#include "irprintf.h"
#include "irgopt.h"
#include "irtools.h"
+#include "array_t.h"
+#include "debug.h"
+#include "irflag.h"
/**
* Walker environment.
*/
typedef struct _env_t {
- unsigned num_confirms; /**< number of inserted Confirm nodes */
- unsigned num_consts; /**< number of constants placed */
- unsigned num_eq; /**< number of equalities placed */
+ unsigned num_confirms; /**< Number of inserted Confirm nodes. */
+ unsigned num_consts; /**< Number of constants placed. */
+ unsigned num_eq; /**< Number of equalities placed. */
+ unsigned num_non_null; /**< Number of non-null Confirms. */
} env_t;
+/** The debug handle. */
+DEBUG_ONLY(static firm_dbg_module_t *dbg;)
+
/**
* Return the effective use block of a node and it's predecessor on
* position pos.
set_irn_n(succ, pos, c);
DBG_OPT_CONFIRM_C(irn, c);
-// ir_printf("1 Replacing input %d of node %n with %n\n", pos, succ, c);
+ DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, succ, c));
env->num_consts += 1;
}
* @param env statistical environment
*/
static void handle_modeb(ir_node *block, ir_node *selector, pn_Cond pnc, env_t *env) {
- ir_node *cond, *old, *cond_block, *other_blk = NULL, *con = NULL;
+ ir_node *cond, *old, *cond_block = NULL, *other_blk = NULL, *con = NULL;
ir_node *c_b = NULL, *c_o = NULL;
const ir_edge_t *edge, *next;
set_irn_n(user, pos, con);
DBG_OPT_CONFIRM_C(old, con);
- // ir_printf("2 Replacing input %d of node %n with %n\n", pos, user, con);
+ DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, user, con));
env->num_consts += 1;
} else {
set_irn_n(user, pos, right);
DBG_OPT_CONFIRM(left, right);
-// ir_printf("2 Replacing input %d of node %n with %n\n", pos, user, right);
+ DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, user, right));
env->num_eq += 1;
} else if (block_dominates(blk, cond_block)) {
pos = get_edge_src_pos(edge);
set_irn_n(succ, pos, c);
-// ir_printf("3 Replacing input %d of node %n with %n\n", pos, user, c);
+ DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, succ, c));
env->num_confirms += 1;
}
} /* handle_if */
/**
- * Pre-walker: Called for every block to insert Confirm nodes
+ * Pre-block-walker: Called for every block to insert Confirm nodes
*/
-static void insert_Confirm(ir_node *block, void *env) {
+static void insert_Confirm_in_block(ir_node *block, void *env) {
ir_node *cond, *proj, *selector;
ir_mode *mode;
/* it's the false branch */
pnc = get_negated_pnc(pnc, mode);
}
-// ir_printf("At %n using %n Confirm %=\n", block, cmp, pnc);
+ DB((dbg, LEVEL_2, "At %+F using %+F Confirm %=\n", block, cmp, pnc));
handle_if(block, cmp, pnc, env);
} else if (mode_is_int(mode)) {
handle_case(block, get_Cond_selector(cond), proj_nr, env);
}
+} /* insert_Confirm_in_block */
+
+/**
+ * Checks if a node is a non-null Confirm.
+ */
+static int is_non_null_Confirm(const ir_node *ptr) {
+ for (;;) {
+ if (! is_Confirm(ptr))
+ break;
+ if (get_Confirm_cmp(ptr) == pn_Cmp_Lg) {
+ ir_node *bound = get_Confirm_bound(ptr);
+
+ if (is_Const(bound) && is_Const_null(bound))
+ return 1;
+ }
+ ptr = get_Confirm_value(ptr);
+ }
+ /*
+ * While a SymConst is not a Confirm, it is non-null
+ * anyway. This helps to reduce the number of
+ * constructed Confirms.
+ */
+ if (is_SymConst_addr_ent(ptr))
+ return 1;
+ return 0;
+} /* is_non_null_Confirm */
+
+/**
+ * The given pointer will be dereferenced, add non-null Confirms.
+ *
+ * @param ptr a node representing an address
+ * @param block the block of the dereferencing instruction
+ * @param env environment
+ */
+static void insert_non_null(ir_node *ptr, ir_node *block, env_t *env) {
+ const ir_edge_t *edge, *next;
+ ir_node *c = NULL;
+
+ foreach_out_edge_safe(ptr, edge, next) {
+ ir_node *succ = get_edge_src_irn(edge);
+ int pos;
+ ir_node *blk;
+
+
+ if (is_Confirm(succ)) {
+ /* beware of loops */
+ continue;
+ }
+
+ if ((is_Load(succ) || is_Store(succ)) &&
+ get_nodes_block(succ) == block) {
+ /* Ignore Loads and Store in the same block for now,
+ because we are not sure if they are dominated.
+ This is not a bad restriction: if exception flow is
+ present, they are in other blocks either. */
+ continue;
+ }
+
+ pos = get_edge_src_pos(edge);
+ blk = get_effective_use_block(succ, pos);
+
+ if (block_dominates(block, blk)) {
+ /*
+ * Ok, we found a usage of ptr in a block
+ * dominated by the Load/Store block.
+ * We can replace the input with a Confirm(ptr, !=, NULL).
+ */
+ if (c == NULL) {
+ ir_mode *mode = get_irn_mode(ptr);
+ c = new_Const(mode, get_mode_null(mode));
+
+ c = new_r_Confirm(current_ir_graph, block, ptr, c, pn_Cmp_Lg);
+ }
+
+ set_irn_n(succ, pos, c);
+ DB((dbg, LEVEL_2, "Replacing input %d of node %+F with %+F\n", pos, succ, c));
+
+ env->num_non_null += 1;
+ env->num_confirms += 1;
+ }
+ }
+} /* insert_non_null */
+
+/**
+ * Pre-walker: Called for every node to insert Confirm nodes
+ */
+static void insert_Confirm(ir_node *node, void *env) {
+ ir_node *ptr;
+
+ switch (get_irn_opcode(node)) {
+ case iro_Block:
+ insert_Confirm_in_block(node, env);
+ break;
+ case iro_Load:
+ ptr = get_Load_ptr(node);
+ if (! is_non_null_Confirm(ptr))
+ insert_non_null(ptr, get_nodes_block(node), env);
+ break;
+ case iro_Store:
+ ptr = get_Store_ptr(node);
+ if (! is_non_null_Confirm(ptr))
+ insert_non_null(ptr, get_nodes_block(node), env);
+ break;
+ default:
+ break;
+ }
} /* insert_Confirm */
/*
env_t env;
int edges_active = edges_activated(irg);
+
+ FIRM_DBG_REGISTER(dbg, "firm.ana.confirm");
+
remove_critical_cf_edges(irg);
/* we need dominance info */
env.num_confirms = 0;
env.num_consts = 0;
env.num_eq = 0;
-
- /* now, visit all blocks and add Confirms where possible */
- irg_block_walk_graph(irg, insert_Confirm, NULL, &env);
+ env.num_non_null = 0;
+
+ if (0 && get_opt_global_null_ptr_elimination()) {
+ /* do global NULL test elimination */
+ irg_walk_graph(irg, insert_Confirm, NULL, &env);
+ } else {
+ /* now, visit all blocks and add Confirms where possible */
+ irg_block_walk_graph(irg, insert_Confirm_in_block, NULL, &env);
+ }
if (env.num_confirms | env.num_consts | env.num_eq) {
/* we have add nodes or changed DF edges */
set_irg_loopinfo_inconsistent(irg);
}
-#if 0
- printf("# Confirms inserted : %u\n", env.num_confirms);
- printf("# Const replacements: %u\n", env.num_consts);
- printf("# node equalities : %u\n", env.num_eq);
-#endif
+ DB((dbg, LEVEL_1, "# Confirms inserted : %u\n", env.num_confirms));
+ DB((dbg, LEVEL_1, "# Const replacements: %u\n", env.num_consts));
+ DB((dbg, LEVEL_1, "# node equalities : %u\n", env.num_eq));
+ DB((dbg, LEVEL_1, "# non-null Confirms : %u\n", env.num_non_null));
/* deactivate edges if they where off */
if (! edges_active)
exchange(n, value);
else {
/*
- * Strange: a Confirm is it's own bound. This can happen
+ * Strange: a Confirm is its own bound. This can happen
* in dead blocks when Phi nodes are already removed.
*/
exchange(n, new_Bad());
* Remove all Confirm nodes from a graph.
*/
void remove_confirms(ir_graph *irg) {
+ int rem = get_opt_remove_confirm();
+
set_opt_remove_confirm(1);
optimize_graph_df(irg);
+ set_opt_remove_confirm(rem);
} /* remove_confirms */
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