valueset: Remove the unused link field.
[libfirm] / ir / ir / iropt.c
index 94cfe01..03f53bd 100644 (file)
@@ -21,7 +21,6 @@
  * @file
  * @brief   iropt --- optimizations intertwined with IR construction.
  * @author  Christian Schaefer, Goetz Lindenmaier, Michael Beck
- * @version $Id$
  */
 #include "config.h"
 
@@ -44,7 +43,6 @@
 #include "irhooks.h"
 #include "irarch.h"
 #include "hashptr.h"
-#include "opt_polymorphy.h"
 #include "irtools.h"
 #include "irhooks.h"
 #include "array_t.h"
@@ -52,8 +50,9 @@
 #include "firm_types.h"
 #include "bitfiddle.h"
 #include "be.h"
+#include "error.h"
+#include "firmstat_t.h"
 
-/* Make types visible to allow most efficient access */
 #include "entity_t.h"
 
 static bool is_Or_Eor_Add(const ir_node *node)
@@ -85,7 +84,6 @@ static ir_tarval *default_value_of(const ir_node *n)
 
 value_of_func value_of_ptr = default_value_of;
 
-/* * Set a new value_of function. */
 void set_value_of_func(value_of_func func)
 {
        if (func != NULL)
@@ -184,48 +182,6 @@ static ir_tarval *computed_value_Sub(const ir_node *n)
        return tarval_bad;
 }
 
-/**
- * Return the value of a Carry.
- * Special : a op 0, 0 op b
- */
-static ir_tarval *computed_value_Carry(const ir_node *n)
-{
-       ir_node   *a  = get_binop_left(n);
-       ir_node   *b  = get_binop_right(n);
-       ir_mode   *m  = get_irn_mode(n);
-       ir_tarval *ta = value_of(a);
-       ir_tarval *tb = value_of(b);
-
-       if ((ta != tarval_bad) && (tb != tarval_bad)) {
-               tarval_add(ta, tb);
-               return tarval_carry() ? get_mode_one(m) : get_mode_null(m);
-       } else {
-               if (tarval_is_null(ta) || tarval_is_null(tb))
-                       return get_mode_null(m);
-       }
-       return tarval_bad;
-}
-
-/**
- * Return the value of a Borrow.
- * Special : a op 0
- */
-static ir_tarval *computed_value_Borrow(const ir_node *n)
-{
-       ir_node   *a  = get_binop_left(n);
-       ir_node   *b  = get_binop_right(n);
-       ir_mode   *m  = get_irn_mode(n);
-       ir_tarval *ta = value_of(a);
-       ir_tarval *tb = value_of(b);
-
-       if ((ta != tarval_bad) && (tb != tarval_bad)) {
-               return tarval_cmp(ta, tb) == ir_relation_less ? get_mode_one(m) : get_mode_null(m);
-       } else if (tarval_is_null(ta)) {
-               return get_mode_null(m);
-       }
-       return tarval_bad;
-}
-
 /**
  * Return the value of an unary Minus.
  */
@@ -588,6 +544,15 @@ ir_relation ir_get_possible_cmp_relations(const ir_node *left,
        /* Alloc nodes never return null (but throw an exception) */
        if (is_Alloc(left) && tarval_is_null(tv_r))
                possible &= ~ir_relation_equal;
+       /* stuff known through confirm nodes */
+       if (is_Confirm(left) && get_Confirm_bound(left) == right) {
+               possible &= get_Confirm_relation(left);
+       }
+       if (is_Confirm(right) && get_Confirm_bound(right) == left) {
+               ir_relation relation = get_Confirm_relation(right);
+               relation = get_inversed_relation(relation);
+               possible &= relation;
+       }
 
        return possible;
 }
@@ -609,6 +574,17 @@ static ir_tarval *compute_cmp(const ir_node *cmp)
        return computed_value_Cmp_Confirm(cmp, left, right, relation);
 }
 
+/**
+ * some people want to call compute_cmp directly, in this case we have to
+ * test the constant folding flag again
+ */
+static ir_tarval *compute_cmp_ext(const ir_node *cmp)
+{
+       if (!get_opt_constant_folding())
+               return tarval_bad;
+       return compute_cmp(cmp);
+}
+
 /**
  * Return the value of a Cmp.
  *
@@ -618,7 +594,7 @@ static ir_tarval *compute_cmp(const ir_node *cmp)
 static ir_tarval *computed_value_Cmp(const ir_node *cmp)
 {
        /* we can't construct Constb after lowering mode_b nodes */
-       if (is_irg_state(get_irn_irg(cmp), IR_GRAPH_STATE_MODEB_LOWERED))
+       if (irg_is_constrained(get_irn_irg(cmp), IR_GRAPH_CONSTRAINT_MODEB_LOWERED))
                return tarval_bad;
 
        return compute_cmp(cmp);
@@ -720,60 +696,6 @@ ir_tarval *computed_value(const ir_node *n)
        return tarval_bad;
 }
 
-/**
- * Set the default computed_value evaluator in an ir_op_ops.
- *
- * @param code   the opcode for the default operation
- * @param ops    the operations initialized
- *
- * @return
- *    The operations.
- */
-static ir_op_ops *firm_set_default_computed_value(ir_opcode code, ir_op_ops *ops)
-{
-#define CASE(a)                                        \
-       case iro_##a:                                      \
-               ops->computed_value      = computed_value_##a; \
-               break
-#define CASE_PROJ(a)                                        \
-       case iro_##a:                                           \
-               ops->computed_value_Proj = computed_value_Proj_##a; \
-               break
-
-       switch (code) {
-       CASE(Add);
-       CASE(And);
-       CASE(Borrow);
-       CASE(Carry);
-       CASE(Cmp);
-       CASE(Confirm);
-       CASE(Const);
-       CASE(Conv);
-       CASE(Eor);
-       CASE(Minus);
-       CASE(Mul);
-       CASE(Mux);
-       CASE(Not);
-       CASE(Or);
-       CASE(Proj);
-       CASE(Rotl);
-       CASE(Shl);
-       CASE(Shr);
-       CASE(Shrs);
-       CASE(Sub);
-       CASE(SymConst);
-       CASE_PROJ(Div);
-       CASE_PROJ(Mod);
-       default:
-               /* leave NULL */
-               break;
-       }
-
-       return ops;
-#undef CASE_PROJ
-#undef CASE
-}
-
 /**
  * Optimize operations that are commutative and have neutral 0,
  * so a op 0 = 0 op a = a.
@@ -937,11 +859,6 @@ static ir_node *equivalent_node_left_zero(ir_node *n)
        return n;
 }
 
-#define equivalent_node_Shl   equivalent_node_left_zero
-#define equivalent_node_Shr   equivalent_node_left_zero
-#define equivalent_node_Shrs  equivalent_node_left_zero
-#define equivalent_node_Rotl  equivalent_node_left_zero
-
 /**
  * Optimize a - 0 and (a + x) - x (for modes with wrap-around).
  *
@@ -989,26 +906,17 @@ static ir_node *equivalent_node_Sub(ir_node *n)
  *   We handle it anyway here but the better way would be a
  *   flag. This would be needed for Pascal for instance.
  */
-static ir_node *equivalent_node_idempotent_unop(ir_node *n)
+static ir_node *equivalent_node_involution(ir_node *n)
 {
        ir_node *oldn = n;
        ir_node *pred = get_unop_op(n);
-
-       /* optimize symmetric unop */
        if (get_irn_op(pred) == get_irn_op(n)) {
                n = get_unop_op(pred);
-               DBG_OPT_ALGSIM2(oldn, pred, n, FS_OPT_IDEM_UNARY);
+               DBG_OPT_ALGSIM2(oldn, pred, n, FS_OPT_INVOLUTION);
        }
        return n;
 }
 
-/** Optimize Not(Not(x)) == x. */
-#define equivalent_node_Not    equivalent_node_idempotent_unop
-
-/** -(-x) == x       ??? Is this possible or can --x raise an
-                       out of bounds exception if min =! max? */
-#define equivalent_node_Minus  equivalent_node_idempotent_unop
-
 /**
  * Optimize a * 1 = 1 * a = a.
  */
@@ -1106,9 +1014,9 @@ static ir_node *equivalent_node_And(ir_node *n)
                                /* Check Conv(all_one) & Const = all_one */
                                ir_tarval *one  = get_mode_all_one(convopmode);
                                ir_tarval *conv = tarval_convert_to(one, mode);
-                               ir_tarval *and  = tarval_and(conv, tv);
+                               ir_tarval *tand = tarval_and(conv, tv);
 
-                               if (tarval_is_all_one(and)) {
+                               if (tarval_is_all_one(tand)) {
                                        /* Conv(X) & Const = X */
                                        n = a;
                                        DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_AND);
@@ -1151,121 +1059,18 @@ static ir_node *equivalent_node_Conv(ir_node *n)
        ir_mode *n_mode = get_irn_mode(n);
        ir_mode *a_mode = get_irn_mode(a);
 
-restart:
        if (n_mode == a_mode) { /* No Conv necessary */
-               if (get_Conv_strict(n)) {
-                       ir_node *p = a;
-
-                       /* neither Minus nor Confirm change the precision,
-                          so we can "look-through" */
-                       for (;;) {
-                               if (is_Minus(p)) {
-                                       p = get_Minus_op(p);
-                               } else if (is_Confirm(p)) {
-                                       p = get_Confirm_value(p);
-                               } else {
-                                       /* stop here */
-                                       break;
-                               }
-                       }
-                       if (is_Conv(p) && get_Conv_strict(p)) {
-                               /* we known already, that a_mode == n_mode, and neither
-                                  Minus change the mode, so the second Conv
-                                  can be kicked */
-                               assert(get_irn_mode(p) == n_mode);
-                               n = a;
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CONV);
-                               return n;
-                       }
-                       if (is_Proj(p)) {
-                               ir_node *pred = get_Proj_pred(p);
-                               if (is_Load(pred)) {
-                                       /* Loads always return with the exact precision of n_mode */
-                                       assert(get_Load_mode(pred) == n_mode);
-                                       n = a;
-                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CONV);
-                                       return n;
-                               }
-                               if (is_Proj(pred) && get_Proj_proj(pred) == pn_Start_T_args) {
-                                       pred = get_Proj_pred(pred);
-                                       if (is_Start(pred)) {
-                                               /* Arguments always return with the exact precision,
-                                                  as strictConv's are place before Call -- if the
-                                                  caller was compiled with the same setting.
-                                                  Otherwise, the semantics is probably still right. */
-                                               assert(get_irn_mode(p) == n_mode);
-                                               n = a;
-                                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CONV);
-                                               return n;
-                                       }
-                               }
-                       }
-                       if (is_Conv(a)) {
-                               /* special case: the immediate predecessor is also a Conv */
-                               if (! get_Conv_strict(a)) {
-                                       /* first one is not strict, kick it */
-                                       a = get_Conv_op(a);
-                                       a_mode = get_irn_mode(a);
-                                       set_Conv_op(n, a);
-                                       goto restart;
-                               }
-                               /* else both are strict conv, second is superfluous */
-                               n = a;
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CONV);
-                               return n;
-                       }
-               } else {
-                       n = a;
-                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CONV);
-                       return n;
-               }
+               n = a;
+               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CONV);
+               return n;
        } else if (is_Conv(a)) { /* Conv(Conv(b)) */
                ir_node *b      = get_Conv_op(a);
                ir_mode *b_mode = get_irn_mode(b);
 
-               if (get_Conv_strict(n) && get_Conv_strict(a)) {
-                       /* both are strict conv */
-                       if (smaller_mode(a_mode, n_mode)) {
-                               /* both are strict, but the first is smaller, so
-                                  the second cannot remove more precision, remove the
-                                  strict bit */
-                               set_Conv_strict(n, 0);
-                       }
-               }
-               if (n_mode == b_mode) {
-                       if (! get_Conv_strict(n) && ! get_Conv_strict(a)) {
-                               if (n_mode == mode_b) {
-                                       n = b; /* Convb(Conv*(xxxb(...))) == xxxb(...) */
-                                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);
-                                       return n;
-                               } else if (get_mode_arithmetic(n_mode) == get_mode_arithmetic(a_mode)) {
-                                       if (values_in_mode(b_mode, a_mode)) {
-                                               n = b;        /* ConvS(ConvL(xxxS(...))) == xxxS(...) */
-                                               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);
-                                               return n;
-                                       }
-                               }
-                       }
-                       if (mode_is_int(n_mode) && get_mode_arithmetic(a_mode) == irma_ieee754) {
-                               /* ConvI(ConvF(I)) -> I, iff float mantissa >= int mode */
-                               unsigned int_mantissa   = get_mode_size_bits(n_mode) - (mode_is_signed(n_mode) ? 1 : 0);
-                               unsigned float_mantissa = get_mode_mantissa_size(a_mode);
-
-                               if (float_mantissa >= int_mantissa) {
-                                       n = b;
-                                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);
-                                       return n;
-                               }
-                       }
-                       if (is_Conv(b)) {
-                               if (smaller_mode(b_mode, a_mode)) {
-                                       if (get_Conv_strict(n))
-                                               set_Conv_strict(b, 1);
-                                       n = b; /* ConvA(ConvB(ConvA(...))) == ConvA(...) */
-                                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);
-                                       return n;
-                               }
-                       }
+               if (n_mode == b_mode && values_in_mode(b_mode, a_mode)) {
+                       n = b;
+                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);
+                       return n;
                }
        }
        return n;
@@ -1283,7 +1088,7 @@ static ir_node *equivalent_node_Phi(ir_node *n)
        ir_node *first_val = NULL; /* to shutup gcc */
 
        if (!get_opt_optimize() &&
-                       get_irg_phase_state(get_irn_irg(n)) != phase_building)
+           !irg_is_constrained(get_irn_irg(n), IR_GRAPH_CONSTRAINT_CONSTRUCTION))
                return n;
 
        n_preds = get_Phi_n_preds(n);
@@ -1388,56 +1193,6 @@ static ir_node *equivalent_node_Proj_CopyB(ir_node *proj)
        return proj;
 }
 
-/**
- * Optimize Bounds(idx, idx, upper) into idx.
- */
-static ir_node *equivalent_node_Proj_Bound(ir_node *proj)
-{
-       ir_node *oldn  = proj;
-       ir_node *bound = get_Proj_pred(proj);
-       ir_node *idx   = get_Bound_index(bound);
-       ir_node *pred  = skip_Proj(idx);
-       int ret_tuple  = 0;
-
-       if (idx == get_Bound_lower(bound))
-               ret_tuple = 1;
-       else if (is_Bound(pred)) {
-               /*
-                * idx was Bounds checked previously, it is still valid if
-                * lower <= pred_lower && pred_upper <= upper.
-                */
-               ir_node *lower = get_Bound_lower(bound);
-               ir_node *upper = get_Bound_upper(bound);
-               if (get_Bound_lower(pred) == lower &&
-                       get_Bound_upper(pred) == upper) {
-                       /*
-                        * One could expect that we simply return the previous
-                        * Bound here. However, this would be wrong, as we could
-                        * add an exception Proj to a new location then.
-                        * So, we must turn in into a tuple.
-                        */
-                       ret_tuple = 1;
-               }
-       }
-       if (ret_tuple) {
-               /* Turn Bound into a tuple (mem, jmp, bad, idx) */
-               switch (get_Proj_proj(proj)) {
-               case pn_Bound_M:
-                       DBG_OPT_EXC_REM(proj);
-                       proj = get_Bound_mem(bound);
-                       break;
-               case pn_Bound_res:
-                       proj = idx;
-                       DBG_OPT_ALGSIM0(oldn, proj, FS_OPT_NOP);
-                       break;
-               default:
-                       /* cannot optimize pn_Bound_X_regular, handled in transform ... */
-                       break;
-               }
-       }
-       return proj;
-}
-
 /**
  * Does all optimizations on nodes that must be done on its Projs
  * because of creating new nodes.
@@ -1477,7 +1232,7 @@ static ir_node *equivalent_node_Mux(ir_node *n)
        if (ts == tarval_bad && is_Cmp(sel)) {
                /* try again with a direct call to compute_cmp, as we don't care
                 * about the MODEB_LOWERED flag here */
-               ts = compute_cmp(sel);
+               ts = compute_cmp_ext(sel);
        }
 
        /* Mux(true, f, t) == t */
@@ -1608,59 +1363,6 @@ ir_node *equivalent_node(ir_node *n)
        return n;
 }
 
-/**
- * Sets the default equivalent node operation for an ir_op_ops.
- *
- * @param code   the opcode for the default operation
- * @param ops    the operations initialized
- *
- * @return
- *    The operations.
- */
-static ir_op_ops *firm_set_default_equivalent_node(ir_opcode code, ir_op_ops *ops)
-{
-#define CASE(a)                                      \
-       case iro_##a:                                    \
-               ops->equivalent_node  = equivalent_node_##a; \
-               break
-#define CASE_PROJ(a)                                          \
-       case iro_##a:                                             \
-               ops->equivalent_node_Proj = equivalent_node_Proj_##a; \
-               break
-
-       switch (code) {
-       CASE(Eor);
-       CASE(Add);
-       CASE(Shl);
-       CASE(Shr);
-       CASE(Shrs);
-       CASE(Rotl);
-       CASE(Sub);
-       CASE(Not);
-       CASE(Minus);
-       CASE(Mul);
-       CASE(Or);
-       CASE(And);
-       CASE(Conv);
-       CASE(Phi);
-       CASE_PROJ(Tuple);
-       CASE_PROJ(Div);
-       CASE_PROJ(CopyB);
-       CASE_PROJ(Bound);
-       CASE(Proj);
-       CASE(Id);
-       CASE(Mux);
-       CASE(Confirm);
-       default:
-               /* leave NULL */
-               break;
-       }
-
-       return ops;
-#undef CASE
-#undef CASE_PROJ
-}
-
 /**
  * Returns non-zero if a node is a Phi node
  * with all predecessors constant.
@@ -1716,44 +1418,40 @@ static ir_tarval *do_eval(eval_func eval, ir_tarval *a, ir_tarval *b, ir_mode *m
  */
 static ir_node *apply_binop_on_phi(ir_node *phi, ir_tarval *other, eval_func eval, ir_mode *mode, int left)
 {
-       ir_tarval *tv;
-       void      **res;
-       ir_node   *pred;
-       ir_graph  *irg;
-       int       i, n = get_irn_arity(phi);
-
-       NEW_ARR_A(void *, res, n);
+       int         n   = get_irn_arity(phi);
+       ir_tarval **tvs = ALLOCAN(ir_tarval*, n);
        if (left) {
-               for (i = 0; i < n; ++i) {
-                       pred = get_irn_n(phi, i);
-                       tv   = get_Const_tarval(pred);
-                       tv   = do_eval(eval, other, tv, mode);
+               for (int i = 0; i < n; ++i) {
+                       ir_node   *pred = get_irn_n(phi, i);
+                       ir_tarval *tv   = get_Const_tarval(pred);
+                       tv = do_eval(eval, other, tv, mode);
 
                        if (tv == tarval_bad) {
                                /* folding failed, bad */
                                return NULL;
                        }
-                       res[i] = tv;
+                       tvs[i] = tv;
                }
        } else {
-               for (i = 0; i < n; ++i) {
-                       pred = get_irn_n(phi, i);
-                       tv   = get_Const_tarval(pred);
-                       tv   = do_eval(eval, tv, other, mode);
+               for (int i = 0; i < n; ++i) {
+                       ir_node   *pred = get_irn_n(phi, i);
+                       ir_tarval *tv   = get_Const_tarval(pred);
+                       tv = do_eval(eval, tv, other, mode);
 
                        if (tv == tarval_bad) {
                                /* folding failed, bad */
                                return 0;
                        }
-                       res[i] = tv;
+                       tvs[i] = tv;
                }
        }
-       irg = get_irn_irg(phi);
-       for (i = 0; i < n; ++i) {
-               pred = get_irn_n(phi, i);
-               res[i] = new_r_Const(irg, (ir_tarval*)res[i]);
+       ir_graph *irg = get_irn_irg(phi);
+       ir_node **res = ALLOCAN(ir_node*, n);
+       for (int i = 0; i < n; ++i) {
+               res[i] = new_r_Const(irg, tvs[i]);
        }
-       return new_r_Phi(get_nodes_block(phi), n, (ir_node **)res, mode);
+       ir_node *block = get_nodes_block(phi);
+       return new_r_Phi(block, n, res, mode);
 }
 
 /**
@@ -1768,37 +1466,31 @@ static ir_node *apply_binop_on_phi(ir_node *phi, ir_tarval *other, eval_func eva
  */
 static ir_node *apply_binop_on_2_phis(ir_node *a, ir_node *b, eval_func eval, ir_mode *mode)
 {
-       ir_tarval *tv_l, *tv_r, *tv;
-       void     **res;
-       ir_node  *pred;
-       ir_graph *irg;
-       int      i, n;
-
        if (get_nodes_block(a) != get_nodes_block(b))
                return NULL;
 
-       n = get_irn_arity(a);
-       NEW_ARR_A(void *, res, n);
-
-       for (i = 0; i < n; ++i) {
-               pred = get_irn_n(a, i);
-               tv_l = get_Const_tarval(pred);
-               pred = get_irn_n(b, i);
-               tv_r = get_Const_tarval(pred);
-               tv   = do_eval(eval, tv_l, tv_r, mode);
+       int         n   = get_irn_arity(a);
+       ir_tarval **tvs = ALLOCAN(ir_tarval*, n);
+       for (int i = 0; i < n; ++i) {
+               ir_node   *pred_a = get_irn_n(a, i);
+               ir_tarval *tv_l   = get_Const_tarval(pred_a);
+               ir_node   *pred_b = get_irn_n(b, i);
+               ir_tarval *tv_r   = get_Const_tarval(pred_b);
+               ir_tarval *tv     = do_eval(eval, tv_l, tv_r, mode);
 
                if (tv == tarval_bad) {
                        /* folding failed, bad */
                        return NULL;
                }
-               res[i] = tv;
+               tvs[i] = tv;
        }
-       irg = get_irn_irg(a);
-       for (i = 0; i < n; ++i) {
-               pred = get_irn_n(a, i);
-               res[i] = new_r_Const(irg, (ir_tarval*)res[i]);
+       ir_graph *irg = get_irn_irg(a);
+       ir_node **res = ALLOCAN(ir_node*, n);
+       for (int i = 0; i < n; ++i) {
+               res[i] = new_r_Const(irg, tvs[i]);
        }
-       return new_r_Phi(get_nodes_block(a), n, (ir_node **)res, mode);
+       ir_node *block = get_nodes_block(a);
+       return new_r_Phi(block, n, res, mode);
 }
 
 /**
@@ -1811,32 +1503,27 @@ static ir_node *apply_binop_on_2_phis(ir_node *a, ir_node *b, eval_func eval, ir
  */
 static ir_node *apply_unop_on_phi(ir_node *phi, ir_tarval *(*eval)(ir_tarval *))
 {
-       ir_tarval *tv;
-       void     **res;
-       ir_node  *pred;
-       ir_mode  *mode;
-       ir_graph *irg;
-       int      i, n = get_irn_arity(phi);
-
-       NEW_ARR_A(void *, res, n);
-       for (i = 0; i < n; ++i) {
-               pred = get_irn_n(phi, i);
-               tv   = get_Const_tarval(pred);
-               tv   = eval(tv);
+       int         n   = get_irn_arity(phi);
+       ir_tarval **tvs = ALLOCAN(ir_tarval*, n);
+       for (int i = 0; i < n; ++i) {
+               ir_node   *pred = get_irn_n(phi, i);
+               ir_tarval *tv   = get_Const_tarval(pred);
+               tv = eval(tv);
 
                if (tv == tarval_bad) {
                        /* folding failed, bad */
                        return 0;
                }
-               res[i] = tv;
+               tvs[i] = tv;
        }
-       mode = get_irn_mode(phi);
-       irg  = get_irn_irg(phi);
-       for (i = 0; i < n; ++i) {
-               pred = get_irn_n(phi, i);
-               res[i] = new_r_Const(irg, (ir_tarval*)res[i]);
+       ir_graph *irg  = get_irn_irg(phi);
+       ir_node **res  = ALLOCAN(ir_node*, n);
+       for (int i = 0; i < n; ++i) {
+               res[i] = new_r_Const(irg, tvs[i]);
        }
-       return new_r_Phi(get_nodes_block(phi), n, (ir_node **)res, mode);
+       ir_node *block = get_nodes_block(phi);
+       ir_mode *mode  = get_irn_mode(phi);
+       return new_r_Phi(block, n, res, mode);
 }
 
 /**
@@ -1848,30 +1535,26 @@ static ir_node *apply_unop_on_phi(ir_node *phi, ir_tarval *(*eval)(ir_tarval *))
  */
 static ir_node *apply_conv_on_phi(ir_node *phi, ir_mode *mode)
 {
-       ir_tarval *tv;
-       void     **res;
-       ir_node  *pred;
-       ir_graph *irg;
-       int      i, n = get_irn_arity(phi);
-
-       NEW_ARR_A(void *, res, n);
-       for (i = 0; i < n; ++i) {
-               pred = get_irn_n(phi, i);
-               tv   = get_Const_tarval(pred);
-               tv   = tarval_convert_to(tv, mode);
+       int         n   = get_irn_arity(phi);
+       ir_tarval **tvs = ALLOCAN(ir_tarval*, n);
+       for (int i = 0; i < n; ++i) {
+               ir_node   *pred = get_irn_n(phi, i);
+               ir_tarval *tv   = get_Const_tarval(pred);
+               tv = tarval_convert_to(tv, mode);
 
                if (tv == tarval_bad) {
                        /* folding failed, bad */
                        return 0;
                }
-               res[i] = tv;
+               tvs[i] = tv;
        }
-       irg = get_irn_irg(phi);
-       for (i = 0; i < n; ++i) {
-               pred = get_irn_n(phi, i);
-               res[i] = new_r_Const(irg, (ir_tarval*)res[i]);
+       ir_graph *irg = get_irn_irg(phi);
+       ir_node **res = ALLOCAN(ir_node*, n);
+       for (int i = 0; i < n; ++i) {
+               res[i] = new_r_Const(irg, tvs[i]);
        }
-       return new_r_Phi(get_nodes_block(phi), n, (ir_node **)res, mode);
+       ir_node *block = get_nodes_block(phi);
+       return new_r_Phi(block, n, res, mode);
 }
 
 /**
@@ -2149,7 +1832,7 @@ static ir_node *transform_node_Or_bf_store(ir_node *irn_or)
                }
 
                /* ok, all conditions met */
-               block = get_irn_n(irn_or, -1);
+               block = get_nodes_block(irn_or);
                irg   = get_irn_irg(block);
 
                new_and = new_r_And(block, value, new_r_Const(irg, tarval_and(tv4, tv2)), mode);
@@ -2375,7 +2058,7 @@ static ir_node *transform_node_bitop_shift(ir_node *n)
        ir_tarval *tv2;
        ir_tarval *tv_bitop;
 
-       if (!is_irg_state(irg, IR_GRAPH_STATE_NORMALISATION2))
+       if (!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_NORMALISATION2))
                return n;
 
        assert(is_And(n) || is_Or(n) || is_Eor(n) || is_Or_Eor_Add(n));
@@ -2461,6 +2144,55 @@ static bool complement_values(const ir_node *a, const ir_node *b)
        return false;
 }
 
+typedef ir_tarval *(tv_fold_binop_func)(ir_tarval *a, ir_tarval *b);
+
+/**
+ * for associative operations fold:
+ *   op(op(x, c0), c1) to op(x, op(c0, c1)) with constants folded.
+ * This is a "light" version of the reassociation phase
+ */
+static ir_node *fold_constant_associativity(ir_node *node,
+                                            tv_fold_binop_func fold)
+{
+       ir_graph  *irg;
+       ir_op     *op;
+       ir_node   *left;
+       ir_node   *right = get_binop_right(node);
+       ir_node   *left_right;
+       ir_node   *left_left;
+       ir_tarval *c0;
+       ir_tarval *c1;
+       ir_tarval *new_c;
+       ir_node   *new_const;
+       ir_node   *new_node;
+       if (!is_Const(right))
+               return node;
+
+       op   = get_irn_op(node);
+       left = get_binop_left(node);
+       if (get_irn_op(left) != op)
+               return node;
+
+       left_right = get_binop_right(left);
+       if (!is_Const(left_right))
+               return node;
+
+       left_left = get_binop_left(left);
+       c0        = get_Const_tarval(left_right);
+       c1        = get_Const_tarval(right);
+       irg       = get_irn_irg(node);
+       if (get_tarval_mode(c0) != get_tarval_mode(c1))
+               return node;
+       new_c     = fold(c0, c1);
+       if (new_c == tarval_bad)
+               return node;
+       new_const = new_r_Const(irg, new_c);
+       new_node  = exact_copy(node);
+       set_binop_left(new_node, left_left);
+       set_binop_right(new_node, new_const);
+       return new_node;
+}
+
 /**
  * Transform an Or.
  */
@@ -2472,6 +2204,10 @@ static ir_node *transform_node_Or_(ir_node *n)
        ir_node *c;
        ir_mode *mode;
 
+       n = fold_constant_associativity(n, tarval_or);
+       if (n != oldn)
+               return n;
+
        if (is_Not(a) && is_Not(b)) {
                /* ~a | ~b = ~(a&b) */
                ir_node *block = get_nodes_block(n);
@@ -2512,9 +2248,9 @@ static ir_node *transform_node_Or_(ir_node *n)
                                ir_node  *xora   = new_rd_Eor(dbgi, block, a_left, a_right, a_mode);
                                ir_node  *xorb   = new_rd_Eor(dbgi, block, b_left, b_right, b_mode);
                                ir_node  *conv   = new_rd_Conv(dbgi, block, xora, b_mode);
-                               ir_node  *or     = new_rd_Or(dbgi, block, conv, xorb, b_mode);
+                               ir_node  *orn    = new_rd_Or(dbgi, block, conv, xorb, b_mode);
                                ir_node  *zero   = create_zero_const(irg, b_mode);
-                               return new_rd_Cmp(dbgi, block, or, zero, ir_relation_less_greater);
+                               return new_rd_Cmp(dbgi, block, orn, zero, ir_relation_less_greater);
                        }
                        if (values_in_mode(get_irn_mode(b_left), get_irn_mode(a_left))) {
                                ir_graph *irg    = get_irn_irg(n);
@@ -2525,9 +2261,9 @@ static ir_node *transform_node_Or_(ir_node *n)
                                ir_node  *xora   = new_rd_Eor(dbgi, block, a_left, a_right, a_mode);
                                ir_node  *xorb   = new_rd_Eor(dbgi, block, b_left, b_right, b_mode);
                                ir_node  *conv   = new_rd_Conv(dbgi, block, xorb, a_mode);
-                               ir_node  *or     = new_rd_Or(dbgi, block, xora, conv, a_mode);
+                               ir_node  *orn    = new_rd_Or(dbgi, block, xora, conv, a_mode);
                                ir_node  *zero   = create_zero_const(irg, a_mode);
-                               return new_rd_Cmp(dbgi, block, or, zero, ir_relation_less_greater);
+                               return new_rd_Cmp(dbgi, block, orn, zero, ir_relation_less_greater);
                        }
                }
        }
@@ -2576,6 +2312,10 @@ static ir_node *transform_node_Eor_(ir_node *n)
        ir_mode *mode = get_irn_mode(n);
        ir_node *c;
 
+       n = fold_constant_associativity(n, tarval_eor);
+       if (n != oldn)
+               return n;
+
        /* we can combine the relations of two compares with the same operands */
        if (is_Cmp(a) && is_Cmp(b)) {
                ir_node *a_left  = get_Cmp_left(a);
@@ -2643,8 +2383,6 @@ static ir_node *transform_node_Eor(ir_node *n)
        return transform_node_Eor_(n);
 }
 
-
-
 /**
  * Do the AddSub optimization, then Transform
  *   Constant folding on Phi
@@ -2662,6 +2400,10 @@ static ir_node *transform_node_Add(ir_node *n)
        ir_node *c;
        ir_node *oldn = n;
 
+       n = fold_constant_associativity(n, tarval_add);
+       if (n != oldn)
+               return n;
+
        n = transform_node_AddSub(n);
        if (n != oldn)
                return n;
@@ -2680,6 +2422,21 @@ static ir_node *transform_node_Add(ir_node *n)
                }
        }
 
+       if (is_Const(b) && get_mode_arithmetic(mode) == irma_twos_complement) {
+               ir_tarval *tv  = get_Const_tarval(b);
+               ir_tarval *min = get_mode_min(mode);
+               /* if all bits are set, then this has the same effect as a Not.
+                * Note that the following == gives false for different modes which
+                * is exactly what we want */
+               if (tv == min) {
+                       dbg_info *dbgi  = get_irn_dbg_info(n);
+                       ir_graph *irg   = get_irn_irg(n);
+                       ir_node  *block = get_nodes_block(n);
+                       ir_node  *cnst  = new_r_Const(irg, min);
+                       return new_rd_Eor(dbgi, block, a, cnst, mode);
+               }
+       }
+
        HANDLE_BINOP_PHI((eval_func) tarval_add, a, b, c, mode);
 
        /* for FP the following optimizations are only allowed if
@@ -2694,7 +2451,7 @@ static ir_node *transform_node_Add(ir_node *n)
                ir_graph *irg = get_irn_irg(n);
                /* the following code leads to endless recursion when Mul are replaced
                 * by a simple instruction chain */
-               if (!is_irg_state(irg, IR_GRAPH_STATE_ARCH_DEP)
+               if (!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_ARCH_DEP)
                                && a == b && mode_is_int(mode)) {
                        ir_node *block = get_nodes_block(n);
 
@@ -2878,26 +2635,6 @@ restart:
                }
                DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_TO_ADD);
                return n;
-#if 0
-       } else if (is_Mul(b)) { /* a - (b * C) -> a + (b * -C) */
-               ir_node *m_right = get_Mul_right(b);
-               if (is_Const(m_right)) {
-                       ir_node *cnst2 = const_negate(m_right);
-                       if (cnst2 != NULL) {
-                               dbg_info *m_dbg   = get_irn_dbg_info(b);
-                               ir_node  *m_block = get_nodes_block(b);
-                               ir_node  *m_left  = get_Mul_left(b);
-                               ir_mode  *m_mode  = get_irn_mode(b);
-                               ir_node  *mul     = new_rd_Mul(m_dbg, m_block, m_left, cnst2, m_mode);
-                               dbg_info *a_dbg   = get_irn_dbg_info(n);
-                               ir_node  *a_block = get_nodes_block(n);
-
-                               n = new_rd_Add(a_dbg, a_block, a, mul, mode);
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_TO_ADD);
-                               return n;
-                       }
-               }
-#endif
        }
 
        /* Beware of Sub(P, P) which cannot be optimized into a simple Minus ... */
@@ -3083,8 +2820,8 @@ restart:
                                ir_node  *block = get_nodes_block(n);
                                ir_mode  *mode  = get_irn_mode(n);
                                ir_node  *notn  = new_rd_Not(dbgi, block, and_right, mode);
-                               ir_node  *and   = new_rd_And(dbgi, block, a, notn, mode);
-                               return and;
+                               ir_node  *andn  = new_rd_And(dbgi, block, a, notn, mode);
+                               return andn;
                        }
                }
        }
@@ -3121,7 +2858,7 @@ static ir_node *transform_node_Mul2n(ir_node *n, ir_mode *mode)
        }
        if (tb == get_mode_one(smode)) {
                /* (L)a * (L)1 = (L)a */
-               ir_node *blk = get_irn_n(a, -1);
+               ir_node *blk = get_nodes_block(a);
                n = new_rd_Conv(get_irn_dbg_info(n), blk, a, mode);
                DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
                return n;
@@ -3149,7 +2886,8 @@ static ir_node *transform_node_Mul(ir_node *n)
        ir_node *a = get_Mul_left(n);
        ir_node *b = get_Mul_right(n);
 
-       if (is_Bad(a) || is_Bad(b))
+       n = fold_constant_associativity(n, tarval_mul);
+       if (n != oldn)
                return n;
 
        if (mode != get_irn_mode(a))
@@ -3315,34 +3053,22 @@ static ir_node *transform_node_Div(ir_node *n)
                assert(mode_is_float(mode));
 
                /* Optimize x/c to x*(1/c) */
-               if (get_mode_arithmetic(mode) == irma_ieee754) {
-                       ir_tarval *tv = value_of(b);
+               ir_tarval *tv = value_of(b);
 
-                       if (tv != tarval_bad) {
-                               int rem = tarval_fp_ops_enabled();
+               if (tv != tarval_bad) {
+                       tv = tarval_div(get_mode_one(mode), tv);
 
-                               /*
-                                * Floating point constant folding might be disabled here to
-                                * prevent rounding.
-                                * However, as we check for exact result, doing it is safe.
-                                * Switch it on.
-                                */
-                               tarval_enable_fp_ops(1);
-                               tv = tarval_div(get_mode_one(mode), tv);
-                               tarval_enable_fp_ops(rem);
-
-                               /* Do the transformation if the result is either exact or we are
-                                  not using strict rules. */
-                               if (tv != tarval_bad &&
-                                       (tarval_ieee754_get_exact() || (get_irg_fp_model(get_irn_irg(n)) & fp_strict_algebraic) == 0)) {
-                                       ir_node  *block = get_nodes_block(n);
-                                       ir_graph *irg   = get_irn_irg(block);
-                                       ir_node  *c     = new_r_Const(irg, tv);
-                                       dbg_info *dbgi  = get_irn_dbg_info(n);
-                                       value = new_rd_Mul(dbgi, block, a, c, mode);
+                       /* Do the transformation if the result is either exact or we are
+                          not using strict rules. */
+                       if (tv != tarval_bad &&
+                               (tarval_ieee754_get_exact() || (get_irg_fp_model(get_irn_irg(n)) & fp_strict_algebraic) == 0)) {
+                               ir_node  *block = get_nodes_block(n);
+                               ir_graph *irg   = get_irn_irg(block);
+                               ir_node  *c     = new_r_Const(irg, tv);
+                               dbg_info *dbgi  = get_irn_dbg_info(n);
+                               value = new_rd_Mul(dbgi, block, a, c, mode);
 
-                                       goto make_tuple;
-                               }
+                               goto make_tuple;
                        }
                }
        }
@@ -3481,11 +3207,11 @@ static ir_node *transform_node_Cond(ir_node *n)
        if (ta == tarval_bad && is_Cmp(a)) {
                /* try again with a direct call to compute_cmp, as we don't care
                 * about the MODEB_LOWERED flag here */
-               ta = compute_cmp(a);
+               ta = compute_cmp_ext(a);
        }
 
-       if (ta != tarval_bad && get_irn_mode(a) == mode_b) {
-               /* It's a boolean Cond, branching on a boolean constant.
+       if (ta != tarval_bad) {
+               /* It's branching on a boolean constant.
                   Replace it by a tuple (Bad, Jmp) or (Jmp, Bad) */
                ir_node *blk = get_nodes_block(n);
                jmp = new_r_Jmp(blk);
@@ -3497,9 +3223,7 @@ static ir_node *transform_node_Cond(ir_node *n)
                        set_Tuple_pred(n, pn_Cond_false, jmp);
                        set_Tuple_pred(n, pn_Cond_true, new_r_Bad(irg, mode_X));
                }
-               /* We might generate an endless loop, so keep it alive. */
-               add_End_keepalive(get_irg_end(irg), blk);
-               clear_irg_state(irg, IR_GRAPH_STATE_NO_UNREACHABLE_CODE);
+               clear_irg_properties(irg, IR_GRAPH_PROPERTY_NO_UNREACHABLE_CODE);
        }
        return n;
 }
@@ -3573,7 +3297,7 @@ static ir_node *transform_node_shift_bitop(ir_node *n)
        ir_tarval *tv2;
        ir_tarval *tv_shift;
 
-       if (is_irg_state(irg, IR_GRAPH_STATE_NORMALISATION2))
+       if (irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_NORMALISATION2))
                return n;
 
        assert(is_Shrs(n) || is_Shr(n) || is_Shl(n) || is_Rotl(n));
@@ -3646,6 +3370,10 @@ static ir_node *transform_node_And(ir_node *n)
        ir_node *b = get_And_right(n);
        ir_mode *mode;
 
+       n = fold_constant_associativity(n, tarval_and);
+       if (n != oldn)
+               return n;
+
        if (is_Cmp(a) && is_Cmp(b)) {
                ir_node    *a_left     = get_Cmp_left(a);
                ir_node    *a_right    = get_Cmp_right(a);
@@ -3673,10 +3401,10 @@ static ir_node *transform_node_And(ir_node *n)
                                ir_node  *xora   = new_rd_Eor(dbgi, block, a_left, a_right, a_mode);
                                ir_node  *xorb   = new_rd_Eor(dbgi, block, b_left, b_right, b_mode);
                                ir_node  *conv   = new_rd_Conv(dbgi, block, xora, b_mode);
-                               ir_node  *or     = new_rd_Or(dbgi, block, conv, xorb, b_mode);
+                               ir_node  *orn    = new_rd_Or(dbgi, block, conv, xorb, b_mode);
                                ir_graph *irg    = get_irn_irg(n);
                                ir_node  *zero   = create_zero_const(irg, b_mode);
-                               return new_rd_Cmp(dbgi, block, or, zero, ir_relation_equal);
+                               return new_rd_Cmp(dbgi, block, orn, zero, ir_relation_equal);
                        }
                        if (values_in_mode(get_irn_mode(b_left), get_irn_mode(a_left))) {
                                dbg_info *dbgi   = get_irn_dbg_info(n);
@@ -3686,10 +3414,10 @@ static ir_node *transform_node_And(ir_node *n)
                                ir_node  *xora   = new_rd_Eor(dbgi, block, a_left, a_right, a_mode);
                                ir_node  *xorb   = new_rd_Eor(dbgi, block, b_left, b_right, b_mode);
                                ir_node  *conv   = new_rd_Conv(dbgi, block, xorb, a_mode);
-                               ir_node  *or     = new_rd_Or(dbgi, block, xora, conv, a_mode);
+                               ir_node  *orn    = new_rd_Or(dbgi, block, xora, conv, a_mode);
                                ir_graph *irg    = get_irn_irg(n);
                                ir_node  *zero   = create_zero_const(irg, a_mode);
-                               return new_rd_Cmp(dbgi, block, or, zero, ir_relation_equal);
+                               return new_rd_Cmp(dbgi, block, orn, zero, ir_relation_equal);
                        }
                }
        }
@@ -4001,27 +3729,25 @@ static ir_node *transform_node_Minus(ir_node *n)
  */
 static ir_node *transform_node_Proj_Load(ir_node *proj)
 {
-       if (get_opt_ldst_only_null_ptr_exceptions()) {
-               if (get_irn_mode(proj) == mode_X) {
-                       ir_node *load = get_Proj_pred(proj);
+       if (get_irn_mode(proj) == mode_X) {
+               ir_node *load = get_Proj_pred(proj);
 
-                       /* get the Load address */
-                       const ir_node *addr = get_Load_ptr(load);
-                       const ir_node *confirm;
+               /* get the Load address */
+               const ir_node *addr = get_Load_ptr(load);
+               const ir_node *confirm;
 
-                       if (value_not_null(addr, &confirm)) {
-                               if (confirm == NULL) {
-                                       /* this node may float if it did not depend on a Confirm */
-                                       set_irn_pinned(load, op_pin_state_floats);
-                               }
-                               if (get_Proj_proj(proj) == pn_Load_X_except) {
-                                       ir_graph *irg = get_irn_irg(proj);
-                                       DBG_OPT_EXC_REM(proj);
-                                       return new_r_Bad(irg, mode_X);
-                               } else {
-                                       ir_node *blk = get_nodes_block(load);
-                                       return new_r_Jmp(blk);
-                               }
+               if (value_not_null(addr, &confirm)) {
+                       if (confirm == NULL) {
+                               /* this node may float if it did not depend on a Confirm */
+                               set_irn_pinned(load, op_pin_state_floats);
+                       }
+                       if (get_Proj_proj(proj) == pn_Load_X_except) {
+                               ir_graph *irg = get_irn_irg(proj);
+                               DBG_OPT_EXC_REM(proj);
+                               return new_r_Bad(irg, mode_X);
+                       } else {
+                               ir_node *blk = get_nodes_block(load);
+                               return new_r_Jmp(blk);
                        }
                }
        }
@@ -4033,27 +3759,25 @@ static ir_node *transform_node_Proj_Load(ir_node *proj)
  */
 static ir_node *transform_node_Proj_Store(ir_node *proj)
 {
-       if (get_opt_ldst_only_null_ptr_exceptions()) {
-               if (get_irn_mode(proj) == mode_X) {
-                       ir_node *store = get_Proj_pred(proj);
+       if (get_irn_mode(proj) == mode_X) {
+               ir_node *store = get_Proj_pred(proj);
 
-                       /* get the load/store address */
-                       const ir_node *addr = get_Store_ptr(store);
-                       const ir_node *confirm;
+               /* get the load/store address */
+               const ir_node *addr = get_Store_ptr(store);
+               const ir_node *confirm;
 
-                       if (value_not_null(addr, &confirm)) {
-                               if (confirm == NULL) {
-                                       /* this node may float if it did not depend on a Confirm */
-                                       set_irn_pinned(store, op_pin_state_floats);
-                               }
-                               if (get_Proj_proj(proj) == pn_Store_X_except) {
-                                       ir_graph *irg = get_irn_irg(proj);
-                                       DBG_OPT_EXC_REM(proj);
-                                       return new_r_Bad(irg, mode_X);
-                               } else {
-                                       ir_node *blk = get_nodes_block(store);
-                                       return new_r_Jmp(blk);
-                               }
+               if (value_not_null(addr, &confirm)) {
+                       if (confirm == NULL) {
+                               /* this node may float if it did not depend on a Confirm */
+                               set_irn_pinned(store, op_pin_state_floats);
+                       }
+                       if (get_Proj_proj(proj) == pn_Store_X_except) {
+                               ir_graph *irg = get_irn_irg(proj);
+                               DBG_OPT_EXC_REM(proj);
+                               return new_r_Bad(irg, mode_X);
+                       } else {
+                               ir_node *blk = get_nodes_block(store);
+                               return new_r_Jmp(blk);
                        }
                }
        }
@@ -4140,7 +3864,7 @@ static ir_node *transform_node_Proj_Mod(ir_node *proj)
                switch (proj_nr) {
 
                case pn_Mod_X_regular:
-                       return new_r_Jmp(get_irn_n(mod, -1));
+                       return new_r_Jmp(get_nodes_block(mod));
 
                case pn_Mod_X_except: {
                        ir_graph *irg = get_irn_irg(proj);
@@ -4199,6 +3923,26 @@ static bool is_single_bit(const ir_node *node)
        return false;
 }
 
+/**
+ * checks if node just flips a bit in another node and returns that other node
+ * if so. @p tv should be a value having just 1 bit set
+ */
+static ir_node *flips_bit(const ir_node *node, ir_tarval *tv)
+{
+       if (is_Not(node))
+               return get_Not_op(node);
+       if (is_Eor(node)) {
+               ir_node *right = get_Eor_right(node);
+               if (is_Const(right)) {
+                       ir_tarval *right_tv = get_Const_tarval(right);
+                       ir_mode   *mode     = get_irn_mode(node);
+                       if (tarval_and(right_tv, tv) != get_mode_null(mode))
+                               return get_Eor_left(node);
+               }
+       }
+       return NULL;
+}
+
 /**
  * Normalizes and optimizes Cmp nodes.
  */
@@ -4221,53 +3965,56 @@ static ir_node *transform_node_Cmp(ir_node *n)
        }
 
        /* Remove unnecessary conversions */
-       if (is_Conv(left) && is_Conv(right)) {
-               ir_node *op_left    = get_Conv_op(left);
-               ir_node *op_right   = get_Conv_op(right);
-               ir_mode *mode_left  = get_irn_mode(op_left);
-               ir_mode *mode_right = get_irn_mode(op_right);
-
-               if (smaller_mode(mode_left, mode) && smaller_mode(mode_right, mode)
-                               && mode_left != mode_b && mode_right != mode_b) {
-                       ir_node *block = get_nodes_block(n);
+       if (!mode_is_float(mode)
+           || be_get_backend_param()->mode_float_arithmetic == NULL) {
+               if (is_Conv(left) && is_Conv(right)) {
+                       ir_node *op_left    = get_Conv_op(left);
+                       ir_node *op_right   = get_Conv_op(right);
+                       ir_mode *mode_left  = get_irn_mode(op_left);
+                       ir_mode *mode_right = get_irn_mode(op_right);
+
+                       if (smaller_mode(mode_left, mode) && smaller_mode(mode_right, mode)
+                                       && mode_left != mode_b && mode_right != mode_b) {
+                               ir_node *block = get_nodes_block(n);
 
-                       if (mode_left == mode_right) {
-                               left    = op_left;
-                               right   = op_right;
-                               changed = true;
-                               DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV_CONV);
-                       } else if (smaller_mode(mode_left, mode_right)) {
-                               left    = new_r_Conv(block, op_left, mode_right);
-                               right   = op_right;
-                               changed = true;
-                               DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV);
-                       } else if (smaller_mode(mode_right, mode_left)) {
-                               left    = op_left;
-                               right   = new_r_Conv(block, op_right, mode_left);
-                               changed = true;
-                               DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV);
+                               if (mode_left == mode_right) {
+                                       left    = op_left;
+                                       right   = op_right;
+                                       changed = true;
+                                       DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV_CONV);
+                               } else if (smaller_mode(mode_left, mode_right)) {
+                                       left    = new_r_Conv(block, op_left, mode_right);
+                                       right   = op_right;
+                                       changed = true;
+                                       DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV);
+                               } else if (smaller_mode(mode_right, mode_left)) {
+                                       left    = op_left;
+                                       right   = new_r_Conv(block, op_right, mode_left);
+                                       changed = true;
+                                       DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV);
+                               }
+                               mode = get_irn_mode(left);
                        }
-                       mode = get_irn_mode(left);
-               }
-       }
-       if (is_Conv(left) && is_Const(right)) {
-               ir_node   *op_left   = get_Conv_op(left);
-               ir_mode   *mode_left = get_irn_mode(op_left);
-               if (smaller_mode(mode_left, mode) && mode_left != mode_b) {
-                       ir_tarval *tv        = get_Const_tarval(right);
-                       tarval_int_overflow_mode_t last_mode
-                               = tarval_get_integer_overflow_mode();
-                       ir_tarval *new_tv;
-                       tarval_set_integer_overflow_mode(TV_OVERFLOW_BAD);
-                       new_tv = tarval_convert_to(tv, mode_left);
-                       tarval_set_integer_overflow_mode(last_mode);
-                       if (new_tv != tarval_bad) {
-                               ir_graph *irg = get_irn_irg(n);
-                               left    = op_left;
-                               right   = new_r_Const(irg, new_tv);
-                               mode    = get_irn_mode(left);
-                               changed = true;
-                               DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV);
+               }
+               if (is_Conv(left) && is_Const(right)) {
+                       ir_node   *op_left   = get_Conv_op(left);
+                       ir_mode   *mode_left = get_irn_mode(op_left);
+                       if (smaller_mode(mode_left, mode) && mode_left != mode_b) {
+                               ir_tarval *tv        = get_Const_tarval(right);
+                               tarval_int_overflow_mode_t last_mode
+                                       = tarval_get_integer_overflow_mode();
+                               ir_tarval *new_tv;
+                               tarval_set_integer_overflow_mode(TV_OVERFLOW_BAD);
+                               new_tv = tarval_convert_to(tv, mode_left);
+                               tarval_set_integer_overflow_mode(last_mode);
+                               if (new_tv != tarval_bad) {
+                                       ir_graph *irg = get_irn_irg(n);
+                                       left    = op_left;
+                                       right   = new_r_Const(irg, new_tv);
+                                       mode    = get_irn_mode(left);
+                                       changed = true;
+                                       DBG_OPT_ALGSIM0(n, n, FS_OPT_CMP_CONV);
+                               }
                        }
                }
        }
@@ -4446,25 +4193,53 @@ static ir_node *transform_node_Cmp(ir_node *n)
                }
        }
 
-       /* Cmp(And(1bit, val), 1bit) "bit-testing" can be replaced
-        * by the simpler Cmp(And(1bit), val), 0) negated pnc */
-       if (mode_is_int(mode) && is_And(left)
-           && (relation == ir_relation_equal
+       if (mode_is_int(mode) && is_And(left)) {
+               /* a complicated Cmp(And(1bit, val), 1bit) "bit-testing" can be replaced
+                * by the simpler Cmp(And(1bit, val), 0) negated pnc */
+               if (relation == ir_relation_equal
                || (mode_is_signed(mode) && relation == ir_relation_less_greater)
-               || (!mode_is_signed(mode) && (relation & ir_relation_less_equal) == ir_relation_less))) {
-               ir_node *and0 = get_And_left(left);
-               ir_node *and1 = get_And_right(left);
-               if (and1 == right) {
-                       ir_node *tmp = and0;
-                       and0 = and1;
-                       and1 = tmp;
-               }
-               if (and0 == right && is_single_bit(and0)) {
-                       ir_graph *irg = get_irn_irg(n);
-                       relation =
-                               relation == ir_relation_equal ? ir_relation_less_greater : ir_relation_equal;
-                       right = create_zero_const(irg, mode);
-                       changed |= 1;
+               || (!mode_is_signed(mode) && (relation & ir_relation_less_equal) == ir_relation_less)) {
+                       ir_node *and0 = get_And_left(left);
+                       ir_node *and1 = get_And_right(left);
+                       if (and1 == right) {
+                               ir_node *tmp = and0;
+                               and0 = and1;
+                               and1 = tmp;
+                       }
+                       if (and0 == right && is_single_bit(and0)) {
+                               ir_graph *irg = get_irn_irg(n);
+                               relation =
+                                       relation == ir_relation_equal ? ir_relation_less_greater
+                                                                     : ir_relation_equal;
+                               right = create_zero_const(irg, mode);
+                               changed |= 1;
+                               goto is_bittest;
+                       }
+               }
+
+               if (is_Const(right) && is_Const_null(right) &&
+                   (relation == ir_relation_equal
+                   || (relation == ir_relation_less_greater)
+                   || (!mode_is_signed(mode) && relation == ir_relation_greater))) {
+is_bittest: {
+                       /* instead of flipping the bit before the bit-test operation negate
+                        * pnc */
+                       ir_node *and0 = get_And_left(left);
+                       ir_node *and1 = get_And_right(left);
+                       if (is_Const(and1)) {
+                               ir_tarval *tv = get_Const_tarval(and1);
+                               if (tarval_is_single_bit(tv)) {
+                                       ir_node *flipped = flips_bit(and0, tv);
+                                       if (flipped != NULL) {
+                                               dbg_info *dbgi  = get_irn_dbg_info(left);
+                                               ir_node  *block = get_nodes_block(left);
+                                               relation = get_negated_relation(relation);
+                                               left = new_rd_And(dbgi, block, flipped, and1, mode);
+                                               changed |= 1;
+                                       }
+                               }
+                       }
+                       }
                }
        }
 
@@ -4528,6 +4303,43 @@ static ir_node *transform_node_Cmp(ir_node *n)
        if (tv != tarval_bad) {
                ir_mode *mode = get_irn_mode(right);
 
+               /* cmp(mux(x, cf, ct), c2) can be eliminated:
+                *   cmp(ct,c2) | cmp(cf,c2) | result
+                *   -----------|------------|--------
+                *   true       | true       | True
+                *   false      | false      | False
+                *   true       | false      | x
+                *   false      | true       | not(x)
+                */
+               if (is_Mux(left)) {
+                       ir_node *mux_true  = get_Mux_true(left);
+                       ir_node *mux_false = get_Mux_false(left);
+                       if (is_Const(mux_true) && is_Const(mux_false)) {
+                               /* we can fold true/false constant separately */
+                               ir_tarval *tv_true  = get_Const_tarval(mux_true);
+                               ir_tarval *tv_false = get_Const_tarval(mux_false);
+                               ir_relation r_true  = tarval_cmp(tv_true, tv);
+                               ir_relation r_false = tarval_cmp(tv_false, tv);
+                               if (r_true != ir_relation_false
+                                   || r_false != ir_relation_false) {
+                                       bool rel_true  = (r_true & relation)  != 0;
+                                       bool rel_false = (r_false & relation) != 0;
+                                       ir_node *cond = get_Mux_sel(left);
+                                       if (rel_true == rel_false) {
+                                               relation = rel_true ? ir_relation_true
+                                                                   : ir_relation_false;
+                                       } else if (rel_true) {
+                                               return cond;
+                                       } else {
+                                               dbg_info *dbgi  = get_irn_dbg_info(n);
+                                               ir_node  *block = get_nodes_block(n);
+                                               ir_node  *notn  = new_rd_Not(dbgi, block, cond, mode_b);
+                                               return notn;
+                                       }
+                               }
+                       }
+               }
+
                /* TODO extend to arbitrary constants */
                if (is_Conv(left) && tarval_is_null(tv)) {
                        ir_node *op      = get_Conv_op(left);
@@ -4848,7 +4660,7 @@ static ir_node *transform_node_Cmp(ir_node *n)
                                if (tarval_is_single_bit(tv)) {
                                        /* special case: (x % 2^n) CMP 0 ==> x & (2^n-1) CMP 0 */
                                        ir_node *v    = get_binop_left(op);
-                                       ir_node *blk  = get_irn_n(op, -1);
+                                       ir_node *blk  = get_nodes_block(op);
                                        ir_graph *irg = get_irn_irg(op);
                                        ir_mode *mode = get_irn_mode(v);
 
@@ -4902,67 +4714,10 @@ static ir_node *transform_node_Proj_CopyB(ir_node *proj)
 }
 
 /**
- * Optimize Bounds(idx, idx, upper) into idx.
+ * Does all optimizations on nodes that must be done on its Projs
+ * because of creating new nodes.
  */
-static ir_node *transform_node_Proj_Bound(ir_node *proj)
-{
-       ir_node *oldn  = proj;
-       ir_node *bound = get_Proj_pred(proj);
-       ir_node *idx   = get_Bound_index(bound);
-       ir_node *pred  = skip_Proj(idx);
-       int ret_tuple  = 0;
-
-       if (idx == get_Bound_lower(bound))
-               ret_tuple = 1;
-       else if (is_Bound(pred)) {
-               /*
-               * idx was Bounds checked previously, it is still valid if
-               * lower <= pred_lower && pred_upper <= upper.
-               */
-               ir_node *lower = get_Bound_lower(bound);
-               ir_node *upper = get_Bound_upper(bound);
-               if (get_Bound_lower(pred) == lower &&
-                       get_Bound_upper(pred) == upper) {
-                       /*
-                        * One could expect that we simply return the previous
-                        * Bound here. However, this would be wrong, as we could
-                        * add an exception Proj to a new location then.
-                        * So, we must turn in into a tuple.
-                        */
-                       ret_tuple = 1;
-               }
-       }
-       if (ret_tuple) {
-               /* Turn Bound into a tuple (mem, jmp, bad, idx) */
-               switch (get_Proj_proj(proj)) {
-               case pn_Bound_M:
-                       DBG_OPT_EXC_REM(proj);
-                       proj = get_Bound_mem(bound);
-                       break;
-               case pn_Bound_X_except:
-                       DBG_OPT_EXC_REM(proj);
-                       proj = new_r_Bad(get_irn_irg(proj), mode_X);
-                       break;
-               case pn_Bound_res:
-                       proj = idx;
-                       DBG_OPT_ALGSIM0(oldn, proj, FS_OPT_NOP);
-                       break;
-               case pn_Bound_X_regular:
-                       DBG_OPT_EXC_REM(proj);
-                       proj = new_r_Jmp(get_nodes_block(bound));
-                       break;
-               default:
-                       break;
-               }
-       }
-       return proj;
-}
-
-/**
- * Does all optimizations on nodes that must be done on its Projs
- * because of creating new nodes.
- */
-static ir_node *transform_node_Proj(ir_node *proj)
+static ir_node *transform_node_Proj(ir_node *proj)
 {
        ir_node *n = get_Proj_pred(proj);
 
@@ -4974,7 +4729,7 @@ static ir_node *transform_node_Proj(ir_node *proj)
 /**
  * Test whether a block is unreachable
  * Note: That this only returns true when
- * IR_GRAPH_STATE_OPTIMIZE_UNREACHABLE_CODE is set.
+ * IR_GRAPH_CONSTRAINT_OPTIMIZE_UNREACHABLE_CODE is set.
  * This is important, as you easily end up producing invalid constructs in the
  * unreachable code when optimizing away edges into the unreachable code.
  * So only set this flag when you iterate localopts to the fixpoint.
@@ -4985,7 +4740,7 @@ static ir_node *transform_node_Proj(ir_node *proj)
 static bool is_block_unreachable(const ir_node *block)
 {
        const ir_graph *irg = get_irn_irg(block);
-       if (!is_irg_state(irg, IR_GRAPH_STATE_OPTIMIZE_UNREACHABLE_CODE))
+       if (!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_OPTIMIZE_UNREACHABLE_CODE))
                return false;
        return get_Block_dom_depth(block) < 0;
 }
@@ -4997,7 +4752,7 @@ static ir_node *transform_node_Block(ir_node *block)
        ir_node  *bad   = NULL;
        int       i;
 
-       if (!is_irg_state(irg, IR_GRAPH_STATE_OPTIMIZE_UNREACHABLE_CODE))
+       if (!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_OPTIMIZE_UNREACHABLE_CODE))
                return block;
 
        for (i = 0; i < arity; ++i) {
@@ -5062,7 +4817,6 @@ static ir_node *transform_node_Phi(ir_node *phi)
                                return phi;
 
                        /* Move the Pin nodes "behind" the Phi. */
-                       block   = get_irn_n(phi, -1);
                        new_phi = new_r_Phi(block, n, in, mode_M);
                        return new_r_Pin(block, new_phi);
                }
@@ -5074,7 +4828,7 @@ static ir_node *transform_node_Phi(ir_node *phi)
                /* Beware of Phi0 */
                if (n > 0) {
                        ir_node    *pred = get_irn_n(phi, 0);
-                       ir_node    *bound, *new_phi, *block, **in;
+                       ir_node    *bound, *new_phi, **in;
                        ir_relation relation;
                        bool        has_confirm = false;
 
@@ -5106,7 +4860,6 @@ static ir_node *transform_node_Phi(ir_node *phi)
                                return phi;
 
                        /* move the Confirm nodes "behind" the Phi */
-                       block = get_irn_n(phi, -1);
                        new_phi = new_r_Phi(block, n, in, get_irn_mode(phi));
                        return new_r_Confirm(block, new_phi, bound, relation);
                }
@@ -5114,9 +4867,6 @@ static ir_node *transform_node_Phi(ir_node *phi)
        return phi;
 }
 
-/* forward */
-static ir_node *transform_node(ir_node *n);
-
 /**
  * Optimize (a >> c1) >> c2), works for Shr, Shrs, Shl, Rotl.
  *
@@ -5205,7 +4955,7 @@ static ir_node *transform_node_shift(ir_node *n)
 
        DBG_OPT_ALGSIM0(n, irn, FS_OPT_REASSOC_SHIFT);
 
-       return transform_node(irn);
+       return irn;
 }
 
 /**
@@ -5511,6 +5261,69 @@ static ir_node *transform_node_Rotl(ir_node *n)
        return n;
 }
 
+/**
+ * returns mode size for may_leave_out_middle_mode
+ */
+static unsigned get_significand_size(ir_mode *mode)
+{
+       const ir_mode_arithmetic arithmetic = get_mode_arithmetic(mode);
+       switch (arithmetic) {
+       case irma_ieee754:
+       case irma_x86_extended_float:
+               return get_mode_mantissa_size(mode) + 1;
+       case irma_twos_complement:
+               return get_mode_size_bits(mode);
+       case irma_none:
+               panic("Conv node with irma_none mode?");
+       }
+       panic("unexpected mode_arithmetic in get_significand_size");
+}
+
+/**
+ * Returns true if a conversion from mode @p m0 to @p m1 has the same effect
+ * as converting from @p m0 to @p m1 and then to @p m2.
+ * Classifying the 3 modes as the big(b), middle(m) and small(s) mode this
+ * gives the following truth table:
+ * s -> b -> m  : true
+ * s -> m -> b  : !signed(s) || signed(m)
+ * m -> b -> s  : true
+ * m -> s -> b  : false
+ * b -> s -> m  : false
+ * b -> m -> s  : true
+ *
+ * s -> b -> b  : true
+ * s -> s -> b  : false
+ *
+ * additional float constraints:
+ * F -> F -> F: fine
+ * F -> I -> I: signedness of Is must match
+ * I -> F -> I: signedness of Is must match
+ * I -> I -> F: signedness of Is must match
+ * F -> I -> F: bad
+ * I -> F -> F: fine
+ * F -> F -> I: fine
+ * at least 1 float involved: signedness must match
+ */
+bool may_leave_out_middle_conv(ir_mode *m0, ir_mode *m1, ir_mode *m2)
+{
+       int n_floats = mode_is_float(m0) + mode_is_float(m1) + mode_is_float(m2);
+       if (n_floats == 1) {
+               /* because overflow gives strange results we don't touch this case */
+               return false;
+       } else if (n_floats == 2 && !mode_is_float(m1)) {
+               return false;
+       }
+
+       unsigned size0 = get_significand_size(m0);
+       unsigned size1 = get_significand_size(m1);
+       unsigned size2 = get_significand_size(m2);
+       if (size1 < size2 && size0 >= size1)
+               return false;
+       if (size1 >= size2)
+               return true;
+       return !mode_is_signed(m0) || mode_is_signed(m1);
+}
+
 /**
  * Transform a Conv.
  */
@@ -5520,6 +5333,17 @@ static ir_node *transform_node_Conv(ir_node *n)
        ir_mode *mode = get_irn_mode(n);
        ir_node *a    = get_Conv_op(n);
 
+       if (is_Conv(a)) {
+               ir_mode *a_mode = get_irn_mode(a);
+               ir_node *b      = get_Conv_op(a);
+               ir_mode *b_mode = get_irn_mode(b);
+               if (may_leave_out_middle_conv(b_mode, a_mode, mode)) {
+                       dbg_info *dbgi  = get_irn_dbg_info(n);
+                       ir_node  *block = get_nodes_block(n);
+                       return new_rd_Conv(dbgi, block, b, mode);
+               }
+       }
+
        if (mode != mode_b && is_const_Phi(a)) {
                /* Do NOT optimize mode_b Conv's, this leads to remaining
                 * Phib nodes later, because the conv_b_lower operation
@@ -5726,6 +5550,92 @@ bool ir_is_optimizable_mux(const ir_node *sel, const ir_node *mux_false,
        return false;
 }
 
+/**
+ * Optimize a Mux(c, 0, 1) node (sometimes called a "set" instruction)
+ */
+static ir_node *transform_Mux_set(ir_node *n)
+{
+       ir_node    *cond = get_Mux_sel(n);
+       ir_mode    *dest_mode;
+       ir_mode    *mode;
+       ir_node    *left;
+       ir_node    *right;
+       ir_relation relation;
+       bool        need_not;
+       dbg_info   *dbgi;
+       ir_node    *block;
+       ir_graph   *irg;
+       ir_node    *a;
+       ir_node    *b;
+       unsigned    bits;
+       ir_tarval  *tv;
+       ir_node    *shift_cnt;
+       ir_node    *res;
+
+       if (!is_Cmp(cond))
+               return n;
+       left = get_Cmp_left(cond);
+       mode = get_irn_mode(left);
+       if (!mode_is_int(mode) && !mode_is_reference(mode))
+               return n;
+       dest_mode = get_irn_mode(n);
+       if (!mode_is_int(dest_mode) && !mode_is_reference(dest_mode))
+               return n;
+       right     = get_Cmp_right(cond);
+       relation  = get_Cmp_relation(cond) & ~ir_relation_unordered;
+       if (get_mode_size_bits(mode) >= get_mode_size_bits(dest_mode)
+           && !(mode_is_signed(mode) && is_Const(right) && is_Const_null(right)
+                && relation != ir_relation_greater))
+           return n;
+
+       need_not = false;
+       switch (relation) {
+       case ir_relation_less:
+               /* a < b  ->  (a - b) >> 31 */
+               a = left;
+               b = right;
+               break;
+       case ir_relation_less_equal:
+               /* a <= b  -> ~(a - b) >> 31 */
+               a        = right;
+               b        = left;
+               need_not = true;
+               break;
+       case ir_relation_greater:
+               /* a > b   -> (b - a) >> 31 */
+               a = right;
+               b = left;
+               break;
+       case ir_relation_greater_equal:
+               /* a >= b   -> ~(a - b) >> 31 */
+               a        = left;
+               b        = right;
+               need_not = true;
+               break;
+       default:
+               return n;
+       }
+
+       dbgi      = get_irn_dbg_info(n);
+       block     = get_nodes_block(n);
+       irg       = get_irn_irg(block);
+       bits      = get_mode_size_bits(dest_mode);
+       tv        = new_tarval_from_long(bits-1, mode_Iu);
+       shift_cnt = new_rd_Const(dbgi, irg, tv);
+
+       if (mode != dest_mode) {
+               a = new_rd_Conv(dbgi, block, a, dest_mode);
+               b = new_rd_Conv(dbgi, block, b, dest_mode);
+       }
+
+       res = new_rd_Sub(dbgi, block, a, b, dest_mode);
+       if (need_not) {
+               res = new_rd_Not(dbgi, block, res, dest_mode);
+       }
+       res = new_rd_Shr(dbgi, block, res, shift_cnt, dest_mode);
+       return res;
+}
+
 /**
  * Optimize a Mux into some simpler cases.
  */
@@ -5774,12 +5684,18 @@ static ir_node *transform_node_Mux(ir_node *n)
                relation = get_negated_relation(relation);
                sel = new_rd_Cmp(seldbgi, block, get_Cmp_left(sel),
                                get_Cmp_right(sel), relation);
-               n = new_rd_Mux(get_irn_dbg_info(n), get_nodes_block(n), sel, f, t, mode);
+               return new_rd_Mux(get_irn_dbg_info(n), get_nodes_block(n), sel, f, t, mode);
+       }
+
+       if (is_Const(f) && is_Const_null(f) && is_Const(t) && is_Const_one(t)) {
+               n = transform_Mux_set(n);
+               if (n != oldn)
+                       return n;
        }
 
        /* the following optimisations create new mode_b nodes, so only do them
         * before mode_b lowering */
-       if (!is_irg_state(irg, IR_GRAPH_STATE_MODEB_LOWERED)) {
+       if (!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_MODEB_LOWERED)) {
                if (is_Mux(t)) {
                        ir_node*  block = get_nodes_block(n);
                        ir_node*  c0    = sel;
@@ -5788,23 +5704,15 @@ static ir_node *transform_node_Mux(ir_node *n)
                        ir_node*  f1    = get_Mux_false(t);
                        if (f == f1) {
                                /* Mux(cond0, Mux(cond1, x, y), y) => Mux(cond0 && cond1, x, y) */
-                               ir_node* and_    = new_r_And(block, c0, c1, mode_b);
-                               ir_node* new_mux = new_r_Mux(block, and_, f1, t1, mode);
-                               n   = new_mux;
-                               sel = and_;
-                               f   = f1;
-                               t   = t1;
-                               DBG_OPT_ALGSIM0(oldn, t, FS_OPT_MUX_COMBINE);
+                               ir_node* and_ = new_r_And(block, c0, c1, mode_b);
+                               DBG_OPT_ALGSIM0(oldn, t1, FS_OPT_MUX_COMBINE);
+                               return new_r_Mux(block, and_, f1, t1, mode);
                        } else if (f == t1) {
                                /* Mux(cond0, Mux(cond1, x, y), x) */
                                ir_node* not_c1  = new_r_Not(block, c1, mode_b);
                                ir_node* and_    = new_r_And(block, c0, not_c1, mode_b);
-                               ir_node* new_mux = new_r_Mux(block, and_, t1, f1, mode);
-                               n   = new_mux;
-                               sel = and_;
-                               f   = t1;
-                               t   = f1;
-                               DBG_OPT_ALGSIM0(oldn, t, FS_OPT_MUX_COMBINE);
+                               DBG_OPT_ALGSIM0(oldn, f1, FS_OPT_MUX_COMBINE);
+                               return new_r_Mux(block, and_, t1, f1, mode);
                        }
                } else if (is_Mux(f)) {
                        ir_node*  block = get_nodes_block(n);
@@ -5814,23 +5722,15 @@ static ir_node *transform_node_Mux(ir_node *n)
                        ir_node*  f1    = get_Mux_false(f);
                        if (t == t1) {
                                /* Mux(cond0, x, Mux(cond1, x, y)) -> typical if (cond0 || cond1) x else y */
-                               ir_node* or_     = new_r_Or(block, c0, c1, mode_b);
-                               ir_node* new_mux = new_r_Mux(block, or_, f1, t1, mode);
-                               n   = new_mux;
-                               sel = or_;
-                               f   = f1;
-                               t   = t1;
-                               DBG_OPT_ALGSIM0(oldn, f, FS_OPT_MUX_COMBINE);
+                               ir_node* or_ = new_r_Or(block, c0, c1, mode_b);
+                               DBG_OPT_ALGSIM0(oldn, f1, FS_OPT_MUX_COMBINE);
+                               return new_r_Mux(block, or_, f1, t1, mode);
                        } else if (t == f1) {
                                /* Mux(cond0, x, Mux(cond1, y, x)) */
                                ir_node* not_c1  = new_r_Not(block, c1, mode_b);
                                ir_node* or_     = new_r_Or(block, c0, not_c1, mode_b);
-                               ir_node* new_mux = new_r_Mux(block, or_, t1, f1, mode);
-                               n   = new_mux;
-                               sel = or_;
-                               f   = t1;
-                               t   = f1;
-                               DBG_OPT_ALGSIM0(oldn, f, FS_OPT_MUX_COMBINE);
+                               DBG_OPT_ALGSIM0(oldn, t1, FS_OPT_MUX_COMBINE);
+                               return new_r_Mux(block, or_, t1, f1, mode);
                        }
                }
 
@@ -5871,28 +5771,6 @@ static ir_node *transform_node_Mux(ir_node *n)
                                }
                        }
                }
-
-               /* more normalization: Mux(sel, 0, 1) is simply a conv from the mode_b
-                * value to integer. */
-               if (is_Const(t) && is_Const(f) && mode_is_int(mode)) {
-                       ir_tarval *a = get_Const_tarval(t);
-                       ir_tarval *b = get_Const_tarval(f);
-
-                       if (tarval_is_one(a) && tarval_is_null(b)) {
-                               ir_node *block = get_nodes_block(n);
-                               ir_node *conv  = new_r_Conv(block, sel, mode);
-                               n = conv;
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_MUX_CONV);
-                               return n;
-                       } else if (tarval_is_null(a) && tarval_is_one(b)) {
-                               ir_node *block = get_nodes_block(n);
-                               ir_node *not_  = new_r_Not(block, sel, mode_b);
-                               ir_node *conv  = new_r_Conv(block, not_, mode);
-                               n = conv;
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_MUX_CONV);
-                               return n;
-                       }
-               }
        }
 
        if (is_Cmp(sel) && mode_is_int(mode) && is_cmp_equality_zero(sel)) {
@@ -5989,7 +5867,8 @@ static ir_node *transform_node_Sync(ir_node *n)
                                        ++arity;
                                        break;
                                }
-                               if (get_Sync_pred(n, k) == pred_pred) break;
+                               if (get_Sync_pred(n, k) == pred_pred)
+                                       break;
                        }
                }
        }
@@ -6007,66 +5886,87 @@ static ir_node *transform_node_Sync(ir_node *n)
        return n;
 }
 
+static ir_node *create_load_replacement_tuple(ir_node *n, ir_node *mem,
+                                              ir_node *res)
+{
+       ir_node  *block = get_nodes_block(n);
+       ir_graph *irg   = get_irn_irg(n);
+       ir_node  *in[pn_Load_max+1];
+       size_t    n_in  = 2;
+       in[pn_Load_M]   = mem;
+       in[pn_Load_res] = res;
+       if (ir_throws_exception(n)) {
+               in[pn_Load_X_regular] = new_r_Jmp(block);
+               in[pn_Load_X_except]  = new_r_Bad(irg, mode_X);
+               n_in                  = 4;
+               assert(pn_Load_max == 4);
+       }
+       ir_node  *tuple = new_r_Tuple(block, n_in, in);
+       return tuple;
+}
+
 static ir_node *transform_node_Load(ir_node *n)
 {
+       /* don't touch volatile loads */
+       if (get_Load_volatility(n) == volatility_is_volatile)
+               return n;
+
+       ir_node *ptr = get_Load_ptr(n);
+       const ir_node *confirm;
+       if (value_not_zero(ptr, &confirm) && confirm == NULL) {
+               set_irn_pinned(n, op_pin_state_floats);
+       }
+
        /* if our memory predecessor is a load from the same address, then reuse the
         * previous result */
        ir_node *mem = get_Load_mem(n);
-       ir_node *mem_pred;
-
        if (!is_Proj(mem))
                return n;
-       /* don't touch volatile loads */
-       if (get_Load_volatility(n) == volatility_is_volatile)
-               return n;
-       mem_pred = get_Proj_pred(mem);
+       ir_node *mem_pred = get_Proj_pred(mem);
        if (is_Load(mem_pred)) {
                ir_node *pred_load = mem_pred;
 
                /* conservatively compare the 2 loads. TODO: This could be less strict
                 * with fixup code in some situations (like smaller/bigger modes) */
-               if (get_Load_ptr(pred_load) != get_Load_ptr(n))
+               if (get_Load_ptr(pred_load) != ptr)
                        return n;
                if (get_Load_mode(pred_load) != get_Load_mode(n))
                        return n;
                /* all combinations of aligned/unaligned pred/n should be fine so we do
                 * not compare the unaligned attribute */
-               {
-                       ir_node  *block = get_nodes_block(n);
-                       ir_node  *jmp   = new_r_Jmp(block);
-                       ir_graph *irg   = get_irn_irg(n);
-                       ir_node  *bad   = new_r_Bad(irg, mode_X);
-                       ir_mode  *mode  = get_Load_mode(n);
-                       ir_node  *res   = new_r_Proj(pred_load, mode, pn_Load_res);
-                       ir_node  *in[]  = { mem, res, jmp, bad };
-                       ir_node  *tuple = new_r_Tuple(block, ARRAY_SIZE(in), in);
-                       return tuple;
-               }
+               ir_mode  *mode  = get_Load_mode(n);
+               ir_node  *res   = new_r_Proj(pred_load, mode, pn_Load_res);
+               return create_load_replacement_tuple(n, mem, res);
        } else if (is_Store(mem_pred)) {
                ir_node *pred_store = mem_pred;
                ir_node *value      = get_Store_value(pred_store);
 
-               if (get_Store_ptr(pred_store) != get_Load_ptr(n))
+               if (get_Store_ptr(pred_store) != ptr)
                        return n;
                if (get_irn_mode(value) != get_Load_mode(n))
                        return n;
                /* all combinations of aligned/unaligned pred/n should be fine so we do
                 * not compare the unaligned attribute */
-               {
-                       ir_node  *block = get_nodes_block(n);
-                       ir_node  *jmp   = new_r_Jmp(block);
-                       ir_graph *irg   = get_irn_irg(n);
-                       ir_node  *bad   = new_r_Bad(irg, mode_X);
-                       ir_node  *res   = value;
-                       ir_node  *in[]  = { mem, res, jmp, bad };
-                       ir_node  *tuple = new_r_Tuple(block, ARRAY_SIZE(in), in);
-                       return tuple;
-               }
+               return create_load_replacement_tuple(n, mem, value);
        }
 
        return n;
 }
 
+static ir_node *transform_node_Store(ir_node *n)
+{
+       /* don't touch volatile stores */
+       if (get_Store_volatility(n) == volatility_is_volatile)
+               return n;
+
+       ir_node *ptr = get_Store_ptr(n);
+       const ir_node *confirm;
+       if (value_not_zero(ptr, &confirm) && confirm == NULL) {
+               set_irn_pinned(n, op_pin_state_floats);
+       }
+       return n;
+}
+
 /**
  * optimize a trampoline Call into a direct Call
  */
@@ -6145,388 +6045,183 @@ static ir_node *transform_node_Call(ir_node *call)
  */
 static ir_node *transform_node(ir_node *n)
 {
-       ir_node *oldn;
-
-       /*
-        * Transform_node is the only "optimizing transformation" that might
-        * return a node with a different opcode. We iterate HERE until fixpoint
-        * to get the final result.
-        */
-       do {
-               oldn = n;
-               if (n->op->ops.transform_node != NULL)
-                       n = n->op->ops.transform_node(n);
-       } while (oldn != n);
-
-       return n;
-}
-
-/**
- * Sets the default transform node operation for an ir_op_ops.
- *
- * @param code   the opcode for the default operation
- * @param ops    the operations initialized
- *
- * @return
- *    The operations.
- */
-static ir_op_ops *firm_set_default_transform_node(ir_opcode code, ir_op_ops *ops)
-{
-#define CASE(a)                                         \
-       case iro_##a:                                       \
-               ops->transform_node      = transform_node_##a;  \
-               break
-#define CASE_PROJ(a)                                         \
-       case iro_##a:                                            \
-               ops->transform_node_Proj = transform_node_Proj_##a;  \
-               break
-#define CASE_PROJ_EX(a)                                      \
-       case iro_##a:                                            \
-               ops->transform_node      = transform_node_##a;       \
-               ops->transform_node_Proj = transform_node_Proj_##a;  \
-               break
-
-       switch (code) {
-       CASE(Add);
-       CASE(And);
-       CASE(Block);
-       CASE(Call);
-       CASE(Cmp);
-       CASE(Cond);
-       CASE(Conv);
-       CASE(End);
-       CASE(Eor);
-       CASE(Minus);
-       CASE(Mul);
-       CASE(Mux);
-       CASE(Not);
-       CASE(Or);
-       CASE(Phi);
-       CASE(Proj);
-       CASE(Rotl);
-       CASE(Sel);
-       CASE(Shl);
-       CASE(Shr);
-       CASE(Shrs);
-       CASE(Sub);
-       CASE(Switch);
-       CASE(Sync);
-       CASE_PROJ(Bound);
-       CASE_PROJ(CopyB);
-       CASE_PROJ(Store);
-       CASE_PROJ_EX(Div);
-       CASE_PROJ_EX(Load);
-       CASE_PROJ_EX(Mod);
-       default:
-               break;
-       }
-
-       return ops;
-#undef CASE_PROJ_EX
-#undef CASE_PROJ
-#undef CASE
-}
-
-
-/* **************** Common Subexpression Elimination **************** */
-
-/** The size of the hash table used, should estimate the number of nodes
-    in a graph. */
-#define N_IR_NODES 512
-
-/** Compares two exception attributes */
-static int node_cmp_exception(const ir_node *a, const ir_node *b)
-{
-       const except_attr *ea = &a->attr.except;
-       const except_attr *eb = &b->attr.except;
-       return ea->pin_state != eb->pin_state;
-}
-
-/** Compares the attributes of two Const nodes. */
-static int node_cmp_attr_Const(const ir_node *a, const ir_node *b)
-{
-       return get_Const_tarval(a) != get_Const_tarval(b);
-}
-
-/** Compares the attributes of two Proj nodes. */
-static int node_cmp_attr_Proj(const ir_node *a, const ir_node *b)
-{
-       return a->attr.proj.proj != b->attr.proj.proj;
-}
-
-/** Compares the attributes of two Alloc nodes. */
-static int node_cmp_attr_Alloc(const ir_node *a, const ir_node *b)
-{
-       const alloc_attr *pa = &a->attr.alloc;
-       const alloc_attr *pb = &b->attr.alloc;
-       if (pa->where != pb->where || pa->type != pb->type)
-               return 1;
-       return node_cmp_exception(a, b);
-}
-
-/** Compares the attributes of two Free nodes. */
-static int node_cmp_attr_Free(const ir_node *a, const ir_node *b)
-{
-       const free_attr *pa = &a->attr.free;
-       const free_attr *pb = &b->attr.free;
-       return (pa->where != pb->where) || (pa->type != pb->type);
-}
-
-/** Compares the attributes of two SymConst nodes. */
-static int node_cmp_attr_SymConst(const ir_node *a, const ir_node *b)
-{
-       const symconst_attr *pa = &a->attr.symc;
-       const symconst_attr *pb = &b->attr.symc;
-       return (pa->kind       != pb->kind)
-           || (pa->sym.type_p != pb->sym.type_p);
-}
-
-/** Compares the attributes of two Call nodes. */
-static int node_cmp_attr_Call(const ir_node *a, const ir_node *b)
-{
-       const call_attr *pa = &a->attr.call;
-       const call_attr *pb = &b->attr.call;
-       if (pa->type != pb->type || pa->tail_call != pb->tail_call)
-               return 1;
-       return node_cmp_exception(a, b);
-}
-
-/** Compares the attributes of two Sel nodes. */
-static int node_cmp_attr_Sel(const ir_node *a, const ir_node *b)
-{
-       const ir_entity *a_ent = get_Sel_entity(a);
-       const ir_entity *b_ent = get_Sel_entity(b);
-       return a_ent != b_ent;
-}
-
-/** Compares the attributes of two Phi nodes. */
-static int node_cmp_attr_Phi(const ir_node *a, const ir_node *b)
-{
-       /* we can only enter this function if both nodes have the same number of inputs,
-          hence it is enough to check if one of them is a Phi0 */
-       if (is_Phi0(a)) {
-               /* check the Phi0 pos attribute */
-               return a->attr.phi.u.pos != b->attr.phi.u.pos;
-       }
-       return 0;
-}
-
-/** Compares the attributes of two Conv nodes. */
-static int node_cmp_attr_Conv(const ir_node *a, const ir_node *b)
-{
-       return get_Conv_strict(a) != get_Conv_strict(b);
-}
-
-/** Compares the attributes of two Cast nodes. */
-static int node_cmp_attr_Cast(const ir_node *a, const ir_node *b)
-{
-       return get_Cast_type(a) != get_Cast_type(b);
-}
-
-/** Compares the attributes of two Load nodes. */
-static int node_cmp_attr_Load(const ir_node *a, const ir_node *b)
-{
-       if (get_Load_volatility(a) == volatility_is_volatile ||
-           get_Load_volatility(b) == volatility_is_volatile)
-               /* NEVER do CSE on volatile Loads */
-               return 1;
-       /* do not CSE Loads with different alignment. Be conservative. */
-       if (get_Load_unaligned(a) != get_Load_unaligned(b))
-               return 1;
-       if (get_Load_mode(a) != get_Load_mode(b))
-               return 1;
-       return node_cmp_exception(a, b);
-}
-
-/** Compares the attributes of two Store nodes. */
-static int node_cmp_attr_Store(const ir_node *a, const ir_node *b)
-{
-       /* do not CSE Stores with different alignment. Be conservative. */
-       if (get_Store_unaligned(a) != get_Store_unaligned(b))
-               return 1;
-       /* NEVER do CSE on volatile Stores */
-       if (get_Store_volatility(a) == volatility_is_volatile ||
-           get_Store_volatility(b) == volatility_is_volatile)
-               return 1;
-       return node_cmp_exception(a, b);
-}
-
-static int node_cmp_attr_CopyB(const ir_node *a, const ir_node *b)
-{
-       if (get_CopyB_type(a) != get_CopyB_type(b))
-               return 1;
-
-       return node_cmp_exception(a, b);
-}
-
-static int node_cmp_attr_Bound(const ir_node *a, const ir_node *b)
-{
-       return node_cmp_exception(a, b);
-}
-
-/** Compares the attributes of two Div nodes. */
-static int node_cmp_attr_Div(const ir_node *a, const ir_node *b)
-{
-       const div_attr *ma = &a->attr.div;
-       const div_attr *mb = &b->attr.div;
-       if (ma->resmode != mb->resmode || ma->no_remainder  != mb->no_remainder)
-               return 1;
-       return node_cmp_exception(a, b);
-}
-
-/** Compares the attributes of two Mod nodes. */
-static int node_cmp_attr_Mod(const ir_node *a, const ir_node *b)
-{
-       const mod_attr *ma = &a->attr.mod;
-       const mod_attr *mb = &b->attr.mod;
-       if (ma->resmode != mb->resmode)
-               return 1;
-       return node_cmp_exception(a, b);
-}
-
-static int node_cmp_attr_Cmp(const ir_node *a, const ir_node *b)
-{
-       const cmp_attr *ma = &a->attr.cmp;
-       const cmp_attr *mb = &b->attr.cmp;
-       return ma->relation != mb->relation;
-}
-
-/** Compares the attributes of two Confirm nodes. */
-static int node_cmp_attr_Confirm(const ir_node *a, const ir_node *b)
-{
-       const confirm_attr *ma = &a->attr.confirm;
-       const confirm_attr *mb = &b->attr.confirm;
-       return ma->relation != mb->relation;
-}
-
-/** Compares the attributes of two Builtin nodes. */
-static int node_cmp_attr_Builtin(const ir_node *a, const ir_node *b)
-{
-       if (get_Builtin_kind(a) != get_Builtin_kind(b))
-               return 1;
-       if (get_Builtin_type(a) != get_Builtin_type(b))
-               return 1;
-       return node_cmp_exception(a, b);
-}
-
-/** Compares the attributes of two ASM nodes. */
-static int node_cmp_attr_ASM(const ir_node *a, const ir_node *b)
-{
-       int i, n;
-       const ir_asm_constraint *ca;
-       const ir_asm_constraint *cb;
-       ident **cla, **clb;
-
-       if (get_ASM_text(a) != get_ASM_text(b))
-               return 1;
+       ir_node *old_n;
+       unsigned iro;
+restart:
+       old_n = n;
+       iro   = get_irn_opcode_(n);
+       /* constant expression evaluation / constant folding */
+       if (get_opt_constant_folding()) {
+               /* neither constants nor Tuple values can be evaluated */
+               if (iro != iro_Const && get_irn_mode(n) != mode_T) {
+                       /* try to evaluate */
+                       ir_tarval *tv = computed_value(n);
+                       if (tv != tarval_bad) {
+                               /* evaluation was successful -- replace the node. */
+                               ir_graph *irg = get_irn_irg(n);
 
-       /* Should we really check the constraints here? Should be better, but is strange. */
-       n = get_ASM_n_input_constraints(a);
-       if (n != get_ASM_n_input_constraints(b))
-               return 1;
+                               n = new_r_Const(irg, tv);
 
-       ca = get_ASM_input_constraints(a);
-       cb = get_ASM_input_constraints(b);
-       for (i = 0; i < n; ++i) {
-               if (ca[i].pos != cb[i].pos || ca[i].constraint != cb[i].constraint
-                   || ca[i].mode != cb[i].mode)
-                       return 1;
+                               DBG_OPT_CSTEVAL(old_n, n);
+                               return n;
+                       }
+               }
        }
 
-       n = get_ASM_n_output_constraints(a);
-       if (n != get_ASM_n_output_constraints(b))
-               return 1;
-
-       ca = get_ASM_output_constraints(a);
-       cb = get_ASM_output_constraints(b);
-       for (i = 0; i < n; ++i) {
-               if (ca[i].pos != cb[i].pos || ca[i].constraint != cb[i].constraint
-                   || ca[i].mode != cb[i].mode)
-                       return 1;
+       /* remove unnecessary nodes */
+       if (get_opt_constant_folding() ||
+               (iro == iro_Phi)  ||   /* always optimize these nodes. */
+               (iro == iro_Id)   ||   /* ... */
+               (iro == iro_Proj) ||   /* ... */
+               (iro == iro_Block)) {  /* Flags tested local. */
+               n = equivalent_node(n);
+               if (n != old_n)
+                       goto restart;
        }
 
-       n = get_ASM_n_clobbers(a);
-       if (n != get_ASM_n_clobbers(b))
-               return 1;
-
-       cla = get_ASM_clobbers(a);
-       clb = get_ASM_clobbers(b);
-       for (i = 0; i < n; ++i) {
-               if (cla[i] != clb[i])
-                       return 1;
+       /* Some more constant expression evaluation. */
+       if (get_opt_algebraic_simplification() ||
+               (iro == iro_Cond) ||
+               (iro == iro_Proj)) {    /* Flags tested local. */
+               if (n->op->ops.transform_node != NULL) {
+                       n = n->op->ops.transform_node(n);
+                       if (n != old_n) {
+                               goto restart;
+                       }
+               }
        }
 
-       return node_cmp_exception(a, b);
-}
-
-/** Compares the inexistent attributes of two Dummy nodes. */
-static int node_cmp_attr_Dummy(const ir_node *a, const ir_node *b)
-{
-       (void) a;
-       (void) b;
-       /* Dummy nodes never equal by definition */
-       return 1;
+       return n;
 }
 
-static int node_cmp_attr_InstOf(const ir_node *a, const ir_node *b)
-{
-       if (get_InstOf_type(a) != get_InstOf_type(b))
-               return 1;
-       return node_cmp_exception(a, b);
+static void register_computed_value_func(ir_op *op, computed_value_func func)
+{
+       assert(op->ops.computed_value == NULL || op->ops.computed_value == func);
+       op->ops.computed_value = func;
+}
+
+static void register_computed_value_func_proj(ir_op *op,
+                                              computed_value_func func)
+{
+       assert(op->ops.computed_value_Proj == NULL
+           || op->ops.computed_value_Proj == func);
+       op->ops.computed_value_Proj = func;
+}
+
+static void register_equivalent_node_func(ir_op *op, equivalent_node_func func)
+{
+       assert(op->ops.equivalent_node == NULL || op->ops.equivalent_node == func);
+       op->ops.equivalent_node = func;
+}
+
+static void register_equivalent_node_func_proj(ir_op *op,
+                                               equivalent_node_func func)
+{
+       assert(op->ops.equivalent_node_Proj == NULL
+           || op->ops.equivalent_node_Proj == func);
+       op->ops.equivalent_node_Proj = func;
+}
+
+static void register_transform_node_func(ir_op *op, transform_node_func func)
+{
+       assert(op->ops.transform_node == NULL || op->ops.transform_node == func);
+       op->ops.transform_node = func;
+}
+
+static void register_transform_node_func_proj(ir_op *op,
+                                              transform_node_func func)
+{
+       assert(op->ops.transform_node_Proj == NULL
+           || op->ops.transform_node_Proj == func);
+       op->ops.transform_node_Proj = func;
+}
+
+void ir_register_opt_node_ops(void)
+{
+       register_computed_value_func(op_Add,      computed_value_Add);
+       register_computed_value_func(op_And,      computed_value_And);
+       register_computed_value_func(op_Cmp,      computed_value_Cmp);
+       register_computed_value_func(op_Confirm,  computed_value_Confirm);
+       register_computed_value_func(op_Const,    computed_value_Const);
+       register_computed_value_func(op_Conv,     computed_value_Conv);
+       register_computed_value_func(op_Eor,      computed_value_Eor);
+       register_computed_value_func(op_Minus,    computed_value_Minus);
+       register_computed_value_func(op_Mul,      computed_value_Mul);
+       register_computed_value_func(op_Mux,      computed_value_Mux);
+       register_computed_value_func(op_Not,      computed_value_Not);
+       register_computed_value_func(op_Or,       computed_value_Or);
+       register_computed_value_func(op_Proj,     computed_value_Proj);
+       register_computed_value_func(op_Rotl,     computed_value_Rotl);
+       register_computed_value_func(op_Shl,      computed_value_Shl);
+       register_computed_value_func(op_Shr,      computed_value_Shr);
+       register_computed_value_func(op_Shrs,     computed_value_Shrs);
+       register_computed_value_func(op_Sub,      computed_value_Sub);
+       register_computed_value_func(op_SymConst, computed_value_SymConst);
+       register_computed_value_func_proj(op_Div, computed_value_Proj_Div);
+       register_computed_value_func_proj(op_Mod, computed_value_Proj_Mod);
+
+       register_equivalent_node_func(op_Add,     equivalent_node_Add);
+       register_equivalent_node_func(op_And,     equivalent_node_And);
+       register_equivalent_node_func(op_Confirm, equivalent_node_Confirm);
+       register_equivalent_node_func(op_Conv,    equivalent_node_Conv);
+       register_equivalent_node_func(op_Eor,     equivalent_node_Eor);
+       register_equivalent_node_func(op_Id,      equivalent_node_Id);
+       register_equivalent_node_func(op_Minus,   equivalent_node_involution);
+       register_equivalent_node_func(op_Mul,     equivalent_node_Mul);
+       register_equivalent_node_func(op_Mux,     equivalent_node_Mux);
+       register_equivalent_node_func(op_Not,     equivalent_node_involution);
+       register_equivalent_node_func(op_Or,      equivalent_node_Or);
+       register_equivalent_node_func(op_Phi,     equivalent_node_Phi);
+       register_equivalent_node_func(op_Proj,    equivalent_node_Proj);
+       register_equivalent_node_func(op_Rotl,    equivalent_node_left_zero);
+       register_equivalent_node_func(op_Shl,     equivalent_node_left_zero);
+       register_equivalent_node_func(op_Shr,     equivalent_node_left_zero);
+       register_equivalent_node_func(op_Shrs,    equivalent_node_left_zero);
+       register_equivalent_node_func(op_Sub,     equivalent_node_Sub);
+       register_equivalent_node_func_proj(op_CopyB, equivalent_node_Proj_CopyB);
+       register_equivalent_node_func_proj(op_Div,   equivalent_node_Proj_Div);
+       register_equivalent_node_func_proj(op_Tuple, equivalent_node_Proj_Tuple);
+
+       register_transform_node_func(op_Add,    transform_node_Add);
+       register_transform_node_func(op_And,    transform_node_And);
+       register_transform_node_func(op_Block,  transform_node_Block);
+       register_transform_node_func(op_Call,   transform_node_Call);
+       register_transform_node_func(op_Cmp,    transform_node_Cmp);
+       register_transform_node_func(op_Cond,   transform_node_Cond);
+       register_transform_node_func(op_Conv,   transform_node_Conv);
+       register_transform_node_func(op_Div,    transform_node_Div);
+       register_transform_node_func(op_End,    transform_node_End);
+       register_transform_node_func(op_Eor,    transform_node_Eor);
+       register_transform_node_func(op_Load,   transform_node_Load);
+       register_transform_node_func(op_Minus,  transform_node_Minus);
+       register_transform_node_func(op_Mod,    transform_node_Mod);
+       register_transform_node_func(op_Mul,    transform_node_Mul);
+       register_transform_node_func(op_Mux,    transform_node_Mux);
+       register_transform_node_func(op_Not,    transform_node_Not);
+       register_transform_node_func(op_Or,     transform_node_Or);
+       register_transform_node_func(op_Phi,    transform_node_Phi);
+       register_transform_node_func(op_Proj,   transform_node_Proj);
+       register_transform_node_func(op_Rotl,   transform_node_Rotl);
+       register_transform_node_func(op_Shl,    transform_node_Shl);
+       register_transform_node_func(op_Shrs,   transform_node_Shrs);
+       register_transform_node_func(op_Shr,    transform_node_Shr);
+       register_transform_node_func(op_Store,  transform_node_Store);
+       register_transform_node_func(op_Sub,    transform_node_Sub);
+       register_transform_node_func(op_Switch, transform_node_Switch);
+       register_transform_node_func(op_Sync,   transform_node_Sync);
+       register_transform_node_func_proj(op_CopyB, transform_node_Proj_CopyB);
+       register_transform_node_func_proj(op_Div,   transform_node_Proj_Div);
+       register_transform_node_func_proj(op_Load,  transform_node_Proj_Load);
+       register_transform_node_func_proj(op_Mod,   transform_node_Proj_Mod);
+       register_transform_node_func_proj(op_Store, transform_node_Proj_Store);
 }
 
-/**
- * Set the default node attribute compare operation for an ir_op_ops.
- *
- * @param code   the opcode for the default operation
- * @param ops    the operations initialized
- *
- * @return
- *    The operations.
- */
-static ir_op_ops *firm_set_default_node_cmp_attr(ir_opcode code, ir_op_ops *ops)
-{
-#define CASE(a)                              \
-       case iro_##a:                              \
-               ops->node_cmp_attr  = node_cmp_attr_##a; \
-               break
-
-       switch (code) {
-       CASE(ASM);
-       CASE(Alloc);
-       CASE(Bound);
-       CASE(Builtin);
-       CASE(Call);
-       CASE(Cast);
-       CASE(Cmp);
-       CASE(Confirm);
-       CASE(Const);
-       CASE(Conv);
-       CASE(CopyB);
-       CASE(Div);
-       CASE(Dummy);
-       CASE(Free);
-       CASE(InstOf);
-       CASE(Load);
-       CASE(Mod);
-       CASE(Phi);
-       CASE(Proj);
-       CASE(Sel);
-       CASE(Store);
-       CASE(SymConst);
-       default:
-               /* leave NULL */
-               break;
-       }
+/* **************** Common Subexpression Elimination **************** */
 
-       return ops;
-#undef CASE
-}
+/** The size of the hash table used, should estimate the number of nodes
+    in a graph. */
+#define N_IR_NODES 512
 
-/*
- * Compare function for two nodes in the value table. Gets two
- * nodes as parameters.  Returns 0 if the nodes are a Common Sub Expression.
- */
 int identities_cmp(const void *elt, const void *key)
 {
        ir_node *a = (ir_node *)elt;
@@ -6549,7 +6244,7 @@ int identities_cmp(const void *elt, const void *key)
 
        if (get_irn_pinned(a) == op_pin_state_pinned) {
                /* for pinned nodes, the block inputs must be equal */
-               if (get_irn_n(a, -1) != get_irn_n(b, -1))
+               if (get_nodes_block(a) != get_nodes_block(b))
                        return 1;
        } else {
                ir_node *block_a = get_nodes_block(a);
@@ -6567,6 +6262,10 @@ int identities_cmp(const void *elt, const void *key)
                        if (!block_dominates(block_a, block_b)
                            && !block_dominates(block_b, block_a))
                            return 1;
+                       /* respect the workaround rule: do not move nodes which are only
+                        * held by keepalive edges */
+                       if (only_used_by_keepalive(a) || only_used_by_keepalive(b))
+                               return 1;
                }
        }
 
@@ -6591,17 +6290,11 @@ int identities_cmp(const void *elt, const void *key)
        return 0;
 }
 
-/*
- * Calculate a hash value of a node.
- *
- * @param node  The IR-node
- */
 unsigned ir_node_hash(const ir_node *node)
 {
        return node->op->ops.hash(node);
 }
 
-
 void new_identities(ir_graph *irg)
 {
        if (irg->value_table != NULL)
@@ -6615,8 +6308,15 @@ void del_identities(ir_graph *irg)
                del_pset(irg->value_table);
 }
 
-/* Normalize a node by putting constants (and operands with larger
- * node index) on the right (operator side). */
+static int cmp_node_nr(const void *a, const void *b)
+{
+       ir_node **p1 = (ir_node**)a;
+       ir_node **p2 = (ir_node**)b;
+       long      n1 = get_irn_node_nr(*p1);
+       long      n2 = get_irn_node_nr(*p2);
+       return (n1>n2) - (n1<n2);
+}
+
 void ir_normalize_node(ir_node *n)
 {
        if (is_op_commutative(get_irn_op(n))) {
@@ -6632,19 +6332,33 @@ void ir_normalize_node(ir_node *n)
                        set_binop_right(n, l);
                        hook_normalize(n);
                }
+       } else if (is_Sync(n)) {
+               /* we assume that most of the time the inputs of a Sync node are already
+                * sorted, so check this first as a shortcut */
+               bool           ins_sorted = true;
+               int            arity      = get_irn_arity(n);
+               const ir_node *last       = get_irn_n(n, 0);
+               int      i;
+               for (i = 1; i < arity; ++i) {
+                       const ir_node *node = get_irn_n(n, i);
+                       if (get_irn_node_nr(node) < get_irn_node_nr(last)) {
+                               ins_sorted = false;
+                               break;
+                       }
+                       last = node;
+               }
+
+               if (!ins_sorted) {
+                       ir_node **ins     = get_irn_in(n)+1;
+                       ir_node **new_ins = XMALLOCN(ir_node*, arity);
+                       memcpy(new_ins, ins, arity*sizeof(ins[0]));
+                       qsort(new_ins, arity, sizeof(new_ins[0]), cmp_node_nr);
+                       set_irn_in(n, arity, new_ins);
+                       xfree(new_ins);
+               }
        }
 }
 
-/*
- * Return the canonical node computing the same value as n.
- * Looks up the node in a hash table, enters it in the table
- * if it isn't there yet.
- *
- * @param n            the node to look up
- *
- * @return a node that computes the same value as n or n if no such
- *         node could be found
- */
 ir_node *identify_remember(ir_node *n)
 {
        ir_graph *irg         = get_irn_irg(n);
@@ -6685,7 +6399,6 @@ static inline ir_node *identify_cons(ir_node *n)
        return n;
 }
 
-/* Add a node to the identities value table. */
 void add_identities(ir_node *node)
 {
        if (!get_opt_cse())
@@ -6696,26 +6409,17 @@ void add_identities(ir_node *node)
        identify_remember(node);
 }
 
-/* Visit each node in the value table of a graph. */
 void visit_all_identities(ir_graph *irg, irg_walk_func visit, void *env)
 {
-       ir_node  *node;
        ir_graph *rem = current_ir_graph;
 
        current_ir_graph = irg;
-       foreach_pset(irg->value_table, ir_node*, node) {
+       foreach_pset(irg->value_table, ir_node, node) {
                visit(node, env);
        }
        current_ir_graph = rem;
 }
 
-/**
- * These optimizations deallocate nodes from the obstack.
- * It can only be called if it is guaranteed that no other nodes
- * reference this one, i.e., right after construction of a node.
- *
- * @param n   The node to optimize
- */
 ir_node *optimize_node(ir_node *n)
 {
        ir_node   *oldn = n;
@@ -6792,12 +6496,13 @@ ir_node *optimize_node(ir_node *n)
           free the node. */
        iro = get_irn_opcode(n);
        if (get_opt_algebraic_simplification() ||
-           (iro == iro_Cond) ||
-           (iro == iro_Proj))     /* Flags tested local. */
+               (iro == iro_Cond) ||
+               (iro == iro_Proj)) {    /* Flags tested local. */
                n = transform_node(n);
+       }
 
        /* Now we have a legal, useful node. Enter it in hash table for CSE */
-       if (get_opt_cse() && (get_irn_opcode(n) != iro_Block)) {
+       if (get_opt_cse()) {
                ir_node *o = n;
                n = identify_remember(o);
                if (o != n)
@@ -6807,75 +6512,40 @@ ir_node *optimize_node(ir_node *n)
        return n;
 }
 
-
-/**
- * These optimizations never deallocate nodes (in place).  This can cause dead
- * nodes lying on the obstack.  Remove these by a dead node elimination,
- * i.e., a copying garbage collection.
- */
 ir_node *optimize_in_place_2(ir_node *n)
 {
-       ir_tarval *tv;
-       ir_node   *oldn = n;
-       unsigned   iro  = get_irn_opcode(n);
-
        if (!get_opt_optimize() && !is_Phi(n)) return n;
 
-       if (iro == iro_Deleted)
+       if (is_Deleted(n))
                return n;
 
-       /* constant expression evaluation / constant folding */
-       if (get_opt_constant_folding()) {
-               /* neither constants nor Tuple values can be evaluated */
-               if (iro != iro_Const && get_irn_mode(n) != mode_T) {
-                       /* try to evaluate */
-                       tv = computed_value(n);
-                       if (tv != tarval_bad) {
-                               /* evaluation was successful -- replace the node. */
-                               ir_graph *irg = get_irn_irg(n);
-
-                               n = new_r_Const(irg, tv);
-
-                               DBG_OPT_CSTEVAL(oldn, n);
-                               return n;
-                       }
-               }
-       }
-
-       /* remove unnecessary nodes */
-       if (get_opt_constant_folding() ||
-           (iro == iro_Phi)  ||   /* always optimize these nodes. */
-           (iro == iro_Id)   ||   /* ... */
-           (iro == iro_Proj) ||   /* ... */
-           (iro == iro_Block)  )  /* Flags tested local. */
-               n = equivalent_node(n);
-
        /** common subexpression elimination **/
        /* Checks whether n is already available. */
-       /* The block input is used to distinguish different subexpressions.  Right
-          now all nodes are op_pin_state_pinned to blocks, i.e., the cse only finds common
-          subexpressions within a block. */
+       /* The block input is used to distinguish different subexpressions.
+        * Right now all nodes are op_pin_state_pinned to blocks, i.e., the cse
+        * only finds common subexpressions within a block. */
        if (get_opt_cse()) {
                ir_node *o = n;
-               n = identify_remember(o);
-               if (o != n)
+               n = identify_remember(n);
+               if (n != o) {
                        DBG_OPT_CSE(o, n);
+                       /* we have another existing node now, we do not optimize it here */
+                       return n;
+               }
        }
 
-       /* Some more constant expression evaluation. */
-       iro = get_irn_opcode(n);
-       if (get_opt_constant_folding() ||
-               (iro == iro_Cond) ||
-               (iro == iro_Proj))     /* Flags tested local. */
-               n = transform_node(n);
+       n = transform_node(n);
 
        /* Now we can verify the node, as it has no dead inputs any more. */
        irn_verify(n);
 
        /* Now we have a legal, useful node. Enter it in hash table for cse.
-          Blocks should be unique anyways.  (Except the successor of start:
-          is cse with the start block!) */
-       if (get_opt_cse() && (get_irn_opcode(n) != iro_Block)) {
+        *
+        * Note: This is only necessary because some of the optimisations
+        * operate in-place (set_XXX_bla, turn_into_tuple, ...) which is considered
+        * bad practice and should be fixed sometime.
+        */
+       if (get_opt_cse()) {
                ir_node *o = n;
                n = identify_remember(o);
                if (o != n)
@@ -6885,94 +6555,15 @@ ir_node *optimize_in_place_2(ir_node *n)
        return n;
 }
 
-/**
- * Wrapper for external use, set proper status bits after optimization.
- */
 ir_node *optimize_in_place(ir_node *n)
 {
        ir_graph *irg = get_irn_irg(n);
-       /* Handle graph state */
-       assert(get_irg_phase_state(irg) != phase_building);
 
        if (get_opt_global_cse())
                set_irg_pinned(irg, op_pin_state_floats);
 
        /* FIXME: Maybe we could also test whether optimizing the node can
           change the control graph. */
-       clear_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_DOMINANCE);
+       clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
        return optimize_in_place_2(n);
 }
-
-/**
- * Calculate a hash value of a Const node.
- */
-static unsigned hash_Const(const ir_node *node)
-{
-       unsigned h;
-
-       /* special value for const, as they only differ in their tarval. */
-       h = HASH_PTR(node->attr.con.tarval);
-
-       return h;
-}
-
-/**
- * Calculate a hash value of a SymConst node.
- */
-static unsigned hash_SymConst(const ir_node *node)
-{
-       unsigned h;
-
-       /* all others are pointers */
-       h = HASH_PTR(node->attr.symc.sym.type_p);
-
-       return h;
-}
-
-/**
- * Set the default hash operation in an ir_op_ops.
- *
- * @param code   the opcode for the default operation
- * @param ops    the operations initialized
- *
- * @return
- *    The operations.
- */
-static ir_op_ops *firm_set_default_hash(unsigned code, ir_op_ops *ops)
-{
-#define CASE(a)                                    \
-       case iro_##a:                                  \
-               ops->hash  = hash_##a; \
-               break
-
-       /* hash function already set */
-       if (ops->hash != NULL)
-               return ops;
-
-       switch (code) {
-       CASE(Const);
-       CASE(SymConst);
-       default:
-               /* use input/mode default hash if no function was given */
-               ops->hash = firm_default_hash;
-       }
-
-       return ops;
-#undef CASE
-}
-
-/*
- * Sets the default operation for an ir_ops.
- */
-ir_op_ops *firm_set_default_operations(unsigned code, ir_op_ops *ops)
-{
-       ops = firm_set_default_hash(code, ops);
-       ops = firm_set_default_computed_value(code, ops);
-       ops = firm_set_default_equivalent_node(code, ops);
-       ops = firm_set_default_transform_node(code, ops);
-       ops = firm_set_default_node_cmp_attr(code, ops);
-       ops = firm_set_default_get_type_attr(code, ops);
-       ops = firm_set_default_get_entity_attr(code, ops);
-
-       return ops;
-}