added -(x >>u 31) and -(x >>s 31)
[libfirm] / ir / ir / iropt.c
index 62f43dd..02ed4e8 100644 (file)
@@ -191,19 +191,25 @@ static tarval *computed_value_Minus(ir_node *n) {
 static tarval *computed_value_Mul(ir_node *n) {
        ir_node *a = get_Mul_left(n);
        ir_node *b = get_Mul_right(n);
+       ir_mode *mode;
 
        tarval *ta = value_of(a);
        tarval *tb = value_of(b);
 
-       if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
+       mode = get_irn_mode(n);
+       if (mode != get_irn_mode(a)) {
+               /* n * n = 2n bit multiplication */
+               ta = tarval_convert_to(ta, mode);
+               tb = tarval_convert_to(tb, mode);
+       }
+
+       if (ta != tarval_bad && tb != tarval_bad) {
                return tarval_mul(ta, tb);
        } else {
-       /* a*0 = 0 or 0*b = 0:
-          calls computed_value recursive and returns the 0 with proper
-          mode. */
-               if ((ta != tarval_bad) && (ta == get_mode_null(get_tarval_mode(ta))))
+               /* a*0 = 0 or 0*b = 0 */
+               if (ta == get_mode_null(mode))
                        return ta;
-               if ((tb != tarval_bad) && (tb == get_mode_null(get_tarval_mode(tb))))
+               if (tb == get_mode_null(mode))
                        return tb;
        }
        return tarval_bad;
@@ -1008,15 +1014,19 @@ static ir_node *equivalent_node_idempotent_unop(ir_node *n) {
 static ir_node *equivalent_node_Mul(ir_node *n) {
        ir_node *oldn = n;
        ir_node *a = get_Mul_left(n);
-       ir_node *b = get_Mul_right(n);
 
-       /* Mul is commutative and has again an other neutral element. */
-       if (classify_tarval(value_of(a)) == TV_CLASSIFY_ONE) {
-               n = b;
-               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
-       } else if (classify_tarval(value_of(b)) == TV_CLASSIFY_ONE) {
-               n = a;
-               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
+       /* we can handle here only the n * n = n bit cases */
+       if (get_irn_mode(n) == get_irn_mode(a)) {
+               ir_node *b = get_Mul_right(n);
+
+               /* Mul is commutative and has again an other neutral element. */
+               if (classify_tarval(value_of(a)) == TV_CLASSIFY_ONE) {
+                       n = b;
+                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
+               } else if (classify_tarval(value_of(b)) == TV_CLASSIFY_ONE) {
+                       n = a;
+                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
+               }
        }
        return n;
 }  /* equivalent_node_Mul */
@@ -1111,7 +1121,7 @@ static ir_node *equivalent_node_Or(ir_node *n) {
 }  /* equivalent_node_Or */
 
 /**
- * Optimize a & 0b1...1 = 0b1...1 & a =  a & a = a.
+ * Optimize a & 0b1...1 = 0b1...1 & a = a & a = (a|X) & a = a.
  */
 static ir_node *equivalent_node_And(ir_node *n) {
        ir_node *oldn = n;
@@ -1122,13 +1132,35 @@ static ir_node *equivalent_node_And(ir_node *n) {
        if (a == b) {
                n = a;    /* And has it's own neutral element */
                DBG_OPT_ALGSIM0(oldn, n, FS_OPT_AND);
-       } else if (classify_tarval(value_of(a)) == TV_CLASSIFY_ALL_ONE) {
+               return n;
+       }
+       if (classify_tarval(value_of(a)) == TV_CLASSIFY_ALL_ONE) {
                n = b;
                DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_AND);
-       } else if (classify_tarval(value_of(b)) == TV_CLASSIFY_ALL_ONE) {
+               return n;
+       }
+       if (classify_tarval(value_of(b)) == TV_CLASSIFY_ALL_ONE) {
                n = a;
                DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_AND);
+               return n;
+       }
+       if (is_Or(a)) {
+               if (b == get_Or_left(a) || b == get_Or_right(a)) {
+                       /* (a|X) & a */
+                       n = b;
+                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_AND);
+                       return n;
+               }
+       }
+       if (is_Or(b)) {
+               if (a == get_Or_left(b) || a == get_Or_right(b)) {
+                       /* a & (a|X) */
+                       n = a;
+                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_AND);
+                       return n;
+               }
        }
+
        return n;
 }  /* equivalent_node_And */
 
@@ -1665,30 +1697,6 @@ static ir_op_ops *firm_set_default_equivalent_node(ir_opcode code, ir_op_ops *op
 #undef CASE
 }  /* firm_set_default_equivalent_node */
 
-/**
- * Do node specific optimizations of nodes predecessors.
- */
-static void optimize_preds(ir_node *n) {
-       switch (get_irn_opcode(n)) {
-
-       case iro_Cmp: { /* We don't want Cast as input to Cmp. */
-               ir_node *a = get_Cmp_left(n), *b = get_Cmp_right(n);
-
-               if (get_irn_op(a) == op_Cast) {
-                       a = get_Cast_op(a);
-                       set_Cmp_left(n, a);
-               }
-               if (get_irn_op(b) == op_Cast) {
-                       b = get_Cast_op(b);
-                       set_Cmp_right(n, b);
-               }
-               break;
-       }
-
-       default: break;
-       } /* end switch */
-}  /* optimize_preds */
-
 /**
  * Returns non-zero if a node is a Phi node
  * with all predecessors constant.
@@ -1873,18 +1881,17 @@ static ir_node *transform_node_AddSub(ir_node *n) {
     return c;                                               \
   }
 
-#define HANDLE_UNOP_PHI(op,a,c)                 \
-  c = NULL;                                     \
-  if (is_const_Phi(a)) {                        \
-    /* check for Op(Phi) */                     \
-    c = apply_unop_on_phi(a, op);               \
-  }                                             \
-  if (c) {                                      \
-    DBG_OPT_ALGSIM0(oldn, c, FS_OPT_CONST_PHI); \
-    return c;                                   \
+#define HANDLE_UNOP_PHI(op,a,c)                   \
+  c = NULL;                                       \
+  if (is_const_Phi(a)) {                          \
+    /* check for Op(Phi) */                       \
+    c = apply_unop_on_phi(a, op);                 \
+    if (c) {                                      \
+      DBG_OPT_ALGSIM0(oldn, c, FS_OPT_CONST_PHI); \
+      return c;                                   \
+    }                                             \
   }
 
-
 /**
  * Do the AddSub optimization, then Transform
  *   Constant folding on Phi
@@ -1912,7 +1919,8 @@ static ir_node *transform_node_Add(ir_node *n) {
                return n;
 
        if (mode_is_num(mode)) {
-               if (a == b && mode_is_int(mode)) {
+               /* the following code leads to endless recursion when Mul are replaced by a simple instruction chain */
+               if (!get_opt_arch_dep_running() && a == b && mode_is_int(mode)) {
                        ir_node *block = get_irn_n(n, -1);
 
                        n = new_rd_Mul(
@@ -1923,7 +1931,9 @@ static ir_node *transform_node_Add(ir_node *n) {
                                new_r_Const_long(current_ir_graph, block, mode, 2),
                                mode);
                        DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_A_A);
-               } else if (get_irn_op(a) == op_Minus) {
+                       return n;
+               }
+               if (is_Minus(a)) {
                        n = new_rd_Sub(
                                        get_irn_dbg_info(n),
                                        current_ir_graph,
@@ -1932,7 +1942,9 @@ static ir_node *transform_node_Add(ir_node *n) {
                                        get_Minus_op(a),
                                        mode);
                        DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_A_MINUS_B);
-               } else if (get_irn_op(b) == op_Minus) {
+                       return n;
+               }
+               if (is_Minus(b)) {
                        n = new_rd_Sub(
                                        get_irn_dbg_info(n),
                                        current_ir_graph,
@@ -1941,82 +1953,123 @@ static ir_node *transform_node_Add(ir_node *n) {
                                        get_Minus_op(b),
                                        mode);
                        DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_A_MINUS_B);
+                       return n;
                }
-               /* do NOT execute this code if reassociation is enabled, it does the inverse! */
-               else if (!get_opt_reassociation() && get_irn_op(a) == op_Mul) {
-                       ir_node *ma = get_Mul_left(a);
-                       ir_node *mb = get_Mul_right(a);
-
-                       if (b == ma) {
-                               ir_node *blk = get_irn_n(n, -1);
-                               n = new_rd_Mul(
-                                               get_irn_dbg_info(n), current_ir_graph, blk,
-                                               ma,
-                                               new_rd_Add(
-                                                       get_irn_dbg_info(n), current_ir_graph, blk,
-                                                       mb,
-                                                       new_r_Const_long(current_ir_graph, blk, mode, 1),
-                                                       mode),
-                                               mode);
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
-                       } else if (b == mb) {
-                               ir_node *blk = get_irn_n(n, -1);
-                               n = new_rd_Mul(
-                                               get_irn_dbg_info(n), current_ir_graph, blk,
-                                               mb,
-                                               new_rd_Add(
+               if (! get_opt_reassociation()) {
+                       /* do NOT execute this code if reassociation is enabled, it does the inverse! */
+                       if (is_Mul(a)) {
+                               ir_node *ma = get_Mul_left(a);
+                               ir_node *mb = get_Mul_right(a);
+
+                               if (b == ma) {
+                                       ir_node *blk = get_irn_n(n, -1);
+                                       n = new_rd_Mul(
                                                        get_irn_dbg_info(n), current_ir_graph, blk,
                                                        ma,
-                                                       new_r_Const_long(current_ir_graph, blk, mode, 1),
-                                                       mode),
-                                               mode);
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
-                       }
-               }
-               /* do NOT execute this code if reassociation is enabled, it does the inverse! */
-               else if (!get_opt_reassociation() && get_irn_op(b) == op_Mul) {
-                       ir_node *ma = get_Mul_left(b);
-                       ir_node *mb = get_Mul_right(b);
-
-                       if (a == ma) {
-                               ir_node *blk = get_irn_n(n, -1);
-                               n = new_rd_Mul(
-                                               get_irn_dbg_info(n), current_ir_graph, blk,
-                                               ma,
-                                               new_rd_Add(
+                                                       new_rd_Add(
+                                                               get_irn_dbg_info(n), current_ir_graph, blk,
+                                                               mb,
+                                                               new_r_Const_long(current_ir_graph, blk, mode, 1),
+                                                               mode),
+                                                       mode);
+                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
+                                       return n;
+                               } else if (b == mb) {
+                                       ir_node *blk = get_irn_n(n, -1);
+                                       n = new_rd_Mul(
                                                        get_irn_dbg_info(n), current_ir_graph, blk,
                                                        mb,
-                                                       new_r_Const_long(current_ir_graph, blk, mode, 1),
-                                                       mode),
-                                               mode);
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
-                       } else if (a == mb) {
-                               ir_node *blk = get_irn_n(n, -1);
-                               n = new_rd_Mul(
-                                               get_irn_dbg_info(n), current_ir_graph, blk,
-                                               mb,
-                                               new_rd_Add(
+                                                       new_rd_Add(
+                                                               get_irn_dbg_info(n), current_ir_graph, blk,
+                                                               ma,
+                                                               new_r_Const_long(current_ir_graph, blk, mode, 1),
+                                                               mode),
+                                                       mode);
+                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
+                                       return n;
+                               }
+                       }
+                       if (is_Mul(b)) {
+                               ir_node *ma = get_Mul_left(b);
+                               ir_node *mb = get_Mul_right(b);
+
+                               if (a == ma) {
+                                       ir_node *blk = get_irn_n(n, -1);
+                                       n = new_rd_Mul(
                                                        get_irn_dbg_info(n), current_ir_graph, blk,
                                                        ma,
-                                                       new_r_Const_long(current_ir_graph, blk, mode, 1),
-                                                       mode),
-                                               mode);
-                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
+                                                       new_rd_Add(
+                                                               get_irn_dbg_info(n), current_ir_graph, blk,
+                                                               mb,
+                                                               new_r_Const_long(current_ir_graph, blk, mode, 1),
+                                                               mode),
+                                                       mode);
+                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
+                                       return n;
+                               }
+                               if (a == mb) {
+                                       ir_node *blk = get_irn_n(n, -1);
+                                       n = new_rd_Mul(
+                                                       get_irn_dbg_info(n), current_ir_graph, blk,
+                                                       mb,
+                                                       new_rd_Add(
+                                                               get_irn_dbg_info(n), current_ir_graph, blk,
+                                                               ma,
+                                                               new_r_Const_long(current_ir_graph, blk, mode, 1),
+                                                               mode),
+                                                       mode);
+                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_MUL_A_X_A);
+                                       return n;
+                               }
                        }
                }
-               /* Here we rely on constants be on the RIGHT side */
-               else if (get_mode_arithmetic(mode) == irma_twos_complement &&
-                        is_Not(a) && classify_Const(b) == CNST_ONE) {
-                       /* ~x + 1 = -x */
-                       ir_node *op = get_Not_op(a);
-                       ir_node *blk = get_irn_n(n, -1);
-                       n = new_rd_Minus(get_irn_dbg_info(n), current_ir_graph, blk, op, mode);
-                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_NOT_PLUS_1);
+               if (get_mode_arithmetic(mode) == irma_twos_complement) {
+                       /* Here we rely on constants be on the RIGHT side */
+                       if (is_Not(a)) {
+                               ir_node *op = get_Not_op(a);
+
+                               if (classify_Const(b) == CNST_ONE) {
+                                       /* ~x + 1 = -x */
+                                       ir_node *blk = get_irn_n(n, -1);
+                                       n = new_rd_Minus(get_irn_dbg_info(n), current_ir_graph, blk, op, mode);
+                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_NOT_PLUS_1);
+                                       return n;
+                               }
+                               if (op == b) {
+                                       /* ~x + x = -1 */
+                                       ir_node *blk = get_irn_n(n, -1);
+                                       n = new_r_Const(current_ir_graph, blk, mode, get_mode_minus_one(mode));
+                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_X_NOT_X);
+                                       return n;
+                               }
+                       }
+                       if (is_Not(b)) {
+                               ir_node *op = get_Not_op(b);
+
+                               if (op == a) {
+                                       /* ~x + x = -1 */
+                                       ir_node *blk = get_irn_n(n, -1);
+                                       n = new_r_Const(current_ir_graph, blk, mode, get_mode_minus_one(mode));
+                                       DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_X_NOT_X);
+                                       return n;
+                               }
+                       }
                }
        }
        return n;
 }  /* transform_node_Add */
 
+/* returns -cnst */
+static ir_node *const_negate(ir_node *cnst) {
+       tarval   *tv    = tarval_neg(get_Const_tarval(cnst));
+       dbg_info *dbgi  = get_irn_dbg_info(cnst);
+       ir_graph *irg   = get_irn_irg(cnst);
+       ir_node  *block = get_nodes_block(cnst);
+       ir_mode  *mode  = get_irn_mode(cnst);
+       if (tv == tarval_bad) return NULL;
+       return new_rd_Const(dbgi, irg, block, mode, tv);
+}
+
 /**
  * Do the AddSub optimization, then Transform
  *   Constant folding on Phi
@@ -2048,11 +2101,8 @@ restart:
 
        /* Sub(a, Const) -> Add(a, -Const) */
        if (is_Const(b) && get_irn_mode(b) != mode_P) {
-               tarval *tv = get_Const_tarval(b);
-
-               tv = tarval_neg(tv);
-               if(tv != tarval_bad) {
-                       ir_node  *cnst  = new_Const(get_irn_mode(b), tv);
+               ir_node* cnst = const_negate(b);
+               if (cnst != NULL) {
                        ir_node  *block = get_nodes_block(n);
                        dbg_info *dbgi  = get_irn_dbg_info(n);
                        ir_graph *irg   = get_irn_irg(n);
@@ -2062,6 +2112,67 @@ restart:
                }
        }
 
+       if (is_Minus(a)) { /* -a - b -> -(a + b) */
+               ir_graph *irg   = current_ir_graph;
+               dbg_info *dbg   = get_irn_dbg_info(n);
+               ir_node  *block = get_nodes_block(n);
+               ir_node  *left  = get_Minus_op(a);
+               ir_mode  *mode  = get_irn_mode(n);
+               ir_node  *add   = new_rd_Add(dbg, irg, block, left, b, mode);
+               ir_node  *neg   = new_rd_Minus(dbg, irg, block, add, mode);
+               return neg;
+       } else if (is_Minus(b)) { /* a - -b -> a + b */
+               ir_graph *irg   = current_ir_graph;
+               dbg_info *dbg   = get_irn_dbg_info(n);
+               ir_node  *block = get_nodes_block(n);
+               ir_node  *right = get_Minus_op(b);
+               ir_mode  *mode  = get_irn_mode(n);
+               ir_node  *add   = new_rd_Add(dbg, irg, block, a, right, mode);
+               return add;
+       } else if (is_Sub(b)) { /* a - (b - c) -> a + (c - b) */
+               ir_graph *irg     = current_ir_graph;
+               dbg_info *s_dbg   = get_irn_dbg_info(b);
+               ir_node  *s_block = get_nodes_block(b);
+               ir_node  *s_left  = get_Sub_right(b);
+               ir_node  *s_right = get_Sub_left(b);
+               ir_mode  *s_mode  = get_irn_mode(b);
+               ir_node  *sub     = new_rd_Sub(s_dbg, irg, s_block, s_left, s_right, s_mode);
+               dbg_info *a_dbg   = get_irn_dbg_info(n);
+               ir_node  *a_block = get_nodes_block(n);
+               ir_mode  *a_mode  = get_irn_mode(n);
+               ir_node  *add     = new_rd_Add(a_dbg, irg, a_block, a, sub, a_mode);
+               return add;
+       } else if (is_Mul(b)) { /* a - (b * const2) -> a + (b * -const2) */
+               ir_node* m_right = get_Mul_right(b);
+               if (is_Const(m_right)) {
+                       ir_node* cnst2 = const_negate(m_right);
+                       if (cnst2 != NULL) {
+                               ir_graph *irg     = current_ir_graph;
+                               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, irg, m_block, m_left, cnst2, m_mode);
+                               dbg_info *a_dbg   = get_irn_dbg_info(n);
+                               ir_node  *a_block = get_nodes_block(n);
+                               ir_mode  *a_mode  = get_irn_mode(n);
+                               ir_node  *add     = new_rd_Add(a_dbg, irg, a_block, a, mul, a_mode);
+                               return add;
+                       }
+               }
+       }
+
+       /* Beware of Sub(P, P) which cannot be optimized into a simple Minus ... */
+       if (mode_is_num(mode) && mode == get_irn_mode(a) && (classify_Const(a) == CNST_NULL)) {
+               n = new_rd_Minus(
+                               get_irn_dbg_info(n),
+                               current_ir_graph,
+                               get_irn_n(n, -1),
+                               b,
+                               mode);
+               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_0_A);
+               return n;
+       }
        if (is_Add(a)) {
                if (mode_wrap_around(mode)) {
                        ir_node *left  = get_Add_left(a);
@@ -2075,6 +2186,7 @@ restart:
                                }
                                n = right;
                                DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+                               return n;
                        } else if (right == b) {
                                if (mode != get_irn_mode(left)) {
                                        /* This Sub is an effective Cast */
@@ -2082,9 +2194,11 @@ restart:
                                }
                                n = left;
                                DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+                               return n;
                        }
                }
-       } else if (is_Add(b)) {
+       }
+       if (is_Add(b)) {
                if (mode_wrap_around(mode)) {
                        ir_node *left  = get_Add_left(b);
                        ir_node *right = get_Add_right(b);
@@ -2099,6 +2213,7 @@ restart:
                                        n = new_r_Conv(get_irn_irg(n), get_irn_n(n, -1), n, mode);
                                }
                                DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+                               return n;
                        } else if (right == a) {
                                ir_mode *l_mode = get_irn_mode(left);
 
@@ -2108,9 +2223,11 @@ restart:
                                        n = new_r_Conv(get_irn_irg(n), get_irn_n(n, -1), n, mode);
                                }
                                DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+                               return n;
                        }
                }
-       } else if (mode_is_int(mode) && is_Conv(a) && is_Conv(b)) {
+       }
+       if (mode_is_int(mode) && is_Conv(a) && is_Conv(b)) {
                ir_mode *mode = get_irn_mode(a);
 
                if (mode == get_irn_mode(b)) {
@@ -2132,18 +2249,8 @@ restart:
                        }
                }
        }
-       /* Beware of Sub(P, P) which cannot be optimized into a simple Minus ... */
-       else if (mode_is_num(mode) && mode == get_irn_mode(a) && (classify_Const(a) == CNST_NULL)) {
-               n = new_rd_Minus(
-                               get_irn_dbg_info(n),
-                               current_ir_graph,
-                               get_irn_n(n, -1),
-                               b,
-                               mode);
-               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_0_A);
-       }
        /* do NOT execute this code if reassociation is enabled, it does the inverse! */
-       else if (get_opt_reassociation() && get_irn_op(a) == op_Mul) {
+       if (get_opt_reassociation() && get_irn_op(a) == op_Mul) {
                ir_node *ma = get_Mul_left(a);
                ir_node *mb = get_Mul_right(a);
 
@@ -2161,6 +2268,7 @@ restart:
                                                mode),
                                        mode);
                        DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_MUL_A_X_A);
+                       return n;
                } else if (mb == b) {
                        ir_node *blk = get_irn_n(n, -1);
                        n = new_rd_Mul(
@@ -2175,8 +2283,10 @@ restart:
                                                mode),
                                        mode);
                        DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_MUL_A_X_A);
+                       return n;
                }
-       } else if (get_irn_op(a) == op_Sub) {
+       }
+       if (is_Sub(a)) {
                ir_node *x   = get_Sub_left(a);
                ir_node *y   = get_Sub_right(a);
                ir_node *blk = get_irn_n(n, -1);
@@ -2203,13 +2313,70 @@ restart:
 
                add = new_r_Add(current_ir_graph, blk, y, b, mode);
 
-               set_Sub_left(n, x);
-               set_Sub_right(n, add);
-               DBG_OPT_ALGSIM0(n, n, FS_OPT_SUB_SUB_X_Y_Z);
+               n = new_rd_Sub(get_irn_dbg_info(n), current_ir_graph, blk, x, add, mode);
+               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_SUB_X_Y_Z);
+               return n;
+       }
+
+       if (get_mode_arithmetic(mode) == irma_twos_complement) {
+               if (is_Const(a) && is_Not(b)) {
+                       /* c - ~X = X + (c+1) */
+                       tarval *tv = get_Const_tarval(a);
+
+                       tv = tarval_add(tv, get_mode_one(mode));
+                       if (tv != tarval_bad) {
+                               ir_node *blk = get_irn_n(n, -1);
+                               ir_node *c = new_r_Const(current_ir_graph, blk, mode, tv);
+                               n = new_rd_Add(get_irn_dbg_info(n), current_ir_graph, blk, get_Not_op(b), c, mode);
+                               DBG_OPT_ALGSIM0(oldn, n, FS_OPT_SUB_C_NOT_X);
+                               return n;
+                       }
+               }
        }
        return n;
 }  /* transform_node_Sub */
 
+/**
+ * Several transformation done on n*n=2n bits mul.
+ * These transformations must be done here because new nodes may be produced.
+ */
+static ir_node *transform_node_Mul2n(ir_node *n, ir_mode *mode) {
+       ir_node *oldn = n;
+       ir_node *a = get_Mul_left(n);
+       ir_node *b = get_Mul_right(n);
+       tarval *ta = value_of(a);
+       tarval *tb = value_of(b);
+       ir_mode *smode = get_irn_mode(a);
+
+       if (ta == get_mode_one(smode)) {
+               ir_node *blk = get_irn_n(n, -1);
+               n = new_rd_Conv(get_irn_dbg_info(n), current_ir_graph, blk, b, mode);
+               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
+               return n;
+       }
+       else if (ta == get_mode_minus_one(smode)) {
+               ir_node *blk = get_irn_n(n, -1);
+               n = new_rd_Minus(get_irn_dbg_info(n), current_ir_graph, blk, b, smode);
+               n = new_rd_Conv(get_irn_dbg_info(n), current_ir_graph, blk, n, mode);
+               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_MUL_MINUS_1);
+               return n;
+       }
+       if (tb == get_mode_one(smode)) {
+               ir_node *blk = get_irn_n(a, -1);
+               n = new_rd_Conv(get_irn_dbg_info(n), current_ir_graph, blk, a, mode);
+               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
+               return n;
+       }
+       else if (tb == get_mode_minus_one(smode)) {
+               ir_node *blk = get_irn_n(n, -1);
+               n = new_rd_Minus(get_irn_dbg_info(n), current_ir_graph, blk, a, smode);
+               n = new_rd_Conv(get_irn_dbg_info(n), current_ir_graph, blk, n, mode);
+               DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_MUL_MINUS_1);
+               return n;
+       }
+       return n;
+}
+
 /**
  * Transform Mul(a,-1) into -a.
  * Do constant evaluation of Phi nodes.
@@ -2217,13 +2384,18 @@ restart:
  */
 static ir_node *transform_node_Mul(ir_node *n) {
        ir_node *c, *oldn = n;
+       ir_mode *mode = get_irn_mode(n);
        ir_node *a = get_Mul_left(n);
        ir_node *b = get_Mul_right(n);
-       ir_mode *mode;
+
+       if (is_Bad(a) || is_Bad(b))
+               return n;
+
+       if (mode != get_irn_mode(a))
+               return transform_node_Mul2n(n, mode);
 
        HANDLE_BINOP_PHI(tarval_mul, a,b,c);
 
-       mode = get_irn_mode(n);
        if (mode_is_signed(mode)) {
                ir_node *r = NULL;
 
@@ -2237,6 +2409,44 @@ static ir_node *transform_node_Mul(ir_node *n) {
                        return n;
                }
        }
+       if (is_Minus(a)) {
+               if (is_Const(b)) { /* -a * const -> a * -const */
+                       ir_node* cnst = const_negate(b);
+                       if (cnst != NULL) {
+                               set_Mul_left( n, get_Minus_op(a));
+                               set_Mul_right(n, cnst);
+                               return n;
+                       }
+               } else if (is_Minus(b)) { /* -a * -b -> a * b */
+                       set_Mul_left( n, get_Minus_op(a));
+                       set_Mul_right(n, get_Minus_op(b));
+                       return n;
+               } else if (is_Sub(b)) { /* -a * (b - c) -> a * (c - b) */
+                       ir_node  *sub_l = get_Sub_left(b);
+                       ir_node  *sub_r = get_Sub_right(b);
+                       dbg_info *dbgi  = get_irn_dbg_info(b);
+                       ir_graph *irg   = current_ir_graph;
+                       ir_mode  *mode  = get_irn_mode(b);
+                       ir_node  *block = get_nodes_block(b);
+                       ir_node  *new_b = new_rd_Sub(dbgi, irg, block, sub_r, sub_l, mode);
+                       set_Mul_left( n, get_Minus_op(a));
+                       set_Mul_right(n, new_b);
+                       return n;
+               }
+       } else if (is_Minus(b)) {
+               if (is_Sub(a)) { /* (a - b) * -c -> (b - a) * c */
+                       ir_node  *sub_l = get_Sub_left(a);
+                       ir_node  *sub_r = get_Sub_right(a);
+                       dbg_info *dbgi  = get_irn_dbg_info(a);
+                       ir_graph *irg   = current_ir_graph;
+                       ir_mode  *mode  = get_irn_mode(a);
+                       ir_node  *block = get_nodes_block(a);
+                       ir_node  *new_a = new_rd_Sub(dbgi, irg, block, sub_r, sub_l, mode);
+                       set_Mul_left (n, new_a);
+                       set_Mul_right(n, get_Minus_op(b));
+                       return n;
+               }
+       }
        if (get_mode_arithmetic(mode) == irma_ieee754) {
                if (is_Const(a)) {
                        tarval *tv = get_Const_tarval(a);
@@ -2660,7 +2870,6 @@ static ir_node *transform_bitwise_distributive(ir_node *n,
                                set_binop_right(n, c);
                        }
 
-
                        DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_SHIFT_AND);
                        return n;
                }
@@ -2673,14 +2882,14 @@ static ir_node *transform_bitwise_distributive(ir_node *n,
  * Transform an And.
  */
 static ir_node *transform_node_And(ir_node *n) {
-       ir_node *c, *oldn;
+       ir_node *c, *oldn = n;
        ir_node *a = get_And_left(n);
        ir_node *b = get_And_right(n);
 
        HANDLE_BINOP_PHI(tarval_and, a,b,c);
 
        /* we can evaluate 2 Projs of the same Cmp */
-       if(get_irn_mode(n) == mode_b && is_Proj(a) && is_Proj(b)) {
+       if (get_irn_mode(n) == mode_b && is_Proj(a) && is_Proj(b)) {
                ir_node *pred_a = get_Proj_pred(a);
                ir_node *pred_b = get_Proj_pred(b);
                if(pred_a == pred_b) {
@@ -2695,6 +2904,45 @@ static ir_node *transform_node_And(ir_node *n) {
                                           new_pnc);
                }
        }
+       if (is_Or(a)) {
+               if (is_Not(b)) {
+                       ir_node *op = get_Not_op(b);
+                       if (is_And(op)) {
+                               ir_node *ba = get_And_left(op);
+                               ir_node *bb = get_And_right(op);
+
+                               /* it's enough to test the following cases due to normalization! */
+                               if (get_Or_left(a) == ba && get_Or_right(a) == bb) {
+                                       /* (a|b) & ~(a&b) = a^b */
+                                       ir_node *block = get_nodes_block(n);
+
+                                       n = new_rd_Eor(get_irn_dbg_info(n), current_ir_graph, block, ba, bb, get_irn_mode(n));
+                                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_TO_EOR);
+                                       return n;
+                               }
+                       }
+               }
+       }
+       if (is_Or(b)) {
+               if (is_Not(a)) {
+                       ir_node *op = get_Not_op(a);
+                       if (is_And(op)) {
+                               ir_node *aa = get_And_left(op);
+                               ir_node *ab = get_And_right(op);
+
+                               /* it's enough to test the following cases due to normalization! */
+                               if (get_Or_left(b) == aa && get_Or_right(b) == ab) {
+                                       /* (a|b) & ~(a&b) = a^b */
+                                       ir_node *block = get_nodes_block(n);
+
+                                       n = new_rd_Eor(get_irn_dbg_info(n), current_ir_graph, block, aa, ab, get_irn_mode(n));
+                                       DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_TO_EOR);
+                                       return n;
+                               }
+                       }
+               }
+
+       }
 
        n = transform_bitwise_distributive(n, transform_node_And);
 
@@ -2793,6 +3041,7 @@ static ir_node *transform_node_Not(ir_node *n) {
  * Transform a Minus.
  * Optimize:
  *   -(~x) = x + 1
+ *   -(a-b) = b - a
  */
 static ir_node *transform_node_Minus(ir_node *n) {
        ir_node *c, *oldn = n;
@@ -2802,15 +3051,52 @@ static ir_node *transform_node_Minus(ir_node *n) {
        HANDLE_UNOP_PHI(tarval_neg,a,c);
 
        mode = get_irn_mode(a);
-       if (get_mode_arithmetic(mode) == irma_twos_complement && is_Not(a)) {
-               /* -(~x) = x + 1 */
-               ir_node *op   = get_Not_op(a);
-               tarval *tv    = get_mode_one(mode);
-               ir_node *blk  = get_irn_n(n, -1);
-               ir_node *c    = new_r_Const(current_ir_graph, blk, mode, tv);
-               n = new_rd_Add(get_irn_dbg_info(n), current_ir_graph, blk, op, c, mode);
-               DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_MINUS_NOT);
-       } else if (is_Sub(a)) {
+       if (get_mode_arithmetic(mode) == irma_twos_complement) {
+               /* the following rules are only to twos-complement */
+               if (is_Not(a)) {
+                       /* -(~x) = x + 1 */
+                       ir_node *op   = get_Not_op(a);
+                       tarval *tv    = get_mode_one(mode);
+                       ir_node *blk  = get_irn_n(n, -1);
+                       ir_node *c    = new_r_Const(current_ir_graph, blk, mode, tv);
+                       n = new_rd_Add(get_irn_dbg_info(n), current_ir_graph, blk, op, c, mode);
+                       DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_MINUS_NOT);
+                       return n;
+               }
+               if (is_Shr(a)) {
+                       ir_node *c = get_Shr_right(a);
+
+                       if (is_Const(c)) {
+                               tarval *tv = get_Const_tarval(c);
+
+                               if (tarval_is_long(tv) && get_tarval_long(tv) == get_mode_size_bits(mode) - 1) {
+                                       /* -(a >>u (size-1)) = a >>s (size-1) */
+                                       ir_node *v = get_Shr_left(a);
+
+                                       n = new_rd_Shrs(get_irn_dbg_info(n), current_ir_graph, get_irn_n(n, -1), v, c, mode);
+                                       DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_PREDICATE);
+                                       return n;
+                               }
+                       }
+               }
+               if (is_Shrs(a)) {
+                       ir_node *c = get_Shrs_right(a);
+
+                       if (is_Const(c)) {
+                               tarval *tv = get_Const_tarval(c);
+
+                               if (tarval_is_long(tv) && get_tarval_long(tv) == get_mode_size_bits(mode) - 1) {
+                                       /* -(a >>s (size-1)) = a >>u (size-1) */
+                                       ir_node *v = get_Shrs_left(a);
+
+                                       n = new_rd_Shr(get_irn_dbg_info(n), current_ir_graph, get_irn_n(n, -1), v, c, mode);
+                                       DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_PREDICATE);
+                                       return n;
+                               }
+                       }
+               }
+       }
+       if (is_Sub(a)) {
                /* - (a-b) = b - a */
                ir_node *la  = get_Sub_left(a);
                ir_node *ra  = get_Sub_right(a);
@@ -2818,6 +3104,7 @@ static ir_node *transform_node_Minus(ir_node *n) {
 
                n = new_rd_Sub(get_irn_dbg_info(n), current_ir_graph, blk, ra, la, mode);
                DBG_OPT_ALGSIM2(oldn, a, n, FS_OPT_MINUS_SUB);
+               return n;
        }
 
        return n;
@@ -3045,41 +3332,118 @@ static ir_node *transform_node_Proj_Cmp(ir_node *proj) {
        /* Remove unnecessary conversions */
        /* TODO handle constants */
        if (is_Conv(left) && is_Conv(right)) {
-               ir_modemode        = get_irn_mode(left);
-               ir_nodeop_left     = get_Conv_op(left);
-               ir_nodeop_right    = get_Conv_op(right);
-               ir_modemode_left   = get_irn_mode(op_left);
-               ir_modemode_right  = get_irn_mode(op_right);
+               ir_mode *mode        = get_irn_mode(left);
+               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)) {
-                       ir_graph* irg   = current_ir_graph;
-                       ir_node*  block = get_nodes_block(n);
-                       ir_node*  new_left;
-                       ir_node*  new_right;
+                       ir_graph *irg   = current_ir_graph;
+                       ir_node  *block = get_nodes_block(n);
 
                        if (mode_left == mode_right) {
-                               new_left  = op_left;
-                               new_right = op_right;
+                               left  = op_left;
+                               right = op_right;
+                               changed |= 1;
                        } else if (smaller_mode(mode_left, mode_right)) {
-                               new_left  = new_r_Conv(irg, block, op_left, mode_right);
-                               new_right = op_right;
+                               left  = new_r_Conv(irg, block, op_left, mode_right);
+                               right = op_right;
+                               changed |= 1;
                        } else if (smaller_mode(mode_right, mode_left)) {
-                               new_left  = op_left;
-                               new_right = new_r_Conv(irg, block, op_right, mode_left);
-                       } else {
-                               goto no_remove_conv;
+                               left  = op_left;
+                               right = new_r_Conv(irg, block, op_right, mode_left);
+                               changed |= 1;
+                       }
+               }
+       }
+
+       /* remove Casts */
+       if (is_Cast(left))
+               left = get_Cast_op(left);
+       if (is_Cast(right))
+               right = get_Cast_op(right);
+
+       /* remove operation of both sides if possible */
+       if (proj_nr == pn_Cmp_Eq || proj_nr == pn_Cmp_Lg) {
+               ir_opcode lop = get_irn_opcode(left);
+
+               if (lop == get_irn_opcode(right)) {
+                       ir_node *ll, *lr, *rl, *rr;
+
+                       /* same operation on both sides, try to remove */
+                       switch (lop) {
+                       case iro_Not:
+                       case iro_Minus:
+                               /* ~a CMP ~b => a CMP b, -a CMP -b ==> a CMP b */
+                               left  = get_unop_op(left);
+                               right = get_unop_op(right);
+                               changed |= 1;
+                               break;
+                       case iro_Add:
+                               ll = get_Add_left(left);
+                               lr = get_Add_right(left);
+                               rl = get_Add_left(right);
+                               rr = get_Add_right(right);
+
+                               if (ll == rl) {
+                                       /* X + a CMP X + b ==> a CMP b */
+                                       left  = lr;
+                                       right = rr;
+                                       changed |= 1;
+                               } else if (ll == rr) {
+                                       /* X + a CMP b + X ==> a CMP b */
+                                       left  = lr;
+                                       right = rl;
+                                       changed |= 1;
+                               } else if (lr == rl) {
+                                       /* a + X CMP X + b ==> a CMP b */
+                                       left  = ll;
+                                       right = rr;
+                                       changed |= 1;
+                               } else if (lr == rr) {
+                                       /* a + X CMP b + X ==> a CMP b */
+                                       left  = ll;
+                                       right = rl;
+                                       changed |= 1;
+                               }
+                               break;
+                       case iro_Sub:
+                               ll = get_Sub_left(left);
+                               lr = get_Sub_right(left);
+                               rl = get_Sub_left(right);
+                               rr = get_Sub_right(right);
+
+                               if (ll == rl) {
+                                       /* X - a CMP X - b ==> a CMP b */
+                                       left  = lr;
+                                       right = rr;
+                                       changed |= 1;
+                               } else if (lr == rr) {
+                                       /* a - X CMP b - X ==> a CMP b */
+                                       left  = ll;
+                                       right = rl;
+                                       changed |= 1;
+                               }
+                               break;
+                       case iro_Rot:
+                               if (get_Rot_right(left) == get_Rot_right(right)) {
+                                       /* a ROT X CMP b ROT X */
+                                       left  = get_Rot_left(left);
+                                       right = get_Rot_left(right);
+                                       changed |= 1;
+                               }
+                               break;
+                       default:
+                               break;
                        }
-                       left  = new_left;
-                       right = new_right;
-                       set_Cmp_left( n, left);
-                       set_Cmp_right(n, right);
-no_remove_conv:;
+
                }
        }
 
        if (get_irn_mode(left) == mode_b) {
-               ir_graphirg   = current_ir_graph;
-               ir_node*  block = get_nodes_block(n);
+               ir_graph *irg   = current_ir_graph;
+               ir_node  *block = get_nodes_block(n);
 
                switch (proj_nr) {
                        case pn_Cmp_Le: return new_r_Or( irg, block, new_r_Not(irg, block, left, mode_b), right, mode_b);
@@ -3096,14 +3460,14 @@ no_remove_conv:;
 
        /*
         * First step: normalize the compare op
-        * by placing the constant on the right site
+        * by placing the constant on the right side
         * or moving the lower address node to the left.
         * We ignore the case that both are constants
         * this case should be optimized away.
         */
-       if (get_irn_op(right) == op_Const) {
+       if (is_Const(right)) {
                c = right;
-       } else if (get_irn_op(left) == op_Const) {
+       } else if (is_Const(left)) {
                c     = left;
                left  = right;
                right = c;
@@ -3139,16 +3503,23 @@ no_remove_conv:;
                         * be optimized, see this:
                         * -MININT < 0 =/=> MININT > 0 !!!
                         */
-                       if (get_opt_constant_folding() && get_irn_op(left) == op_Minus &&
+                       if (is_Minus(left) &&
                                (!mode_overflow_on_unary_Minus(mode) ||
                                (mode_is_int(mode) && (proj_nr == pn_Cmp_Eq || proj_nr == pn_Cmp_Lg)))) {
-                               left = get_Minus_op(left);
                                tv = tarval_neg(tv);
 
                                if (tv != tarval_bad) {
+                                       left = get_Minus_op(left);
                                        proj_nr = get_inversed_pnc(proj_nr);
                                        changed |= 2;
                                }
+                       } else if (is_Not(left) && (proj_nr == pn_Cmp_Eq || proj_nr == pn_Cmp_Lg)) {
+                               tv = tarval_not(tv);
+
+                               if (tv != tarval_bad) {
+                                       left = get_Not_op(left);
+                                       changed |= 2;
+                               }
                        }
 
                        /* for integer modes, we have more */
@@ -3185,14 +3556,12 @@ no_remove_conv:;
                                if (proj_nr == pn_Cmp_Eq || proj_nr == pn_Cmp_Lg) {
 
                                        /* a-b == 0  ==>  a == b,  a-b != 0  ==>  a != b */
-                                       if (classify_tarval(tv) == TV_CLASSIFY_NULL && get_irn_op(left) == op_Sub) {
-                                               right = get_Sub_right(left);
+                                       if (classify_tarval(tv) == TV_CLASSIFY_NULL && is_Sub(left)) {
+                                               right =get_Sub_right(left);
                                                left  = get_Sub_left(left);
 
                                                tv = value_of(right);
-                                               if (tv != tarval_bad) {
-                                                       changed = 1;
-                                               }
+                                               changed = 1;
                                        }
 
                                        if (tv != tarval_bad) {
@@ -3270,8 +3639,7 @@ no_remove_conv:;
                         *
                         * if C is a single Bit constant.
                         */
-                       if ((proj_nr == pn_Cmp_Eq || proj_nr == pn_Cmp_Lg) &&
-                               (get_irn_op(left) == op_And)) {
+                       if ((proj_nr == pn_Cmp_Eq || proj_nr == pn_Cmp_Lg) && is_And(left)) {
                                if (tarval_is_single_bit(tv)) {
                                        /* check for Constant's match. We have check hare the tarvals,
                                           because our const might be changed */
@@ -3296,8 +3664,7 @@ no_remove_conv:;
                        right = new_Const(mode, tv);
 
                /* create a new compare */
-               n = new_rd_Cmp(get_irn_dbg_info(n), current_ir_graph, block,
-                       left, right);
+               n = new_rd_Cmp(get_irn_dbg_info(n), current_ir_graph, block, left, right);
 
                set_Proj_pred(proj, n);
                set_Proj_proj(proj, proj_nr);
@@ -3842,7 +4209,7 @@ static ir_node *transform_node_Mux(ir_node *n) {
                ir_node *t   = get_Mux_true(n);
 
                /*
-                * Note: normalization puts the constant on the right site,
+                * Note: normalization puts the constant on the right side,
                 * so we check only one case.
                 *
                 * Note further that these optimization work even for floating point
@@ -4503,6 +4870,8 @@ ir_node *optimize_node(ir_node *n) {
        if (get_opt_constant_folding()) {
                /* neither constants nor Tuple values can be evaluated */
                if (iro != iro_Const && (get_irn_mode(n) != mode_T)) {
+                       unsigned fp_model = get_irg_fp_model(current_ir_graph);
+                       int old_fp_mode = tarval_enable_fp_ops((fp_model & fp_strict_algebraic) == 0);
                        /* try to evaluate */
                        tv = computed_value(n);
                        if (tv != tarval_bad) {
@@ -4540,8 +4909,10 @@ ir_node *optimize_node(ir_node *n) {
                                if (old_tp && get_type_mode(old_tp) == get_tarval_mode (tv))
                                        set_Const_type(nw, old_tp);
                                DBG_OPT_CSTEVAL(oldn, nw);
+                               tarval_enable_fp_ops(old_fp_mode);
                                return nw;
                        }
+                       tarval_enable_fp_ops(old_fp_mode);
                }
        }
 
@@ -4553,8 +4924,6 @@ ir_node *optimize_node(ir_node *n) {
            (iro == iro_Block)  )  /* Flags tested local. */
                n = equivalent_node(n);
 
-       optimize_preds(n);                  /* do node specific optimizations of nodes predecessors. */
-
        /* Common Subexpression Elimination.
         *
         * Checks whether n is already available.
@@ -4610,6 +4979,8 @@ ir_node *optimize_in_place_2(ir_node *n) {
        if (get_opt_constant_folding()) {
                /* neither constants nor Tuple values can be evaluated */
                if (iro != iro_Const && get_irn_mode(n) != mode_T) {
+                       unsigned fp_model = get_irg_fp_model(current_ir_graph);
+                       int old_fp_mode = tarval_enable_fp_ops((fp_model & fp_strict_algebraic) == 0);
                        /* try to evaluate */
                        tv = computed_value(n);
                        if (tv != tarval_bad) {
@@ -4629,8 +5000,10 @@ ir_node *optimize_in_place_2(ir_node *n) {
                                        set_Const_type(n, old_tp);
 
                                DBG_OPT_CSTEVAL(oldn, n);
+                               tarval_enable_fp_ops(old_fp_mode);
                                return n;
                        }
+                       tarval_enable_fp_ops(old_fp_mode);
                }
        }
 
@@ -4642,8 +5015,6 @@ ir_node *optimize_in_place_2(ir_node *n) {
            (iro == iro_Block)  )  /* Flags tested local. */
                n = equivalent_node(n);
 
-       optimize_preds(n);                  /* do node specific optimizations of nodes predecessors. */
-
        /** common subexpression elimination **/
        /* Checks whether n is already available. */
        /* The block input is used to distinguish different subexpressions.  Right