval_null(mode);
-               ir_node *zero_cmp = new_d_Const(dbgi, mode, tv_zeroc);
-               ir_node *set;
-
-               ir_node *cmp      = new_rd_Cmp(dbgi, irg, block, pred, zero_cmp);
-               ir_node *proj     = new_rd_Proj(dbgi, irg, block, cmp, mode_b,
-                                               pn_Cmp_Lg);
-               set = create_set(proj);
-
-               set_irn_link(node, set);
-               pdeq_putr(lowered_nodes, node);
-               return set;
+               ir_node *cmp      = new_rd_Cmp(dbgi, block, pred, zero_cmp, ir_relation_less_greater);
+               res = config->create_set(cmp);
+               break;
        }
-       if(op == op_Proj) {
-               ir_node *pred = get_Proj_pred(node);
 
-               if(is_Cmp(pred)) {
-                       ir_node *left  = get_Cmp_left(pred);
-                       ir_node *right = get_Cmp_right(pred);
-                       ir_mode *cmp_mode  = get_irn_mode(left);
-                       ir_node *set;
-
-                       if ((mode_is_int(cmp_mode) || mode_is_reference(cmp_mode)) && (
-                                               get_mode_size_bits(cmp_mode) < get_mode_size_bits(mode) ||
-                                               (mode_is_signed(cmp_mode) && is_Const(right) && is_Const_null(right))
-                                       )) {
-                               int      pnc      = get_Proj_proj(node);
-                               int      need_not = 0;
-                               ir_node *a        = NULL;
-                               ir_node *b        = NULL;
-
-                               if(pnc == pn_Cmp_Lt) {
-                                       /* a < b  ->  (a - b) >> 31 */
-                                       a = left;
-                                       b = right;
-                               } else if(pnc == pn_Cmp_Le) {
-                                       /* a <= b  -> ~(a - b) >> 31 */
-                                       a        = right;
-                                       b        = left;
-                                       need_not = 1;
-                               } else if(pnc == pn_Cmp_Gt) {
-                                       /* a > b   -> (b - a) >> 31 */
-                                       a = right;
-                                       b = left;
-                               } else if(pnc == pn_Cmp_Ge) {
-                                       /* a >= b   -> ~(a - b) >> 31 */
-                                       a        = left;
-                                       b        = right;
-                                       need_not = 1;
-                               }
+       case iro_Cmp: {
+               ir_node    *left     = get_Cmp_left(node);
+               ir_node    *right    = get_Cmp_right(node);
+               ir_mode    *cmp_mode = get_irn_mode(left);
+               ir_relation relation = get_Cmp_relation(node);
+
+               if ((mode_is_int(cmp_mode) || mode_is_reference(cmp_mode)) &&
+                       (get_mode_size_bits(cmp_mode) < get_mode_size_bits(mode) ||
+                       (mode_is_signed(cmp_mode) && is_Const(right) && is_Const_null(right) && relation != ir_relation_greater))) {
+                       int         need_not = 0;
+                       ir_node    *a        = NULL;
+                       ir_node    *b        = NULL;
+                       int         bits;
+                       ir_tarval  *tv;
+                       ir_node    *shift_cnt;
+
+                       if (relation == ir_relation_less) {
+                               /* a < b  ->  (a - b) >> 31 */
+                               a = left;
+                               b = right;
+                       } else if (relation == ir_relation_less_equal) {
+                               /* a <= b  -> ~(a - b) >> 31 */
+                               a        = right;
+                               b        = left;
+                               need_not = 1;
+                       } else if (relation == ir_relation_greater) {
+                               /* a > b   -> (b - a) >> 31 */
+                               a = right;
+                               b = left;
+                       } else if (relation == ir_relation_greater_equal) {
+                               /* a >= b   -> ~(a - b) >> 31 */
+                               a        = left;
+                               b        = right;
+                               need_not = 1;
+                       } else {
+                               goto synth_zero_one;
+                       }
 
-                               if(a != NULL) {
-                                       int      bits      = get_mode_size_bits(mode);
-                                       tarval  *tv        = new_tarval_from_long(bits-1, mode_Iu);
-                                       ir_node *shift_cnt = new_d_Const(dbgi, mode_Iu, tv);
-
-                                       if(cmp_mode != mode) {
-                                               a = new_rd_Conv(dbgi, irg, block, a, mode);
-                                               b = new_rd_Conv(dbgi, irg, block, b, mode);
-                                       }
-
-                                       res = new_rd_Sub(dbgi, irg, block, a, b, mode);
-                                       if(need_not) {
-                                               res = new_rd_Not(dbgi, irg, block, res, mode);
-                                       }
-                                       res = new_rd_Shr(dbgi, irg, block, res, shift_cnt, mode);
-
-                                       set_irn_link(node, res);
-                                       pdeq_putr(lowered_nodes, node);
-                                       return res;
-                               }
+                       bits      = get_mode_size_bits(mode);
+                       tv        = new_tarval_from_long(bits-1, mode_Iu);
+                       shift_cnt = new_rd_Const(dbgi, irg, tv);
+
+                       if (cmp_mode != mode) {
+                               a = new_rd_Conv(dbgi, block, a, mode);
+                               b = new_rd_Conv(dbgi, block, b, mode);
                        }
 
+                       res = new_rd_Sub(dbgi, block, a, b, mode);
+                       if (need_not) {
+                               res = new_rd_Not(dbgi, block, res, mode);
+                       }
+                       res = new_rd_Shr(dbgi, block, res, shift_cnt, mode);
+               } else {
                        /* synthesize the 0/1 value */
-                       set = create_set(node);
-                       set_irn_link(node, set);
-                       pdeq_putr(lowered_nodes, node);
-                       return set;
-               } else if(is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
-                       ir_type   *type   = get_Call_type(get_Proj_pred(pred));
+synth_zero_one:
+                       res = config->create_set(node);
+               }
+               break;
+       }
+
+       case iro_Proj: {
+               ir_node *pred = get_Proj_pred(node);
+
+               if (is_Proj(pred) && is_Call(get_Proj_pred(pred))) {
+                       ir_type *type = get_Call_type(get_Proj_pred(pred));
                        adjust_method_type(type);
                        set_irn_mode(node, mode);
-                       return node;
-               } else if(is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
+                       res = node;
+                       goto own_replacement;
+               } else if (is_Proj(pred) && is_Start(get_Proj_pred(pred))) {
+                       ir_graph  *irg    = get_irn_irg(node);
                        ir_entity *entity = get_irg_entity(irg);
                        ir_type   *type   = get_entity_type(entity);
                        adjust_method_type(type);
                        set_irn_mode(node, mode);
-                       return node;
+                       res = node;
+                       goto own_replacement;
                }
-
                panic("unexpected projb: %+F (pred: %+F)", node, pred);
        }
-       if(op == op_Const) {
-               tarval *tv = get_Const_tarval(node);
-               if(tv == get_tarval_b_true()) {
-                       tarval  *tv_one  = get_tarval_one(mode);
-                       res              = new_d_Const(dbgi, mode, tv_one);
-               } else if(tv == get_tarval_b_false()) {
-                       tarval  *tv_zero = get_tarval_null(mode);
-                       res              = new_d_Const(dbgi, mode, tv_zero);
+
+       case iro_Const: {
+               ir_tarval *tv = get_Const_tarval(node);
+               if (tv == get_tarval_b_true()) {
+                       ir_tarval *tv_one = get_mode_one(mode);
+                       res               = new_rd_Const(dbgi, irg, tv_one);
+               } else if (tv == get_tarval_b_false()) {
+                       ir_tarval *tv_zero = get_mode_null(mode);
+                       res                = new_rd_Const(dbgi, irg, tv_zero);
                } else {
                        panic("invalid boolean const %+F", node);
                }
-               set_irn_link(node, res);
-               pdeq_putr(lowered_nodes, node);
-               return res;
+               break;
        }
-       if (op == op_Unknown) {
-               return new_Unknown(config.lowered_mode);
+
+       case iro_Unknown:
+               res = new_r_Unknown(irg, mode);
+               break;
+
+       default:
+               panic("didn't expect %+F to have mode_b", node);
        }
 
-       panic("didn't expect %+F to have mode_b", node);
+       ARR_APP1(ir_node*, lowered_nodes, node);
+own_replacement:
+       set_irn_link(node, res);
+       return res;
 }
 
 static void lower_mode_b_walker(ir_node *node, void *env)
 {
        int i, arity;
-       int changed = 0;
-       (void) env;
+       bool changed = false;
 
        arity = get_irn_arity(node);
-       for(i = 0; i < arity; ++i) {
+       for (i = 0; i < arity; ++i) {
                ir_node *lowered_in;
                ir_node *in = get_irn_n(node, i);
-               if(get_irn_mode(in) != mode_b)
+               if (get_irn_mode(in) != mode_b)
                        continue;
 
-               if(! config.lower_direct_cmp) {
-                       if(is_Cond(node)
-                                       || (is_Psi(node) && get_irn_mode(node) != mode_b)) {
-                               if(is_Proj(in)) {
-                                       ir_node *pred = get_Proj_pred(in);
-                                       if(is_Cmp(pred))
-                                               continue;
+               if (! config->lower_direct_cmp) {
+                       /* Cmp as input for Cond and Mux nodes needs no changes.
+                          (Mux with mode_b is an exception as it gets replaced by and/or
+                           anyway so we still lower the inputs then) */
+                       if (is_Cond(node) ||
+                           (is_Mux(node) && get_irn_mode(node) != mode_b)) {
+                               if (is_Cmp(in)) {
+                                       continue;
                                }
                        }
                }
 
                lowered_in = lower_node(in);
 
-               if(is_Return(node)) {
-                       ir_entity *entity = get_irg_entity(current_ir_graph);
-                       ir_type   *type   = get_entity_type(entity);
-                       adjust_method_type(type);
-               } else if(is_Call(node)) {
+               if (is_Call(node)) {
                        ir_type *type = get_Call_type(node);
                        adjust_method_type(type);
-               } else {
+               } else if (is_Cond(node) || (is_Mux(node) && i == 0)) {
                        lowered_in = create_convb(lowered_in);
                }
                set_irn_n(node, i, lowered_in);
-               changed = 1;
+               changed = true;
        }
-       if(changed) {
-               add_identities(current_ir_graph->value_table, node);
+       if (changed) {
+               bool *global_changed = (bool*)env;
+               *global_changed = true;
+               add_identities(node);
        }
 }
 
-static void clear_links(ir_node *node, void *env)
-{
-       (void) env;
-       set_irn_link(node, NULL);
-}
-
 void ir_lower_mode_b(ir_graph *irg, const lower_mode_b_config_t *nconfig)
 {
-       config        = *nconfig;
-       lowered_nodes = new_pdeq();
-       set_using_irn_link(irg);
+       ir_entity *entity  = get_irg_entity(irg);
+       ir_type   *type    = get_entity_type(entity);
+       bool       changed = false;
+       size_t     i;
+       size_t     n;
+
+       config        = nconfig;
+       lowered_nodes = NEW_ARR_F(ir_node*, 0);
+       check_later   = NEW_ARR_F(ir_node*, 0);
+       lowered_type  = NULL;
 
-       irg_walk_graph(irg, clear_links, NULL, NULL);
-       irg_walk_graph(irg, lower_mode_b_walker, NULL, NULL);
+       edges_assure(irg);
 
-       while(!pdeq_empty(lowered_nodes)) {
-               ir_node *node = (ir_node*) pdeq_getr(lowered_nodes);
+       /* ensure no optimisation touches muxes anymore */
+       set_irg_state(irg, IR_GRAPH_STATE_KEEP_MUX | IR_GRAPH_STATE_BCONV_ALLOWED);
+
+       ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
+
+       adjust_method_type(type);
+
+       irg_walk_graph(irg, firm_clear_link, NULL, NULL);
+       irg_walk_graph(irg, lower_mode_b_walker, NULL, &changed);
+
+       for (i = 0, n = ARR_LEN(check_later); i < n; ++i) {
+               ir_node *node = check_later[i];
+               irg_walk_core(node, lower_mode_b_walker, NULL, &changed);
+       }
+
+       for (i = 0, n = ARR_LEN(lowered_nodes); i < n; ++i) {
+               ir_node *node = lowered_nodes[i];
                maybe_kill_node(node);
        }
-       del_pdeq(lowered_nodes);
+       DEL_ARR_F(check_later);
+       DEL_ARR_F(lowered_nodes);
 
-       clear_using_irn_link(irg);
+       ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
+
+       if (changed) {
+               /* lowering might create new blocks, so be sure to handle this */
+               set_irg_extblk_inconsistent(irg);
+               set_irg_doms_inconsistent(irg);
+               edges_deactivate(irg);
+       }
 }