+# include "irflag_t.h"
+# include "irhooks.h"
+# include "irarch.h"
+# include "hashptr.h"
+# include "archop.h"
+# include "opt_polymorphy.h"
+# include "opt_confirms.h"
+
+/* Make types visible to allow most efficient access */
+# include "entity_t.h"
+
+/**
+ * return the value of a Constant
+ */
+static tarval *computed_value_Const(ir_node *n)
+{
+ return get_Const_tarval(n);
+}
+
+/**
+ * return the value of a 'sizeof' SymConst
+ */
+static tarval *computed_value_SymConst(ir_node *n)
+{
+ if ((get_SymConst_kind(n) == symconst_size) &&
+ (get_type_state(get_SymConst_type(n))) == layout_fixed)
+ return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(n)), get_irn_mode(n));
+ return tarval_bad;
+}
+
+/**
+ * return the value of an Add
+ */
+static tarval *computed_value_Add(ir_node *n)
+{
+ ir_node *a = get_Add_left(n);
+ ir_node *b = get_Add_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b)))
+ return tarval_add(ta, tb);
+
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Sub
+ * Special case: a - a
+ */
+static tarval *computed_value_Sub(ir_node *n)
+{
+ ir_node *a = get_Sub_left(n);
+ ir_node *b = get_Sub_right(n);
+ tarval *ta;
+ tarval *tb;
+
+ /* a - a */
+ if (a == b && !is_Bad(a))
+ return get_mode_null(get_irn_mode(n));
+
+ ta = value_of(a);
+ tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b)))
+ return tarval_sub(ta, tb);
+
+ return tarval_bad;
+}
+
+/**
+ * return the value of an unary Minus
+ */
+static tarval *computed_value_Minus(ir_node *n)
+{
+ ir_node *a = get_Minus_op(n);
+ tarval *ta = value_of(a);
+
+ if ((ta != tarval_bad) && mode_is_signed(get_irn_mode(a)))
+ return tarval_neg(ta);
+
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Mul
+ */
+static tarval *computed_value_Mul(ir_node *n)
+{
+ ir_node *a = get_Mul_left(n);
+ ir_node *b = get_Mul_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
+ return tarval_mul(ta, tb);
+ } else {
+ /* a*0 = 0 or 0*b = 0:
+ calls computed_value recursive and returns the 0 with proper
+ mode. */
+ if ((ta != tarval_bad) && (ta == get_mode_null(get_tarval_mode(ta))))
+ return ta;
+ if ((tb != tarval_bad) && (tb == get_mode_null(get_tarval_mode(tb))))
+ return tb;
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of a floating point Quot
+ */
+static tarval *computed_value_Quot(ir_node *n)
+{
+ ir_node *a = get_Quot_left(n);
+ ir_node *b = get_Quot_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ /* This was missing in original implementation. Why? */
+ if ((ta != tarval_bad) && (tb != tarval_bad) && (get_irn_mode(a) == get_irn_mode(b))) {
+ if (tb != get_mode_null(get_tarval_mode(tb))) /* div by zero: return tarval_bad */
+ return tarval_quo(ta, tb);
+ }
+ return tarval_bad;
+}
+
+/**
+ * calculate the value of an integer Div of two nodes
+ * Special case: 0 / b
+ */
+static tarval *do_computed_value_Div(ir_node *a, ir_node *b)
+{
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ /* Compute c1 / c2 or 0 / a, a != 0 */
+ if (ta != tarval_bad) {
+ if ((tb != tarval_bad) && (tb != get_mode_null(get_irn_mode(b)))) /* div by zero: return tarval_bad */
+ return tarval_div(ta, tb);
+ else if (ta == get_mode_null(get_tarval_mode(ta))) /* 0 / b == 0 */
+ return ta;
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of an integer Div
+ */
+static tarval *computed_value_Div(ir_node *n)
+{
+ return do_computed_value_Div(get_Div_left(n), get_Div_right(n));
+}
+
+/**
+ * calculate the value of an integer Mod of two nodes
+ * Special case: a % 1
+ */
+static tarval *do_computed_value_Mod(ir_node *a, ir_node *b)
+{
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ /* Compute c1 % c2 or a % 1 */
+ if (tb != tarval_bad) {
+ if ((ta != tarval_bad) && (tb != get_mode_null(get_tarval_mode(tb)))) /* div by zero: return tarval_bad */
+ return tarval_mod(ta, tb);
+ else if (tb == get_mode_one(get_tarval_mode(tb))) /* x mod 1 == 0 */
+ return get_mode_null(get_irn_mode(a));
+ }
+
+ return tarval_bad;
+}
+
+/**
+ * return the value of an integer Mod
+ */
+static tarval *computed_value_Mod(ir_node *n)
+{
+ return do_computed_value_Mod(get_Mod_left(n), get_Mod_right(n));
+}
+
+/**
+ * return the value of an Abs
+ */
+static tarval *computed_value_Abs(ir_node *n)
+{
+ ir_node *a = get_Abs_op(n);
+ tarval *ta = value_of(a);
+
+ if (ta != tarval_bad)
+ return tarval_abs(ta);
+
+ return tarval_bad;
+}
+
+/**
+ * return the value of an And
+ * Special case: a & 0, 0 & b
+ */
+static tarval *computed_value_And(ir_node *n)
+{
+ ir_node *a = get_And_left(n);
+ ir_node *b = get_And_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_and (ta, tb);
+ } else {
+ tarval *v;
+
+ if ( (classify_tarval ((v = ta)) == TV_CLASSIFY_NULL)
+ || (classify_tarval ((v = tb)) == TV_CLASSIFY_NULL)) {
+ return v;
+ }
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of an Or
+ * Special case: a | 1...1, 1...1 | b
+ */
+static tarval *computed_value_Or(ir_node *n)
+{
+ ir_node *a = get_Or_left(n);
+ ir_node *b = get_Or_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_or (ta, tb);
+ } else {
+ tarval *v;
+ if ( (classify_tarval ((v = ta)) == TV_CLASSIFY_ALL_ONE)
+ || (classify_tarval ((v = tb)) == TV_CLASSIFY_ALL_ONE)) {
+ return v;
+ }
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of an Eor
+ */
+static tarval *computed_value_Eor(ir_node *n)
+{
+ ir_node *a = get_Eor_left(n);
+ ir_node *b = get_Eor_right(n);
+
+ tarval *ta, *tb;
+
+ if (a == b)
+ return get_mode_null(get_irn_mode(n));
+
+ ta = value_of(a);
+ tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_eor (ta, tb);
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Not
+ */
+static tarval *computed_value_Not(ir_node *n)
+{
+ ir_node *a = get_Not_op(n);
+ tarval *ta = value_of(a);
+
+ if (ta != tarval_bad)
+ return tarval_not(ta);
+
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Shl
+ */
+static tarval *computed_value_Shl(ir_node *n)
+{
+ ir_node *a = get_Shl_left(n);
+ ir_node *b = get_Shl_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_shl (ta, tb);
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Shr
+ */
+static tarval *computed_value_Shr(ir_node *n)
+{
+ ir_node *a = get_Shr_left(n);
+ ir_node *b = get_Shr_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_shr (ta, tb);
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Shrs
+ */
+static tarval *computed_value_Shrs(ir_node *n)
+{
+ ir_node *a = get_Shrs_left(n);
+ ir_node *b = get_Shrs_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_shrs (ta, tb);
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Rot
+ */
+static tarval *computed_value_Rot(ir_node *n)
+{
+ ir_node *a = get_Rot_left(n);
+ ir_node *b = get_Rot_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_rot (ta, tb);
+ }
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Conv
+ */
+static tarval *computed_value_Conv(ir_node *n)
+{
+ ir_node *a = get_Conv_op(n);
+ tarval *ta = value_of(a);
+
+ if (ta != tarval_bad)
+ return tarval_convert_to(ta, get_irn_mode(n));
+
+ return tarval_bad;
+}
+
+/**
+ * return the value of a Proj(Cmp)
+ *
+ * This performs a first step of unreachable code elimination.
+ * Proj can not be computed, but folding a Cmp above the Proj here is
+ * not as wasteful as folding a Cmp into a Tuple of 16 Consts of which
+ * only 1 is used.
+ * There are several case where we can evaluate a Cmp node, see later.
+ */
+static tarval *computed_value_Proj_Cmp(ir_node *n)
+{
+ ir_node *a = get_Proj_pred(n);
+ ir_node *aa = get_Cmp_left(a);
+ ir_node *ab = get_Cmp_right(a);
+ long proj_nr = get_Proj_proj(n);
+
+ /*
+ * BEWARE: a == a is NOT always True for floating Point values, as
+ * NaN != NaN is defined, so we must check this here.
+ */
+ if (aa == ab && (
+ !mode_is_float(get_irn_mode(aa)) || proj_nr == pn_Cmp_Lt || proj_nr == pn_Cmp_Gt)
+ ) { /* 1.: */
+
+ /* This is a trick with the bits used for encoding the Cmp
+ Proj numbers, the following statement is not the same:
+ return new_tarval_from_long (proj_nr == pn_Cmp_Eq, mode_b) */
+ return new_tarval_from_long (proj_nr & pn_Cmp_Eq, mode_b);
+ }
+ else {
+ tarval *taa = value_of(aa);
+ tarval *tab = value_of(ab);
+ ir_mode *mode = get_irn_mode(aa);
+
+ /*
+ * The predecessors of Cmp are target values. We can evaluate
+ * the Cmp.
+ */
+ if ((taa != tarval_bad) && (tab != tarval_bad)) {
+ /* strange checks... */
+ pn_Cmp flags = tarval_cmp(taa, tab);
+ if (flags != pn_Cmp_False) {
+ return new_tarval_from_long (proj_nr & flags, mode_b);
+ }
+ }
+ /* for integer values, we can check against MIN/MAX */
+ else if (mode_is_int(mode)) {
+ /* MIN <=/> x. This results in true/false. */
+ if (taa == get_mode_min(mode)) {
+ /* a compare with the MIN value */
+ if (proj_nr == pn_Cmp_Le)
+ return get_tarval_b_true();
+ else if (proj_nr == pn_Cmp_Gt)
+ return get_tarval_b_false();
+ }
+ /* x >=/< MIN. This results in true/false. */
+ else
+ if (tab == get_mode_min(mode)) {
+ /* a compare with the MIN value */
+ if (proj_nr == pn_Cmp_Ge)
+ return get_tarval_b_true();
+ else if (proj_nr == pn_Cmp_Lt)
+ return get_tarval_b_false();
+ }
+ /* MAX >=/< x. This results in true/false. */
+ else if (taa == get_mode_max(mode)) {
+ if (proj_nr == pn_Cmp_Ge)
+ return get_tarval_b_true();
+ else if (proj_nr == pn_Cmp_Lt)
+ return get_tarval_b_false();
+ }
+ /* x <=/> MAX. This results in true/false. */
+ else if (tab == get_mode_max(mode)) {
+ if (proj_nr == pn_Cmp_Le)
+ return get_tarval_b_true();
+ else if (proj_nr == pn_Cmp_Gt)
+ return get_tarval_b_false();
+ }
+ }
+ /*
+ * The predecessors are Allocs or (void*)(0) constants. Allocs never
+ * return NULL, they raise an exception. Therefore we can predict
+ * the Cmp result.
+ */
+ else {
+ ir_node *aaa = skip_Id(skip_Proj(aa));
+ ir_node *aba = skip_Id(skip_Proj(ab));
+
+ if ( ( (/* aa is ProjP and aaa is Alloc */
+ (get_irn_op(aa) == op_Proj)
+ && (mode_is_reference(get_irn_mode(aa)))
+ && (get_irn_op(aaa) == op_Alloc))
+ && ( (/* ab is NULL */
+ (get_irn_op(ab) == op_Const)
+ && (mode_is_reference(get_irn_mode(ab)))
+ && (get_Const_tarval(ab) == get_mode_null(get_irn_mode(ab))))
+ || (/* ab is other Alloc */
+ (get_irn_op(ab) == op_Proj)
+ && (mode_is_reference(get_irn_mode(ab)))
+ && (get_irn_op(aba) == op_Alloc)
+ && (aaa != aba))))
+ || (/* aa is NULL and aba is Alloc */
+ (get_irn_op(aa) == op_Const)
+ && (mode_is_reference(get_irn_mode(aa)))
+ && (get_Const_tarval(aa) == get_mode_null(get_irn_mode(aa)))
+ && (get_irn_op(ab) == op_Proj)
+ && (mode_is_reference(get_irn_mode(ab)))
+ && (get_irn_op(aba) == op_Alloc)))
+ /* 3.: */
+ return new_tarval_from_long(proj_nr & pn_Cmp_Ne, mode_b);
+ }
+ }
+
+ return computed_value_Cmp_Confirm(a, aa, ab, proj_nr);
+}
+
+/**
+ * return the value of a Proj, handle Proj(Cmp), Proj(Div), Proj(Mod), Proj(DivMod)
+ */
+static tarval *computed_value_Proj(ir_node *n)
+{
+ ir_node *a = get_Proj_pred(n);
+ long proj_nr;
+
+ switch (get_irn_opcode(a)) {
+ case iro_Cmp:
+ return computed_value_Proj_Cmp(n);
+
+ case iro_DivMod:
+ /* compute either the Div or the Mod part */
+ proj_nr = get_Proj_proj(n);
+ if (proj_nr == pn_DivMod_res_div)
+ return do_computed_value_Div(get_DivMod_left(a), get_DivMod_right(a));
+ else if (proj_nr == pn_DivMod_res_mod)
+ return do_computed_value_Mod(get_DivMod_left(a), get_DivMod_right(a));
+ break;
+
+ case iro_Div:
+ if (get_Proj_proj(n) == pn_Div_res)
+ return computed_value(a);
+ break;
+
+ case iro_Mod:
+ if (get_Proj_proj(n) == pn_Mod_res)
+ return computed_value(a);
+ break;
+
+ default:
+ return tarval_bad;
+ }
+ return tarval_bad;
+}
+
+/**
+ * calculate the value of a Mux: can be evaluated, if the
+ * sel and the right input are known
+ */
+static tarval *computed_value_Mux(ir_node *n)
+{
+ ir_node *sel = get_Mux_sel(n);
+ tarval *ts = value_of(sel);
+
+ if (ts == get_tarval_b_true()) {
+ ir_node *v = get_Mux_true(n);
+ return value_of(v);
+ }
+ else if (ts == get_tarval_b_false()) {
+ ir_node *v = get_Mux_false(n);
+ return value_of(v);
+ }
+ return tarval_bad;
+}
+
+/**
+ * calculate the value of a Confirm: can be evaluated,
+ * if it has the form Confirm(x, '=', Const).
+ */
+static tarval *computed_value_Confirm(ir_node *n)
+{
+ return get_Confirm_cmp(n) == pn_Cmp_Eq ?
+ value_of(get_Confirm_bound(n)) : tarval_bad;
+}
+
+/**
+ * If the parameter n can be computed, return its value, else tarval_bad.
+ * Performs constant folding.
+ *
+ * @param n The node this should be evaluated
+ */
+tarval *computed_value(ir_node *n)
+{
+ if (n->op->computed_value)
+ return n->op->computed_value(n);
+ return tarval_bad;
+}
+
+/**
+ * set the default computed_value evaluator
+ */
+static ir_op *firm_set_default_computed_value(ir_op *op)
+{
+#define CASE(a) \
+ case iro_##a: \
+ op->computed_value = computed_value_##a; \
+ break
+
+ switch (op->code) {
+ CASE(Const);
+ CASE(SymConst);
+ CASE(Add);
+ CASE(Sub);
+ CASE(Minus);
+ CASE(Mul);
+ CASE(Quot);
+ CASE(Div);
+ CASE(Mod);
+ CASE(Abs);
+ CASE(And);
+ CASE(Or);
+ CASE(Eor);
+ CASE(Not);
+ CASE(Shl);
+ CASE(Shr);
+ CASE(Shrs);
+ CASE(Rot);
+ CASE(Conv);
+ CASE(Proj);
+ CASE(Mux);
+ CASE(Confirm);
+ default:
+ op->computed_value = NULL;
+ }
+
+ return op;
+#undef CASE
+}
+
+#if 0
+/* returns 1 if the a and b are pointers to different locations. */
+static bool
+different_identity (ir_node *a, ir_node *b)
+{
+ assert (mode_is_reference(get_irn_mode (a))
+ && mode_is_reference(get_irn_mode (b)));
+
+ if (get_irn_op (a) == op_Proj && get_irn_op(b) == op_Proj) {
+ ir_node *a1 = get_Proj_pred (a);
+ ir_node *b1 = get_Proj_pred (b);
+ if (a1 != b1 && get_irn_op (a1) == op_Alloc
+ && get_irn_op (b1) == op_Alloc)
+ return 1;
+ }
+ return 0;
+}
+#endif
+
+/**
+ * Returns a equivalent block for another block.
+ * If the block has only one predecessor, this is
+ * the equivalent one. If the only predecessor of a block is
+ * the block itself, this is a dead block.
+ *
+ * If both predecessors of a block are the branches of a binary
+ * Cond, the equivalent block is Cond's block.
+ *
+ * If all predecessors of a block are bad or lies in a dead
+ * block, the current block is dead as well.
+ *
+ * Note, that blocks are NEVER turned into Bad's, instead
+ * the dead_block flag is set. So, never test for is_Bad(block),
+ * always use is_dead_Block(block).
+ */
+static ir_node *equivalent_node_Block(ir_node *n)
+{
+ ir_node *oldn = n;
+ int n_preds = get_Block_n_cfgpreds(n);
+
+ /* The Block constructor does not call optimize, but mature_immBlock
+ calls the optimization. */
+ assert(get_Block_matured(n));
+
+ /* Straightening: a single entry Block following a single exit Block
+ can be merged, if it is not the Start block. */
+ /* !!! Beware, all Phi-nodes of n must have been optimized away.
+ This should be true, as the block is matured before optimize is called.
+ But what about Phi-cycles with the Phi0/Id that could not be resolved?
+ Remaining Phi nodes are just Ids. */
+ if ((n_preds == 1) && (get_irn_op(get_Block_cfgpred(n, 0)) == op_Jmp)) {
+ ir_node *predblock = get_nodes_block(get_Block_cfgpred(n, 0));
+ if (predblock == oldn) {
+ /* Jmp jumps into the block it is in -- deal self cycle. */
+ n = set_Block_dead(n);
+ DBG_OPT_DEAD_BLOCK(oldn, n);
+ } else if (get_opt_control_flow_straightening()) {
+ n = predblock;
+ DBG_OPT_STG(oldn, n);
+ }
+ }
+ else if ((n_preds == 1) &&
+ (get_irn_op(skip_Proj(get_Block_cfgpred(n, 0))) == op_Cond)) {
+ ir_node *predblock = get_Block_cfgpred_block(n, 0);
+ if (predblock == oldn) {
+ /* Jmp jumps into the block it is in -- deal self cycle. */
+ n = set_Block_dead(n);
+ DBG_OPT_DEAD_BLOCK(oldn, n);
+ }
+ }
+ else if ((n_preds == 2) &&
+ (get_opt_control_flow_weak_simplification())) {
+ /* Test whether Cond jumps twice to this block
+ * The more general case which more than 2 predecessors is handles
+ * in optimize_cf(), we handle only this special case for speed here.
+ */
+ ir_node *a = get_Block_cfgpred(n, 0);
+ ir_node *b = get_Block_cfgpred(n, 1);
+
+ if ((get_irn_op(a) == op_Proj) &&
+ (get_irn_op(b) == op_Proj) &&
+ (get_Proj_pred(a) == get_Proj_pred(b)) &&
+ (get_irn_op(get_Proj_pred(a)) == op_Cond) &&
+ (get_irn_mode(get_Cond_selector(get_Proj_pred(a))) == mode_b)) {
+ /* Also a single entry Block following a single exit Block. Phis have
+ twice the same operand and will be optimized away. */
+ n = get_nodes_block(a);
+ DBG_OPT_IFSIM1(oldn, a, b, n);
+ }
+ }
+ else if (get_opt_unreachable_code() &&
+ (n != current_ir_graph->start_block) &&
+ (n != current_ir_graph->end_block) ) {
+ int i, n_cfg = get_Block_n_cfgpreds(n);
+
+ /* If all inputs are dead, this block is dead too, except if it is
+ the start or end block. This is a step of unreachable code
+ elimination */
+ for (i = 0; i < n_cfg; i++) {
+ ir_node *pred = get_Block_cfgpred(n, i);
+ ir_node *pred_blk;
+
+ if (is_Bad(pred)) continue;
+ pred_blk = get_nodes_block(skip_Proj(pred));
+
+ if (is_Block_dead(pred_blk)) continue;
+
+ if (pred_blk != n) {
+ /* really found a living input */
+ break;
+ }
+ }
+ if (i == n_cfg)
+ n = set_Block_dead(n);
+ }
+
+ return n;
+}
+
+/**
+ * Returns a equivalent node for a Jmp, a Bad :-)
+ * Of course this only happens if the Block of the Jmp is Bad.
+ */
+static ir_node *equivalent_node_Jmp(ir_node *n)
+{
+ /* GL: Why not same for op_Raise?? */
+ /* unreachable code elimination */
+ if (is_Block_dead(get_nodes_block(n)))
+ n = new_Bad();
+
+ return n;
+}
+
+/* We do not evaluate Cond here as we replace it by a new node, a Jmp.
+ See transform_node_Proj_Cond(). */
+
+/**
+ * optimize operations that are commutative and have neutral 0,
+ * so a op 0 = 0 op a = a.
+ */
+static ir_node *equivalent_node_neutral_zero(ir_node *n)
+{
+ ir_node *oldn = n;
+
+ ir_node *a = get_binop_left(n);
+ ir_node *b = get_binop_right(n);
+
+ tarval *tv;
+ ir_node *on;
+
+ /* After running compute_node there is only one constant predecessor.
+ Find this predecessors value and remember the other node: */
+ if ((tv = value_of(a)) != tarval_bad) {
+ on = b;
+ } else if ((tv = value_of(b)) != tarval_bad) {
+ on = a;
+ } else
+ return n;
+
+ /* If this predecessors constant value is zero, the operation is
+ * unnecessary. Remove it.
+ *
+ * Beware: If n is a Add, the mode of on and n might be different
+ * which happens in this rare construction: NULL + 3.
+ * Then, a Conv would be needed which we cannot include here.
+ */
+ if (classify_tarval (tv) == TV_CLASSIFY_NULL) {
+ if (get_irn_mode(on) == get_irn_mode(n)) {
+ n = on;
+
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_0);
+ }
+ }
+
+ return n;
+}
+
+#define equivalent_node_Eor equivalent_node_neutral_zero
+
+/*
+ * Optimize a - 0 and (a - x) + x (for modes with wrap-around).
+ *
+ * The second one looks strange, but this construct
+ * is used heavily in the LCC sources :-).
+ *
+ * Beware: The Mode of an Add may be different than the mode of its
+ * predecessors, so we could not return a predecessors in all cases.
+ */
+static ir_node *equivalent_node_Add(ir_node *n)
+{
+ ir_node *oldn = n;
+ ir_node *left, *right;
+
+ n = equivalent_node_neutral_zero(n);
+ if (n != oldn)
+ return n;
+
+ left = get_Add_left(n);
+ right = get_Add_right(n);
+
+ if (get_irn_op(left) == op_Sub) {
+ if (get_Sub_right(left) == right) {
+ /* (a - x) + x */
+
+ n = get_Sub_left(left);
+ if (get_irn_mode(oldn) == get_irn_mode(n)) {
+ DBG_OPT_ALGSIM1(oldn, left, right, n, FS_OPT_ADD_SUB);
+ return n;
+ }
+ }
+ }
+ if (get_irn_op(right) == op_Sub) {
+ if (get_Sub_right(right) == left) {
+ /* x + (a - x) */
+
+ n = get_Sub_left(right);
+ if (get_irn_mode(oldn) == get_irn_mode(n)) {
+ DBG_OPT_ALGSIM1(oldn, left, right, n, FS_OPT_ADD_SUB);
+ return n;
+ }
+ }
+ }
+ return n;
+}
+
+/**
+ * optimize operations that are not commutative but have neutral 0 on left,
+ * so a op 0 = a.
+ */
+static ir_node *equivalent_node_left_zero(ir_node *n)
+{
+ ir_node *oldn = n;
+
+ ir_node *a = get_binop_left(n);
+ ir_node *b = get_binop_right(n);
+
+ if (classify_tarval(value_of(b)) == TV_CLASSIFY_NULL) {
+ n = a;
+
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_0);
+ }
+
+ return n;
+}
+
+#define equivalent_node_Shl equivalent_node_left_zero
+#define equivalent_node_Shr equivalent_node_left_zero
+#define equivalent_node_Shrs equivalent_node_left_zero
+#define equivalent_node_Rot equivalent_node_left_zero
+
+/**
+ * Optimize a - 0 and (a + x) - x (for modes with wrap-around).
+ *
+ * The second one looks strange, but this construct
+ * is used heavily in the LCC sources :-).
+ *
+ * Beware: The Mode of a Sub may be different than the mode of its
+ * predecessors, so we could not return a predecessors in all cases.
+ */
+static ir_node *equivalent_node_Sub(ir_node *n)
+{
+ ir_node *oldn = n;
+
+ ir_node *a = get_Sub_left(n);
+ ir_node *b = get_Sub_right(n);
+
+ /* Beware: modes might be different */
+ if (classify_tarval(value_of(b)) == TV_CLASSIFY_NULL) {
+ if (get_irn_mode(n) == get_irn_mode(a)) {
+ n = a;
+
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_0);
+ }
+ }
+ else if (get_irn_op(a) == op_Add) {
+ ir_mode *mode = get_irn_mode(n);
+
+ if (mode_wrap_around(mode)) {
+ ir_node *left = get_Add_left(a);
+ ir_node *right = get_Add_right(a);
+
+ if (left == b) {
+ if (get_irn_mode(n) == get_irn_mode(right)) {
+ n = right;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+ }
+ }
+ else if (right == b) {
+ if (get_irn_mode(n) == get_irn_mode(left)) {
+ n = left;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_ADD_SUB);
+ }
+ }
+ }
+ }
+
+ return n;
+}
+
+
+/**
+ * Optimize an "idempotent unary op", ie op(op(n)) = n.
+ *
+ * @fixme -(-a) == a, but might overflow two times.
+ * We handle it anyway here but the better way would be a
+ * flag. This would be needed for Pascal for instance.
+ */
+static ir_node *equivalent_node_idempotent_unop(ir_node *n)
+{
+ ir_node *oldn = n;
+ ir_node *pred = get_unop_op(n);
+
+ /* optimize symmetric unop */
+ if (get_irn_op(pred) == get_irn_op(n)) {
+ n = get_unop_op(pred);
+ DBG_OPT_ALGSIM2(oldn, pred, n);
+ }
+ return n;
+}
+
+/* Not(Not(x)) == x */
+#define equivalent_node_Not equivalent_node_idempotent_unop
+
+/* --x == x */ /* ??? Is this possible or can --x raise an
+ out of bounds exception if min =! max? */
+#define equivalent_node_Minus equivalent_node_idempotent_unop
+
+/**
+ * Optimize a * 1 = 1 * a = a.
+ */
+static ir_node *equivalent_node_Mul(ir_node *n)
+{
+ ir_node *oldn = n;
+
+ ir_node *a = get_Mul_left(n);
+ ir_node *b = get_Mul_right(n);
+
+ /* Mul is commutative and has again an other neutral element. */
+ if (classify_tarval(value_of(a)) == TV_CLASSIFY_ONE) {
+ n = b;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
+ } else if (classify_tarval(value_of(b)) == TV_CLASSIFY_ONE) {
+ n = a;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_NEUTRAL_1);
+ }
+ return n;
+}
+
+/**
+ * Optimize a / 1 = a.
+ */
+static ir_node *equivalent_node_Div(ir_node *n)
+{
+ ir_node *a = get_Div_left(n);
+ ir_node *b = get_Div_right(n);
+
+ /* Div is not commutative. */
+ if (classify_tarval(value_of(b)) == TV_CLASSIFY_ONE) { /* div(x, 1) == x */
+ /* Turn Div into a tuple (mem, bad, a) */
+ ir_node *mem = get_Div_mem(n);
+ turn_into_tuple(n, 3);
+ set_Tuple_pred(n, pn_Div_M, mem);
+ set_Tuple_pred(n, pn_Div_X_except, new_Bad()); /* no exception */
+ set_Tuple_pred(n, pn_Div_res, a);
+ }
+ return n;
+}
+
+/**
+ * Optimize a / 1 = a.
+ */
+static ir_node *equivalent_node_DivMod(ir_node *n)
+{
+ ir_node *a = get_DivMod_left(n);
+ ir_node *b = get_DivMod_right(n);
+
+ /* Div is not commutative. */
+ if (classify_tarval(value_of(b)) == TV_CLASSIFY_ONE) { /* div(x, 1) == x */
+ /* Turn DivMod into a tuple (mem, bad, a, 0) */
+ ir_node *mem = get_Div_mem(n);
+ ir_mode *mode = get_irn_mode(b);
+
+ turn_into_tuple(n, 4);
+ set_Tuple_pred(n, pn_DivMod_M, mem);
+ set_Tuple_pred(n, pn_DivMod_X_except, new_Bad()); /* no exception */
+ set_Tuple_pred(n, pn_DivMod_res_div, a);
+ set_Tuple_pred(n, pn_DivMod_res_mod, new_Const(mode, get_mode_null(mode)));
+ }
+ return n;
+}
+
+/**
+ * Use algebraic simplification a | a = a | 0 = 0 | a = a.
+ */
+static ir_node *equivalent_node_Or(ir_node *n)
+{
+ ir_node *oldn = n;
+
+ ir_node *a = get_Or_left(n);
+ ir_node *b = get_Or_right(n);
+
+ if (a == b) {
+ n = a; /* Or has it's own neutral element */
+ DBG_OPT_ALGSIM0(oldn, n, FS_OPT_OR);
+ } else if (classify_tarval(value_of(a)) == TV_CLASSIFY_NULL) {
+ n = b;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_OR);
+ } else if (classify_tarval(value_of(b)) == TV_CLASSIFY_NULL) {
+ n = a;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_OR);
+ }
+
+ return n;
+}
+
+/**
+ * Optimize a & 0b1...1 = 0b1...1 & a = a & a = a.
+ */
+static ir_node *equivalent_node_And(ir_node *n)
+{
+ ir_node *oldn = n;
+
+ ir_node *a = get_And_left(n);
+ ir_node *b = get_And_right(n);
+
+ if (a == b) {
+ n = a; /* And has it's own neutral element */
+ DBG_OPT_ALGSIM0(oldn, n, FS_OPT_AND);
+ } else if (classify_tarval(value_of(a)) == TV_CLASSIFY_ALL_ONE) {
+ n = b;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_AND);
+ } else if (classify_tarval(value_of(b)) == TV_CLASSIFY_ALL_ONE) {
+ n = a;
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_AND);
+ }
+ return n;
+}
+
+/**
+ * Try to remove useless Conv's:
+ */
+static ir_node *equivalent_node_Conv(ir_node *n)
+{
+ ir_node *oldn = n;
+ ir_node *a = get_Conv_op(n);
+ ir_node *b;
+
+ ir_mode *n_mode = get_irn_mode(n);
+ ir_mode *a_mode = get_irn_mode(a);
+
+ if (n_mode == a_mode) { /* No Conv necessary */
+ n = a;
+ DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CONV);
+ } else if (get_irn_op(a) == op_Conv) { /* Conv(Conv(b)) */
+ ir_mode *b_mode;
+
+ b = get_Conv_op(a);
+ n_mode = get_irn_mode(n);
+ b_mode = get_irn_mode(b);
+
+ if (n_mode == b_mode) {
+ if (n_mode == mode_b) {
+ n = b; /* Convb(Conv*(xxxb(...))) == xxxb(...) */
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);
+ }
+ else if (mode_is_int(n_mode) || mode_is_character(n_mode)) {
+ if (smaller_mode(b_mode, a_mode)){
+ n = b; /* ConvS(ConvL(xxxS(...))) == xxxS(...) */
+ DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);
+ }
+ }
+ }
+ }
+ return n;
+}
+
+/**
+ * A Cast may be removed if the type of the previous node
+ * is already the type of the Cast.
+ */
+static ir_node *equivalent_node_Cast(ir_node *n) {
+ ir_node *oldn = n;
+ ir_node *pred = get_Cast_op(n);
+
+ if (get_irn_type(pred) == get_Cast_type(n)) {
+ n = pred;
+ DBG_OPT_ALGSIM0(oldn, n, FS_OPT_CAST);
+ }
+ return n;
+}
+
+/* Several optimizations:
+ - no Phi in start block.
+ - remove Id operators that are inputs to Phi
+ - fold Phi-nodes, iff they have only one predecessor except
+ themselves.
+*/
+static ir_node *equivalent_node_Phi(ir_node *n)
+{
+ int i, n_preds;
+
+ ir_node *oldn = n;
+ ir_node *block = NULL; /* to shutup gcc */
+ ir_node *first_val = NULL; /* to shutup gcc */
+ ir_node *scnd_val = NULL; /* to shutup gcc */
+
+ if (!get_opt_normalize()) return n;
+
+ n_preds = get_Phi_n_preds(n);
+
+ block = get_nodes_block(n);
+ /* @@@ fliegt 'raus, sollte aber doch immer wahr sein!!!
+ assert(get_irn_arity(block) == n_preds && "phi in wrong block!"); */
+ if ((is_Block_dead(block)) || /* Control dead */
+ (block == current_ir_graph->start_block)) /* There should be no Phi nodes */
+ return new_Bad(); /* in the Start Block. */
+
+ if (n_preds == 0) return n; /* Phi of dead Region without predecessors. */
+
+ /* If the Block has a Bad pred, we also have one. */
+ for (i = 0; i < n_preds; ++i)
+ if (is_Bad(get_Block_cfgpred(block, i)))
+ set_Phi_pred(n, i, new_Bad());
+
+ /* Find first non-self-referencing input */
+ for (i = 0; i < n_preds; ++i) {
+ first_val = get_Phi_pred(n, i);
+ if ( (first_val != n) /* not self pointer */
+#if 1
+ && (! is_Bad(first_val))
+#endif
+ ) { /* value not dead */
+ break; /* then found first value. */
+ }
+ }
+
+ if (i >= n_preds) {
+ /* A totally Bad or self-referencing Phi (we didn't break the above loop) */
+ return new_Bad();
+ }
+
+ scnd_val = NULL;
+
+ /* follow_Id () for rest of inputs, determine if any of these
+ are non-self-referencing */
+ while (++i < n_preds) {
+ scnd_val = get_Phi_pred(n, i);
+ if ( (scnd_val != n)
+ && (scnd_val != first_val)
+#if 1
+ && (! is_Bad(scnd_val))
+#endif
+ ) {
+ break;
+ }
+ }
+
+ if (i >= n_preds) {
+ /* Fold, if no multiple distinct non-self-referencing inputs */
+ n = first_val;
+ DBG_OPT_PHI(oldn, n);
+ } else {
+ /* skip the remaining Ids (done in get_Phi_pred). */
+ /* superfluous, since we walk all to propagate Block's Bads.
+ while (++i < n_preds) get_Phi_pred(n, i); */
+ }
+ return n;
+}
+
+/**
+ * optimize Proj(Tuple) and gigo() for ProjX in Bad block
+ */
+static ir_node *equivalent_node_Proj(ir_node *n)
+{
+ ir_node *oldn = n;
+
+ ir_node *a = get_Proj_pred(n);
+
+ if ( get_irn_op(a) == op_Tuple) {
+ /* Remove the Tuple/Proj combination. */
+ if ( get_Proj_proj(n) <= get_Tuple_n_preds(a) ) {
+ n = get_Tuple_pred(a, get_Proj_proj(n));
+ DBG_OPT_TUPLE(oldn, a, n);
+ } else {
+ assert(0); /* This should not happen! */
+ n = new_Bad();
+ }
+ } else if (get_irn_mode(n) == mode_X) {
+ if (is_Block_dead(get_nodes_block(skip_Proj(n)))) {
+ /* Remove dead control flow -- early gigo(). */
+ n = new_Bad();
+ }
+ }
+ return n;
+}
+
+/**
+ * Remove Id's.
+ */
+static ir_node *equivalent_node_Id(ir_node *n)
+{
+ ir_node *oldn = n;