verify: Clarify assertion message.
[libfirm] / ir / opt / boolopt.c
index 1de20a5..e1d70eb 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2011 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -19,9 +19,8 @@
 
 /**
  * @file
- * @brief   boolean condition/controlflow optimisations
- * @author  Matthias Braun, Christoph Mallon
- * @version $Id: cfopt.c 22579 2008-10-07 14:54:04Z beck $
+ * @brief   boolean condition/control flow optimizations
+ * @author  Matthias Braun, Christoph Mallon, Michael Beck
  */
 #include "config.h"
 
 #include <string.h>
 
 #include "adt/obst.h"
+#include "../adt/array_t.h"
+#include "iroptimize.h"
 #include "ircons.h"
 #include "irgmod.h"
 #include "irgwalk.h"
 #include "irprintf.h"
 #include "irnode_t.h"
 #include "tv.h"
+#include "irpass.h"
+#include "debug.h"
 
+/** Describes a pair of relative conditions lo < hi, lo rel_lo x, hi rel_hi x */
 typedef struct cond_pair {
-       ir_node *cmp_lo;
-       ir_node *cmp_hi;
-       pn_Cmp   pnc_lo;
-       pn_Cmp   pnc_hi;
-       ir_node *proj_lo;
-       ir_node *proj_hi;
-       tarval  *tv_lo;
-       tarval  *tv_hi;
+       ir_node    *cmp_lo;  /**< The lo compare node. */
+       ir_node    *cmp_hi;  /**< The hi compare node. */
+       ir_relation rel_lo;  /**< The lo relation node. */
+       ir_relation rel_hi;  /**< The hi relation node. */
+       ir_tarval  *tv_lo;   /**< The tarval of cmp_lo node. */
+       ir_tarval  *tv_hi;   /**< The tarval of cmp_hi node. */
+       ir_mode    *lo_mode; /**< The mode of the cmp_lo operands. */
 } cond_pair;
 
-static int find_cond_pair(ir_node *const l, ir_node *const r, cond_pair *const res)
+/** Environment for all walker in boolopt. */
+typedef struct {
+       int changed;  /**< Set if the graph was changed. */
+} bool_opt_env_t;
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg;)
+
+/**
+ * Check if tho given nodes, l and r, represent two compares with
+ * ... . If yes, return non-zero and fill the res struct.
+ */
+static bool find_cond_pair(ir_node *const l, ir_node *const r, cond_pair *const res)
 {
-       if (is_Proj(l) && is_Proj(r)) {
-               ir_node *const lo = get_Proj_pred(l);
-               ir_node *const ro = get_Proj_pred(r);
-
-               if (is_Cmp(lo) && is_Cmp(ro)) {
-                       ir_node *const lol = get_Cmp_left(lo);
-                       ir_node *const lor = get_Cmp_right(lo);
-                       ir_node *const rol = get_Cmp_left(ro);
-                       ir_node *const ror = get_Cmp_right(ro);
-
-                       if(is_Const(lor) && is_Const_null(lor) && is_Const(ror) && is_Const_null(ror) && get_Proj_proj(l) == pn_Cmp_Lg && get_Proj_proj(r) == pn_Cmp_Lg) {
-                               ir_fprintf(stderr, "found zero zero\n");
-                       }
+       if (is_Cmp(l) && is_Cmp(r)) {
+               ir_node    *const lol   = get_Cmp_left(l);
+               ir_node    *const lor   = get_Cmp_right(l);
+               ir_node    *const rol   = get_Cmp_left(r);
+               ir_node    *const ror   = get_Cmp_right(r);
+               ir_relation const pnc_l = get_Cmp_relation(l);
+               ir_relation const pnc_r = get_Cmp_relation(r);
+
+               if (is_Const(lor) && is_Const_null(lor) &&
+                       is_Const(ror) && is_Const_null(ror) &&
+                       pnc_l == pnc_r &&
+                       (pnc_l == ir_relation_less_greater || pnc_l == ir_relation_equal)) {
+                       /* l == (lol !=|== NULL) && r == (rol !=|== NULL) */
+                       res->cmp_lo  = l;
+                       res->cmp_hi  = r;
+                       res->rel_lo  = pnc_l;
+                       res->rel_hi  = pnc_l;
+                       res->tv_lo   = get_Const_tarval(lor);
+                       res->tv_hi   = get_Const_tarval(ror);
+                       res->lo_mode = get_irn_mode(lor);
+
+                       return true;
+               }
 
-                       /* TODO float */
-                       /* The constants shall be unequal.  Local optimisations handle the
-                        * equal case */
-                       if (lol == rol && mode_is_int(get_irn_mode(lol)) && lor != ror && is_Const(lor) && is_Const(ror)) {
-                               tarval *const tv_l  = get_Const_tarval(lor);
-                               tarval *const tv_r  = get_Const_tarval(ror);
-                               pn_Cmp  const pnc_l = get_Proj_proj(l);
-                               pn_Cmp  const pnc_r = get_Proj_proj(r);
-                               pn_Cmp  const rel   = tarval_cmp(tv_l, tv_r);
-
-                               assert(rel != pn_Cmp_Eq);
-
-                               if (rel == pn_Cmp_Lt) {
-                                       res->cmp_lo  = lo;
-                                       res->cmp_hi  = ro;
-                                       res->pnc_lo  = pnc_l;
-                                       res->pnc_hi  = pnc_r;
-                                       res->proj_lo = l;
-                                       res->proj_hi = r;
-                                       res->tv_lo   = tv_l;
-                                       res->tv_hi   = tv_r;
-                               } else {
-                                       assert(rel == pn_Cmp_Gt);
-                                       res->cmp_lo  = ro;
-                                       res->cmp_hi  = lo;
-                                       res->pnc_lo  = pnc_r;
-                                       res->pnc_hi  = pnc_l;
-                                       res->proj_lo = r;
-                                       res->proj_hi = l;
-                                       res->tv_lo   = tv_r;
-                                       res->tv_hi   = tv_l;
-                               }
-                               return 1;
+               if (lol == rol && lor != ror && is_Const(lor) && is_Const(ror)) {
+                       /* l == (x CMP c_l), r == (x cmp c_r) */
+                       ir_tarval  *const tv_l  = get_Const_tarval(lor);
+                       ir_tarval  *const tv_r  = get_Const_tarval(ror);
+                       ir_relation const rel   = tarval_cmp(tv_l, tv_r);
+
+                       res->lo_mode = get_irn_mode(lol);
+
+                       if (rel == ir_relation_less) {
+                               /* c_l < c_r */
+                               res->cmp_lo  = l;
+                               res->cmp_hi  = r;
+                               res->rel_lo  = pnc_l;
+                               res->rel_hi  = pnc_r;
+                               res->tv_lo   = tv_l;
+                               res->tv_hi   = tv_r;
+                       } else if (rel == ir_relation_greater) {
+                               /* c_l > c_r */
+                               res->cmp_lo  = r;
+                               res->cmp_hi  = l;
+                               res->rel_lo  = pnc_r;
+                               res->rel_hi  = pnc_l;
+                               res->tv_lo   = tv_r;
+                               res->tv_hi   = tv_l;
+                       } else {
+                               /* The constants shall be unequal but comparable.
+                                * Local optimizations handle the equal case. */
+                               return false;
                        }
+                       return true;
                }
        }
-       return 0;
+       return false;
 }
 
-static ir_node *bool_and(cond_pair* const cpair)
+/**
+ * Handle (lo rel_lo x) AND (hi rel_hi x)
+ */
+static ir_node *bool_and(cond_pair* const cpair, ir_node *dst_block)
 {
-       ir_node *const cmp_lo  = cpair->cmp_lo;
-       ir_node *const cmp_hi  = cpair->cmp_hi;
-       pn_Cmp   const pnc_lo  = cpair->pnc_lo;
-       pn_Cmp   const pnc_hi  = cpair->pnc_hi;
-       ir_node *const proj_lo = cpair->proj_lo;
-       ir_node *const proj_hi = cpair->proj_hi;
-       tarval  *const tv_lo   = cpair->tv_lo;
-       tarval  *const tv_hi   = cpair->tv_hi;
+       ir_node    *const cmp_lo  = cpair->cmp_lo;
+       ir_node    *const cmp_hi  = cpair->cmp_hi;
+       ir_relation       rel_lo  = cpair->rel_lo;
+       ir_relation const rel_hi  = cpair->rel_hi;
+       ir_tarval  *      tv_lo   = cpair->tv_lo;
+       ir_tarval  *      tv_hi   = cpair->tv_hi;
+       ir_mode    *      mode    = cpair->lo_mode;
+       ir_graph   *      irg     = get_irn_irg(cmp_lo);
+
+       if (rel_lo == ir_relation_equal && rel_hi == rel_lo &&
+           tarval_is_null(tv_lo) && tarval_is_null(tv_hi) &&
+           mode == get_tarval_mode(tv_hi)) {
+               /* p == NULL && q == NULL ==> (p&q) == NULL) */
+               ir_node *lol, *hil, *cmp, *c, *p;
+
+               if (mode_is_reference(mode)) {
+                       mode = find_unsigned_mode(mode);
+                       if (! mode)
+                               return NULL;
+                       tv_lo = tarval_convert_to(tv_lo, mode);
+                       if (tv_lo == tarval_bad)
+                               return NULL;
+               }
+               if (mode_is_int(mode)) {
+                       lol   = get_Cmp_left(cmp_lo);
+                       lol   = new_r_Conv(dst_block, lol, mode);
+                       hil   = get_Cmp_left(cmp_hi);
+                       hil   = new_r_Conv(dst_block, hil, mode);
+                       p     = new_r_And(dst_block, lol, hil, mode);
+                       c     = new_r_Const(irg, tv_lo);
+                       cmp   = new_r_Cmp(dst_block, p, c, ir_relation_equal);
+                       return cmp;
+               }
+       }
+
+       /* the following tests expect one common operand */
+       if (get_Cmp_left(cmp_lo) !=  get_Cmp_left(cmp_hi))
+               return 0;
+
+       /* TODO: for now reject float modes */
+       if (! mode_is_int(mode))
+               return 0;
 
        /* Beware of NaN's, we can only check for (ordered) != here (which is Lg, not Ne) */
-       if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
-                       (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
-               /* x <|<=|== lo | x ==|>=|> hi -> false */
-               ir_node *const t = new_Const(tarval_b_false);
+       if ((rel_lo == ir_relation_less || rel_lo == ir_relation_less_equal || rel_lo == ir_relation_equal) &&
+           (rel_hi == ir_relation_equal || rel_hi == ir_relation_greater_equal || rel_hi == ir_relation_greater)) {
+               /* x <|<=|== lo && x ==|>=|> hi ==> false */
+               ir_node *const t = new_r_Const(irg, tarval_b_false);
                return t;
-       } else if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
-                                                (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Lg)) {
-               /* x <|<=|== lo && x <|<=|!= hi -> x <|<=|== lo */
-               return proj_lo;
-       } else if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Lg) &&
-                                                (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
-               /* x >=|>|!= lo || x ==|>=|> hi -> x ==|>=|> hi */
-               return proj_hi;
+       } else if ((rel_lo == ir_relation_less || rel_lo == ir_relation_less_equal || rel_lo == ir_relation_equal) &&
+                  (rel_hi == ir_relation_less || rel_hi == ir_relation_less_equal || rel_hi == ir_relation_less_greater)) {
+               /* x <|<=|== lo && x <|<=|!= hi ==> x <|<=|== lo */
+               return cmp_lo;
+       } else if ((rel_lo == ir_relation_greater_equal || rel_lo == ir_relation_greater || rel_lo == ir_relation_less_greater) &&
+                  (rel_hi == ir_relation_equal || rel_hi == ir_relation_greater_equal || rel_hi == ir_relation_greater)) {
+               /* x >=|>|!= lo && x ==|>=|> hi ==> x ==|>=|> hi */
+               return cmp_hi;
        } else if (tarval_is_one(tarval_sub(tv_hi, tv_lo, NULL))) { /* lo + 1 == hi */
-               if (pnc_lo == pn_Cmp_Ge && pnc_hi == pn_Cmp_Lt) {
-                       /* x >= c || x < c + 1 -> x == c */
-                       ir_node  *const block = get_nodes_block(cmp_lo);
-                       ir_node  *const p = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Eq);
+               if (rel_lo == ir_relation_greater_equal && rel_hi == ir_relation_less) {
+                       /* x >= c && x < c + 1 ==> x == c */
+                       ir_node  *const p = new_r_Proj(cmp_lo, mode_b, ir_relation_equal);
                        return p;
-               } else if (pnc_lo == pn_Cmp_Gt) {
-                       if (pnc_hi == pn_Cmp_Lg) {
-                               /* x > c || x != c + 1 -> x > c + 1 */
-                               ir_node  *const block = get_nodes_block(cmp_hi);
-                               ir_node  *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Gt);
+               } else if (rel_lo == ir_relation_greater) {
+                       if (rel_hi == ir_relation_less_greater) {
+                               /* x > c && x != c + 1 ==> x > c + 1 */
+                               ir_node  *const p = new_r_Proj(cmp_hi, mode_b, ir_relation_greater);
                                return p;
-                       } else if (pnc_hi == pn_Cmp_Lt) {
-                               /* x > c || x < c + 1 -> false */
-                               ir_node *const t = new_Const(tarval_b_false);
+                       } else if (rel_hi == ir_relation_less) {
+                               /* x > c && x < c + 1 ==> false */
+                               ir_node *const t = new_r_Const(irg, tarval_b_false);
                                return t;
-                       } else if (pnc_hi == pn_Cmp_Le) {
-                               /* x > c || x <= c + 1 -> x != c + 1 */
-                               ir_node  *const block = get_nodes_block(cmp_hi);
-                               ir_node  *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Eq);
+                       } else if (rel_hi == ir_relation_less_equal) {
+                               /* x > c && x <= c + 1 ==> x != c + 1 */
+                               ir_node  *const p = new_r_Proj(cmp_hi, mode_b, ir_relation_equal);
                                return p;
                        }
-               } else if (pnc_lo == pn_Cmp_Lg && pnc_hi == pn_Cmp_Lt) {
-                       /* x != c || c < c + 1 -> x < c */
-                       ir_node  *const block = get_nodes_block(cmp_lo);
-                       ir_node  *const p     = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Lt);
+               } else if (rel_lo == ir_relation_less_greater && rel_hi == ir_relation_less) {
+                       /* x != c && c < c + 1 ==> x < c */
+                       ir_node  *const p     = new_r_Proj(cmp_lo, mode_b, ir_relation_less);
                        return p;
                }
+       } else if ((rel_lo == ir_relation_greater || rel_lo == ir_relation_greater_equal) &&
+                  (rel_hi == ir_relation_less || rel_lo == ir_relation_less_equal) &&
+                  get_mode_arithmetic(mode) == irma_twos_complement) {
+               /* works for two-complements only */
+               /* x >|\= lo && x <|<= hi ==> (x - lo) <u|<=u (hi-lo) */
+               if (rel_lo == ir_relation_greater) {
+                       /* must convert to >= */
+                       ir_mode   *mode = get_tarval_mode(tv_lo);
+                       ir_tarval *n    = tarval_add(tv_lo, get_mode_one(mode));
+                       if (n != tarval_bad && tarval_cmp(n, tv_lo) == ir_relation_greater) {
+                               /* no overflow */
+                               tv_lo = n;
+                               rel_lo = ir_relation_greater_equal;
+                       }
+               }
+               if (rel_lo == ir_relation_greater_equal) {
+                       /* all fine */
+                       ir_node *const block = get_nodes_block(cmp_hi);
+                       ir_node *      x     = get_Cmp_left(cmp_hi);
+                       ir_mode *      mode  = get_irn_mode(x);
+                       ir_node *sub, *cmp, *c, *subc;
+
+                       if (mode_is_signed(mode)) {
+                               /* convert to unsigned */
+                               mode = find_unsigned_mode(mode);
+                               if (mode == NULL)
+                                       return NULL;
+                               x     = new_r_Conv(block, x, mode);
+                               tv_lo = tarval_convert_to(tv_lo, mode);
+                               tv_hi = tarval_convert_to(tv_hi, mode);
+                               if (tv_lo == tarval_bad || tv_hi == tarval_bad)
+                                       return NULL;
+                       }
+                       c    = new_r_Const(irg, tv_lo);
+                       sub  = new_r_Sub(block, x, c, mode);
+                       subc = new_r_Sub(block, new_r_Const(irg, tv_hi), c, mode);
+                       cmp  = new_r_Cmp(block, sub, subc, rel_hi);
+                       return cmp;
+               }
        }
        return NULL;
 }
 
-static ir_node *bool_or(cond_pair *const cpair)
+/**
+ * Handle (lo rel_lo x) OR (hi rel_hi x)
+ */
+static ir_node *bool_or(cond_pair *const cpair, ir_node *dst_block)
 {
-       ir_node *const cmp_lo  = cpair->cmp_lo;
-       ir_node *const cmp_hi  = cpair->cmp_hi;
-       pn_Cmp   const pnc_lo  = cpair->pnc_lo;
-       pn_Cmp   const pnc_hi  = cpair->pnc_hi;
-       ir_node *const proj_lo = cpair->proj_lo;
-       ir_node *const proj_hi = cpair->proj_hi;
-       tarval  *const tv_lo   = cpair->tv_lo;
-       tarval  *const tv_hi   = cpair->tv_hi;
+       ir_node    *const cmp_lo  = cpair->cmp_lo;
+       ir_node    *const cmp_hi  = cpair->cmp_hi;
+       ir_relation       rel_lo  = cpair->rel_lo;
+       ir_relation const rel_hi  = cpair->rel_hi;
+       ir_tarval  *      tv_lo   = cpair->tv_lo;
+       ir_tarval  *      tv_hi   = cpair->tv_hi;
+       ir_mode    *      mode    = cpair->lo_mode;
+       ir_graph   *      irg     = get_irn_irg(cmp_lo);
+
+       if (rel_lo == ir_relation_less_greater && rel_hi == ir_relation_less_greater &&
+               tarval_is_null(tv_lo) && tarval_is_null(tv_hi) &&
+               mode == get_tarval_mode(tv_hi)) {
+               /* p != NULL || q != NULL ==> (p|q) != NULL) */
+               ir_node *lol, *hil, *cmp, *c, *p;
+
+               if (mode_is_reference(mode)) {
+                       mode = find_unsigned_mode(mode);
+                       if (! mode)
+                               return NULL;
+                       tv_lo = tarval_convert_to(tv_lo, mode);
+                       if (tv_lo == tarval_bad)
+                               return NULL;
+               }
+               if (mode_is_int(mode)) {
+                       lol   = get_Cmp_left(cmp_lo);
+                       lol   = new_r_Conv(dst_block, lol, mode);
+                       hil   = get_Cmp_left(cmp_hi);
+                       hil   = new_r_Conv(dst_block, hil, mode);
+                       p     = new_r_Or(dst_block, lol, hil, mode);
+                       c     = new_r_Const(irg, tv_lo);
+                       cmp   = new_r_Cmp(dst_block, p, c, ir_relation_less_greater);
+                       return cmp;
+               }
+       }
+
+       /* the following tests expect one common operand */
+       if (get_Cmp_left(cmp_lo) !=  get_Cmp_left(cmp_hi))
+               return 0;
+
+       /* TODO: for now reject float modes */
+       if (! mode_is_int(mode))
+               return 0;
 
        /* Beware of NaN's, we can only check for (ordered) != here (which is Lg, not Ne) */
-       if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Lg) &&
-                       (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Lg)) {
-               /* x >=|>|!= lo | x <|<=|!= hi -> true */
-               ir_node *const t = new_Const(tarval_b_true);
+       if ((rel_lo == ir_relation_greater_equal || rel_lo == ir_relation_greater || rel_lo == ir_relation_less_greater) &&
+           (rel_hi == ir_relation_less || rel_hi == ir_relation_less_equal || rel_hi == ir_relation_less_greater)) {
+               /* x >=|>|!= lo | x <|<=|!= hi ==> true */
+               ir_node *const t = new_r_Const(irg, tarval_b_true);
                return t;
-       } else if ((pnc_lo == pn_Cmp_Lt || pnc_lo == pn_Cmp_Le || pnc_lo == pn_Cmp_Eq) &&
-                                                (pnc_hi == pn_Cmp_Lt || pnc_hi == pn_Cmp_Le || pnc_hi == pn_Cmp_Lg)) {
-               /* x <|<=|== lo || x <|<=|!= hi -> x <|<=|!= hi */
-               return proj_hi;
-       } else if ((pnc_lo == pn_Cmp_Ge || pnc_lo == pn_Cmp_Gt || pnc_lo == pn_Cmp_Lg) &&
-                                                (pnc_hi == pn_Cmp_Eq || pnc_hi == pn_Cmp_Ge || pnc_hi == pn_Cmp_Gt)) {
-               /* x >=|>|!= lo || x ==|>=|> hi -> x >=|>|!= lo */
-               return proj_lo;
+       } else if ((rel_lo == ir_relation_less || rel_lo == ir_relation_less_equal || rel_lo == ir_relation_equal) &&
+                  (rel_hi == ir_relation_less || rel_hi == ir_relation_less_equal || rel_hi == ir_relation_less_greater)) {
+               /* x <|<=|== lo || x <|<=|!= hi ==> x <|<=|!= hi */
+               return cmp_hi;
+       } else if ((rel_lo == ir_relation_greater_equal || rel_lo == ir_relation_greater || rel_lo == ir_relation_less_greater) &&
+                  (rel_hi == ir_relation_equal || rel_hi == ir_relation_greater_equal || rel_hi == ir_relation_greater)) {
+               /* x >=|>|!= lo || x ==|>=|> hi ==> x >=|>|!= lo */
+               return cmp_lo;
        } else if (tarval_is_one(tarval_sub(tv_hi, tv_lo, NULL))) { /* lo + 1 == hi */
-               if (pnc_lo == pn_Cmp_Lt && pnc_hi == pn_Cmp_Ge) {
-                       /* x < c || x >= c + 1 -> x != c */
-                       ir_node  *const block = get_nodes_block(cmp_lo);
-                       ir_node  *const p = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Lg);
+               if (rel_lo == ir_relation_less && rel_hi == ir_relation_greater_equal) {
+                       /* x < c || x >= c + 1 ==> x != c */
+                       ir_node  *const p = new_r_Proj(cmp_lo, mode_b, ir_relation_less_greater);
                        return p;
-               } else if (pnc_lo == pn_Cmp_Le) {
-                       if (pnc_hi == pn_Cmp_Eq) {
-                               /* x <= c || x == c + 1 -> x <= c + 1 */
-                               ir_node  *const block = get_nodes_block(cmp_hi);
-                               ir_node  *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Le);
+               } else if (rel_lo == ir_relation_less_equal) {
+                       if (rel_hi == ir_relation_equal) {
+                               /* x <= c || x == c + 1 ==> x <= c + 1 */
+                               ir_node  *const p = new_r_Proj(cmp_hi, mode_b, ir_relation_less_equal);
                                return p;
-                       } else if (pnc_hi == pn_Cmp_Ge) {
-                               /* x <= c || x >= c + 1 -> true */
-                               ir_node *const t = new_Const(tarval_b_true);
+                       } else if (rel_hi == ir_relation_greater_equal) {
+                               /* x <= c || x >= c + 1 ==> true */
+                               ir_node *const t = new_r_Const(irg, tarval_b_true);
                                return t;
-                       } else if (pnc_hi == pn_Cmp_Gt) {
-                               /* x <= c || x > c + 1 -> x != c + 1 */
-                               ir_node  *const block = get_nodes_block(cmp_hi);
-                               ir_node  *const p = new_r_Proj(block, cmp_hi, mode_b, pn_Cmp_Lg);
+                       } else if (rel_hi == ir_relation_greater) {
+                               /* x <= c || x > c + 1 ==> x != c + 1 */
+                               ir_node  *const p = new_r_Proj(cmp_hi, mode_b, ir_relation_less_greater);
                                return p;
                        }
-               } else if (pnc_lo == pn_Cmp_Eq && pnc_hi == pn_Cmp_Ge) {
-                       /* x == c || x >= c + 1 -> x >= c */
-                       ir_node  *const block = get_nodes_block(cmp_lo);
-                       ir_node  *const p     = new_r_Proj(block, cmp_lo, mode_b, pn_Cmp_Ge);
+               } else if (rel_lo == ir_relation_equal && rel_hi == ir_relation_greater_equal) {
+                       /* x == c || x >= c + 1 ==> x >= c */
+                       ir_node  *const p     = new_r_Proj(cmp_lo, mode_b, ir_relation_greater_equal);
                        return p;
                }
+       } else if ((rel_lo == ir_relation_less || rel_lo == ir_relation_less_equal) &&
+                  (rel_hi == ir_relation_greater || rel_lo == ir_relation_greater_equal) &&
+                  get_mode_arithmetic(mode) == irma_twos_complement) {
+               /* works for two-complements only */
+               /* x <|<= lo  || x >|>= hi ==> (x - lo) >u|>=u (hi-lo) */
+               if (rel_lo == ir_relation_less_equal) {
+                       /* must convert to < */
+                       ir_mode   *mode = get_tarval_mode(tv_lo);
+                       ir_tarval *n    = tarval_add(tv_lo, get_mode_one(mode));
+                       if (n != tarval_bad && tarval_cmp(n, tv_lo) == ir_relation_greater) {
+                               /* no overflow */
+                               tv_lo = n;
+                               rel_lo = ir_relation_less;
+                       }
+               }
+               if (rel_lo == ir_relation_less) {
+                       /* all fine */
+                       ir_node *const block = get_nodes_block(cmp_hi);
+                       ir_node *      x     = get_Cmp_left(cmp_hi);
+                       ir_mode *      mode  = get_irn_mode(x);
+                       ir_node *sub, *cmp, *c, *subc;
+
+                       if (mode_is_signed(mode)) {
+                               /* convert to unsigned */
+                               mode = find_unsigned_mode(mode);
+                               if (mode == NULL)
+                                       return NULL;
+                               x     = new_r_Conv(block, x, mode);
+                               tv_lo = tarval_convert_to(tv_lo, mode);
+                               tv_hi = tarval_convert_to(tv_hi, mode);
+                               if (tv_lo == tarval_bad || tv_hi == tarval_bad)
+                                       return NULL;
+                       }
+                       c    = new_r_Const(irg, tv_lo);
+                       sub  = new_r_Sub(block, x, c, mode);
+                       subc = new_r_Sub(block, new_r_Const(irg, tv_hi), c, mode);
+                       cmp  = new_r_Cmp(block, sub, subc, rel_hi);
+                       return cmp;
+               }
        }
        return NULL;
 }
 
-static void bool_walk(ir_node *n, void *env)
+/**
+ * Walker, tries to optimize Andb and Orb nodes.
+ */
+static void bool_walk(ir_node *n, void *ctx)
 {
-       (void)env;
+       bool_opt_env_t *env = (bool_opt_env_t*)ctx;
 
        if (get_irn_mode(n) != mode_b)
                return;
@@ -230,9 +397,11 @@ static void bool_walk(ir_node *n, void *env)
                cond_pair      cpair;
                if (!find_cond_pair(l, r, &cpair))
                        return;
-               replacement = bool_and(&cpair);
-               if (replacement)
+               replacement = bool_and(&cpair, get_nodes_block(n));
+               if (replacement) {
                        exchange(n, replacement);
+                       env->changed = 1;
+               }
        } else if (is_Or(n)) {
                ir_node *const l = get_Or_left(n);
                ir_node *const r = get_Or_right(n);
@@ -240,14 +409,16 @@ static void bool_walk(ir_node *n, void *env)
                cond_pair      cpair;
                if (!find_cond_pair(l, r, &cpair))
                        return;
-               replacement = bool_or(&cpair);
-               if (replacement)
+               replacement = bool_or(&cpair, get_nodes_block(n));
+               if (replacement) {
                        exchange(n, replacement);
+                       env->changed = 1;
+               }
        }
 }
 
 /**
- * Walker, clear Block mark and Phi list
+ * Walker, clear Block marker and Phi lists.
  */
 static void clear_block_infos(ir_node *node, void *env)
 {
@@ -263,7 +434,7 @@ static void clear_block_infos(ir_node *node, void *env)
 }
 
 /**
- * Walker: collect Phi nodes and update the
+ * Walker: collect Phi nodes and mark
  */
 static void collect_phis(ir_node *node, void *env)
 {
@@ -278,6 +449,7 @@ static void collect_phis(ir_node *node, void *env)
        /* Ignore control flow nodes, these will be removed. */
        if (get_irn_pinned(node) == op_pin_state_pinned &&
                        !is_Block(node) && !is_cfop(node)) {
+                               /* found a pinned non-cf node, mark its block */
                ir_node *block = get_nodes_block(node);
                set_Block_mark(block, 1);
        }
@@ -288,151 +460,243 @@ static void collect_phis(ir_node *node, void *env)
  * and having only one predecessor, skip the block and return its
  * cf predecessor, else the node itself.
  */
-static ir_node *skip_empty_block(ir_node *node)
+static ir_node *skip_empty_blocks(ir_node *node)
 {
-       ir_node      *block;
+       while (is_Jmp(node)) {
+               ir_node *block = get_nodes_block(node);
 
-       if(!is_Jmp(node))
-               return node;
+               if (get_Block_n_cfgpreds(block) != 1)
+                       break;
 
-       block = get_nodes_block(node);
-       if(get_Block_n_cfgpreds(block) != 1)
-               return node;
+               if (get_Block_mark(block))
+                       break;
 
-       if(get_Block_mark(block))
-               return node;
+               node = get_Block_cfgpred(block, 0);
+       }
+       return node;
+}
 
-       return get_Block_cfgpred(block, 0);
+/**
+ * Check if two block inputs can be fused.
+ * This can be done, if block contains no Phi node that depends on
+ * different inputs idx_i and idx_j.
+ */
+static int can_fuse_block_inputs(const ir_node *block, int idx_i, int idx_j)
+{
+       const ir_node *phi;
+
+       for (phi = get_Block_phis(block); phi != NULL; phi = get_Phi_next(phi)) {
+               if (get_Phi_pred(phi, idx_i) != get_Phi_pred(phi, idx_j))
+                       return 0;
+       }
+       return 1;
 }
 
-static void find_cf_and_or_walker(ir_node *block, void *env)
+/**
+ * Remove block input with given index.
+ */
+static void remove_block_input(ir_node *block, int idx)
 {
-       int i, i2;
-       int n_cfgpreds = get_Block_n_cfgpreds(block);
-       (void) env;
+       int i, j, n = get_Block_n_cfgpreds(block) - 1;
+       ir_node *phi, **ins;
 
-       if(n_cfgpreds < 2)
-               return;
+       NEW_ARR_A(ir_node *, ins, n);
+
+       if (n == 1) {
+               /* all Phis will be deleted */
+               ir_node *next_phi;
+
+               for (phi = get_Block_phis(block); phi != NULL; phi = next_phi) {
+                       next_phi = get_Phi_next(phi);
+                       exchange(phi, get_Phi_pred(phi, idx ^ 1));
+               }
+               set_Block_phis(block, NULL);
+       } else {
+               for (phi = get_Block_phis(block); phi != NULL; phi = get_Phi_next(phi)) {
+                       for (i = j = 0; i <= n; ++i) {
+                               if (i != idx)
+                                       ins[j++] = get_Phi_pred(phi, i);
+                       }
+                       set_irn_in(phi, n, ins);
+               }
+       }
+       for (i = j = 0; i <= n; ++i) {
+               if (i != idx)
+                       ins[j++] = get_Block_cfgpred(block, i);
+       }
+       set_irn_in(block, n, ins);
+}
+
+/**
+ * Under the preposition that we have a chain of blocks from
+ * from_block to to_block, collapse them all into to_block.
+ */
+static void move_nodes_to_block(ir_node *jmp, ir_node *to_block)
+{
+       ir_node *new_jmp = NULL;
+       ir_node *block, *next_block;
+
+       for (block = get_nodes_block(jmp); block != to_block; block = next_block) {
+               new_jmp = get_Block_cfgpred(block, 0);
+               next_block = get_nodes_block(new_jmp);
+               exchange(block, to_block);
+       }
+       if (new_jmp)
+               exchange(jmp, new_jmp);
+}
+
+/**
+ * Block walker:
+ *
+ * if we can find the following structure,
+ *
+ *        upper_block
+ *         /       |
+ *        /        |
+ *   lower_block   |
+ *     /  \        |
+ *   ... low_idx up_idx
+ *          \      |
+ *            block
+ *
+ * try to convert it into a (x rel_lo c_lo) || (x rel_hi c_hi)
+ * and optimize.
+ */
+static void find_cf_and_or_walker(ir_node *block, void *ctx)
+{
+       bool_opt_env_t *env = (bool_opt_env_t*)ctx;
+       int low_idx, up_idx;
+       int n_cfgpreds;
 
-       /* Find the following structure:
-        *
-        *        upper_block
-        *         /       |
-        *        /        |
-        *   lower_block   |
-        *     /  \        |
-        *   ...   \       |
-        *           block
+       /* because we modify the graph in regions we might not visited yet,
+        * Id nodes might arise here. Ignore them.
         */
+       if (is_Id(block))
+               return;
 
+       n_cfgpreds = get_Block_n_cfgpreds(block);
 restart:
-       for(i = 0; i < n_cfgpreds; ++i) {
+       if (n_cfgpreds < 2)
+               return;
+
+       for (low_idx = 0; low_idx < n_cfgpreds; ++low_idx) {
                ir_node      *lower_block;
                ir_node      *lower_cf;
                ir_node      *cond;
-               ir_node      *cond_selector;
-               ir_node      *lower_pred;
 
-               lower_cf = get_Block_cfgpred(block, i);
-               lower_cf = skip_empty_block(lower_cf);
-               if(!is_Proj(lower_cf))
+               lower_cf = get_Block_cfgpred(block, low_idx);
+               lower_cf = skip_empty_blocks(lower_cf);
+               if (!is_Proj(lower_cf))
                        continue;
 
                cond = get_Proj_pred(lower_cf);
-               if(!is_Cond(cond))
+               if (!is_Cond(cond))
                        continue;
 
                lower_block = get_nodes_block(cond);
-               if(get_Block_n_cfgpreds(lower_block) != 1)
+               if (get_Block_n_cfgpreds(lower_block) != 1)
                        continue;
 
                /* the block must not produce any side-effects */
-               if(get_Block_mark(lower_block))
-                       continue;
-
-               cond_selector = get_Cond_selector(cond);
-               if(get_irn_mode(cond_selector) != mode_b)
+               if (get_Block_mark(lower_block))
                        continue;
 
-               lower_pred = get_Block_cfgpred_block(lower_block, 0);
-
-               for(i2 = 0; i2 < n_cfgpreds; ++i2) {
+               ir_node *const cond_selector = get_Cond_selector(cond);
+               ir_node *const lower_pred    = get_Block_cfgpred_block(lower_block, 0);
+               for (up_idx = 0; up_idx < n_cfgpreds; ++up_idx) {
                        ir_node   *upper_block;
                        ir_node   *upper_cf;
-                       ir_node   *upper_cond;
-                       ir_node   *upper_cond_selector;
                        ir_node   *replacement;
                        cond_pair  cpair;
 
-                       upper_cf    = get_Block_cfgpred(block, i2);
-                       upper_cf    = skip_empty_block(upper_cf);
-                       if(is_Bad(upper_cf))
+                       upper_cf = get_Block_cfgpred(block, up_idx);
+                       upper_cf = skip_empty_blocks(upper_cf);
+                       if (is_Bad(upper_cf))
                                continue;
                        upper_block = get_nodes_block(upper_cf);
-                       if(upper_block != lower_pred)
+                       if (upper_block != lower_pred)
                                continue;
-
-                       assert(is_Proj(upper_cf));
-                       upper_cond = get_Proj_pred(upper_cf);
-                       assert(is_Cond(upper_cond));
-                       upper_cond_selector = get_Cond_selector(upper_cond);
-                       if(get_irn_mode(upper_cond_selector) != mode_b)
+                       if (!block_dominates(upper_block, block))
                                continue;
 
                        /* we have found the structure */
-                       /* TODO: check phis */
-                       if(!find_cond_pair(cond_selector, upper_cond_selector, &cpair))
+                       /* check Phis: There must be NO Phi in block that
+                          depends on the existence of low block */
+                       if (!can_fuse_block_inputs(block, low_idx, up_idx))
+                               continue;
+
+                       /* all fine, try it */
+                       ir_node *const upper_cond          = get_Proj_pred(upper_cf);
+                       ir_node *const upper_cond_selector = get_Cond_selector(upper_cond);
+                       if (!find_cond_pair(cond_selector, upper_cond_selector, &cpair))
                                continue;
 
                        /* normalize pncs: we need the true case to jump into the
-                        * common block (ie. conjunctive normal form) */
-                       if(get_Proj_proj(lower_cf) == pn_Cond_false) {
-                               if(cpair.proj_lo == cond_selector) {
-                                       ir_mode *mode = get_tarval_mode(cpair.tv_lo);
-                                       cpair.pnc_lo  = get_negated_pnc(cpair.pnc_lo, mode);
-                                       cpair.proj_lo = new_r_Proj(lower_block,
-                                                       get_Proj_pred(cpair.proj_lo), mode_b, cpair.pnc_lo);
+                        * common block (i.e. conjunctive normal form) */
+                       if (get_Proj_proj(lower_cf) == pn_Cond_false) {
+                               if (cpair.cmp_lo == cond_selector) {
+                                       ir_node  *cmp   = cpair.cmp_lo;
+                                       ir_node  *block = get_nodes_block(cmp);
+                                       dbg_info *dbgi  = get_irn_dbg_info(cmp);
+                                       cpair.rel_lo    = get_negated_relation(cpair.rel_lo);
+                                       cpair.cmp_lo    = new_rd_Cmp(dbgi, block,
+                                                       get_Cmp_left(cmp), get_Cmp_right(cmp), cpair.rel_lo);
                                } else {
-                                       ir_mode *mode = get_tarval_mode(cpair.tv_hi);
-                                       assert(cpair.proj_hi == cond_selector);
-                                       cpair.pnc_hi  = get_negated_pnc(cpair.pnc_hi, mode);
-                                       cpair.proj_hi = new_r_Proj(lower_block,
-                                                       get_Proj_pred(cpair.proj_hi), mode_b, cpair.pnc_hi);
+                                       ir_node  *cmp   = cpair.cmp_hi;
+                                       ir_node  *block = get_nodes_block(cmp);
+                                       dbg_info *dbgi  = get_irn_dbg_info(cmp);
+                                       assert(cmp == cond_selector);
+                                       cpair.rel_hi = get_negated_relation(cpair.rel_hi);
+                                       cpair.cmp_hi = new_rd_Cmp(dbgi, block,
+                                                       get_Cmp_left(cmp), get_Cmp_right(cmp), cpair.rel_hi);
                                }
                        }
-                       if(get_Proj_proj(upper_cf) == pn_Cond_false) {
-                               if(cpair.proj_lo == upper_cond_selector) {
-                                       ir_mode *mode = get_tarval_mode(cpair.tv_lo);
-                                       cpair.pnc_lo  = get_negated_pnc(cpair.pnc_lo, mode);
-                                       cpair.proj_lo = new_r_Proj(upper_block,
-                                                       get_Proj_pred(cpair.proj_lo), mode_b, cpair.pnc_lo);
+                       if (get_Proj_proj(upper_cf) == pn_Cond_false) {
+                               if (cpair.cmp_lo == upper_cond_selector) {
+                                       ir_node  *cmp   = cpair.cmp_lo;
+                                       ir_node  *block = get_nodes_block(cmp);
+                                       dbg_info *dbgi  = get_irn_dbg_info(cmp);
+                                       cpair.rel_lo    = get_negated_relation(cpair.rel_lo);
+                                       cpair.cmp_lo    = new_rd_Cmp(dbgi, block,
+                                                       get_Cmp_left(cmp), get_Cmp_right(cmp), cpair.rel_lo);
                                } else {
-                                       ir_mode *mode = get_tarval_mode(cpair.tv_hi);
-                                       assert(cpair.proj_hi == upper_cond_selector);
-                                       cpair.pnc_hi  = get_negated_pnc(cpair.pnc_hi, mode);
-                                       cpair.proj_hi = new_r_Proj(upper_block,
-                                                       get_Proj_pred(cpair.proj_hi), mode_b, cpair.pnc_hi);
+                                       ir_node  *cmp   = cpair.cmp_hi;
+                                       ir_node  *block = get_nodes_block(cmp);
+                                       dbg_info *dbgi  = get_irn_dbg_info(cmp);
+                                       assert(cmp == upper_cond_selector);
+                                       cpair.rel_hi   = get_negated_relation(cpair.rel_hi);
+                                       cpair.cmp_hi   = new_rd_Cmp(dbgi, block,
+                                                       get_Cmp_left(cmp), get_Cmp_right(cmp), cpair.rel_hi);
                                }
                        }
 
                        /* can we optimize the case? */
-                       replacement = bool_or(&cpair);
-                       if(replacement == NULL)
+                       replacement = bool_or(&cpair, upper_block);
+                       if (replacement == NULL)
                                continue;
 
+                       env->changed = 1;
+
+                       DB((dbg, LEVEL_1, "boolopt: %+F: fusing (ub %+F lb %+F)\n",
+                               get_irn_irg(upper_block), upper_block, lower_block));
+
+                       /* move all expressions on the path to lower/upper block */
+                       move_nodes_to_block(get_Block_cfgpred(block, up_idx), upper_block);
+                       move_nodes_to_block(get_Block_cfgpred(block, low_idx), lower_block);
+
                        /* move all nodes from lower block to upper block */
                        exchange(lower_block, upper_block);
 
-                       set_Block_cfgpred(block, i2, new_Bad());
+                       remove_block_input(block, up_idx);
+                       --n_cfgpreds;
 
-                       /* the optimisations expected the true case to jump */
-                       if(get_Proj_proj(lower_cf) == pn_Cond_false) {
+                       /* the optimizations expected the true case to jump */
+                       if (get_Proj_proj(lower_cf) == pn_Cond_false) {
                                ir_node *block = get_nodes_block(replacement);
                                replacement    = new_rd_Not(NULL, block, replacement, mode_b);
                        }
                        set_Cond_selector(cond, replacement);
 
-                       ir_fprintf(stderr, "replaced (ub %+F)\n", upper_block);
                        goto restart;
                }
        }
@@ -440,18 +704,28 @@ restart:
 
 void opt_bool(ir_graph *const irg)
 {
-       irg_walk_graph(irg, NULL, bool_walk, NULL);
-
-       ir_reserve_resources(irg, IR_RESOURCE_BLOCK_MARK | IR_RESOURCE_PHI_LIST);
+       bool_opt_env_t env;
 
-       irg_walk_graph(irg, clear_block_infos, collect_phis, NULL);
+       /* register a debug mask */
+       FIRM_DBG_REGISTER(dbg, "firm.opt.bool");
 
-       irg_block_walk_graph(irg, NULL, find_cf_and_or_walker, NULL);
+       env.changed = 0;
 
-       set_irg_outs_inconsistent(irg);
-       set_irg_doms_inconsistent(irg);
-       set_irg_extblk_inconsistent(irg);
-       set_irg_loopinfo_inconsistent(irg);
+       /* optimize simple Andb and Orb cases */
+       irg_walk_graph(irg, NULL, bool_walk, &env);
 
+       /* now more complicated cases: find control flow And/Or and optimize. */
+       ir_reserve_resources(irg, IR_RESOURCE_BLOCK_MARK | IR_RESOURCE_PHI_LIST);
+       irg_walk_graph(irg, clear_block_infos, collect_phis, NULL);
+       irg_block_walk_graph(irg, NULL, find_cf_and_or_walker, &env);
        ir_free_resources(irg, IR_RESOURCE_BLOCK_MARK | IR_RESOURCE_PHI_LIST);
+
+       confirm_irg_properties(irg,
+               env.changed ? IR_GRAPH_PROPERTIES_NONE : IR_GRAPH_PROPERTIES_ALL);
+}
+
+/* Creates an ir_graph pass for opt_bool. */
+ir_graph_pass_t *opt_bool_pass(const char *name)
+{
+       return def_graph_pass(name ? name : "opt_bool", opt_bool);
 }