*
* 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_graph *irg;
/* don't optimize dead or labeled blocks */
- if (is_Block_dead(n) || has_Block_entity(n))
+ if (has_Block_entity(n))
return n;
n_preds = get_Block_n_cfgpreds(n);
irg = get_irn_irg(n);
+ /* if all predecessors of a block are unreachable, then the block is
+ * unreachable */
+ if (is_irg_state(irg, IR_GRAPH_STATE_BAD_BLOCK)) {
+ int i;
+ int n_cfgpreds = get_Block_n_cfgpreds(n);
+
+ for (i = 0; i < n_cfgpreds; ++i) {
+ ir_node *pred = get_Block_cfgpred(n, i);
+ if (!is_Bad(pred))
+ break;
+ }
+ /* only bad inputs? It's unreachable code (unless it is the start or
+ * end block) */
+ if (i >= n_cfgpreds && n != get_irg_start_block(irg)
+ && n != get_irg_end_block(irg)) {
+ return get_irg_bad(irg);
+ }
+ }
+
/* 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. */
+ * can be merged. */
if (n_preds == 1) {
- ir_node *pred = skip_Proj(get_Block_cfgpred(n, 0));
+ ir_node *pred = get_Block_cfgpred(n, 0);
if (is_Jmp(pred)) {
- ir_node *predblock = get_nodes_block(pred);
- 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 {
- n = predblock;
- DBG_OPT_STG(oldn, n);
- }
- } else if (is_Cond(pred)) {
- ir_node *predblock = get_nodes_block(pred);
- 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);
- }
+ ir_node *pred_block = get_nodes_block(pred);
+ DBG_OPT_STG(n, pred_block);
+ return pred_block;
}
} else if (n_preds == 2) {
/* Test whether Cond jumps twice to this block
if (cond == get_Proj_pred(b) && is_Cond(cond) &&
get_irn_mode(get_Cond_selector(cond)) == mode_b) {
- /* Also a single entry Block following a single exit Block. Phis have
- twice the same operand and will be optimized away. */
+ /* 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(cond);
DBG_OPT_IFSIM1(oldn, a, b, n);
}
}
- } else if (get_opt_unreachable_code() &&
- (n != get_irg_start_block(irg)) &&
- (n != get_irg_end_block(irg))) {
- int i;
-
- /* If all inputs are dead, this block is dead too, except if it is
- the start or end block. This is one step of unreachable code
- elimination */
- for (i = get_Block_n_cfgpreds(n) - 1; i >= 0; --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 < 0) {
- n = set_Block_dead(n);
- DBG_OPT_DEAD_BLOCK(oldn, n);
- }
}
return n;
} /* equivalent_node_Block */
-/**
- * Returns a equivalent node for a Jmp, a Bad :-)
- * Of course this only happens if the Block of the Jmp is dead.
- */
-static ir_node *equivalent_node_Jmp(ir_node *n)
-{
- ir_node *oldn = n;
-
- /* unreachable code elimination */
- if (is_Block_dead(get_nodes_block(n))) {
- ir_graph *irg = get_irn_irg(n);
- n = get_irg_bad(irg);
- DBG_OPT_DEAD_BLOCK(oldn, n);
- }
- return n;
-} /* equivalent_node_Jmp */
-
-/** Raise is handled in the same way as Jmp. */
-#define equivalent_node_Raise equivalent_node_Jmp
-
-
/* We do not evaluate Cond here as we replace it by a new node, a Jmp.
See transform_node_Proj_Cond(). */
n_preds = get_Phi_n_preds(n);
block = get_nodes_block(n);
- /* Control dead */
- if (is_Block_dead(block)) {
- ir_graph *irg = get_irn_irg(n);
- return get_irg_bad(irg);
- }
- if (n_preds == 0) return n; /* Phi of dead Region without predecessors. */
+ /* Phi of dead Region without predecessors. */
+ if (n_preds == 0)
+ return n;
/* 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 0
- /* BEWARE: when the if is changed to 1, Phis will ignore their Bad
- * predecessors. Then, Phi nodes in unreachable code might be removed,
- * causing nodes pointing to themselev (Adds for instance).
- * This is really bad and causes endless recursion on several
- * code pathes, so we do NOT optimize such code.
- * This is not that bad as it sounds, optimize_cf() removes bad control flow
- * (and bad Phi predecessors), so live code is optimized later.
- */
- && (! is_Bad(get_Block_cfgpred(block, i)))
-#endif
- ) { /* value not dead */
- break; /* then found first value. */
+ /* not self pointer */
+ if (first_val != n) {
+ /* then found first value. */
+ break;
}
}
are non-self-referencing */
while (++i < n_preds) {
ir_node *scnd_val = get_Phi_pred(n, i);
- if ( (scnd_val != n)
- && (scnd_val != first_val)
-#if 0
- /* see above */
- && (! is_Bad(get_Block_cfgpred(block, i)))
-#endif
- ) {
+ if (scnd_val != n && scnd_val != first_val) {
break;
}
}
static ir_node *equivalent_node_Proj(ir_node *proj)
{
ir_node *n = get_Proj_pred(proj);
-
- if (get_irn_mode(proj) == mode_X) {
- if (is_Block_dead(get_nodes_block(n))) {
- /* Remove dead control flow -- early gigo(). */
- ir_graph *irg = get_irn_irg(proj);
- return get_irg_bad(irg);
- }
- }
if (n->op->ops.equivalent_node_Proj)
return n->op->ops.equivalent_node_Proj(proj);
return proj;
switch (code) {
CASE(Block);
- CASE(Jmp);
- CASE(Raise);
CASE(Eor);
CASE(Add);
CASE(Shl);
return proj;
} /* transform_node_Proj */
-/**
- * Move Confirms down through Phi nodes.
- */
static ir_node *transform_node_Phi(ir_node *phi)
{
- int i, n;
- ir_mode *mode = get_irn_mode(phi);
+ int n = get_irn_arity(phi);
+ ir_mode *mode = get_irn_mode(phi);
+ ir_node *block = get_nodes_block(phi);
+ ir_graph *irg = get_irn_irg(phi);
+ ir_node *bad = get_irg_bad(irg);
+ int i;
+
+ /* Set phi-operands for bad-block inputs to bad */
+ for (i = 0; i < n; ++i) {
+ ir_node *pred = get_Block_cfgpred(block, i);
+ if (!is_Bad(pred))
+ continue;
+ set_irn_n(phi, i, bad);
+ }
+ /* Move Confirms down through Phi nodes. */
if (mode_is_reference(mode)) {
n = get_irn_arity(phi);
for (i = j = 0; i < n_keepalives; ++i) {
ir_node *ka = get_End_keepalive(n, i);
- if (is_Block(ka)) {
- if (! is_Block_dead(ka)) {
- in[j++] = ka;
- }
- continue;
- } else if (is_irn_pinned_in_irg(ka) && is_Block_dead(get_nodes_block(ka))) {
- continue;
- } else if (is_Bad(ka)) {
+ if (is_Bad(ka)) {
/* no need to keep Bad */
continue;
}
return n;
} /* transform_node_Sync */
+static ir_node *transform_node_Load(ir_node *n)
+{
+ /* if our memory predecessor is a load from the same address, then reuse the
+ * previous result */
+ ir_node *mem = get_Load_mem(n);
+ ir_node *mem_pred;
+
+ if (!is_Proj(mem))
+ return n;
+ /* don't touch volatile loads */
+ if (get_Load_volatility(n) == volatility_is_volatile)
+ return n;
+ mem_pred = get_Proj_pred(mem);
+ if (is_Load(mem_pred)) {
+ ir_node *pred_load = mem_pred;
+
+ /* conservatively compare the 2 loads. TODO: This could be less strict
+ * with fixup code in some situations (like smaller/bigger modes) */
+ if (get_Load_ptr(pred_load) != get_Load_ptr(n))
+ return n;
+ if (get_Load_mode(pred_load) != get_Load_mode(n))
+ return n;
+ /* all combinations of aligned/unaligned pred/n should be fine so we do
+ * not compare the unaligned attribute */
+ {
+ ir_node *block = get_nodes_block(n);
+ ir_node *jmp = new_r_Jmp(block);
+ ir_graph *irg = get_irn_irg(n);
+ ir_node *bad = get_irg_bad(irg);
+ ir_mode *mode = get_Load_mode(n);
+ ir_node *res = new_r_Proj(pred_load, mode, pn_Load_res);
+ ir_node *in[pn_Load_max] = { mem, jmp, bad, res };
+ ir_node *tuple = new_r_Tuple(block, ARRAY_SIZE(in), in);
+ return tuple;
+ }
+ } else if (is_Store(mem_pred)) {
+ ir_node *pred_store = mem_pred;
+ ir_node *value = get_Store_value(pred_store);
+
+ if (get_Store_ptr(pred_store) != get_Load_ptr(n))
+ return n;
+ if (get_irn_mode(value) != get_Load_mode(n))
+ return n;
+ /* all combinations of aligned/unaligned pred/n should be fine so we do
+ * not compare the unaligned attribute */
+ {
+ ir_node *block = get_nodes_block(n);
+ ir_node *jmp = new_r_Jmp(block);
+ ir_graph *irg = get_irn_irg(n);
+ ir_node *bad = get_irg_bad(irg);
+ ir_node *res = value;
+ ir_node *in[pn_Load_max] = { mem, jmp, bad, res };
+ ir_node *tuple = new_r_Tuple(block, ARRAY_SIZE(in), in);
+ return tuple;
+ }
+ }
+
+ return n;
+}
+
/**
* optimize a trampoline Call into a direct Call
*/
CASE(Sync);
CASE_PROJ(Bound);
CASE_PROJ(CopyB);
- CASE_PROJ(Load);
CASE_PROJ(Store);
CASE_PROJ_EX(Cond);
CASE_PROJ_EX(Div);
+ CASE_PROJ_EX(Load);
CASE_PROJ_EX(Mod);
default:
/* leave NULL */;
/* Should we really check the constraints here? Should be better, but is strange. */
n = get_ASM_n_input_constraints(a);
if (n != get_ASM_n_input_constraints(b))
- return 0;
+ return 1;
ca = get_ASM_input_constraints(a);
cb = get_ASM_input_constraints(b);
for (i = 0; i < n; ++i) {
- if (ca[i].pos != cb[i].pos || ca[i].constraint != cb[i].constraint)
+ if (ca[i].pos != cb[i].pos || ca[i].constraint != cb[i].constraint
+ || ca[i].mode != cb[i].mode)
return 1;
}
n = get_ASM_n_output_constraints(a);
if (n != get_ASM_n_output_constraints(b))
- return 0;
+ return 1;
ca = get_ASM_output_constraints(a);
cb = get_ASM_output_constraints(b);
for (i = 0; i < n; ++i) {
- if (ca[i].pos != cb[i].pos || ca[i].constraint != cb[i].constraint)
+ if (ca[i].pos != cb[i].pos || ca[i].constraint != cb[i].constraint
+ || ca[i].mode != cb[i].mode)
return 1;
}
n = get_ASM_n_clobbers(a);
if (n != get_ASM_n_clobbers(b))
- return 0;
+ return 1;
cla = get_ASM_clobbers(a);
clb = get_ASM_clobbers(b);
*/
static ir_node *gigo(ir_node *node)
{
- int i, irn_arity;
ir_op *op = get_irn_op(node);
- /* remove garbage blocks by looking at control flow that leaves the block
- and replacing the control flow by Bad. */
- if (get_irn_mode(node) == mode_X) {
- ir_node *block = get_nodes_block(skip_Proj(node));
- ir_graph *irg = get_irn_irg(block);
-
- /* Don't optimize nodes in immature blocks. */
- if (!get_Block_matured(block))
- return node;
- /* Don't optimize End, may have Bads. */
- if (op == op_End) return node;
-
- if (is_Block(block)) {
- if (is_Block_dead(block)) {
- /* control flow from dead block is dead */
- return get_irg_bad(irg);
- }
-
- for (i = get_irn_arity(block) - 1; i >= 0; --i) {
- if (!is_Bad(get_irn_n(block, i)))
- break;
- }
- if (i < 0) {
- ir_graph *irg = get_irn_irg(block);
- /* the start block is never dead */
- if (block != get_irg_start_block(irg)
- && block != get_irg_end_block(irg)) {
- /*
- * Do NOT kill control flow without setting
- * the block to dead of bad things can happen:
- * We get a Block that is not reachable be irg_block_walk()
- * but can be found by irg_walk()!
- */
- set_Block_dead(block);
- return get_irg_bad(irg);
- }
- }
- }
+ /* Code in "Bad" blocks is unreachable and can be replaced by Bad */
+ if (op != op_Block && is_Bad(get_nodes_block(node))) {
+ ir_graph *irg = get_irn_irg(node);
+ return get_irg_bad(irg);
}
/* Blocks, Phis and Tuples may have dead inputs, e.g., if one of the
blocks predecessors is dead. */
- if (op != op_Block && op != op_Phi && op != op_Tuple && op != op_Anchor) {
+ if (op != op_Block && op != op_Phi && op != op_Tuple && op != op_Anchor
+ && op != op_Sync && op != op_End) {
ir_graph *irg = get_irn_irg(node);
- irn_arity = get_irn_arity(node);
-
- /*
- * Beware: we can only read the block of a non-floating node.
- */
- if (is_irn_pinned_in_irg(node) &&
- is_Block_dead(get_nodes_block(skip_Proj(node))))
- return get_irg_bad(irg);
+ int irn_arity = get_irn_arity(node);
+ int i;
for (i = 0; i < irn_arity; i++) {
ir_node *pred = get_irn_n(node, i);
- if (is_Bad(pred))
- return get_irg_bad(irg);
-#if 0
- /* Propagating Unknowns here seems to be a bad idea, because
- sometimes we need a node as a input and did not want that
- it kills its user.
- However, it might be useful to move this into a later phase
- (if you think that optimizing such code is useful). */
- if (is_Unknown(pred) && mode_is_data(get_irn_mode(node)))
- return new_r_Unknown(irg, get_irn_mode(node));
-#endif
- }
- }
-#if 0
- /* With this code we violate the agreement that local_optimize
- only leaves Bads in Block, Phi and Tuple nodes. */
- /* If Block has only Bads as predecessors it's garbage. */
- /* If Phi has only Bads as predecessors it's garbage. */
- if ((op == op_Block && get_Block_matured(node)) || op == op_Phi) {
- irn_arity = get_irn_arity(node);
- for (i = 0; i < irn_arity; i++) {
- if (!is_Bad(get_irn_n(node, i))) break;
+ if (is_Bad(pred)) {
+ /* be careful not to kill cfopts too early or we might violate
+ * the 1 cfop per block property */
+ if (!is_cfop(node)
+ || is_irg_state(irg, IR_GRAPH_STATE_BAD_BLOCK))
+ return get_irg_bad(irg);
+ }
}
- if (i == irn_arity) node = get_irg_bad(irg);
}
-#endif
+
return node;
-} /* gigo */
+}
/**
* These optimizations deallocate nodes from the obstack.
* @return
* The operations.
*/
-static ir_op_ops *firm_set_default_hash(ir_opcode code, ir_op_ops *ops)
+static ir_op_ops *firm_set_default_hash(unsigned code, ir_op_ops *ops)
{
#define CASE(a) \
case iro_##a: \
/*
* Sets the default operation for an ir_ops.
*/
-ir_op_ops *firm_set_default_operations(ir_opcode code, ir_op_ops *ops)
+ir_op_ops *firm_set_default_operations(unsigned code, ir_op_ops *ops)
{
ops = firm_set_default_hash(code, ops);
ops = firm_set_default_computed_value(code, ops);
projects / libfirm / blobdiff