X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fboolopt.c;h=1ca652717ec2f9f8dfded0c46038c3c3a30a9b77;hb=64f5f0cf11fe4a0d4753060e45639604d725652d;hp=ec68c6217dc25991ed30a1f377e80a07610e2272;hpb=1dfee524c7ebf64f463a51b5b4c8a68bb8000c7b;p=libfirm

diff --git a/ir/opt/boolopt.c b/ir/opt/boolopt.c
index ec68c6217..1ca652717 100644
--- a/ir/opt/boolopt.c
+++ b/ir/opt/boolopt.c
@@ -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.
  *
@@ -19,216 +19,373 @@
 
 /**
  * @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
  */
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include "config.h"
 
 #include <assert.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(mode_b, 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_graph *const irg   = current_ir_graph;
-			ir_node  *const block = get_nodes_block(cmp_lo);
-			ir_node  *const p = new_r_Proj(irg, 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_graph *const irg   = current_ir_graph;
-				ir_node  *const block = get_nodes_block(cmp_hi);
-				ir_node  *const p = new_r_Proj(irg, 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(mode_b, 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_graph *const irg   = current_ir_graph;
-				ir_node  *const block = get_nodes_block(cmp_hi);
-				ir_node  *const p = new_r_Proj(irg, 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_graph *const irg   = current_ir_graph;
-			ir_node  *const block = get_nodes_block(cmp_lo);
-			ir_node  *const p     = new_r_Proj(irg, 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(mode_b, 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_graph *const irg   = current_ir_graph;
-			ir_node  *const block = get_nodes_block(cmp_lo);
-			ir_node  *const p = new_r_Proj(irg, 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_graph *const irg   = current_ir_graph;
-				ir_node  *const block = get_nodes_block(cmp_hi);
-				ir_node  *const p = new_r_Proj(irg, 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(mode_b, 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_graph *const irg   = current_ir_graph;
-				ir_node  *const block = get_nodes_block(cmp_hi);
-				ir_node  *const p = new_r_Proj(irg, 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_graph *const irg   = current_ir_graph;
-			ir_node  *const block = get_nodes_block(cmp_lo);
-			ir_node  *const p     = new_r_Proj(irg, 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;
@@ -240,9 +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);
@@ -250,14 +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)
 {
@@ -273,7 +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)
 {
@@ -288,6 +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);
 	}
@@ -298,154 +460,256 @@ 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)
+{
+	while (is_Jmp(node)) {
+		ir_node *block = get_nodes_block(node);
+
+		if (get_Block_n_cfgpreds(block) != 1)
+			break;
+
+		if (get_Block_mark(block))
+			break;
+
+		node = get_Block_cfgpred(block, 0);
+	}
+	return node;
+}
+
+/**
+ * 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)
 {
-	ir_node      *block;
+	const ir_node *phi;
 
-	if(!is_Jmp(node))
-		return node;
+	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;
+}
 
-	block = get_nodes_block(node);
-	if(get_Block_n_cfgpreds(block) != 1)
-		return node;
+/**
+ * Remove block input with given index.
+ */
+static void remove_block_input(ir_node *block, int idx)
+{
+	int i, j, n = get_Block_n_cfgpreds(block) - 1;
+	ir_node *phi, **ins;
+
+	NEW_ARR_A(ir_node *, ins, n);
 
-	if(get_Block_mark(block))
-		return node;
+	if (n == 1) {
+		/* all Phis will be deleted */
+		ir_node *next_phi;
 
-	return get_Block_cfgpred(block, 0);
+		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);
 }
 
-static void find_cf_and_or_walker(ir_node *block, void *env)
+/**
+ * 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)
 {
-	int i, i2;
-	int n_cfgpreds = get_Block_n_cfgpreds(block);
-	(void) env;
+	ir_node *new_jmp = NULL;
+	ir_node *block, *next_block;
 
-	if(n_cfgpreds < 2)
-		return;
+	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);
+}
 
-	/* Find the following structure:
-	 *
-	 *        upper_block
-	 *         /       |
-	 *        /        |
-	 *   lower_block   |
-	 *     /  \        |
-	 *   ...   \       |
-	 *           block
+/**
+ * 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;
+
+	/* 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))
+		if (get_Block_mark(lower_block))
 			continue;
 
 		cond_selector = get_Cond_selector(cond);
-		if(get_irn_mode(cond_selector) != mode_b)
+		if (get_irn_mode(cond_selector) != mode_b)
 			continue;
 
 		lower_pred = get_Block_cfgpred_block(lower_block, 0);
 
-		for(i2 = 0; i2 < n_cfgpreds; ++i2) {
+		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;
-			ir_graph  *irg;
 			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;
+			if (!block_dominates(upper_block, block))
 				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 (get_irn_mode(upper_cond_selector) != mode_b)
 				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 */
+			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) */
-			irg = current_ir_graph;
-			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(irg, lower_block,
-							get_Proj_pred(cpair.proj_lo), mode_b, cpair.pnc_lo);
+			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(irg, 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(irg, 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(irg, 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, current_ir_graph, block,
-				                            replacement, mode_b);
+				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;
 		}
 	}
@@ -453,18 +717,28 @@ restart:
 
 void opt_bool(ir_graph *const irg)
 {
-	irg_walk_graph(irg, NULL, bool_walk, NULL);
+	bool_opt_env_t env;
 
-	ir_reserve_resources(irg, IR_RESOURCE_BLOCK_MARK);
+	/* register a debug mask */
+	FIRM_DBG_REGISTER(dbg, "firm.opt.bool");
 
-	irg_walk_graph(irg, clear_block_infos, collect_phis, NULL);
+	env.changed = 0;
 
-	irg_block_walk_graph(irg, NULL, find_cf_and_or_walker, NULL);
+	/* optimize simple Andb and Orb cases */
+	irg_walk_graph(irg, NULL, bool_walk, &env);
 
-	set_irg_outs_inconsistent(irg);
-	set_irg_doms_inconsistent(irg);
-	set_irg_extblk_inconsistent(irg);
-	set_irg_loopinfo_inconsistent(irg);
+	/* 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);
 
-	ir_free_resources(irg, IR_RESOURCE_BLOCK_MARK);
+	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);
 }