Commit 277830bf authored by Matthias Braun's avatar Matthias Braun
Browse files

- first real peephole optimisation mov 0, reg -> xor reg, reg when we don't

  care about flags
- fixed some bugs in bepeephole

[r16013]
parent 28337840
......@@ -19,14 +19,16 @@
/**
* @file
* @brief modifies schedule so flags dependencies are respected.
* @author Matthias Braun, Christoph Mallon
* @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 "bepeephole.h"
#include "iredges_t.h"
#include "irgwalk.h"
#include "irprintf.h"
......@@ -38,8 +40,8 @@
#include "besched_t.h"
static const arch_env_t *arch_env;
static const be_lv_t *lv;
ir_node ***register_values;
static be_lv_t *lv;
ir_node ***register_values;
static void clear_value(ir_node *node)
{
......@@ -61,6 +63,7 @@ static void clear_value(ir_node *node)
reg_idx = arch_register_get_index(reg);
cls_idx = arch_register_class_index(cls);
//assert(register_values[cls_idx][reg_idx] != NULL);
register_values[cls_idx][reg_idx] = NULL;
}
......@@ -93,10 +96,8 @@ static void set_value(ir_node *node)
register_values[cls_idx][reg_idx] = node;
}
static void advance(ir_node *node)
static void clear_defs(ir_node *node)
{
int i, arity;
/* clear values defined */
if(get_irn_mode(node) == mode_T) {
const ir_edge_t *edge;
......@@ -107,6 +108,11 @@ static void advance(ir_node *node)
} else {
clear_value(node);
}
}
static void set_uses(ir_node *node)
{
int i, arity;
/* set values used */
arity = get_irn_arity(node);
......@@ -140,11 +146,28 @@ static void process_block(ir_node *block, void *data)
}
/* walk the block */
sched_foreach_reverse(block, node) {
node = sched_last(block);
for( ; !sched_is_begin(node); node = sched_prev(node)) {
ir_op *op;
peephole_opt_func func;
if(is_Phi(node))
break;
advance(node);
clear_defs(node);
set_uses(node);
op = get_irn_op(node);
func = (peephole_opt_func) op->ops.generic;
if(func != NULL) {
ir_node *new_node = func(node);
if(new_node != NULL && new_node != node) {
be_liveness_remove(lv, node);
be_liveness_introduce(lv, new_node);
node = new_node;
set_uses(node);
}
}
}
}
......@@ -174,3 +197,8 @@ void be_peephole_opt(be_irg_t *birg)
irg_block_walk_graph(irg, process_block, NULL, NULL);
}
void be_peephole_init(void)
{
clear_irp_opcodes_generic_func();
}
/*
* Copyright (C) 1995-2007 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.
*/
/**
* @file
* @brief peephole optimisation framework
* @author Matthias Braun
* @version $Id$
*/
#ifndef BEPEEPHOLE_H
#define BEPEEPHOLE_H
#include "beirg.h"
#include "bearch_t.h"
extern ir_node ***register_values;
static inline ir_node *get_value_in_reg(unsigned regclass_idx,
unsigned register_idx)
static inline ir_node *be_peephole_get_value(unsigned regclass_idx,
unsigned register_idx)
{
return register_values[regclass_idx][register_idx];
}
static inline ir_node *be_peephole_get_reg_value(const arch_register_t *reg)
{
unsigned regclass_idx = arch_register_class_index(arch_register_get_class(reg));
unsigned register_idx = arch_register_get_index(reg);
return be_peephole_get_value(regclass_idx, register_idx);
}
typedef ir_node*(*peephole_opt_func) (ir_node *node);
/**
* Do peephole optimisations, works backwards over blockschedules and calls the generic op handler function
* which should be of type peephole_opt_func. The values of the values in the registers are availble
* in the register_values variable during the optimisation functions.
*/
void be_peephole_opt(be_irg_t *birg);
#endif
......@@ -1621,21 +1621,10 @@ static void emit_be_Perm(const ir_node *node)
*/
static void emit_ia32_Const(const ir_node *node)
{
const ia32_immediate_attr_t *attr = get_ia32_immediate_attr_const(node);
/* a zero? */
if(attr->symconst == NULL && attr->offset == 0) {
assert(get_ia32_flags(node) & arch_irn_flags_modify_flags);
be_emit_cstring("\txorl ");
ia32_emit_dest_register(node, 0);
be_emit_cstring(", ");
ia32_emit_dest_register(node, 0);
} else {
be_emit_cstring("\tmovl ");
emit_ia32_Immediate(node);
be_emit_cstring(", ");
ia32_emit_dest_register(node, 0);
}
be_emit_cstring("\tmovl ");
emit_ia32_Immediate(node);
be_emit_cstring(", ");
ia32_emit_dest_register(node, 0);
be_emit_finish_line_gas(node);
}
......
......@@ -54,6 +54,9 @@
DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
static const arch_env_t *arch_env;
static ia32_code_gen_t *cg;
typedef int is_op_func_t(const ir_node *n);
typedef ir_node *load_func_t(dbg_info *db, ir_graph *irg, ir_node *block, ir_node *base, ir_node *index, ir_node *mem);
......@@ -85,7 +88,8 @@ static INLINE int be_is_NoReg(ia32_code_gen_t *cg, const ir_node *irn) {
/**
* Tries to create pushs from IncSP,Store combinations
*/
static void ia32_create_Pushs(ir_node *irn, ia32_code_gen_t *cg) {
static void ia32_create_Pushs(ir_node *irn)
{
int i;
int offset;
ir_node *node;
......@@ -265,32 +269,75 @@ static void ia32_optimize_IncSP(ir_node *node)
/**
* Performs Peephole Optimizations.
*/
static void ia32_peephole_optimize_node(ir_node *node, void *env) {
ia32_code_gen_t *cg = env;
static void ia32_peephole_optimize_node(ir_node *node, void *env)
{
(void) env;
if (be_is_IncSP(node)) {
ia32_optimize_IncSP(node);
if (cg->opt & IA32_OPT_PUSHARGS)
ia32_create_Pushs(node, cg);
ia32_create_Pushs(node);
}
}
void ia32_peephole_optimization(ir_graph *irg, ia32_code_gen_t *cg)
static ir_node *optimize_ia32_Const(ir_node *node)
{
be_peephole_opt(cg->birg);
irg_walk_graph(irg, ia32_peephole_optimize_node, NULL, cg);
const ia32_immediate_attr_t *attr = get_ia32_immediate_attr_const(node);
const arch_register_t *reg;
ir_graph *irg = current_ir_graph;
ir_node *block;
dbg_info *dbgi;
ir_node *produceval;
ir_node *xor;
ir_node *noreg;
/* try to transform a mov 0, reg to xor reg reg */
if(attr->offset != 0 || attr->symconst != NULL)
return NULL;
/* xor destroys the flags, so noone must be using them */
if(be_peephole_get_value(CLASS_ia32_flags, REG_EFLAGS) != NULL)
return NULL;
reg = arch_get_irn_register(arch_env, node);
assert(be_peephole_get_reg_value(reg) == NULL);
/* create xor(produceval, produceval) */
block = get_nodes_block(node);
dbgi = get_irn_dbg_info(node);
produceval = new_rd_ia32_ProduceVal(dbgi, irg, block);
arch_set_irn_register(arch_env, produceval, reg);
noreg = ia32_new_NoReg_gp(cg);
xor = new_rd_ia32_Xor(dbgi, irg, block, noreg, noreg, new_NoMem(),
produceval, produceval);
arch_set_irn_register(arch_env, xor, reg);
sched_add_before(node, produceval);
sched_add_before(node, xor);
exchange(node, xor);
sched_remove(node);
return xor;
}
/******************************************************************
* _ _ __ __ _
* /\ | | | | | \/ | | |
* / \ __| | __| |_ __ ___ ___ ___| \ / | ___ __| | ___
* / /\ \ / _` |/ _` | '__/ _ \/ __/ __| |\/| |/ _ \ / _` |/ _ \
* / ____ \ (_| | (_| | | | __/\__ \__ \ | | | (_) | (_| | __/
* /_/ \_\__,_|\__,_|_| \___||___/___/_| |_|\___/ \__,_|\___|
*
******************************************************************/
static void register_peephole_optimisation(ir_op *op, peephole_opt_func func)
{
assert(op->ops.generic == NULL);
op->ops.generic = (void*) func;
}
void ia32_peephole_optimization(ir_graph *irg, ia32_code_gen_t *new_cg)
{
cg = new_cg;
arch_env = cg->arch_env;
/* register peephole optimisations */
clear_irp_opcodes_generic_func();
register_peephole_optimisation(op_ia32_Const, optimize_ia32_Const);
be_peephole_opt(cg->birg);
irg_walk_graph(irg, ia32_peephole_optimize_node, NULL, NULL);
}
/**
* Removes node from schedule if it is not used anymore. If irn is a mode_T node
......
......@@ -330,10 +330,6 @@ static ir_node *gen_Const(ir_node *node) {
cnst = new_rd_ia32_Const(dbgi, irg, block, NULL, 0, val);
SET_IA32_ORIG_NODE(cnst, ia32_get_old_node_name(env_cg, node));
if(val == 0) {
set_ia32_flags(cnst,
get_ia32_flags(cnst) | arch_irn_flags_modify_flags);
}
/* see above */
if (get_irg_start_block(irg) == block) {
......
......@@ -36,7 +36,7 @@ typedef struct {
int use_sse2;
/** use ffreep instead of fpop */
int use_ffreep;
/** use ftst instead of compare */
/** use ftst where possible */
int use_ftst;
/** use femms to pop all float registers */
int use_femms;
......
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