+ }
+ return proj;
+}
+
+/**
+ * Normalizes and optimizes Cmp nodes.
+ */
+static ir_node *transform_node_Proj_Cmp(ir_node *proj)
+{
+ if (get_opt_reassociation()) {
+ ir_node *n = get_Proj_pred(proj);
+ ir_node *left = get_Cmp_left(n);
+ ir_node *right = get_Cmp_right(n);
+ ir_node *c = NULL;
+ tarval *tv = NULL;
+ int changed = 0;
+ ir_mode *mode = NULL;
+ long proj_nr = get_Proj_proj(proj);
+
+ /*
+ * First step: normalize the compare op
+ * by placing the constant on the right site
+ * 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)
+ c = right;
+ else if (get_irn_op(left) == op_Const) {
+ c = left;
+ left = right;
+ right = c;
+
+ proj_nr = get_inversed_pnc(proj_nr);
+ changed |= 1;
+ }
+ else if (left > right) {
+ ir_node *t = left;
+
+ left = right;
+ right = t;
+
+ proj_nr = get_inversed_pnc(proj_nr);
+ changed |= 1;
+ }
+
+ /*
+ * Second step: Try to reduce the magnitude
+ * of a constant. This may help to generate better code
+ * later and may help to normalize more compares.
+ * Of course this is only possible for integer values.
+ */
+ if (c) {
+ mode = get_irn_mode(c);
+ tv = get_Const_tarval(c);
+
+ if (tv != tarval_bad) {
+ /* the following optimization is possible on modes without Overflow
+ * on Unary Minus or on == and !=:
+ * -a CMP c ==> a swap(CMP) -c
+ *
+ * Beware: for two-complement Overflow may occur, so only == and != can
+ * be optimized, see this:
+ * -MININT < 0 =/=> MININT > 0 !!!
+ */
+ if (get_opt_constant_folding() && get_irn_op(left) == op_Minus &&
+ (!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_sub(get_mode_null(mode), tv);
+
+ proj_nr = get_inversed_pnc(proj_nr);
+ changed |= 2;
+ }
+
+ /* for integer modes, we have more */
+ if (mode_is_int(mode)) {
+ /* Ne includes Unordered which is not possible on integers.
+ * However, frontends often use this wrong, so fix it here */
+ if (proj_nr & pn_Cmp_Uo) {
+ proj_nr &= ~pn_Cmp_Uo;
+ set_Proj_proj(proj, proj_nr);
+ }
+
+ /* c > 0 : a < c ==> a <= (c-1) a >= c ==> a > (c-1) */
+ if ((proj_nr == pn_Cmp_Lt || proj_nr == pn_Cmp_Ge) &&
+ tarval_cmp(tv, get_mode_null(mode)) == pn_Cmp_Gt) {
+ tv = tarval_sub(tv, get_mode_one(mode));
+
+ proj_nr ^= pn_Cmp_Eq;
+ changed |= 2;
+ }
+ /* c < 0 : a > c ==> a >= (c+1) a <= c ==> a < (c+1) */
+ else if ((proj_nr == pn_Cmp_Gt || proj_nr == pn_Cmp_Le) &&
+ tarval_cmp(tv, get_mode_null(mode)) == pn_Cmp_Lt) {
+ tv = tarval_add(tv, get_mode_one(mode));
+
+ proj_nr ^= pn_Cmp_Eq;
+ changed |= 2;
+ }
+
+ /* the following reassociations work only for == and != */
+ 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);
+ left = get_Sub_left(left);
+
+ tv = value_of(right);
+ changed = 1;
+ }
+
+ if (tv != tarval_bad) {
+ ir_op *op = get_irn_op(left);
+
+ /* a-c1 == c2 ==> a == c2+c1, a-c1 != c2 ==> a != c2+c1 */
+ if (op == op_Sub) {
+ ir_node *c1 = get_Sub_right(left);
+ tarval *tv2 = value_of(c1);
+
+ if (tv2 != tarval_bad) {
+ tv2 = tarval_add(tv, value_of(c1));
+
+ if (tv2 != tarval_bad) {
+ left = get_Sub_left(left);
+ tv = tv2;
+ changed |= 2;
+ }
+ }
+ }
+ /* a+c1 == c2 ==> a == c2-c1, a+c1 != c2 ==> a != c2-c1 */
+ else if (op == op_Add) {
+ ir_node *a_l = get_Add_left(left);
+ ir_node *a_r = get_Add_right(left);
+ ir_node *a;
+ tarval *tv2;
+
+ if (get_irn_op(a_l) == op_Const) {
+ a = a_r;
+ tv2 = value_of(a_l);
+ }
+ else {
+ a = a_l;
+ tv2 = value_of(a_r);
+ }
+
+ if (tv2 != tarval_bad) {
+ tv2 = tarval_sub(tv, tv2);
+
+ if (tv2 != tarval_bad) {
+ left = a;
+ tv = tv2;
+ changed |= 2;
+ }
+ }
+ }
+ /* -a == c ==> a == -c, -a != c ==> a != -c */
+ else if (op == op_Minus) {
+ tarval *tv2 = tarval_sub(get_mode_null(mode), tv);
+
+ if (tv2 != tarval_bad) {
+ left = get_Minus_op(left);
+ tv = tv2;
+ changed |= 2;
+ }
+ }
+ }
+ } /* == or != */
+ /* the following reassociations work only for <= */
+ else if (proj_nr == pn_Cmp_Le || proj_nr == pn_Cmp_Lt) {
+ if (tv != tarval_bad) {
+ ir_op *op = get_irn_op(left);
+
+ /* c >= 0 : Abs(a) <= c ==> (unsigned)(a + c) <= 2*c */
+ if (op == op_Abs) {
+ }
+ }
+ }
+ } /* mode_is_int */
+ }
+ }
+
+ if (changed) {
+ ir_node *block = get_irn_n(n, -1); /* Beware of get_nodes_Block() */
+
+ if (changed & 2) /* need a new Const */
+ right = new_Const(mode, tv);
+
+ /* create a new compare */
+ 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);
+ }
+ }
+ return proj;
+}
+
+/**
+ * Does all optimizations on nodes that must be done on it's Proj's
+ * because of creating new nodes.
+ */
+static ir_node *transform_node_Proj(ir_node *proj)
+{
+ ir_node *n = get_Proj_pred(proj);
+
+ switch (get_irn_opcode(n)) {
+ case iro_Div:
+ return transform_node_Proj_Div(proj);
+
+ case iro_Mod:
+ return transform_node_Proj_Mod(proj);
+
+ case iro_DivMod:
+ return transform_node_Proj_DivMod(proj);
+
+ case iro_Cond:
+ return transform_node_Proj_Cond(proj);
+
+ case iro_Cmp:
+ return transform_node_Proj_Cmp(proj);