When making a 'Minus', automatically infer its mode from its operand.

ir/ir/irgmod.c

@@ -363,8 +363,7 @@ ir_node *duplicate_subgraph(dbg_info *dbg, ir_node *n, ir_node *block)
 		                   mode);
 	case iro_Minus:
 		return new_rd_Minus(dbg, block,
-		                    duplicate_subgraph(dbg, get_Minus_op(n), block),
-		                    mode);
+		                    duplicate_subgraph(dbg, get_Minus_op(n), block));
 	case iro_Not:
 		return new_rd_Not(dbg, block,
 		                  duplicate_subgraph(dbg, get_Not_op(n), block));

ir/lower/lower_intrinsics.c

@@ -173,7 +173,7 @@ int i_mapper_abs(ir_node *call)
 
 	ir_node  *zero     = new_r_Const_null(irg, mode);
 	ir_node  *cmp      = new_rd_Cmp(dbg, block, op, zero, ir_relation_less);
-	ir_node  *minus_op = new_rd_Minus(dbg, block, op, mode);
+	ir_node  *minus_op = new_rd_Minus(dbg, block, op);
 	ir_node  *mux;
 	arch_allow_ifconv_func allow_ifconv = be_get_backend_param()->allow_ifconv;
 
@@ -802,7 +802,7 @@ replace_by_call:
 
 			if (v == right) {
 				/* negate in the ("", s) case */
-				irn = new_rd_Minus(dbg, block, irn, mode);
+				irn = new_rd_Minus(dbg, block, irn);
 			}
 		}
 	}

ir/opt/iropt.c

@@ -3341,7 +3341,7 @@ static ir_node *transform_node_Sub(ir_node *n)
 		ir_node  *left  = get_Minus_op(a);
 		ir_node  *add   = new_rd_Add(dbg, block, left, b, mode);
 
-		n = new_rd_Minus(dbg, block, add, mode);
+		n = new_rd_Minus(dbg, block, add);
 		DBG_OPT_ALGSIM0(oldn, n);
 		return n;
 	}
@@ -3386,7 +3386,7 @@ static ir_node *transform_node_Sub(ir_node *n)
 
 	/* Beware of Sub(P, P) which cannot be optimized into a simple Minus ... */
 	if (mode_is_num(mode) && mode == get_irn_mode(a) && is_Const(a) && is_Const_null(a)) {
-		n = new_rd_Minus(get_irn_dbg_info(n), get_nodes_block(n), b, mode);
+		n = new_rd_Minus(get_irn_dbg_info(n), get_nodes_block(n), b);
 		DBG_OPT_ALGSIM0(oldn, n);
 		return n;
 	}
@@ -3417,20 +3417,16 @@ static ir_node *transform_node_Sub(ir_node *n)
 
 		/* FIXME: Does the Conv's work only for two complement or generally? */
 		if (left == a) {
-			ir_mode *r_mode = get_irn_mode(right);
-
-			n = new_r_Minus(get_nodes_block(n), right, r_mode);
+			n = new_r_Minus(get_nodes_block(n), right);
 			/* This Sub is an effective Cast */
-			if (mode != r_mode)
+			if (mode != get_irn_mode(right))
 				n = new_r_Conv(get_nodes_block(n), n, mode);
 			DBG_OPT_ALGSIM1(oldn, a, b, n);
 			return n;
 		} else if (right == a) {
-			ir_mode *l_mode = get_irn_mode(left);
-
-			n = new_r_Minus(get_nodes_block(n), left, l_mode);
+			n = new_r_Minus(get_nodes_block(n), left);
 			/* This Sub is an effective Cast */
-			if (mode != l_mode)
+			if (mode != get_irn_mode(left))
 				n = new_r_Conv(get_nodes_block(n), n, mode);
 			DBG_OPT_ALGSIM1(oldn, a, b, n);
 			return n;
@@ -3534,7 +3530,7 @@ static ir_node *transform_node_Sub(ir_node *n)
 					ir_tarval *const tv_not = tarval_not(tv);
 					ir_node   *const not_c  = new_rd_Const(dbgi, irg, tv_not);
 					ir_node   *const and    = new_rd_And(dbgi, block, other, not_c, mode);
-					ir_node   *const minus  = new_rd_Minus(dbgi, block, and, mode);
+					ir_node   *const minus  = new_rd_Minus(dbgi, block, and);
 					return minus;
 				}
 			}
@@ -3736,7 +3732,7 @@ static ir_node *transform_node_Mul(ir_node *n)
 		  || (mode_is_float(mode) && tarval_is_minus_one(c1))) {
 			dbg_info *dbgi  = get_irn_dbg_info(n);
 			ir_node  *block = get_nodes_block(n);
-			return new_rd_Minus(dbgi, block, a, mode);
+			return new_rd_Minus(dbgi, block, a);
 		} else if (arith == irma_twos_complement
 		        && get_tarval_popcount(c1) == 1) {
 			/* multiplication behaves Shl-like */
@@ -3763,7 +3759,7 @@ static ir_node *transform_node_Mul(ir_node *n)
 			/* a * (b & 1) -> a & -(b & 1) */
 			dbg_info *dbgi  = get_irn_dbg_info(n);
 			ir_node  *block = get_nodes_block(n);
-			ir_node  *minus = new_rd_Minus(dbgi, block, bit, mode);
+			ir_node  *minus = new_rd_Minus(dbgi, block, bit);
 			return new_rd_And(dbgi, block, other, minus, mode);
 		}
 	}
@@ -3929,7 +3925,7 @@ static ir_node *transform_node_Div(ir_node *n)
 
 				if (tarval_is_all_one(tv)) {
 					/* a / -1 */
-					value = new_rd_Minus(get_irn_dbg_info(n), get_nodes_block(n), a, mode);
+					value = new_rd_Minus(get_irn_dbg_info(n), get_nodes_block(n), a);
 					DBG_OPT_CSTEVAL(n, value);
 					goto make_tuple;
 				}
@@ -6942,7 +6938,7 @@ static ir_node *transform_node_Mux(ir_node *n)
 
 					if (rel_eq == ir_relation_equal ? is_Const_one(cmp_r) : is_Const_null(cmp_r)) {
 						/* Mux((a & 1) != 0, 0, b) => -a & b */
-						cmp_l = new_rd_Minus(dbgi, block, cmp_l, mode);
+						cmp_l = new_rd_Minus(dbgi, block, cmp_l);
 					} else {
 						/* Mux((a & 1) == 0, 0, b) => (a - 1) & b */
 						ir_node *one = new_rd_Const_one(dbgi, irg, mode);

ir/opt/loop.c

@@ -1418,7 +1418,7 @@ static ir_node *new_Abs(ir_node *const op, ir_mode *const mode)
 	ir_graph *const irg      = get_irn_irg(op);
 	ir_node  *const zero     = new_r_Const_null(irg, mode);
 	ir_node  *const cmp      = new_r_Cmp(block, op, zero, ir_relation_less);
-	ir_node  *const minus_op = new_r_Minus(block, op, mode);
+	ir_node  *const minus_op = new_r_Minus(block, op);
 	ir_node  *const mux      = new_r_Mux(block, cmp, op, minus_op, mode);
 	return mux;
 }

ir/opt/reassoc.c

@@ -1861,7 +1861,7 @@ static void rebuild(multi_op_env *multi_env)
 				}
 
 				if (!curr) {
-					curr = new_rd_Minus(dbgi, block, inner, mode);
+					curr = new_rd_Minus(dbgi, block, inner);
 				} else {
 					curr = new_rd_Sub(dbgi, block, curr, inner, mode);
 				}

scripts/ir_spec.py

@@ -548,6 +548,7 @@ class Load(Node):
 @op
 class Minus(Node):
 	"""returns the additive inverse of its operand"""
+	mode   = "get_irn_mode(irn_op)"
 	flags  = []
 	ins    = [
 		("op", "operand")