Commit 29b409cf authored by Michael Beck's avatar Michael Beck
Browse files

- simplified get_effective_use_block()

- add support for mode_b nodes:
  - propagate true/false
  - create Phi's at dominance frontier for cond_eval()

[r19754]
parent 745a5c9a
......@@ -57,11 +57,11 @@ typedef struct _env_t {
* This handles correctly Phi nodes.
*/
static ir_node *get_effective_use_block(ir_node *node, int pos) {
/* the effective use of a Phi is in its predecessor block */
if (is_Phi(node))
return get_nodes_block(get_irn_n(node, pos));
else
return get_nodes_block(node);
if (is_Phi(node)) {
/* the effective use of a Phi is in its predecessor block */
node = get_irn_n(node, pos);
}
return get_nodes_block(node);
}
/**
......@@ -113,6 +113,109 @@ static void handle_case(ir_node *block, ir_node *irn, long nr, env_t *env) {
}
} /* handle_case */
/**
* Handle a mode_b input of Cond nodes.
*
* @param block the block which is entered by the branch
* @param selector the mode_b node expressing the branch condition
* @param pnc the true/false condition branch
* @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 *c_b = NULL, *c_o = NULL;
const ir_edge_t *edge, *next;
for (edge = get_irn_out_edge_first(selector); edge; edge = next) {
ir_node *user = get_edge_src_irn(edge);
int pos = get_edge_src_pos(edge);
ir_node *user_blk = get_effective_use_block(user, pos);
next = get_irn_out_edge_next(selector, edge);
if (block_dominates(block, user_blk)) {
/*
* Ok, we found a usage of selector in a block
* dominated by the branch block.
* We can replace the input with true/false.
*/
if (con == NULL) {
con = new_Const(mode_b, pnc == pn_Cond_true ? tarval_b_true : tarval_b_false);
}
old = get_irn_n(user, pos);
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);
env->num_consts += 1;
} else {
int i, n;
/* get the other block */
if (other_blk == NULL) {
/* we have already tested, that block has only ONE Cond predecessor */
cond = get_Proj_pred(get_Block_cfgpred(block, 0));
cond_block = get_nodes_block(cond);
foreach_out_edge(cond, edge) {
ir_node *proj = get_edge_src_irn(edge);
if (get_Proj_proj(proj) == pnc)
continue;
edge = get_irn_out_edge_first(proj);
other_blk = get_edge_src_irn(edge);
break;
}
assert(other_blk);
}
n = get_Block_n_cfgpreds(user_blk);
/*
* We have found a user in a non-dominated block:
* check, if all its block predecessors are dominated.
* If yes, place a Phi.
*
* Note the special case here: if block is a then, there might be no else
* block. In that case the other_block is the user_blk itself and pred_block
* is the cond_block ...
*/
for (i = n - 1; i >= 0; --i) {
ir_node *pred_blk = get_Block_cfgpred_block(user_blk, i);
if (cond_block != pred_blk &&
!block_dominates(block, pred_blk) &&
!block_dominates(other_blk, pred_blk)) {
/* can't do anything */
break;
}
}
if (i < 0) {
ir_node *phi, **in;
NEW_ARR_A(ir_node *, in, n);
/* ok, ALL predecessors are either dominated by block OR other block */
if (c_b == NULL) {
ir_node *c_true = new_Const(mode_b, tarval_b_true);
ir_node *c_false = new_Const(mode_b, tarval_b_false);
c_b = new_r_Confirm(current_ir_graph, cond_block, selector,
pnc == pn_Cond_true ? c_true : c_false, pn_Cmp_Eq);
c_o = new_r_Confirm(current_ir_graph, cond_block, selector,
pnc == pn_Cond_false ? c_true : c_false, pn_Cmp_Eq);
}
for (i = n - 1; i >= 0; --i) {
ir_node *pred_blk = get_Block_cfgpred_block(user_blk, i);
if (block_dominates(block, pred_blk))
in[i] = c_b;
else
in[i] = c_o;
}
phi = new_r_Phi(current_ir_graph, user_blk, n, in, mode_b);
set_irn_n(user, pos, phi);
}
}
}
}
/**
* Handle an IF-branch.
*
......@@ -129,7 +232,7 @@ static void handle_if(ir_node *block, ir_node *cmp, pn_Cmp pnc, env_t *env) {
const ir_edge_t *edge, *next;
/* Beware of Bads */
if (is_Bad(left) ||is_Bad(right))
if (is_Bad(left) || is_Bad(right))
return;
op = get_irn_op(left);
......@@ -253,11 +356,11 @@ static void insert_Confirm(ir_node *block, void *env) {
return;
proj = get_Block_cfgpred(block, 0);
if (get_irn_op(proj) != op_Proj)
if (! is_Proj(proj))
return;
cond = get_Proj_pred(proj);
if (get_irn_op(cond) != op_Cond)
if (! is_Cond(cond))
return;
selector = get_Cond_selector(cond);
......@@ -267,6 +370,8 @@ static void insert_Confirm(ir_node *block, void *env) {
ir_node *cmp;
pn_Cmp pnc;
handle_modeb(block, selector, get_Proj_proj(proj), env);
/* this should be an IF, check this */
if (get_irn_op(selector) != op_Proj)
return;
......@@ -362,5 +467,6 @@ static void rem_Confirm(ir_node *n, void *env) {
* Remove all Confirm nodes from a graph.
*/
void remove_confirms(ir_graph *irg) {
irg_walk_graph(irg, NULL, rem_Confirm, NULL);
set_opt_remove_confirm(1);
optimize_graph_df(irg);
} /* remove_confirms */
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