/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
#include "irtools.h"
#include "irgraph.h"
#include "tv.h"
+#include "opt_confirms.h"
-//#define AVOID_PHIB
+#undef AVOID_PHIB
DEBUG_ONLY(static firm_dbg_module_t *dbg);
ir_node *phi;
ir_node **in;
- // This is needed because we create bads sometimes
+ /* This is needed because we create bads sometimes */
if(is_Bad(block))
return new_Bad();
- // already processed this block?
+ /* already processed this block? */
if(irn_visited(block)) {
ir_node *value = (ir_node*) get_irn_link(block);
return value;
}
- // blocks with only 1 pred need no phi
+ irg = get_irn_irg(block);
+ assert(block != get_irg_start_block(irg));
+
+ /* a Blocks with only 1 predecessor need no Phi */
n_cfgpreds = get_Block_n_cfgpreds(block);
if(n_cfgpreds == 1) {
ir_node *pred_block = get_Block_cfgpred_block(block, 0);
- ir_node *value = search_def_and_create_phis(pred_block, mode);
+ ir_node *value = search_def_and_create_phis(pred_block, mode);
set_irn_link(block, value);
mark_irn_visited(block);
return value;
}
- // create a new phi
+ /* create a new Phi */
NEW_ARR_A(ir_node*, in, n_cfgpreds);
for(i = 0; i < n_cfgpreds; ++i)
in[i] = new_Unknown(mode);
- irg = get_irn_irg(block);
phi = new_r_Phi(irg, block, n_cfgpreds, in, mode);
set_irn_link(block, phi);
mark_irn_visited(block);
- // set phi preds
+ /* set Phi predecessors */
for(i = 0; i < n_cfgpreds; ++i) {
ir_node *pred_block = get_Block_cfgpred_block(block, i);
ir_node *pred_val = search_def_and_create_phis(pred_block, mode);
const ir_edge_t *next;
ir_node *value;
- assert(n_vals > 0);
+ assert(n_vals == 2);
irg = get_irn_irg(vals[0]);
inc_irg_visited(irg);
ir_node *value = vals[i];
ir_node *value_block = blocks[i];
- assert(get_irn_mode(value) == mode);
+ assert(get_irn_mode(value) == mode || is_Bad(value));
set_irn_link(value_block, value);
mark_irn_visited(value_block);
}
- // Only fix the users of the first, i.e. the original node
+ /* Only fix the users of the first, i.e. the original node */
value = vals[0];
- // this can happen when fixing phi preds, we mustn't fix the users
- if(get_nodes_block(value) != blocks[0]) return;
-
foreach_out_edge_safe(value, edge, next) {
ir_node *user = get_edge_src_irn(edge);
int j = get_edge_src_pos(edge);
ir_node *user_block = get_nodes_block(user);
ir_node *newval;
- // ignore keeps
- if(get_irn_op(user) == op_End)
+ /* ignore keeps */
+ if (is_End(user))
+ continue;
+
+ if (user_block == blocks[1])
continue;
DB((dbg, LEVEL_3, ">>> Fixing user %+F (pred %d == %+F)\n", user, j, get_irn_n(user, j)));
newval = search_def_and_create_phis(user_block, mode);
}
- // don't fix newly created phis from the SSA construction
+ /* don't fix newly created Phis from the SSA construction */
if (newval != user) {
DB((dbg, LEVEL_4, ">>>> Setting input %d of %+F to %+F\n", j, user, newval));
set_irn_n(user, j, newval);
typedef struct condeval_env_t {
ir_node *true_block;
- pn_Cmp pnc;
+ ir_node *cmp; /**< The Compare node that might be partial evaluated */
+ pn_Cmp pnc; /**< The Compare mode of the Compare node. */
ir_node *cnst;
tarval *tv;
- unsigned long visited_nr;
+ ir_visited_t visited_nr;
ir_node *cnst_pred; /**< the block before the constant */
int cnst_pos; /**< the pos to the constant block (needed to
kill that edge later) */
} condeval_env_t;
+static ir_node *copy_and_fix_node(const condeval_env_t *env, ir_node *block,
+ ir_node *copy_block, int j, ir_node *node) {
+ int i, arity;
+ ir_node *copy;
+
+ /* we can evaluate Phis right now, all other nodes get copied */
+ if (is_Phi(node)) {
+ copy = get_Phi_pred(node, j);
+ /* we might have to evaluate a Phi-cascade */
+ if(get_irn_visited(copy) >= env->visited_nr) {
+ copy = get_irn_link(copy);
+ }
+ } else {
+ copy = exact_copy(node);
+ set_nodes_block(copy, copy_block);
+
+ assert(get_irn_mode(copy) != mode_X);
+
+ arity = get_irn_arity(copy);
+ for(i = 0; i < arity; ++i) {
+ ir_node *pred = get_irn_n(copy, i);
+ ir_node *new_pred;
+
+ if(get_nodes_block(pred) != block)
+ continue;
+
+ if(get_irn_visited(pred) >= env->visited_nr) {
+ new_pred = get_irn_link(pred);
+ } else {
+ new_pred = copy_and_fix_node(env, block, copy_block, j, pred);
+ }
+ set_irn_n(copy, i, new_pred);
+ }
+ }
+
+ set_irn_link(node, copy);
+ set_irn_visited(node, env->visited_nr);
+
+ return copy;
+}
+
static void copy_and_fix(const condeval_env_t *env, ir_node *block,
ir_node *copy_block, int j) {
const ir_edge_t *edge;
foreach_out_edge(block, edge) {
ir_node *node = get_edge_src_irn(edge);
ir_node *copy;
- ir_mode *mode = get_irn_mode(node);
+ ir_mode *mode;
+
+ if (is_Block(node)) {
+ /* Block->Block edge, should be the MacroBlock edge */
+ assert(get_Block_MacroBlock(node) == block && "Block->Block edge found");
+ continue;
+ }
/* ignore control flow */
+ mode = get_irn_mode(node);
if (mode == mode_X || is_Cond(node))
continue;
#ifdef AVOID_PHIB
- /* we may not copy mode_b nodes, because this could produce phi with
+ /* we may not copy mode_b nodes, because this could produce Phi with
* mode_bs which can't be handled in all backends. Instead we duplicate
- * the node and move it to it's users */
+ * the node and move it to its users */
if (mode == mode_b) {
const ir_edge_t *edge, *next;
ir_node *pred;
}
#endif
- /* we can evaluate Phis right now, all other nodes get copied */
- if (is_Phi(node)) {
- copy = get_Phi_pred(node, j);
- } else {
- copy = exact_copy(node);
- set_nodes_block(copy, copy_block);
- }
-
- set_irn_link(node, copy);
- set_irn_visited(node, env->visited_nr);
+ copy = copy_and_fix_node(env, block, copy_block, j, node);
/* we might hit values in blocks that have already been processed by a
- * recursive find_phi_with_const call */
+ * recursive find_phi_with_const() call */
assert(get_irn_visited(copy) <= env->visited_nr);
if(get_irn_visited(copy) >= env->visited_nr) {
ir_node *prev_copy = get_irn_link(copy);
ir_node *vals[2];
ir_node *blocks[2];
ir_node *node = get_edge_src_irn(edge);
- ir_mode *mode = get_irn_mode(node);
+ ir_mode *mode;
+
+ if (is_Block(node)) {
+ /* Block->Block edge, should be the MacroBlock edge */
+ assert(get_Block_MacroBlock(node) == block && "Block->Block edge found");
+ continue;
+ }
+ mode = get_irn_mode(node);
if (mode == mode_X || is_Cond(node))
continue;
#ifdef AVOID_PHIB
}
}
-static int eval_cmp(pn_Cmp pnc, tarval *tv1, tarval *tv2) {
- pn_Cmp cmp_result = tarval_cmp(tv1, tv2);
+/**
+ * returns whether the cmp evaluates to true or false, or can't be evaluated!
+ * 1: true, 0: false, -1: can't evaluate
+ *
+ * @param pnc the compare mode of the Compare
+ * @param tv_left the left tarval
+ * @param tv_right the right tarval
+ */
+static int eval_cmp_tv(pn_Cmp pnc, tarval *tv_left, tarval *tv_right) {
+ pn_Cmp cmp_result = tarval_cmp(tv_left, tv_right);
- // does the compare evaluate to true?
- if(cmp_result == pn_Cmp_False)
- return 0;
- if((cmp_result & pnc) != cmp_result)
+ /* does the compare evaluate to true? */
+ if (cmp_result == pn_Cmp_False)
+ return -1;
+ if ((cmp_result & pnc) != cmp_result)
return 0;
return 1;
}
-static ir_node *find_const(condeval_env_t *env, ir_node *jump, ir_node *value)
+/**
+ * returns whether the cmp evaluates to true or false, or can't be evaluated!
+ * 1: true, 0: false, -1: can't evaluate
+ *
+ * @param env the environment
+ * @param cand the candidate node, either a Const or a Confirm
+ */
+static int eval_cmp(condeval_env_t *env, ir_node *cand) {
+ if (is_Const(cand)) {
+ tarval *tv_cand = get_Const_tarval(cand);
+ tarval *tv_cmp = get_Const_tarval(env->cnst);
+
+ return eval_cmp_tv(env->pnc, tv_cand, tv_cmp);
+ } else { /* a Confirm */
+ tarval *res = computed_value_Cmp_Confirm(env->cmp, cand, env->cnst, env->pnc);
+
+ if (res == tarval_bad)
+ return -1;
+ return res == tarval_b_true;
+ }
+}
+
+/**
+ * Check for Const or Confirm with Const.
+ */
+static int is_Const_or_Confirm(const ir_node *node) {
+ if (is_Confirm(node))
+ node = get_Confirm_bound(node);
+ return is_Const(node);
+}
+
+/**
+ * get the tarval of a Const or Confirm with
+ */
+static tarval *get_Const_or_Confirm_tarval(const ir_node *node) {
+ if (is_Confirm(node)) {
+ if (get_Confirm_bound(node))
+ node = get_Confirm_bound(node);
+ }
+ return get_Const_tarval(node);
+}
+
+static ir_node *find_const_or_confirm(condeval_env_t *env, ir_node *jump, ir_node *value)
{
ir_node *block = get_nodes_block(jump);
- if(irn_visited(value))
+ if (irn_visited(value))
return NULL;
mark_irn_visited(value);
- if(is_Const(value)) {
- tarval *tv_const = get_Const_tarval(env->cnst);
- tarval *tv = get_Const_tarval(value);
-
- if(!eval_cmp(env->pnc, tv, tv_const)) {
+ if (is_Const_or_Confirm(value)) {
+ if (eval_cmp(env, value) <= 0) {
return NULL;
}
env->true_block, block
));
- // adjust true_block to point directly towards our jump
+ /* adjust true_block to point directly towards our jump */
add_pred(env->true_block, jump);
split_critical_edge(env->true_block, 0);
- // we need a bigger visited nr when going back
+ /* we need a bigger visited nr when going back */
env->visited_nr++;
return block;
if(is_Phi(value)) {
int i, arity;
- // the phi has to be in the same block as the jump
+ /* the Phi has to be in the same Block as the Jmp */
if(get_nodes_block(value) != block) {
return NULL;
}
ir_node *phi_pred = get_Phi_pred(value, i);
ir_node *cfgpred = get_Block_cfgpred(block, i);
- copy_block = find_const(env, cfgpred, phi_pred);
+ copy_block = find_const_or_confirm(env, cfgpred, phi_pred);
if(copy_block == NULL)
continue;
env->cnst_pos = i;
}
- // return now as we can't process more possibilities in 1 run
+ /* return now as we can't process more possibilities in 1 run */
return copy_block;
}
}
}
mark_irn_visited(value);
- if(is_Const(value)) {
- tarval *tv = get_Const_tarval(value);
+ if (is_Const_or_Confirm(value)) {
+ tarval *tv = get_Const_or_Confirm_tarval(value);
- if(tv != env->tv)
+ if (tv != env->tv)
return NULL;
DB((
env->true_block, block
));
- // adjust true_block to point directly towards our jump
+ /* adjust true_block to point directly towards our jump */
add_pred(env->true_block, jump);
split_critical_edge(env->true_block, 0);
- // we need a bigger visited nr when going back
+ /* we need a bigger visited nr when going back */
env->visited_nr++;
return block;
if(is_Phi(value)) {
int i, arity;
- // the phi has to be in the same block as the jump
+ /* the Phi has to be in the same Block as the Jmp */
if(get_nodes_block(value) != block)
return NULL;
env->cnst_pos = i;
}
- // return now as we can't process more possibilities in 1 run
+ /* return now as we can't process more possibilities in 1 run */
return copy_block;
}
}
}
/* negate condition when we're looking for the false block */
- if(env->tv == get_tarval_b_false()) {
+ if(env->tv == tarval_b_false) {
pnc = get_negated_pnc(pnc, get_irn_mode(right));
}
- // (recursively) look if a pred of a phi is a constant
+ /* (recursively) look if a pred of a Phi is a constant or a Confirm */
+ env->cmp = cmp;
env->pnc = pnc;
env->cnst = right;
- return find_const(env, jump, left);
+ return find_const_or_confirm(env, jump, left);
}
return NULL;
ir_node *projx;
ir_node *cond;
ir_node *copy_block;
+ int selector_evaluated;
const ir_edge_t *edge, *next;
ir_node* bad;
size_t cnst_pos;
return;
selector = get_Cond_selector(cond);
- // TODO handle switch Conds
+ /* TODO handle switch Conds */
if (get_irn_mode(selector) != mode_b)
return;
+ /* handle cases that can be immediately evaluated */
+ selector_evaluated = -1;
+ if(is_Proj(selector)) {
+ ir_node *cmp = get_Proj_pred(selector);
+ if(is_Cmp(cmp)) {
+ ir_node *left = get_Cmp_left(cmp);
+ ir_node *right = get_Cmp_right(cmp);
+ if(is_Const(left) && is_Const(right)) {
+ int pnc = get_Proj_proj(selector);
+ tarval *tv_left = get_Const_tarval(left);
+ tarval *tv_right = get_Const_tarval(right);
+
+ selector_evaluated = eval_cmp_tv(pnc, tv_left, tv_right);
+ if(selector_evaluated < 0)
+ return;
+ }
+ }
+ } else if (is_Const_or_Confirm(selector)) {
+ tarval *tv = get_Const_or_Confirm_tarval(selector);
+ if(tv == tarval_b_true) {
+ selector_evaluated = 1;
+ } else {
+ assert(tv == tarval_b_false);
+ selector_evaluated = 0;
+ }
+ }
+
+ env.cnst_pred = NULL;
if (get_Proj_proj(projx) == pn_Cond_false) {
- env.tv = get_tarval_b_false();
+ env.tv = tarval_b_false;
+ if(selector_evaluated >= 0)
+ selector_evaluated = !selector_evaluated;
} else {
- env.tv = get_tarval_b_true();
+ env.tv = tarval_b_true;
+ }
+
+ if(selector_evaluated == 0) {
+ bad = new_Bad();
+ exchange(projx, bad);
+ *changed = 1;
+ return;
+ } else if(selector_evaluated == 1) {
+ dbg_info *dbgi = get_irn_dbg_info(selector);
+ ir_node *jmp = new_rd_Jmp(dbgi, current_ir_graph, get_nodes_block(projx));
+ exchange(projx, jmp);
+ *changed = 1;
+ return;
}
- // (recursively) look if a pred of a phi is a constant
+ /* (recursively) look if a pred of a Phi is a constant or a Confirm */
env.true_block = block;
inc_irg_visited(current_ir_graph);
env.visited_nr = get_irg_visited(current_ir_graph);
return;
/* we have to remove the edge towards the pred as the pred now
- * jumps into the true_block. We also have to shorten phis
+ * jumps into the true_block. We also have to shorten Phis
* in our block because of this */
bad = new_Bad();
cnst_pos = env.cnst_pos;
- /* shorten phis */
+ /* shorten Phis */
foreach_out_edge_safe(env.cnst_pred, edge, next) {
ir_node *node = get_edge_src_irn(edge);
normalize_proj_nodes(irg);
edges_assure(irg);
- set_using_irn_link(irg);
- set_using_visited(irg);
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_IRN_VISITED);
changed = 0;
do {
changed |= rerun;
} while (rerun);
+ ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_IRN_VISITED);
+
if (changed) {
/* control flow changed, some blocks may become dead */
set_irg_outs_inconsistent(irg);
set_irg_doms_inconsistent(irg);
set_irg_extblk_inconsistent(irg);
set_irg_loopinfo_inconsistent(irg);
+
+ /* Dead code might be created. Optimize it away as it is dangerous
+ * to call optimize_df() an dead code. */
+ optimize_cf(irg);
}
- clear_using_visited(irg);
- clear_using_irn_link(irg);
}
projects / libfirm / blobdiff