X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Fir%2Firarch.c;h=acd02825c5d21fc7c780379d350e4d7e7bdd204d;hb=3c3425a50a1d721b74a015c6812257e32feeac85;hp=fc0bc2227571cc1ffbe870718125a8da299ccba7;hpb=1d06728563d3008e214b800bdc20ca29c1070614;p=libfirm

diff --git a/ir/ir/irarch.c b/ir/ir/irarch.c
index fc0bc2227..acd02825c 100644
--- a/ir/ir/irarch.c
+++ b/ir/ir/irarch.c
@@ -22,7 +22,6 @@
  * @brief   Machine dependent Firm optimizations.
  * @date    28.9.2004
  * @author  Sebastian Hack, Michael Beck
- * @version $Id$
  *
  * Implements "Strength Reduction of Multiplications by Integer Constants"
  * by Youfeng Wu.
@@ -572,19 +571,19 @@ ir_node *arch_dep_replace_mul_with_shifts(ir_node *irn)
 	ir_tarval *tv;
 	const ir_settings_arch_dep_t *params = be_get_backend_param()->dep_param;
 
-
 	/* If the architecture dependent optimizations were not initialized
 	   or this optimization was not enabled. */
 	if (params == NULL || (opts & arch_dep_mul_to_shift) == 0)
-		return irn;
+		return res;
 
-	if (!is_Mul(irn) || !mode_is_int(mode))
+	assert(is_Mul(irn));
+	if (!mode_is_int(mode))
 		return res;
 
 	/* we should never do the reverse transformations again
 	   (like x+x -> 2*x) */
 	irg = get_irn_irg(irn);
-	set_irg_state(irg, IR_GRAPH_STATE_ARCH_DEP);
+	add_irg_constraints(irg, IR_GRAPH_CONSTRAINT_ARCH_DEP);
 
 	left    = get_binop_left(irn);
 	right   = get_binop_right(irn);
@@ -600,6 +599,11 @@ ir_node *arch_dep_replace_mul_with_shifts(ir_node *irn)
 		operand = left;
 	}
 
+	/* multiplications with 0 are a special case which we leave for
+	 * equivalent_node_Mul because the code here can't handle them */
+	if (tv == get_mode_null(mode))
+		return res;
+
 	if (tv != NULL) {
 		res = do_decomposition(irn, operand, tv);
 
@@ -826,7 +830,7 @@ static ir_node *replace_div_by_mulh(ir_node *div, ir_tarval *tv)
 {
 	dbg_info *dbg  = get_irn_dbg_info(div);
 	ir_node *n     = get_binop_left(div);
-	ir_node *block = get_irn_n(div, -1);
+	ir_node *block = get_nodes_block(div);
 	ir_mode *mode  = get_irn_mode(n);
 	int bits       = get_mode_size_bits(mode);
 	ir_node *q;
@@ -932,7 +936,7 @@ ir_node *arch_dep_replace_div_by_const(ir_node *irn)
 	if (!mode_is_int(mode))
 		return irn;
 
-	block = get_irn_n(irn, -1);
+	block = get_nodes_block(irn);
 	dbg   = get_irn_dbg_info(irn);
 
 	bits = get_mode_size_bits(mode);
@@ -951,7 +955,7 @@ ir_node *arch_dep_replace_div_by_const(ir_node *irn)
 		k = tv_ld2(tv, n);
 	}
 
-	if (k >= 0) { /* division by 2^k or -2^k */
+	if (k > 0) { /* division by 2^k or -2^k */
 		ir_graph *irg = get_irn_irg(irn);
 		if (mode_is_signed(mode)) {
 			ir_node *k_node;
@@ -990,10 +994,12 @@ ir_node *arch_dep_replace_div_by_const(ir_node *irn)
 			k_node = new_r_Const_long(irg, mode_Iu, k);
 			res    = new_rd_Shr(dbg, block, left, k_node, mode);
 		}
-	} else {
+	} else if (k != 0) {
 		/* other constant */
 		if (allow_Mulh(params, mode))
 			res = replace_div_by_mulh(irn, tv);
+	} else { /* k == 0  i.e. division by 1 */
+		res = left;
 	}
 
 	if (res != irn)
@@ -1033,7 +1039,7 @@ ir_node *arch_dep_replace_mod_by_const(ir_node *irn)
 
 		left  = get_Mod_left(irn);
 		mode  = get_irn_mode(left);
-		block = get_irn_n(irn, -1);
+		block = get_nodes_block(irn);
 		dbg   = get_irn_dbg_info(irn);
 		bits = get_mode_size_bits(mode);
 		n    = (bits + 7) / 8;
@@ -1049,7 +1055,13 @@ ir_node *arch_dep_replace_mod_by_const(ir_node *irn)
 			k = tv_ld2(tv, n);
 		}
 
-		if (k >= 0) {
+		/* k == 0  i.e. modulo by 1 */
+		if (k == 0) {
+			ir_graph *irg = get_irn_irg(irn);
+
+			res = new_r_Const(irg, get_mode_null(mode));
+		}
+		else if (k > 0) {
 			ir_graph *irg = get_irn_irg(irn);
 			/* division by 2^k or -2^k:
 			 * we use "modulus" here, so x % y == x % -y that's why is no difference between the case 2^k and -2^k