X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fstrength_red.c;h=2e0d749c5cb7654957877d3bc301d2b87b97a78d;hb=9bb022c5e36fbfa02b79241d8c1c7e0102cf83d5;hp=5489098f8675cf29852ec6c143b73debd2806cd5;hpb=473ce801ac8b8a59af8fad122675806298de108a;p=libfirm diff --git a/ir/opt/strength_red.c b/ir/opt/strength_red.c index 5489098f8..2e0d749c5 100644 --- a/ir/opt/strength_red.c +++ b/ir/opt/strength_red.c @@ -1,3 +1,22 @@ +/* + * 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 strength_red.c @@ -10,39 +29,22 @@ * Created: 22.8.2004 * CVS-ID: $Id$ * Copyright: (c) 2004 Universität Karlsruhe - * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. */ - - -/* - -reducible(o) - while (reducible) - o = reduce(o) - -reduce_itervar(induct_var_info *iv) - for each (out o of iv) { - if (o is reducible) { - if (o is strong (Mul)) - iv_new = reduce(o), remember_pattern(o) - else // o is not strong (Add ...) - if (o is the only user) - iv_new = reducible(o) - } - } - -*/ - -# include "strength_red.h" - -# include "irouts.h" -# include "irnode_t.h" -# include "irgwalk.h" -# include "irloop_t.h" -# include "ircons.h" -# include "irgmod.h" -# include "irdump_t.h" -# include "firmstat.h" +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "strength_red_t.h" +#include "iroptimize.h" +#include "irouts.h" +#include "irnode_t.h" +#include "irgwalk.h" +#include "irloop_t.h" +#include "ircons.h" +#include "irgmod.h" +#include "irdump_t.h" +#include "irprintf.h" +#include "firmstat.h" /** Counter for verbose information about optimization. */ @@ -51,66 +53,73 @@ static int n_made_new_phis; /** Detect basic iteration variables. * - * The variable ir represented by a subgraph as this: + * The variable is represented by a subgraph as this: + * @verbatim * * init - * /|\ + * ^ * | - * |-- Phi - * | /|\ + * +-- Phi + * | ^ * | | - * |-->op + * +-->op + * + * @endverbatim * - * Where op is a Add or Sub, and init is loop invariant. - * @@@ So far we only accept Phi nodes with two predecessors. - * We could expand this to Phi nodes where all preds are either - * op or loop invariant. + * Where op is a Add or Sub node and init is loop invariant. + * + * @note + * So far we only accept Phi nodes with two predecessors. + * We could expand this to Phi nodes where all predecessors + * are either op or loop invariant. * - * @param n A phi node. * @param info After call contains the induction variable information. + * + * @return + * The info structure. */ - -induct_var_info *is_induction_variable (induct_var_info *info) { - - int i; - int op_pred, Store_in_op, Store_in_phi, cmp_in_phi; - - info->c = NULL; - info->cmp = NULL; - info->cmp_const = NULL; - info->cmp_init_block = NULL; - info->increment = NULL; - info->init = NULL; - info->l_itervar_phi = NULL; - info->new_add = NULL; - info->new_cmp = NULL; - info->new_increment = NULL; - info->new_init = NULL; - info->new_op = NULL; - info->new_phi = NULL; - info->operation_code = NULL; - info->op = NULL; - info->old_ind = NULL; - info->reducible_node = NULL; - info->out_loop_res = 1; - info->reducible = 0; - info->phi_pred = 0; - info->strong_reduced = 0; - info->init_pred_pos = -1; - info->op_pred_pos = -1; +induct_var_info *is_induction_variable(induct_var_info *info) { + + int i, q, r; + int op_pred, Store_in_op, Store_in_phi; + ir_node *cmp_pred_bl, *cond_succ_0, *cond_succ_1, *cmp_const; + ir_node *loop_head; + ir_node *cmp_const_block; + + info->operation_code = NULL; /* The opcode of "op". */ + info->increment = NULL; /* The value which increase or decrease the iteration variable. */ + info->init = NULL; /* The start value of the iteration variable. */ + info->op = NULL; /* The operation which increase or decrease the iteration variable. */ + info->l_itervar_phi = NULL; /* The iteration variable. */ + info->new_phi = NULL; /* The new iteration variable. */ + info->new_increment = NULL; /* The new increment which replace the old one.*/ + info->new_init = NULL; /* The new init value of the iteration variable. */ + info->new_op = NULL; /* The new operation that we need after replace. */ + info->new_cmp = NULL; /* The new Cmp which replaces the old one. */ + info->cmp = NULL; /* The Cmp which breaks the loop and compares the iteration variable with a constant. */ + info->cmp_const = NULL; /* The other operand of Cmp. */ + info->cmp_init_block = NULL; /* The initial block of the Cmp. */ + info->reducible_node = NULL; /* The reducible nodes are save here. */ + info->is_reducible = 0; /* To save information if anything is reducible. */ + info->phi_pred = 0; /* To save the value of iteration variable predecessors. */ + info->init_pred_pos = -1; /* To save the position of iteration variable start value. */ + info->op_pred_pos = -1; /* To save the backedge of iteration variable. */ + info->l_itervar_phi = NULL; /* Information about loop of itervar_phi. */ assert(get_irn_op(info->itervar_phi) == op_Phi); - /* The necessary conditions for the phi node. */ - if (get_irn_arity(info->itervar_phi) != 2 || - !has_backedges(get_nodes_block(info->itervar_phi)) ) + /* + * The necessary conditions for the phi node: + * We can handle currently Phi's with 2 predecessors, one must be a backedge. + */ + if (get_irn_arity(info->itervar_phi) != 2 || !has_backedges(get_nodes_block(info->itervar_phi))) return NULL; for (i = 0; i < 2; ++i) { ir_node *pred = get_Phi_pred(info->itervar_phi, i); ir_op *op = get_irn_op(pred); - /* Compute if the induction variable is added or substracted with a constant . */ + /* Compute if the induction variable is added or subtracted with a constant. */ if (op == op_Add || op == op_Sub) { ir_node *n_l = get_binop_left(pred); ir_node *n_r = get_binop_right(pred); @@ -136,73 +145,144 @@ induct_var_info *is_induction_variable (induct_var_info *info) { return NULL; /* Compute the position of the backedge. */ - if (is_backedge(get_nodes_block(info->itervar_phi), info->op_pred_pos)){ - info->op = get_Phi_pred(info->itervar_phi, info->op_pred_pos); - info->init = get_Phi_pred(info->itervar_phi, info->init_pred_pos); + if (is_backedge(get_nodes_block(info->itervar_phi), info->op_pred_pos)) { + info->op = get_Phi_pred(info->itervar_phi, info->op_pred_pos); + info->init = get_Phi_pred(info->itervar_phi, info->init_pred_pos); } else { /* irregular control flow detected. */ return NULL; } + /* + * the block of the init code should dominate the loop, else + * we have an irregular control flow + */ if (get_Block_dom_depth(get_nodes_block(info->init)) >= get_Block_dom_depth(get_nodes_block(info->itervar_phi))) { return NULL; } - /* This "for" marks if the iteration operation have a Store successor .*/ op_pred = get_irn_n_outs(info->op); Store_in_op = 0; Store_in_phi = 0; - cmp_in_phi = 0; - for (i = 0; i < op_pred; ++i){ - ir_node *out = get_irn_out(info->op, i); - ir_op *out_op = get_irn_op(out); - if (out_op == op_Store) - Store_in_op++; - } /* Information about loop of itervar_phi. */ info->l_itervar_phi = get_irn_loop(get_nodes_block(info->itervar_phi)); - /* This "for" searches for the Cmp successor of the - iter_var to reduce and marks if the iter_var have a Store - successor or a successor out of loop.*/ + info->phi_pred = get_irn_n_outs(info->itervar_phi); - for (i = 0; i < info->phi_pred; ++i) { + loop_head = get_nodes_block(info->itervar_phi); + + /* + * This "for" searches for the Cmp successor of the + * iter_var to reduce and marks if the iter_var have a Store + * successor or a successor out of loop. + */ + for (i = 0; i < info->phi_pred; i++) { ir_node *out = get_irn_out(info->itervar_phi, i); ir_op *out_op = get_irn_op(out); - if ((get_irn_loop(get_nodes_block(out)) != info->l_itervar_phi) && - ( get_Block_dom_depth(get_nodes_block(out)) > - get_Block_dom_depth(get_nodes_block(info->itervar_phi)))) - info->out_loop_res = 0; - if (out_op == op_Store) Store_in_phi++; - else if (out_op == op_Cmp){ - info->cmp = out; - cmp_in_phi++; + else if (out_op == op_Cmp && !is_loop_invariant(out, loop_head)) { + /* a Cmp can have more than one successor therefore we need this loop.*/ + for (q = get_irn_n_outs(out) - 1; q >= 0; --q) { + ir_node *proj = get_irn_out(out, q); + + for (r = get_irn_n_outs(proj) -1; r >= 0; --r) { + cmp_pred_bl = get_irn_out(proj, r); + + /* The wanted Cmp must be followed by a Cond successor + not by a Mux. */ + if (get_irn_op(cmp_pred_bl) != op_Cond) + continue; + + /* the binary Cond should have two successors */ + if (get_irn_n_outs(cmp_pred_bl) != 2) + continue; + + cond_succ_0 = get_irn_out(cmp_pred_bl, 0); + cond_succ_1 = get_irn_out(cmp_pred_bl, 1); + + if (is_loop_invariant(get_irn_out(cond_succ_1, 0), loop_head) || + is_loop_invariant(get_irn_out(cond_succ_0, 0), loop_head)) { + if (get_Cmp_left(out) == info->itervar_phi) + cmp_const = get_Cmp_right(out); + else + cmp_const = get_Cmp_left(out); + } else + continue; + if (info->cmp == NULL) { + /* A cmp is found.*/ + info->cmp = out; + info->cmp_const = cmp_const; + } + else { + /* We have more then one cmp with our requests, that mean cmp isn't found */ + info->cmp = NULL; + return NULL; + } + } + } } } - if((info->phi_pred == 3 && op_pred == 1 && Store_in_phi == 0 && cmp_in_phi == 1) || - (info->phi_pred == 2 && op_pred == 2 && Store_in_op == 0 && info->cmp != NULL ) || - (info->phi_pred == 1 && Store_in_op == 0)) - info->reducible = 1; + for (i = 0; i < op_pred; ++i) { + ir_node *out = get_irn_out(info->op, i); + ir_op *out_op = get_irn_op(out); - // Search for loop invariant of Cmp. - if (info->cmp != NULL) { - ir_node *cmp_const_block; + if (out_op == op_Store) + Store_in_op++; + else if (out_op == op_Cmp && !is_loop_invariant(out, loop_head)) { + /* a Cmp can have more as one successor therefore + I need this for loop. */ + for (q = get_irn_n_outs(out) - 1; q >= 0; --q) { + ir_node *proj = get_irn_out(out, q); + + for (r = get_irn_n_outs(proj) -1; r >= 0; --r) { + cmp_pred_bl = get_irn_out(proj, r); + + /* The wanted Cmp must be followed by a Cond successor. */ + if (get_irn_op(cmp_pred_bl) != op_Cond) + continue; + + cond_succ_0 = get_irn_out(cmp_pred_bl, 0); + cond_succ_1 = get_irn_out(cmp_pred_bl, 1); + + if (is_loop_invariant(get_irn_out(cond_succ_0, 0), loop_head) || + is_loop_invariant(get_irn_out(cond_succ_1, 0), loop_head)) { + if (get_Cmp_left(out) == info->op) + cmp_const = get_Cmp_right(out); + else + cmp_const = get_Cmp_left(out); + } else + continue; + if (info->cmp == NULL) { + /* A cmp is found*/ + info->cmp = out; + info->cmp_const = cmp_const; + } + else { + /* We have more then one cmp with our requests, that mean cmp isn't found*/ + info->cmp = NULL; + return NULL; + } + } + } + } + } - if (get_Cmp_left(info->cmp) == info->itervar_phi) - info->cmp_const = get_Cmp_right(info->cmp); - else - info->cmp_const = get_Cmp_left(info->cmp); + if ((info->phi_pred == 3 && op_pred == 1 && Store_in_phi == 0 && info->cmp != NULL) || + (info->phi_pred == 2 && op_pred == 2 && Store_in_op == 0 && info->cmp != NULL ) || + (info->phi_pred == 1 && Store_in_op == 0)) + info->is_reducible = 1; + /* Search for loop invariant of Cmp.*/ + if (info->cmp != NULL) { cmp_const_block = get_nodes_block(info->cmp_const); if (get_Block_dom_depth(get_nodes_block(info->init)) >= - get_Block_dom_depth(cmp_const_block)) + get_Block_dom_depth(cmp_const_block)) info->cmp_init_block = get_nodes_block(info->init); else info->cmp_init_block = cmp_const_block; @@ -211,23 +291,24 @@ induct_var_info *is_induction_variable (induct_var_info *info) { } /** - * Creates a new Add node from operands. + * Creates a new Add node with the correct mode from its two operands. */ static INLINE ir_node * -my_new_r_Add (ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) { +my_new_r_Add(ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) { ir_mode *m = get_irn_mode(op1); ir_mode *m2 = get_irn_mode(op2); if (mode_is_reference(m2)) m = m2; + return new_r_Add(irg, b, op1, op2, m); } /** - * Creates a new Sub node from operands. + * Creates a new Sub node with the correct mode from its two operands. */ static INLINE ir_node * -my_new_r_Sub (ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) { +my_new_r_Sub(ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) { ir_mode *m = get_irn_mode(op1); ir_mode *m2 = get_irn_mode(op2); @@ -238,31 +319,48 @@ my_new_r_Sub (ir_graph *irg, ir_node *b, ir_node *op1, ir_node *op2) { return new_r_Sub(irg, b, op1, op2, m); } -/* Reduce a Add, Sub or Mul node +/** + * Reduce an Add, Sub or Mul node * * @param *reduce_var The node to reduce. * @param *ivi Contains the induction variable information. */ static int reduce(ir_node *reduce_var, induct_var_info *ivi) { - // Essential conditions for a reducable node. + ir_node *iter_varblk, *init_block, *irg_startblk, *block_init; + + /* Essential conditions for a reducible node. */ if (get_irn_loop(get_nodes_block(reduce_var)) != ivi->l_itervar_phi) return 0; + iter_varblk = get_nodes_block(ivi->itervar_phi); + init_block = get_nodes_block(ivi->init); + irg_startblk = get_irg_start_block(current_ir_graph); + + /* The "new_init" and the "new_cmp_const" must not be in the start block.*/ + if (get_Block_dom_depth(init_block) > get_Block_dom_depth(irg_startblk) && + init_block != iter_varblk) + block_init = init_block; + else + block_init = get_nodes_block(get_Block_cfgpred(iter_varblk, ivi->init_pred_pos)); + + /* To avoid that cmp is placed in the start block.*/ + if (ivi->cmp_init_block == irg_startblk) + ivi->cmp_init_block = iter_varblk; + if (get_irn_op(reduce_var) == op_Mul) { ir_node *mul_init = NULL; ir_node *mul_const = NULL; - // Search for constant and init of strong. + /* Search for constant and init of strong. */ ir_node *mul_right = get_Mul_right(reduce_var); ir_node *mul_left = get_Mul_left(reduce_var); ir_op *mul_right_op = get_irn_op(mul_right); ir_op *mul_left_op = get_irn_op(mul_left); - ir_node *in[2], *block_init; + ir_node *in[2]; ir_node *block_inc; - ir_node *init_block; ir_node *increment_block; ir_node *c_block; @@ -280,7 +378,6 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) if (mul_const == NULL || mul_init == NULL) return 0; - init_block = get_nodes_block(mul_init); increment_block = get_nodes_block(ivi->increment); c_block = get_nodes_block(mul_const); @@ -289,24 +386,19 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) else block_inc = c_block; - if (get_Block_dom_depth(init_block) >= get_Block_dom_depth(c_block)) - block_init = init_block; - else - block_init = c_block; - - if (! ivi->reducible){ + if (! ivi->is_reducible){ int reduce_var_pred; - // Essential condition for the constant of strong. + /* Essential condition for the constant of strong. */ if (get_Block_dom_depth(get_nodes_block(mul_const)) >= get_Block_dom_depth(get_nodes_block(ivi->itervar_phi))) return 0; n_made_new_phis++; if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) { - printf("The new Phi node is : "); DDMN(ivi->itervar_phi); - printf("reducing operation is : "); DDMN(reduce_var); - printf("in graph : "); DDMG(current_ir_graph); + ir_printf("The new Phi node is : %+F\n", ivi->itervar_phi); + ir_printf("reducing operation is : %+F\n", reduce_var); + ir_printf("in graph : %+F\n", current_ir_graph); } ivi->new_increment = new_r_Mul (current_ir_graph, block_inc, ivi->increment, mul_const, @@ -339,17 +431,13 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) set_Phi_pred(ivi->new_phi, ivi->op_pred_pos, ivi->new_op); - - - - // This for search for a reducible successor of reduc_var. reduce_var_pred = get_irn_n_outs(reduce_var); if (reduce_var_pred == 1) { ir_node *old_ind =get_irn_out(reduce_var, 0); if(get_irn_op(old_ind) == op_Add || get_irn_op(old_ind) == op_Sub || get_irn_op(old_ind) == op_Mul){ - ivi->reducible = 1; + ivi->is_reducible = 1; ivi->reducible_node = old_ind; } } @@ -357,42 +445,43 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) exchange(reduce_var, ivi->new_phi); return 1; } - else { /* ivi->reducible */ - if(ivi->new_phi == NULL){ - ivi->init = new_r_Mul (current_ir_graph, get_nodes_block(ivi->init), + else { /* ivi->is_reducible */ + if (ivi->new_phi == NULL) { + ivi->init = new_r_Mul (current_ir_graph, block_init, mul_const, ivi->init, get_irn_mode(mul_const)); if(ivi->cmp != NULL) ivi->cmp_const = new_r_Mul (current_ir_graph, ivi->cmp_init_block, ivi->cmp_const, mul_const, get_irn_mode(mul_const)); - ivi->increment = new_r_Mul (current_ir_graph, block_init, + ivi->increment = new_r_Mul (current_ir_graph, block_inc, ivi->increment, mul_const, get_irn_mode(mul_const)); - }else { - ivi->new_init = new_r_Mul (current_ir_graph, get_nodes_block(ivi->init), + } + else { + ivi->new_init = new_r_Mul (current_ir_graph, block_init, mul_const, ivi->new_init, get_irn_mode(mul_const)); - ivi->new_increment = new_r_Mul (current_ir_graph, block_init, + ivi->new_increment = new_r_Mul (current_ir_graph, block_inc, ivi->new_increment, mul_const, get_irn_mode(mul_const)); } if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) { - printf("\nReducing operation is : "); DDMN(reduce_var); - printf("in graph : "); DDMG(current_ir_graph); + ir_printf("\nReducing operation is : %+F\n", reduce_var); + ir_printf("in graph : %+F\n", current_ir_graph); } return 1; } - - }else if (get_irn_op (reduce_var) == op_Add){ + } + else if (get_irn_op (reduce_var) == op_Add){ ir_node *add_init = NULL; ir_node *add_const = NULL; - // Search for constant of add. + /* Search for constant of add. */ ir_node *add_right = get_Add_right(reduce_var); ir_node *add_left = get_Add_left(reduce_var); ir_op *add_right_op = get_irn_op(add_right); ir_op *add_left_op = get_irn_op(add_left); - n_reduced_expressions++; + ++n_reduced_expressions; if (add_right_op != op_Const) add_init = add_right; @@ -402,33 +491,36 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) add_const = add_right; else if (add_left_op == op_Const || add_left_op == op_SymConst) add_const = add_left; - if (add_const == NULL) return 0; - if (ivi->new_phi == NULL){ - ivi->init = my_new_r_Add (current_ir_graph, get_nodes_block(ivi->init), - add_const, ivi->init); - if(ivi->cmp != NULL) - ivi->cmp_const = my_new_r_Add (current_ir_graph, ivi->cmp_init_block, - add_const, ivi->cmp_const); - } else{ - ivi->new_init = my_new_r_Add (current_ir_graph, get_nodes_block(ivi->init), - add_const, ivi->new_init); + if (add_const == NULL) + return 0; + if (ivi->new_phi == NULL) { + ivi->init = my_new_r_Add(current_ir_graph, block_init, + add_const, ivi->init); + if (ivi->cmp != NULL) + ivi->cmp_const = my_new_r_Add(current_ir_graph, ivi->cmp_init_block, + add_const, ivi->cmp_const); + } + else { + ivi->new_init = my_new_r_Add(current_ir_graph, block_init, + add_const, ivi->new_init); } if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) { - printf("\nReducing operation is : "); DDMN(reduce_var); - printf("in graph : "); DDMG(current_ir_graph); + ir_printf("\nReducing operation is : %+F\n", reduce_var); + ir_printf("in graph : %+F\n", current_ir_graph); } return 1; - } else if(get_irn_op(reduce_var) == op_Sub ){ + } + else if (get_irn_op(reduce_var) == op_Sub) { ir_node *sub_init = NULL; ir_node *sub_const = NULL; - // Search for constant of sub. ir_node *sub_right = get_Sub_right(reduce_var); ir_node *sub_left = get_Sub_left(reduce_var); ir_op *sub_right_op = get_irn_op(sub_right); ir_op *sub_left_op = get_irn_op(sub_left); - n_reduced_expressions++; + ++n_reduced_expressions; + /* Search for constant of Sub. */ if (sub_right_op != op_Const) sub_init = sub_right; else if (sub_left_op != op_Const) @@ -438,26 +530,35 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) else if (sub_left_op == op_Const) sub_const = sub_left; - if (sub_const == NULL) return 0; + if (sub_const == NULL) + return 0; if (ivi->new_phi == NULL) { - ivi->init = my_new_r_Sub (current_ir_graph, get_nodes_block(ivi->init), - ivi->init, sub_const); + ivi->init = my_new_r_Sub(current_ir_graph, block_init, + ivi->init, sub_const); if (ivi->cmp != NULL) - ivi->cmp_const =my_new_r_Sub (current_ir_graph, get_nodes_block(ivi->init), + ivi->cmp_const = my_new_r_Sub(current_ir_graph, ivi->cmp_init_block, ivi->cmp_const,sub_const); } else - ivi->new_init = my_new_r_Sub (current_ir_graph, get_nodes_block(ivi->init), + ivi->new_init = my_new_r_Sub (current_ir_graph, block_init, ivi->new_init, sub_const); if (get_opt_strength_red_verbose() && get_firm_verbosity() > 1) { - printf("\nReducing operation is : "); DDMN(reduce_var); - printf("in graph : "); DDMG(current_ir_graph); + ir_printf("\nReducing operation is : %+F", reduce_var); + ir_printf("in graph : %+F", current_ir_graph); } return 1; } return 0; } +/** + * Search for reducible successor of iteration variable. + * If such successor is found it will be reduced and returned, + * else return NULL. + * + * @param ivi Contains information about the induction variable. + * @param out A successor of iteration variable. + */ static ir_node *reducible(ir_node *out, induct_var_info *ivi) { ir_node *reduced = NULL; @@ -474,39 +575,51 @@ static ir_node *reducible(ir_node *out, induct_var_info *ivi) } /** - * Reduce a node. + * Post walker: Find a Phi node that is a iteration variable and + * try to reduce it. * - * @param *itervar_phi The iteration variable of a loop. - * @param *env Free environment pointer. + * @param itervar_phi The iteration variable of a loop. + * @param env Free environment pointer. */ static void reduce_itervar(ir_node *itervar_phi, void *env) { induct_var_info ivi; + /* check if a iteration variable be reduced.*/ + int reduced = 0; + (void) env; - if (get_irn_op(itervar_phi) != op_Phi) + if (! is_Phi(itervar_phi)) return; + /* A potential candidate is found.*/ ivi.itervar_phi = itervar_phi; - /* This "if" finds the iteration variable. */ + /* check if it's a induction variable.*/ if (is_induction_variable(&ivi)) { int i, op_out; for (i = 0; i < ivi.phi_pred; i++) { ir_node *out = get_irn_out(ivi.itervar_phi, i); ir_op *out_op = get_irn_op(out); - if(ivi.reducible){ - if(ivi.phi_pred == 3 && out != ivi.op && out !=ivi.cmp){ - ir_node *reduced = reducible(out, &ivi); - if (reduced != NULL) - exchange( reduced, ivi.itervar_phi); + /* Reduce a induction variable.*/ + if (ivi.is_reducible) { + if (ivi.phi_pred == 3 && out != ivi.op && out != ivi.cmp) { + ir_node *irn_reduced = reducible(out, &ivi); + if (irn_reduced != NULL){ + reduced = 1; + exchange(irn_reduced, ivi.itervar_phi); + } } - } else if (out_op == op_Mul) - if(reduce(out, &ivi) && ivi.reducible){ + } + /* Reduce a multiplication*/ + else if (out_op == op_Mul) + if (reduce(out, &ivi) && ivi.is_reducible) { ir_node *reduced = reducible(ivi.reducible_node, &ivi); - if(reduced != NULL) + + if (reduced != NULL) exchange(reduced, ivi.new_phi); - ivi.reducible = 0; + + ivi.is_reducible = 0; set_Phi_pred(ivi.new_phi, ivi.init_pred_pos, ivi.new_init); set_irn_mode(ivi.new_phi,get_irn_mode(ivi.new_init)); set_irn_mode(ivi.new_op,get_irn_mode(ivi.new_phi)); @@ -517,23 +630,26 @@ static void reduce_itervar(ir_node *itervar_phi, void *env) for (i = 0; i < op_out; i++){ ir_node *out = get_irn_out(ivi.op, i); ir_op *out_op = get_irn_op(out); - if(op_out == 2 && out != ivi.itervar_phi){ + /* Try to reduce the second successor of the "ivi.op"*/ + if (op_out == 2 && out != ivi.itervar_phi){ ir_node *reduced = reducible(out, &ivi); if(reduced != NULL) exchange( reduced, ivi.op); - }else if (out_op == op_Mul) - if(reduce(out, &ivi) && ivi.reducible){ + } + /* Try to reduce a multiplication, that is successor of "ivi.op".*/ + else if (out_op == op_Mul) + if (reduce(out, &ivi) && ivi.is_reducible){ ir_node *reduced = reducible(ivi.reducible_node, &ivi); if(reduced != NULL) exchange(reduced, ivi.new_phi); - ivi.reducible = 0; + ivi.is_reducible = 0; set_Phi_pred(ivi.new_phi, ivi.init_pred_pos, ivi.new_init); set_irn_mode(ivi.new_phi,get_irn_mode(ivi.new_init)); set_irn_mode(ivi.new_op,get_irn_mode(ivi.new_phi)); } } - - if(ivi.reducible){ + /* Set some predecessors and modes after reduce.*/ + if (ivi.is_reducible && reduced) { if(get_irn_op(ivi.op) == op_Add) if(get_Add_left(ivi.op) == ivi.itervar_phi) set_Add_right(ivi.op, ivi.increment); @@ -560,6 +676,7 @@ static void reduce_itervar(ir_node *itervar_phi, void *env) /* Performs strength reduction for the passed graph. */ void reduce_strength(ir_graph *irg) { ir_graph *rem = current_ir_graph; + int modifiyed = 1; if (!get_optimize() || !get_opt_strength_red()) return; @@ -571,9 +688,9 @@ void reduce_strength(ir_graph *irg) { /* Call algorithm that computes the backedges */ construct_cf_backedges(irg); /* Call algorithm that computes the dominator trees. */ - compute_doms(irg); + assure_doms(irg); /* Call algorithm that computes the out edges */ - compute_outs(irg); + assure_irg_outs(irg); /* -- Search expressions that can be optimized -- */ irg_walk_graph(irg, NULL, reduce_itervar, NULL); @@ -586,5 +703,10 @@ void reduce_strength(ir_graph *irg) { get_entity_name(get_irg_entity(irg))); } + if (modifiyed) { + set_irg_outs_inconsistent(irg); + set_irg_loopinfo_inconsistent(irg); + } + current_ir_graph = rem; }