/*
- * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
- *
* This file is part of libFirm.
- *
- * This file may be distributed and/or modified under the terms of the
- * GNU General Public License version 2 as published by the Free Software
- * Foundation and appearing in the file LICENSE.GPL included in the
- * packaging of this file.
- *
- * Licensees holding valid libFirm Professional Edition licenses may use
- * this file in accordance with the libFirm Commercial License.
- * Agreement provided with the Software.
- *
- * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
- * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE.
+ * Copyright (C) 2012 University of Karlsruhe.
*/
/**
* @file
* @brief Peephole optimisation framework keeps track of which registers contain which values
* @author Matthias Braun
- * @version $Id$
*/
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif
+#include "array_t.h"
#include "bepeephole.h"
#include "iredges_t.h"
#include "irgwalk.h"
#include "irprintf.h"
+#include "ircons.h"
#include "irgmod.h"
+#include "heights.h"
#include "error.h"
-#include "beirg_t.h"
+#include "beirg.h"
#include "belive_t.h"
-#include "bearch_t.h"
-#include "benode_t.h"
-#include "besched_t.h"
+#include "bearch.h"
+#include "beintlive_t.h"
+#include "benode.h"
+#include "besched.h"
#include "bemodule.h"
DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
static const arch_env_t *arch_env;
static be_lv_t *lv;
static ir_node *current_node;
-ir_node ***register_values;
+ir_node **register_values;
static void clear_reg_value(ir_node *node)
{
- const arch_register_t *reg;
- const arch_register_class_t *cls;
- unsigned reg_idx;
- unsigned cls_idx;
+ const arch_register_t *reg;
+ unsigned reg_idx;
- if(!mode_is_data(get_irn_mode(node)))
+ if (!mode_is_data(get_irn_mode(node)))
return;
- reg = arch_get_irn_register(arch_env, node);
- if(reg == NULL) {
- panic("No register assigned at %+F\n", node);
+ reg = arch_get_irn_register(node);
+ if (reg == NULL) {
+ panic("No register assigned at %+F", node);
}
- if(arch_register_type_is(reg, virtual))
+ if (reg->type & arch_register_type_virtual)
return;
- cls = arch_register_get_class(reg);
- reg_idx = arch_register_get_index(reg);
- cls_idx = arch_register_class_index(cls);
+ reg_idx = reg->global_index;
- //assert(register_values[cls_idx][reg_idx] != NULL);
- DBG((dbg, LEVEL_1, "Clear Register %s\n", reg->name));
- register_values[cls_idx][reg_idx] = NULL;
+ DB((dbg, LEVEL_1, "Clear Register %s\n", reg->name));
+ register_values[reg_idx] = NULL;
}
static void set_reg_value(ir_node *node)
{
- const arch_register_t *reg;
- const arch_register_class_t *cls;
- unsigned reg_idx;
- unsigned cls_idx;
+ const arch_register_t *reg;
+ unsigned reg_idx;
- if(!mode_is_data(get_irn_mode(node)))
+ if (!mode_is_data(get_irn_mode(node)))
return;
- reg = arch_get_irn_register(arch_env, node);
- if(reg == NULL) {
- panic("No register assigned at %+F\n", node);
+ reg = arch_get_irn_register(node);
+ if (reg == NULL) {
+ panic("No register assigned at %+F", node);
}
- if(arch_register_type_is(reg, virtual))
+ if (reg->type & arch_register_type_virtual)
return;
- cls = arch_register_get_class(reg);
- reg_idx = arch_register_get_index(reg);
- cls_idx = arch_register_class_index(cls);
+ reg_idx = reg->global_index;
- DBG((dbg, LEVEL_1, "Set Register %s: %+F\n", reg->name, node));
- register_values[cls_idx][reg_idx] = node;
+ DB((dbg, LEVEL_1, "Set Register %s: %+F\n", reg->name, node));
+ register_values[reg_idx] = node;
}
static void clear_defs(ir_node *node)
{
/* clear values defined */
- if(get_irn_mode(node) == mode_T) {
- const ir_edge_t *edge;
- foreach_out_edge(node, edge) {
- ir_node *proj = get_edge_src_irn(edge);
- clear_reg_value(proj);
- }
- } else {
- clear_reg_value(node);
- }
+ be_foreach_value(node, value,
+ clear_reg_value(value);
+ );
}
static void set_uses(ir_node *node)
/* set values used */
arity = get_irn_arity(node);
- for(i = 0; i < arity; ++i) {
+ for (i = 0; i < arity; ++i) {
ir_node *in = get_irn_n(node, i);
set_reg_value(in);
}
}
-void be_peephole_before_exchange(const ir_node *old_node, ir_node *new_node)
+/**
+ * must be called from peephole optimisations before a node will be killed
+ * and its users will be redirected to new_node.
+ * so bepeephole can update its internal state.
+ *
+ * Note: killing a node and rewiring is only allowed if new_node produces
+ * the same registers as old_node.
+ */
+static void be_peephole_before_exchange(const ir_node *old_node,
+ ir_node *new_node)
{
- const arch_register_t *reg;
- const arch_register_class_t *cls;
- unsigned reg_idx;
- unsigned cls_idx;
-
- DBG((dbg, LEVEL_1, "About to exchange %+F with %+F\n", old_node, new_node));
-
- if(old_node == current_node) {
- if(is_Proj(new_node)) {
- current_node = get_Proj_pred(new_node);
- } else {
- current_node = new_node;
- }
+ const arch_register_t *reg;
+ unsigned reg_idx;
+ bool old_is_current = false;
+
+ DB((dbg, LEVEL_1, "About to exchange and kill %+F with %+F\n", old_node, new_node));
+
+ assert(sched_is_scheduled(skip_Proj_const(old_node)));
+ assert(sched_is_scheduled(skip_Proj(new_node)));
+
+ if (current_node == old_node) {
+ old_is_current = true;
+
+ /* next node to be processed will be killed. Its scheduling predecessor
+ * must be processed next. */
+ current_node = sched_next(current_node);
+ assert (!is_Bad(current_node));
+
+ /* we can't handle liveness updates correctly when exchange current node
+ * with something behind it */
+ assert(value_dominates(skip_Proj(new_node), skip_Proj_const(old_node)));
}
- if(!mode_is_data(get_irn_mode(old_node)))
+ if (!mode_is_data(get_irn_mode(old_node)))
return;
- reg = arch_get_irn_register(arch_env, old_node);
- if(reg == NULL) {
- panic("No register assigned at %+F\n", old_node);
+ reg = arch_get_irn_register(old_node);
+ if (reg == NULL) {
+ panic("No register assigned at %+F", old_node);
}
- cls = arch_register_get_class(reg);
- reg_idx = arch_register_get_index(reg);
- cls_idx = arch_register_class_index(cls);
+ assert(reg == arch_get_irn_register(new_node) &&
+ "KILLING a node and replacing by different register is not allowed");
- if(register_values[cls_idx][reg_idx] == old_node) {
- register_values[cls_idx][reg_idx] = new_node;
+ reg_idx = reg->global_index;
+ if (register_values[reg_idx] == old_node || old_is_current) {
+ register_values[reg_idx] = new_node;
}
be_liveness_remove(lv, old_node);
}
-void be_peephole_after_exchange(ir_node *new_node)
+void be_peephole_exchange(ir_node *old, ir_node *nw)
{
- be_liveness_introduce(lv, new_node);
+ be_peephole_before_exchange(old, nw);
+ sched_remove(old);
+ exchange(old, nw);
+ be_liveness_introduce(lv, nw);
}
+/**
+ * block-walker: run peephole optimization on the given block.
+ */
static void process_block(ir_node *block, void *data)
{
- unsigned n_classes;
- unsigned i;
- int l;
(void) data;
/* construct initial register assignment */
- n_classes = arch_env_get_n_reg_class(arch_env);
- for(i = 0; i < n_classes; ++i) {
- const arch_register_class_t *cls = arch_env_get_reg_class(arch_env, i);
- unsigned n_regs = arch_register_class_n_regs(cls);
- memset(register_values[i], 0, sizeof(ir_node*) * n_regs);
- }
+ memset(register_values, 0, sizeof(ir_node*) * arch_env->n_registers);
- assert(lv->nodes && "live sets must be computed");
- DBG((dbg, LEVEL_1, "\nProcessing block %+F (from end)\n", block));
- be_lv_foreach(lv, block, be_lv_state_end, l) {
- ir_node *node = be_lv_get_irn(lv, block, l);
+ assert(lv->sets_valid && "live sets must be computed");
+ DB((dbg, LEVEL_1, "\nProcessing block %+F (from end)\n", block));
+ be_lv_foreach(lv, block, be_lv_state_end, node) {
set_reg_value(node);
}
- DBG((dbg, LEVEL_1, "\nstart processing\n"));
+ DB((dbg, LEVEL_1, "\nstart processing\n"));
/* walk the block from last insn to the first */
current_node = sched_last(block);
- for( ; !sched_is_begin(current_node);
+ for ( ; !sched_is_begin(current_node);
current_node = sched_prev(current_node)) {
ir_op *op;
- ir_node *last;
- peephole_opt_func func;
+ peephole_opt_func peephole_node;
- if(is_Phi(current_node))
+ assert(!is_Bad(current_node));
+ if (is_Phi(current_node))
break;
clear_defs(current_node);
set_uses(current_node);
- op = get_irn_op(current_node);
- func = (peephole_opt_func) op->ops.generic;
- if(func == NULL)
+ op = get_irn_op(current_node);
+ peephole_node = (peephole_opt_func)op->ops.generic;
+ if (peephole_node == NULL)
continue;
- last = current_node;
- func(current_node);
- /* was the current node replaced? */
- if(current_node != last) {
- set_uses(current_node);
- }
+ DB((dbg, LEVEL_2, "optimize %+F\n", current_node));
+ peephole_node(current_node);
+ assert(!is_Bad(current_node));
}
}
/**
- * Walk through the block schedule and skip all barrier nodes.
+ * Check whether the node has only one user. Explicitly ignore the anchor.
*/
-static void skip_barrier(ir_node *ret_blk, ir_graph *irg) {
- ir_node *irn;
+bool be_has_only_one_user(ir_node *node)
+{
+ int n = get_irn_n_edges(node);
+ int n_users;
- sched_foreach_reverse(ret_blk, irn) {
- if (be_is_Barrier(irn)) {
- const ir_edge_t *edge, *next;
+ if (n <= 1)
+ return 1;
- foreach_out_edge_safe(irn, edge, next) {
- ir_node *proj = get_edge_src_irn(edge);
- int pn = (int)get_Proj_proj(proj);
- ir_node *pred = get_irn_n(irn, pn);
+ n_users = 0;
+ foreach_out_edge(node, edge) {
+ ir_node *src = get_edge_src_irn(edge);
+ /* ignore anchor and keep-alive edges */
+ if (is_Anchor(src) || is_End(src))
+ continue;
+ n_users++;
+ }
- edges_reroute_kind(proj, pred, EDGE_KIND_NORMAL, irg);
- edges_reroute_kind(proj, pred, EDGE_KIND_DEP, irg);
+ return n_users == 1;
+}
+
+static inline bool overlapping_regs(const arch_register_t *reg0,
+ const arch_register_req_t *req0, const arch_register_t *reg1,
+ const arch_register_req_t *req1)
+{
+ if (reg0 == NULL || reg1 == NULL)
+ return false;
+ return reg0->global_index < (unsigned)reg1->global_index + req1->width
+ && reg1->global_index < (unsigned)reg0->global_index + req0->width;
+}
+
+bool be_can_move_down(ir_heights_t *heights, const ir_node *node,
+ const ir_node *before)
+{
+ assert(get_nodes_block(node) == get_nodes_block(before));
+ assert(sched_get_time_step(node) < sched_get_time_step(before));
+
+ int node_arity = get_irn_arity(node);
+ ir_node *schedpoint = sched_next(node);
+
+ while (schedpoint != before) {
+ /* schedpoint must not use our computed values */
+ if (heights_reachable_in_block(heights, schedpoint, node))
+ return false;
+
+ /* schedpoint must not overwrite registers of our inputs */
+ for (int i = 0; i < node_arity; ++i) {
+ ir_node *in = get_irn_n(node, i);
+ const arch_register_t *reg = arch_get_irn_register(in);
+ if (reg == NULL)
+ continue;
+ const arch_register_req_t *in_req
+ = arch_get_irn_register_req_in(node, i);
+ be_foreach_out(schedpoint, o) {
+ const arch_register_t *outreg
+ = arch_get_irn_register_out(schedpoint, o);
+ const arch_register_req_t *outreq
+ = arch_get_irn_register_req_out(schedpoint, o);
+ if (overlapping_regs(reg, in_req, outreg, outreq))
+ return false;
}
- sched_remove(irn);
- kill_node(irn);
- break;
}
+
+ schedpoint = sched_next(schedpoint);
}
+ return true;
}
-/**
- * Kill the Barrier nodes for better peephole optimization.
- */
-static void kill_barriers(ir_graph *irg) {
- ir_node *end_blk = get_irg_end_block(irg);
- ir_node *start_blk;
- int i;
-
- /* skip the barrier on all return blocks */
- for (i = get_Block_n_cfgpreds(end_blk) - 1; i >= 0; --i) {
- ir_node *be_ret = get_Block_cfgpred(end_blk, i);
- ir_node *ret_blk = get_nodes_block(be_ret);
+bool be_can_move_up(ir_heights_t *heights, const ir_node *node,
+ const ir_node *after)
+{
+ const ir_node *node_block = get_nodes_block(node);
+ const ir_node *after_block = get_block_const(after);
+ const ir_node *schedpoint;
+ if (node_block != after_block) {
+ /* currently we can move up exactly 1 block */
+ assert(get_Block_cfgpred_block(node_block, 0) == after_block);
+ ir_node *first = sched_first(node_block);
+
+ /* do not move nodes changing memory */
+ if (is_memop(node)) {
+ ir_node *meminput = get_memop_mem(node);
+ if (!is_NoMem(meminput))
+ return false;
+ }
- skip_barrier(ret_blk, irg);
+ /* make sure we can move to the beginning of the succ block */
+ if (node != first && !be_can_move_up(heights, node, sched_prev(first)))
+ return false;
+
+ /* check if node overrides any of live-in values of other successors */
+ ir_graph *irg = get_irn_irg(node);
+ be_lv_t *lv = be_get_irg_liveness(irg);
+ foreach_block_succ(after_block, edge) {
+ ir_node *succ = get_edge_src_irn(edge);
+ if (succ == node_block)
+ continue;
+
+ be_lv_foreach(lv, succ, be_lv_state_in, live_node) {
+ const arch_register_t *reg = arch_get_irn_register(live_node);
+ const arch_register_req_t *req = arch_get_irn_register_req(live_node);
+ be_foreach_out(node, o) {
+ const arch_register_t *outreg
+ = arch_get_irn_register_out(node, o);
+ const arch_register_req_t *outreq
+ = arch_get_irn_register_req_out(node, o);
+ if (overlapping_regs(outreg, outreq, reg, req))
+ return false;
+ }
+ }
+ sched_foreach(succ, phi) {
+ if (!is_Phi(phi))
+ break;
+ const arch_register_t *reg = arch_get_irn_register(phi);
+ const arch_register_req_t *req = arch_get_irn_register_req(phi);
+ be_foreach_out(node, o) {
+ const arch_register_t *outreg
+ = arch_get_irn_register_out(node, o);
+ const arch_register_req_t *outreq
+ = arch_get_irn_register_req_out(node, o);
+ if (overlapping_regs(outreg, outreq, reg, req))
+ return false;
+ }
+ }
+ }
+ schedpoint = sched_last(after_block);
+ } else {
+ schedpoint = sched_prev(node);
}
- /* skip the barrier on the start block */
- start_blk = get_irg_start_block(irg);
- skip_barrier(start_blk, irg);
-}
+ /* move schedule upwards until we hit the "after" node */
+ while (schedpoint != after) {
+ /* TODO: the following heights query only works for nodes in the same
+ * block, otherwise we have to be conservative here */
+ if (get_nodes_block(node) != get_nodes_block(schedpoint))
+ return false;
+ /* node must not depend on schedpoint */
+ if (heights_reachable_in_block(heights, node, schedpoint))
+ return false;
+
+ /* node must not overwrite registers used by schedpoint */
+ int arity = get_irn_arity(schedpoint);
+ for (int i = 0; i < arity; ++i) {
+ const arch_register_t *reg
+ = arch_get_irn_register_in(schedpoint, i);
+ if (reg == NULL)
+ continue;
+ const arch_register_req_t *in_req
+ = arch_get_irn_register_req_in(schedpoint, i);
+ be_foreach_out(node, o) {
+ const arch_register_t *outreg
+ = arch_get_irn_register_out(node, o);
+ const arch_register_req_t *outreq
+ = arch_get_irn_register_req_out(node, o);
+ if (overlapping_regs(outreg, outreq, reg, in_req))
+ return false;
+ }
+ }
+ schedpoint = sched_prev(schedpoint);
+ }
+ return true;
+}
-void be_peephole_opt(be_irg_t *birg)
+/*
+ * Tries to optimize a beIncSP node with its previous IncSP node.
+ * Must be run from a be_peephole_opt() context.
+ */
+ir_node *be_peephole_IncSP_IncSP(ir_node *node)
{
- ir_graph *irg = be_get_birg_irg(birg);
- unsigned n_classes;
- unsigned i;
-
- /* barrier nodes are used for register allocations. They hinders
- * peephole optimizations, so remove them here. */
- kill_barriers(irg);
-
- /* we sometimes find BadE nodes in float apps like optest_float.c or
- * kahansum.c for example... */
- be_liveness_invalidate(birg->lv);
- be_liveness_assure_sets(be_assure_liveness(birg));
-
- arch_env = be_get_birg_arch_env(birg);
- lv = be_get_birg_liveness(birg);
-
- n_classes = arch_env_get_n_reg_class(arch_env);
- register_values = alloca(sizeof(register_values[0]) * n_classes);
- for(i = 0; i < n_classes; ++i) {
- const arch_register_class_t *cls = arch_env_get_reg_class(arch_env, i);
- unsigned n_regs = arch_register_class_n_regs(cls);
- register_values[i] = alloca(sizeof(ir_node*) * n_regs);
- }
+ int pred_offs;
+ int curr_offs;
+ int offs;
+ ir_node *pred = be_get_IncSP_pred(node);
- irg_block_walk_graph(irg, process_block, NULL, NULL);
+ if (!be_is_IncSP(pred))
+ return node;
+
+ if (!be_has_only_one_user(pred))
+ return node;
+
+ pred_offs = be_get_IncSP_offset(pred);
+ curr_offs = be_get_IncSP_offset(node);
+ offs = curr_offs + pred_offs;
+
+ /* add node offset to pred and remove our IncSP */
+ be_set_IncSP_offset(pred, offs);
+
+ be_peephole_exchange(node, pred);
+ return pred;
}
-void be_peephole_init(void)
+void be_peephole_opt(ir_graph *irg)
{
- clear_irp_opcodes_generic_func();
+ be_assure_live_sets(irg);
+
+ arch_env = be_get_irg_arch_env(irg);
+ lv = be_get_irg_liveness(irg);
+
+ register_values = XMALLOCN(ir_node*, arch_env->n_registers);
+
+ irg_block_walk_graph(irg, process_block, NULL, NULL);
+
+ xfree(register_values);
}
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_peephole)
void be_init_peephole(void)
{
FIRM_DBG_REGISTER(dbg, "firm.be.peephole");
}
-
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);