X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fstrength_red.c;h=73e896aff886f36aa76d73a7612f6780fb35d666;hb=ff0e8d7fcb34481652f0bf521ba04b1eca5e2106;hp=9653e04f6284e01a64192ed07aa1d7b5a84185a7;hpb=725702cbc2a63dc826bdfe7771baa796363edff5;p=libfirm diff --git a/ir/opt/strength_red.c b/ir/opt/strength_red.c index 9653e04f6..73e896aff 100644 --- a/ir/opt/strength_red.c +++ b/ir/opt/strength_red.c @@ -13,26 +13,6 @@ * 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" @@ -84,29 +64,25 @@ induct_var_info *is_induction_variable(induct_var_info *info) { ir_node *loop_head; ir_node *cmp_const_block; - 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; + 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); @@ -172,62 +148,59 @@ induct_var_info *is_induction_variable(induct_var_info *info) { /* Information about loop of itervar_phi. */ info->l_itervar_phi = get_irn_loop(get_nodes_block(info->itervar_phi)); + + info->phi_pred = get_irn_n_outs(info->itervar_phi); + 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. */ - info->phi_pred = get_irn_n_outs(info->itervar_phi); - loop_head = get_nodes_block(info->itervar_phi); - 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 && !is_loop_invariant(out, loop_head)) { - /* "Cmp" can have more as one successor therefore we need this loop.*/ + /* 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); + cmp_pred_bl = get_irn_out(proj, r); - /* The wanted "Cmp" must be followed with a "Cond" successor - not with a "Mux".*/ - if (get_irn_op(cmp_pred_bl) != op_Cond) - continue; + /* 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_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); + 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) { - info->cmp = out; - info->cmp_const = cmp_const; - } + continue; + if (info->cmp == NULL) { + /* A cmp is found.*/ + info->cmp = out; + info->cmp_const = cmp_const; + } else { - info->cmp = NULL; - return NULL; - } + /* We have more then one cmp with our requests, that mean cmp isn't found */ + info->cmp = NULL; + return NULL; + } } } } @@ -240,37 +213,39 @@ induct_var_info *is_induction_variable(induct_var_info *info) { if (out_op == op_Store) Store_in_op++; else if (out_op == op_Cmp && !is_loop_invariant(out, loop_head)) { - /* "Cmp" can have more as one successor therefore - i need this for loop.*/ + /* 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); + cmp_pred_bl = get_irn_out(proj, r); - /* The wanted "Cmp" must be followed with a "Cond" successor. */ - if (get_irn_op(cmp_pred_bl) != op_Cond) - continue; + /* 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); + 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); + 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) { - info->cmp = out; - info->cmp_const = cmp_const; - } + continue; + if (info->cmp == NULL) { + /* A cmp is found*/ + info->cmp = out; + info->cmp_const = cmp_const; + } else { - info->cmp = NULL; - return NULL; - } + /* We have more then one cmp with our requests, that mean cmp isn't found*/ + info->cmp = NULL; + return NULL; + } } } } @@ -279,9 +254,9 @@ induct_var_info *is_induction_variable(induct_var_info *info) { 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->reducible = 1; + info->is_reducible = 1; - // Search for loop invariant of Cmp. + /* 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)) >= @@ -294,7 +269,7 @@ 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) { @@ -303,11 +278,12 @@ my_new_r_Add(ir_graph *irg, ir_node *b, ir_node *op1, ir_node *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) { @@ -321,7 +297,8 @@ 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. @@ -330,7 +307,7 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) { ir_node *iter_varblk, *init_block, *irg_startblk, *block_init; - // Essential conditions for a reducible node. + /* Essential conditions for a reducible node. */ if (get_irn_loop(get_nodes_block(reduce_var)) != ivi->l_itervar_phi) return 0; @@ -338,14 +315,14 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) init_block = get_nodes_block(ivi->init); irg_startblk = get_irg_start_block(current_ir_graph); - /* The "new_init" and the "new_cmp_const" mussn't be in the start block.*/ + /* 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)); - /* Warum? */ + /* To avoid that cmp is placed in the start block.*/ if (ivi->cmp_init_block == irg_startblk) ivi->cmp_init_block = iter_varblk; @@ -353,7 +330,7 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) 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); @@ -387,10 +364,10 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) else block_inc = 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; @@ -438,7 +415,7 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) 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; } } @@ -446,8 +423,8 @@ 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){ + 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)); @@ -456,7 +433,8 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) ivi->cmp_const, mul_const, get_irn_mode(mul_const)); ivi->increment = new_r_Mul (current_ir_graph, block_inc, ivi->increment, mul_const, get_irn_mode(mul_const)); - }else { + } + else { ivi->new_init = new_r_Mul (current_ir_graph, block_init, mul_const, ivi->new_init, get_irn_mode(mul_const)); @@ -475,13 +453,13 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) 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; @@ -491,14 +469,16 @@ 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){ + 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 { + } + else { ivi->new_init = my_new_r_Add(current_ir_graph, block_init, add_const, ivi->new_init); } @@ -516,7 +496,7 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) 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) @@ -550,7 +530,12 @@ static int reduce(ir_node *reduce_var, induct_var_info *ivi) } /** - * What? + * 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) { @@ -577,33 +562,40 @@ static ir_node *reducible(ir_node *out, induct_var_info *ivi) static void reduce_itervar(ir_node *itervar_phi, void *env) { induct_var_info ivi; + /* check if a iteration variable be reduced.*/ + int reduced = 0; if (get_irn_op(itervar_phi) != op_Phi) return; - + /* A candidate is found.*/ ivi.itervar_phi = itervar_phi; + /* It musss be 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) { + /* Reduce a induction variable.*/ + if (ivi.is_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); + ir_node *irn_reduced = reducible(out, &ivi); + if (irn_reduced != NULL){ + reduced = 1; + exchange(irn_reduced, ivi.itervar_phi); + } } } + /* Reduce a multiplication*/ else if (out_op == op_Mul) - if (reduce(out, &ivi) && ivi.reducible) { + 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)); @@ -614,25 +606,26 @@ 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); - + /* 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); } + /* Try to reduce a multiplication, that is successor of "ivi.op".*/ else if (out_op == op_Mul) - if (reduce(out, &ivi) && ivi.reducible){ + 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); @@ -671,9 +664,9 @@ 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_irg_outs(irg); + assure_irg_outs(irg); /* -- Search expressions that can be optimized -- */ irg_walk_graph(irg, NULL, reduce_itervar, NULL);