+ return tarval_bad;
+}
+
+/**
+ * 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;
+}
+
+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))
+ && !(get_mode_sort(get_irn_mode(a)) == irms_reference)) {
+ return tarval_add(ta, tb);
+ }
+ return tarval_bad;
+}
+
+static tarval *computed_value_Sub(ir_node *n)
+{
+ ir_node *a = get_Sub_left(n);
+ ir_node *b = get_Sub_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))
+ && !(get_mode_sort(get_irn_mode(a)) == irms_reference)) {
+ return tarval_sub(ta, tb);
+ }
+ return tarval_bad;
+}
+
+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;
+}
+
+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. */
+ tarval *v;
+
+ if ( ( ((v = ta) != tarval_bad)
+ && (v == get_mode_null(get_tarval_mode(v))) )
+ || ( ((v = tb) != tarval_bad)
+ && (v == get_mode_null(get_tarval_mode(v))) )) {
+ return v;
+ }
+ }
+ return tarval_bad;
+}
+
+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;
+}
+
+static tarval *computed_value_Div(ir_node *n)
+{
+ ir_node *a = get_Div_left(n);
+ ir_node *b = get_Div_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_div(ta, tb);
+ }
+ return tarval_bad;
+}
+
+static tarval *computed_value_Mod(ir_node *n)
+{
+ ir_node *a = get_Mod_left(n);
+ ir_node *b = get_Mod_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_mod(ta, tb);
+ }
+ return tarval_bad;
+}
+
+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;
+}
+
+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 = computed_value (a))) == TV_CLASSIFY_NULL)
+ || (classify_tarval ((v = computed_value (b))) == TV_CLASSIFY_NULL)) {
+ return v;
+ }
+ }
+ return tarval_bad;
+}
+
+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 = computed_value (a))) == TV_CLASSIFY_ALL_ONE)
+ || (classify_tarval ((v = computed_value (b))) == TV_CLASSIFY_ALL_ONE)) {
+ return v;
+ }
+ }
+ return tarval_bad;
+}
+
+static tarval *computed_value_Eor(ir_node *n)
+{
+ ir_node *a = get_Eor_left(n);
+ ir_node *b = get_Eor_right(n);
+
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if ((ta != tarval_bad) && (tb != tarval_bad)) {
+ return tarval_eor (ta, tb);
+ }
+ return tarval_bad;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+static tarval *computed_value_Proj(ir_node *n)
+{
+ ir_node *a = get_Proj_pred(n), *b;
+ ir_node *aa, *ab;
+
+ /* Optimize Cmp nodes.
+ 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:
+ 1. The nodes compared are both the same. If we compare for
+ equal, greater equal, ... this will return true, else it
+ will return false. This step relies on cse.
+ 2. The predecessors of Cmp are target values. We can evaluate
+ the Cmp.
+ 3. The predecessors are Allocs or void* constants. Allocs never
+ return NULL, they raise an exception. Therefore we can predict
+ the Cmp result. */
+ switch (get_irn_opcode(a)) {
+ case iro_Cmp:
+ aa = get_Cmp_left(a);
+ ab = get_Cmp_right(a);
+
+ if (aa == ab) { /* 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 ((get_Proj_proj(n) == Eq), mode_b) */
+ return new_tarval_from_long ((get_Proj_proj(n) & Eq), mode_b);
+ } else {
+ tarval *taa = computed_value (aa);
+ tarval *tab = computed_value (ab);
+
+ if ((taa != tarval_bad) && (tab != tarval_bad)) { /* 2.: */
+ /* strange checks... */
+ pnc_number flags = tarval_cmp (taa, tab);
+ if (flags != False) {
+ return new_tarval_from_long (get_Proj_proj(n) & flags, mode_b);
+ }
+ } else { /* check for 3.: */
+ 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 constant void */
+ (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 void 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 (get_Proj_proj(n) & Ne, mode_b);
+ }
+ }
+ break;
+
+ case iro_DivMod:
+ {
+ tarval *tb = value_of(b = get_DivMod_right(a));
+ tarval *ta = value_of(a = get_DivMod_left(a));
+
+ 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_bad;
+ if (get_Proj_proj(n)== pn_DivMod_res_div)
+ return tarval_div(ta, tb);
+ else if (get_Proj_proj(n)== pn_DivMod_res_mod)
+ return tarval_mod(ta, tb);
+ }
+ break;
+ }
+
+ case iro_Div:
+ {
+ tarval *tb = value_of(b = get_Div_right(a));
+ tarval *ta = value_of(a = get_Div_left(a));
+
+ 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_bad;
+ if (get_Proj_proj(n)== pn_Div_res)
+ return tarval_div(ta, tb);
+ }
+ break;
+ }
+
+ case iro_Mod:
+ {
+ tarval *tb = value_of(b = get_Mod_right(a));
+ tarval *ta = value_of(a = get_Mod_left(a));
+
+ 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_bad;
+ if (get_Proj_proj(n)== pn_Mod_res)
+ return tarval_mod(ta, tb);
+ }
+ break;
+ }
+
+ default:
+ return tarval_bad;
+ }
+ return 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);
+ 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
+
+static ir_node *equivalent_node_Block(ir_node *n)
+{
+ ir_node *oldn = 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 ((get_Block_n_cfgpreds(n) == 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 = new_Bad(); DBG_OPT_DEAD;
+ } else if (get_opt_control_flow_straightening()) {
+ n = predblock; DBG_OPT_STG;
+ }
+ }
+ else if ((get_Block_n_cfgpreds(n) == 1) &&
+ (get_irn_op(skip_Proj(get_Block_cfgpred(n, 0))) == op_Cond)) {
+ 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 = new_Bad(); DBG_OPT_DEAD;
+ }
+ }
+ else if ((get_Block_n_cfgpreds(n) == 2) &&
+ (get_opt_control_flow_weak_simplification())) {
+ /* Test whether Cond jumps twice to this block
+ @@@ we could do this also with two loops finding two preds from several ones. */
+ 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_IFSIM;
+ }
+ } else if (get_opt_unreachable_code() &&
+ (n != current_ir_graph->start_block) &&
+ (n != current_ir_graph->end_block) ) {
+ int i;
+ /* 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 < get_Block_n_cfgpreds(n); i++) {
+ if (!is_Bad(get_Block_cfgpred(n, i))) break;
+ }
+ if (i == get_Block_n_cfgpreds(n))
+ n = new_Bad();
+ }
+
+ 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_Bad(get_nodes_block(n)))
+ n = new_Bad();
+
+ return n;
+}
+
+static ir_node *equivalent_node_Cond(ir_node *n)
+{
+ /* We do not evaluate Cond here as we replace it by a new node, a Jmp.
+ See cases for iro_Cond and iro_Proj in transform_node. */
+ return n;
+}
+
+/**
+ * Use algebraic simplification a v 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);
+
+ /* remove a v a */
+ if (a == b) {
+ n = a; DBG_OPT_ALGSIM1;
+ }
+
+ return n;
+}
+
+/**
+ * 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 = computed_value(a)) != tarval_bad) {
+ on = b;
+ } else if ((tv = computed_value(b)) != tarval_bad) {
+ on = a;
+ } else
+ return n;
+
+ /* If this predecessors constant value is zero, the operation is
+ unnecessary. Remove it: */
+ if (classify_tarval (tv) == TV_CLASSIFY_NULL) {
+ n = on; DBG_OPT_ALGSIM1;
+ }
+
+ return n;
+}
+
+#define equivalent_node_Add equivalent_node_neutral_zero
+#define equivalent_node_Eor equivalent_node_neutral_zero
+
+/**
+ * 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(computed_value(b)) == TV_CLASSIFY_NULL) {
+ n = a; DBG_OPT_ALGSIM1;
+ }
+
+ return n;
+}
+
+#define equivalent_node_Sub equivalent_node_left_zero
+#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
+
+/**
+ * Er, a "symmetic unop", ie op(op(n)) = n.
+ */
+static ir_node *equivalent_node_symmetric_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;
+ }
+ return n;
+}
+
+/* NotNot x == x */
+#define equivalent_node_Not equivalent_node_symmetric_unop
+
+/* --x == x */ /* ??? Is this possible or can --x raise an
+ out of bounds exception if min =! max? */
+#define equivalent_node_Minus equivalent_node_symmetric_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 (computed_value (a)) == TV_CLASSIFY_ONE) {
+ n = b; DBG_OPT_ALGSIM1;
+ } else if (classify_tarval (computed_value (b)) == TV_CLASSIFY_ONE) {
+ n = a; DBG_OPT_ALGSIM1;
+ }
+ 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(computed_value(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 & 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 */
+ } else if (classify_tarval(computed_value(a)) == TV_CLASSIFY_ALL_ONE) {
+ n = b;
+ } else if (classify_tarval(computed_value(b)) == TV_CLASSIFY_ALL_ONE) {
+ n = a;
+ }
+ if (n != oldn) DBG_OPT_ALGSIM1;
+ 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_ALGSIM3;
+ } 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;
+ }
+ 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;
+ }
+ }
+ }
+ }
+ return n;
+}
+
+static ir_node *equivalent_node_Phi(ir_node *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.
+ */
+ 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_Bad(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 0
+ /* first we test for a special case: */
+ /* Confirm is a special node fixing additional information for a
+ value that is known at a certain point. This is useful for
+ dataflow analysis. */
+ if (n_preds == 2) {
+ ir_node *a = get_Phi_pred(n, 0);
+ ir_node *b = get_Phi_pred(n, 1);
+ if ( (get_irn_op(a) == op_Confirm)
+ && (get_irn_op(b) == op_Confirm)
+ && follow_Id (get_irn_n(a, 0) == get_irn_n(b, 0))
+ && (get_irn_n(a, 1) == get_irn_n (b, 1))
+ && (a->data.num == (~b->data.num & irpn_True) )) {
+ return get_irn_n(a, 0);
+ }
+ }
+#endif
+
+ /* 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
+ && (get_irn_op(first_val) != op_Bad)
+#endif
+ ) { /* value not dead */
+ break; /* then found first value. */
+ }
+ }
+
+ /* A totally Bad or self-referencing Phi (we didn't break the above loop) */
+ if (i >= n_preds) { 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
+ && (get_irn_op(scnd_val) != op_Bad)
+#endif
+ ) {
+ break;
+ }
+ }
+
+ /* Fold, if no multiple distinct non-self-referencing inputs */
+ if (i >= n_preds) {
+ n = first_val; DBG_OPT_PHI;
+ } 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;
+ } else {
+ assert(0); /* This should not happen! */
+ n = new_Bad();
+ }
+ } else if (get_irn_mode(n) == mode_X &&
+ is_Bad(get_nodes_block(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;
+
+ n = follow_Id(n); DBG_OPT_ID;
+ return n;
+}
+
+/**
+ * equivalent_node() returns a node equivalent to input n. It skips all nodes that
+ * perform no actual computation, as, e.g., the Id nodes. It does not create
+ * new nodes. It is therefore safe to free n if the node returned is not n.
+ * If a node returns a Tuple we can not just skip it. If the size of the
+ * in array fits, we transform n into a tuple (e.g., Div).
+ */
+ir_node *
+equivalent_node(ir_node *n)
+{
+ if (n->op->equivalent_node)
+ return n->op->equivalent_node(n);
+ return n;
+}
+
+/**
+ * set the default equivalent node operation
+ */
+static ir_op *firm_set_default_equivalent_node(ir_op *op)
+{
+#define CASE(a) \
+ case iro_##a: \
+ op->equivalent_node = equivalent_node_##a; \
+ break
+
+ switch (op->code) {
+ CASE(Block);
+ CASE(Jmp);
+ CASE(Cond);
+ CASE(Or);
+ CASE(Add);
+ CASE(Eor);
+ CASE(Sub);
+ CASE(Shl);
+ CASE(Shr);
+ CASE(Shrs);
+ CASE(Rot);
+ CASE(Not);
+ CASE(Minus);
+ CASE(Mul);
+ CASE(Div);
+ CASE(And);
+ CASE(Conv);
+ CASE(Phi);
+ CASE(Proj);
+ CASE(Id);
+ default:
+ op->equivalent_node = NULL;
+ }
+
+ return op;
+#undef CASE
+}
+
+/**
+ * Do node specific optimizations of nodes predecessors.
+ */
+static void
+optimize_preds(ir_node *n) {
+ ir_node *a = NULL, *b = NULL;
+
+ /* get the operands we will work on for simple cases. */
+ if (is_binop(n)) {
+ a = get_binop_left(n);
+ b = get_binop_right(n);
+ } else if (is_unop(n)) {
+ a = get_unop_op(n);
+ }
+
+ switch (get_irn_opcode(n)) {
+
+ case iro_Cmp:
+ /* We don't want Cast as input to Cmp. */
+ if (get_irn_op(a) == op_Cast) {
+ a = get_Cast_op(a);
+ set_Cmp_left(n, a);
+ }
+ if (get_irn_op(b) == op_Cast) {
+ b = get_Cast_op(b);
+ set_Cmp_right(n, b);
+ }
+ break;
+
+ default: break;
+ } /* end switch */
+}
+
+static ir_node *transform_node_Div(ir_node *n)
+{
+ tarval *tv = computed_value(n);
+
+ /* BEWARE: it is NOT possible to optimize a/a to 1, as this may cause a exception */
+
+ if (tv != tarval_bad) {
+ /* Turn Div into a tuple (mem, bad, value) */
+ 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());
+ set_Tuple_pred(n, pn_Div_res, new_Const(get_tarval_mode(tv), tv));
+ }
+ return n;
+}
+
+static ir_node *transform_node_Mod(ir_node *n)
+{
+ tarval *tv = computed_value(n);
+
+ /* BEWARE: it is NOT possible to optimize a%a to 0, as this may cause a exception */
+
+ if (tv != tarval_bad) {
+ /* Turn Mod into a tuple (mem, bad, value) */
+ ir_node *mem = get_Mod_mem(n);
+ turn_into_tuple(n, 3);
+ set_Tuple_pred(n, pn_Mod_M, mem);
+ set_Tuple_pred(n, pn_Mod_X_except, new_Bad());
+ set_Tuple_pred(n, pn_Mod_res, new_Const(get_tarval_mode(tv), tv));
+ }
+ return n;
+}
+
+static ir_node *transform_node_DivMod(ir_node *n)
+{
+ int evaluated = 0;
+
+ ir_node *a = get_DivMod_left(n);
+ ir_node *b = get_DivMod_right(n);
+ ir_mode *mode = get_irn_mode(a);
+ tarval *ta = value_of(a);
+ tarval *tb = value_of(b);
+
+ if (!(mode_is_int(mode) && mode_is_int(get_irn_mode(b))))
+ return n;
+
+ /* BEWARE: it is NOT possible to optimize a/a to 1, as this may cause a exception */
+
+ if (tb != tarval_bad) {
+ if (tb == get_mode_one(get_tarval_mode(tb))) {
+ b = new_Const (mode, get_mode_null(mode));
+ evaluated = 1;
+ } else if (ta != tarval_bad) {
+ tarval *resa, *resb;
+ resa = tarval_div (ta, tb);
+ if (resa == tarval_bad) return n; /* Causes exception!!! Model by replacing through
+ Jmp for X result!? */
+ resb = tarval_mod (ta, tb);
+ if (resb == tarval_bad) return n; /* Causes exception! */
+ a = new_Const (mode, resa);
+ b = new_Const (mode, resb);
+ evaluated = 1;
+ }
+ } else if (ta == get_mode_null(mode)) {
+ b = a;
+ evaluated = 1;
+ }
+ if (evaluated) { /* replace by tuple */
+ ir_node *mem = get_DivMod_mem(n);
+ 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, b);
+ assert(get_nodes_block(n));
+ }
+
+ return n;
+}
+
+static ir_node *transform_node_Cond(ir_node *n)
+{
+ /* Replace the Cond by a Jmp if it branches on a constant
+ condition. */
+ ir_node *jmp;
+ ir_node *a = get_Cond_selector(n);
+ tarval *ta = value_of(a);
+
+ if ((ta != tarval_bad) &&
+ (get_irn_mode(a) == mode_b) &&
+ (get_opt_unreachable_code())) {
+ /* It's a boolean Cond, branching on a boolean constant.
+ Replace it by a tuple (Bad, Jmp) or (Jmp, Bad) */
+ jmp = new_r_Jmp(current_ir_graph, get_nodes_block(n));
+ turn_into_tuple(n, 2);
+ if (ta == tarval_b_true) {
+ set_Tuple_pred(n, pn_Cond_false, new_Bad());
+ set_Tuple_pred(n, pn_Cond_true, jmp);
+ } else {
+ set_Tuple_pred(n, pn_Cond_false, jmp);
+ set_Tuple_pred(n, pn_Cond_true, new_Bad());
+ }
+ /* We might generate an endless loop, so keep it alive. */
+ add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_block(n));
+ } else if ((ta != tarval_bad) &&
+ (get_irn_mode(a) == mode_Iu) &&
+ (get_Cond_kind(n) == dense) &&
+ (get_opt_unreachable_code())) {
+ /* I don't want to allow Tuples smaller than the biggest Proj.
+ Also this tuple might get really big...
+ I generate the Jmp here, and remember it in link. Link is used
+ when optimizing Proj. */
+ set_irn_link(n, new_r_Jmp(current_ir_graph, get_nodes_block(n)));
+ /* We might generate an endless loop, so keep it alive. */
+ add_End_keepalive(get_irg_end(current_ir_graph), get_nodes_block(n));
+ } else if ((get_irn_op(a) == op_Eor)
+ && (get_irn_mode(a) == mode_b)
+ && (classify_tarval(computed_value(get_Eor_right(a))) == TV_CLASSIFY_ONE)) {
+ /* The Eor is a negate. Generate a new Cond without the negate,
+ simulate the negate by exchanging the results. */
+ set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_block(n),
+ get_Eor_left(a)));
+ } else if ((get_irn_op(a) == op_Not)
+ && (get_irn_mode(a) == mode_b)) {
+ /* A Not before the Cond. Generate a new Cond without the Not,
+ simulate the Not by exchanging the results. */
+ set_irn_link(n, new_r_Cond(current_ir_graph, get_nodes_block(n),
+ get_Not_op(a)));
+ }
+ return n;