X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fifconv.c;h=99696af99e5e78f1207f4efe6ea74dc5493bd5bf;hb=77c348bef494a5d4e1fbf754957884de5c0bfe99;hp=e989a3052525f926ee802232219bace1cf81b834;hpb=2620c51c7c0939dc2ba6d8fbc56e824781371f4e;p=libfirm diff --git a/ir/opt/ifconv.c b/ir/opt/ifconv.c index e989a3052..99696af99 100644 --- a/ir/opt/ifconv.c +++ b/ir/opt/ifconv.c @@ -1,965 +1,563 @@ -/** - * If conversion. - * Make Mux nodes from Conds where it its possible. - * @author Sebastian Hack - * @date 4.2.2005 - * $Id$ +/* + * 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. + */ + +/* + * @file ir/opt/ifconv.c + * @brief If conversion + * @author Christoph Mallon + * @version $Id$ */ -#include -#include -#include +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif -#include "irgraph_t.h" +#include +#include "iroptimize.h" +#include "obst.h" #include "irnode_t.h" -#include "iropt_t.h" +#include "cdep.h" +#include "ircons.h" +#include "irdom.h" #include "irgmod.h" -#include "irmode_t.h" -#include "ircons_t.h" -#include "irdom_t.h" - -#include "ifconv.h" -#include "irflag_t.h" - -#include "irprintf.h" +#include "irgopt.h" +#include "irgwalk.h" +#include "irtools.h" +#include "array.h" +#include "xmalloc.h" + +// debug +#include "irdump.h" #include "debug.h" -#include "obst.h" -#include "set.h" -#include "bitset.h" -#include "bitfiddle.h" - -#define MAX_DEPTH 20 -/* - * Mux optimization routines. - */ +DEBUG_ONLY(static firm_dbg_module_t *dbg); -#if 0 -static ir_node *local_optimize_mux(ir_node *mux) +/** allow every Mux to be created. */ +static int default_allow_ifconv(ir_node *sel, ir_node* phi_list, int i, int j) { - int i, n; - ir_node *res = mux; - ir_node *sel = get_Mux_sel(mux); - ir_node *cmp = skip_Proj(sel); - - /* Optimize the children */ - for(i = 1, n = get_irn_arity(mux); i < n; ++i) { - ir_node *operand = get_irn_n(mux, i); - if(get_irn_op(operand) == op_Mux) - optimize_mux(operand); - } - - /* If we have no cmp above the mux, get out. */ - if(is_Proj(sel) && get_irn_mode(sel) == mode_b && get_irn_opcode(cmp) == iro_Cmp) { - - pn_Cmp cc = get_Proj_proj(sel); - ir_mode *mode = get_irn_mode(mux); - ir_node *block = get_nodes_block(n); - ir_node *cmp_left = get_Cmp_left(cmp); - ir_node *cmp_right = get_Cmp_right(cmp); - ir_node *mux_true = get_Mux_true(mux); - ir_node *mux_false = get_Mux_false(mux); - - /* - * Check for comparisons with signed integers. - */ - if(mode_is_int(mode) /* We need an integral mode */ - && mode_is_signed(mode) /* which is signed */ - && cc == Lt) { /* and have to compare for < */ - - /* - * Mux(x:T < 0, -1, 0) -> Shrs(x, sizeof_bits(T) - 1) - * Conditions: - * T must be signed. - */ - if(classify_Const(cmp_right) == CNST_NULL - && classify_Const(mux_true) == CNST_ALL_ONE - && classify_Const(mux_false) == CNST_NULL) { - - ir_mode *u_mode = find_unsigned_mode(mode); - - res = new_r_Shrs(current_ir_graph, block, cmp_left, - new_r_Const_long(current_ir_graph, block, u_mode, - get_mode_size_bits(mode) - 1), - mode); - } - - /* - * Mux(0 < x:T, 1, 0) -> Shr(-x, sizeof_bits(T) - 1) - * Conditions: - * T must be signed. - */ - else if(classify_Const(cmp_left) == CNST_NULL - && classify_Const(mux_true) == CNST_ONE - && classify_Const(mux_false) == CNST_NULL) { - - ir_mode *u_mode = find_unsigned_mode(mode); - - res = new_r_Shr(current_ir_graph, block, - - /* -x goes to 0 - x in Firm (cmp_left is 0, see the if) */ - new_r_Sub(current_ir_graph, block, cmp_left, cmp_right, mode), - - /* This is sizeof_bits(T) - 1 */ - new_r_Const_long(current_ir_graph, block, u_mode, - get_mode_size_bits(mode) - 1), - mode); - } - } - } - - return res; + (void) sel; + (void) phi_list; + (void) i; + (void) j; + return 1; } -#endif /** - * check, if a node is const and return its tarval or - * return a default tarval. - * @param cnst The node whose tarval to get. - * @param or The alternative tarval, if the node is no Const. - * @return The tarval of @p cnst, if the node is Const, @p otherwise. + * Default options. */ -static tarval *get_value_or(ir_node *cnst, tarval *or) -{ - return get_irn_op(cnst) == op_Const ? get_Const_tarval(cnst) : or; -} - +static const ir_settings_if_conv_t default_info = { + 0, /* doesn't matter for Mux */ + default_allow_ifconv +}; /** - * Try to optimize nested muxes into a dis- or conjunction - * of two muxes. - * @param mux The parent mux, which has muxes as operands. - * @return The replacement node for this mux. If the optimization is - * successful, this might be an And or Or node, if not, its the mux - * himself. + * Returns non-zero if a Block can be emptied. */ -static ir_node *optimize_mux_chain(ir_node *mux) +static int can_empty_block(ir_node *block) { + return get_Block_mark(block) == 0; +} + + +static ir_node* walk_to_projx(ir_node* start, const ir_node* dependency) { + int arity; int i; - ir_node *res; - ir_node *ops[2]; - ir_mode *mode = get_irn_mode(mux); - tarval *null; - tarval *minus_one; - - /* - * If we have no mux, or its mode is not integer, we - * can return. - */ - if(get_irn_op(mux) != op_Mux || !mode_is_int(mode)) - return mux; - - res = mux; - null = get_tarval_null(mode); - minus_one = tarval_sub(null, get_tarval_one(mode)); - - ops[0] = get_Mux_false(mux); - ops[1] = get_Mux_true(mux); - - for(i = 0; i < 2; ++i) { - ir_node *a, *b, *d; - tarval *tva, *tvb, *tvd; - ir_node *child_mux; - - /* - * A mux operand at the first position can be factored - * out, if the operands fulfill several conditions: - * - * mux(c1, mux(c2, a, b), d) - * - * This can be made into: - * 1) mux(c1, 0, d) | mux(c2, a, b) - * if a | d == d and b | d == d - * - * 2) mux(c1, -1, d) & mux(c2, a, b) - * if a & d == d and a & b == b - */ - if(get_irn_op(ops[i]) == op_Mux) { - - child_mux = ops[i]; - a = get_Mux_false(child_mux); - b = get_Mux_true(child_mux); - d = ops[1 - i]; - - /* Try the or stuff */ - tva = get_value_or(a, minus_one); - tvb = get_value_or(b, minus_one); - tvd = get_value_or(d, null); - - if(tarval_cmp(tarval_or(tva, tvd), tvd) == pn_Cmp_Eq - && tarval_cmp(tarval_or(tvb, tvd), tvd) == pn_Cmp_Eq) { - - ops[i] = new_Const(mode, null); - res = new_r_Or(current_ir_graph, get_nodes_block(mux), - mux, child_mux, mode); - break; - } - /* If the or didn't go, try the and stuff */ - tva = get_value_or(a, null); - tvb = get_value_or(b, null); - tvd = get_value_or(d, minus_one); + /* No need to find the conditional block if this block cannot be emptied and + * therefore not moved */ + if (!can_empty_block(start)) return NULL; - if(tarval_cmp(tarval_and(tva, tvd), tvd) == pn_Cmp_Eq - && tarval_cmp(tarval_and(tvb, tvd), tvd) == pn_Cmp_Eq) { + arity = get_irn_arity(start); + for (i = 0; i < arity; ++i) { + ir_node* pred = get_irn_n(start, i); + ir_node* pred_block = get_nodes_block(pred); - ops[i] = new_Const(mode, minus_one); - res = new_r_And(current_ir_graph, get_nodes_block(mux), - mux, child_mux, mode); - break; + if (pred_block == dependency) { + if (is_Proj(pred)) { + assert(get_irn_mode(pred) == mode_X); + return pred; } + return NULL; } - } - /* recursively optimize nested muxes. */ - set_irn_n(mux, 1, optimize_mux_chain(ops[0])); - set_irn_n(mux, 2, optimize_mux_chain(ops[1])); + if (is_Proj(pred)) { + assert(get_irn_mode(pred) == mode_X); + return NULL; + } - return res; + if (is_cdep_on(pred_block, dependency)) { + return walk_to_projx(pred_block, dependency); + } + } + return NULL; } -/*********************************************************** - * The If conversion itself. - ***********************************************************/ - -/** - * Default options. - */ -static opt_if_conv_info_t default_info = { - MAX_DEPTH -}; - -/** The debugging module. */ -static firm_dbg_module_t *dbg; - /** - * A simple check for sde effects upton an opcode of a ir node. - * @param irn The ir node to check, - * @return 1 if the opcode itself may produce side effects, 0 if not. + * Copies the DAG starting at node to the ith predecessor block of src_block + * -if the node isn't in the src_block, this is a nop and the node is returned + * -if the node is a phi in the src_block, the ith predecessor of the phi is + * returned + * otherwise returns the copy of the passed node */ -static INLINE int has_side_effects(const ir_node *irn) +static ir_node* copy_to(ir_node* node, ir_node* src_block, int i) { - opcode opc = get_irn_opcode(irn); + ir_node* dst_block; + ir_node* copy; + int arity; + int j; - if(opc == iro_Cmp) - return 0; + if (get_nodes_block(node) != src_block) return node; + if (get_irn_op(node) == op_Phi) return get_irn_n(node, i); - return !mode_is_datab(get_irn_mode(irn)); -} + copy = exact_copy(node); + dst_block = get_nodes_block(get_irn_n(src_block, i)); + set_nodes_block(copy, dst_block); -/** - * Decdies, if a given expression and its subexpressions - * (to certain, also given extent) can be moved to a block. - * @param expr The expression to examine. - * @param block The block where the expression should go. - * @param depth The current depth, passed recursively. Use 0 for - * non-recursive calls. - * @param max_depth The maximum depth to which the expression should be - * examined. - */ -static int _can_move_to(ir_node *expr, ir_node *dest_block, int depth, int max_depth) -{ - int i, n; - int res = 1; - ir_node *expr_block = get_nodes_block(expr); - - - /* - * If we are forced to look too deep into the expression, - * treat it like it could not be moved. - */ - if(depth >= max_depth) { - res = 0; - goto end; - } - - /* - * If the block of the expression dominates the specified - * destination block, it does not matter if the expression - * has side effects or anything else. It is executed on each - * path the destination block is reached. - */ - if(block_dominates(expr_block, dest_block)) - goto end; - - /* - * We cannot move phis! - */ - if(is_Phi(expr)) { - res = 0; - goto end; - } + DB((dbg, LEVEL_1, "Copying node %+F to block %+F, copy is %+F\n", + node, dst_block, copy)); - /* - * This should be superflous and could be converted into a assertion. - * The destination block _must_ dominate the block of the expression, - * else the expression could be used without its definition. - */ - if(!block_dominates(dest_block, expr_block)) { - res = 0; - goto end; + arity = get_irn_arity(node); + for (j = 0; j < arity; ++j) { + set_irn_n(copy, j, copy_to(get_irn_n(node, j), src_block, i)); + DB((dbg, LEVEL_2, "-- pred %d is %+F\n", j, get_irn_n(copy, j))); } - - /* - * Surely, if the expression does not have a data mode, it is not - * movable. Perhaps onw should also test the floating property of - * the opcode/node. - */ - if(has_side_effects(expr)) { - res = 0; - goto end; - } - - /* - * If the node looks alright so far, look at its operands and - * check them out. If one of them cannot be moved, this one - * cannot be moved either. - */ - for(i = 0, n = get_irn_arity(expr); i < n; ++i) { - ir_node *op = get_irn_n(expr, i); - int new_depth = is_Proj(op) ? depth : depth + 1; - if(!_can_move_to(op, dest_block, new_depth, max_depth)) { - res = 0; - goto end; - } - } - -end: - DBG((dbg, LEVEL_3, "\t\t\t%Dcan move to %n: %d\n", depth, expr, res)); - - return res; + return copy; } + /** - * Convenience function for _can_move_to. - * Checks, if an expression can be moved to another block. The check can - * be limited to a expression depth meaning if we need to crawl in - * deeper into an expression than a given threshold to examine if - * it can be moved, the expression is rejected and the test returns - * false. - * @param expr The expression to check for. - * @param dest_block The destination block you want @p expr to be. - * @param max_depth The maximum depth @p expr should be investigated. - * @return 1, if the expression can be moved to the destination block, - * 0 if not. + * Remove predecessors i and j from node and add predecessor new_pred */ -static INLINE int can_move_to(ir_node *expr, ir_node *dest_block, int max_depth) +static void rewire(ir_node* node, int i, int j, ir_node* new_pred) { - return _can_move_to(expr, dest_block, 0, max_depth); -} - -static void move_to(ir_node *expr, ir_node *dest_block) -{ - int i, n; - ir_node *expr_block = get_nodes_block(expr); - - /* - * If we reached the dominator, we are done. - * We will never put code through the dominator - */ - if(block_dominates(expr_block, dest_block)) - return; - - for(i = 0, n = get_irn_arity(expr); i < n; ++i) - move_to(get_irn_n(expr, i), dest_block); - - set_nodes_block(expr, dest_block); -} - -static INLINE ir_node *common_idom(ir_node *b1, ir_node *b2) -{ - if(block_dominates(b1, b2)) - return b1; - else if(block_dominates(b2, b1)) - return b2; - else { - ir_node *p; - - for(p = b1; !block_dominates(p, b2); p = get_Block_idom(p)); - return p; - } + int arity = get_irn_arity(node); + ir_node **ins; + int k; + int l; + + NEW_ARR_A(ir_node *, ins, arity - 1); + + l = 0; + for (k = 0; k < i; ++k) ins[l++] = get_irn_n(node, k); + for (++k; k < j; ++k) ins[l++] = get_irn_n(node, k); + for (++k; k < arity; ++k) ins[l++] = get_irn_n(node, k); + ins[l++] = new_pred; + assert(l == arity - 1); + set_irn_in(node, l, ins); } /** - * Information about a cond node. + * Remove the jth predecessors from the ith predecessor of block and add it to block */ -typedef struct _cond_t { - ir_node *cond; /**< The cond node. */ - struct list_head list; /**< List head which is used for queueing this cond - into the cond bunch it belongs to. */ - unsigned in_list : 1; - unsigned is_new : 1; - struct _cond_t *link; - long visited_nr; - - /** - * Information about the both 'branches' - * (true and false), the cond creates. - */ - struct { - int pos; /**< Number of the predecessor of the - phi block by which this branch is - reached. It is -1, if this branch is - only reached through another cond. */ - - struct _cond_t *masked_by; /**< If this cond's branch is only reached - through another cond, we store this - cond ir_node here. */ - } cases[2]; -} cond_t; - -static INLINE cond_t *get_cond(ir_node *irn, set *cond_set) +static void split_block(ir_node* block, int i, int j) { - cond_t templ; + ir_node* pred_block = get_nodes_block(get_irn_n(block, i)); + int arity = get_irn_arity(block); + int new_pred_arity; + ir_node *phi, *next; + ir_node **ins; + ir_node **pred_ins; + int k; + + DB((dbg, LEVEL_1, "Splitting predecessor %d of predecessor %d of %+F\n", j, i, block)); + + NEW_ARR_A(ir_node*, ins, arity + 1); + + for (phi = get_Block_phis(block); phi != NULL; phi = get_Phi_next(phi)) { + ir_node* copy = copy_to(get_irn_n(phi, i), pred_block, j); + + for (k = 0; k < i; ++k) ins[k] = get_irn_n(phi, k); + ins[k++] = copy; + for (; k < arity; ++k) ins[k] = get_irn_n(phi, k); + ins[k] = get_irn_n(phi, i); + assert(k == arity); + set_irn_in(phi, arity + 1, ins); + } - templ.cond = irn; - return set_find(cond_set, &templ, sizeof(templ), HASH_PTR(templ.cond)); -} + for (k = 0; k < i; ++k) ins[k] = get_irn_n(block, k); + ins[k++] = get_irn_n(pred_block, j); + for (; k < arity; ++k) ins[k] = get_irn_n(block, k); + ins[k] = get_irn_n(block, i); + assert(k == arity); + set_irn_in(block, arity + 1, ins); + + new_pred_arity = get_irn_arity(pred_block) - 1; + NEW_ARR_A(ir_node*, pred_ins, new_pred_arity); + + for (phi = get_Block_phis(pred_block); phi != NULL; phi = next) { + for (k = 0; k < j; ++k) pred_ins[k] = get_irn_n(phi, k); + for (; k < new_pred_arity; ++k) pred_ins[k] = get_irn_n(phi, k + 1); + assert(k == new_pred_arity); + next = get_Phi_next(phi); + if (new_pred_arity > 1) { + set_irn_in(phi, new_pred_arity, pred_ins); + } else { + exchange(phi, pred_ins[0]); + } + } + for (k = 0; k < j; ++k) pred_ins[k] = get_irn_n(pred_block, k); + for (; k < new_pred_arity; ++k) pred_ins[k] = get_irn_n(pred_block, k + 1); + assert(k == new_pred_arity); + if (new_pred_arity > 1) { + set_irn_in(pred_block, new_pred_arity, pred_ins); + } else { + exchange(pred_block, get_nodes_block(pred_ins[0])); + } +} -typedef void (cond_walker_t)(cond_t *cond, void *env); -static void _walk_conds(cond_t *cond, cond_walker_t *pre, cond_walker_t *post, - long visited_nr, void *env) +static void prepare_path(ir_node* block, int i, const ir_node* dependency) { - int i; + ir_node* pred = get_nodes_block(get_irn_n(block, i)); + int pred_arity; + int j; - if(cond->visited_nr >= visited_nr) - return; + DB((dbg, LEVEL_1, "Preparing predecessor %d of %+F\n", i, block)); - cond->visited_nr = visited_nr; + pred_arity = get_irn_arity(pred); + for (j = 0; j < pred_arity; ++j) { + ir_node* pred_pred = get_nodes_block(get_irn_n(pred, j)); - if(pre) - pre(cond, env); - - for(i = 0; i < 2; ++i) { - cond_t *c = cond->cases[i].masked_by; - - if(c) - _walk_conds(c, pre, post, visited_nr, env); + if (is_cdep_on(pred_pred, dependency)) { + prepare_path(pred, j, dependency); + split_block(block, i, j); + break; + } } - - if(post) - post(cond, env); } -static void walk_conds(cond_t *cond, cond_walker_t *pre, cond_walker_t *post, void *env) -{ - static long visited_nr = 0; - _walk_conds(cond, pre, post, ++visited_nr, env); -} -static void link_conds(cond_t *cond, void *env) +static void if_conv_walker(ir_node* block, void* env) { - cond_t **ptr = (cond_t **) env; + ir_settings_if_conv_t* opt_info = env; + int arity; + int i; - cond->link = *ptr; - *ptr = cond; + /* Bail out, if there are no Phis at all */ + if (get_Block_phis(block) == NULL) return; + +restart: + arity = get_irn_arity(block); + for (i = 0; i < arity; ++i) { + ir_node* pred0; + ir_cdep* cdep; + + pred0 = get_Block_cfgpred_block(block, i); + for (cdep = find_cdep(pred0); cdep != NULL; cdep = cdep->next) { + const ir_node* dependency = cdep->node; + ir_node* projx0 = walk_to_projx(pred0, dependency); + ir_node* cond; + int j; + + if (projx0 == NULL) continue; + + cond = get_Proj_pred(projx0); + if (! is_Cond(cond)) + continue; + + /* We only handle boolean decisions, no switches */ + if (get_irn_mode(get_Cond_selector(cond)) != mode_b) continue; + + for (j = i + 1; j < arity; ++j) { + ir_node* projx1; + ir_node* sel; + ir_node* mux_block; + ir_node* phi; + ir_node* pred1; + dbg_info* cond_dbg; + + pred1 = get_Block_cfgpred_block(block, j); + + if (!is_cdep_on(pred1, dependency)) continue; + + projx1 = walk_to_projx(pred1, dependency); + + if (projx1 == NULL) continue; + + phi = get_Block_phis(block); + if (!opt_info->allow_ifconv(get_Cond_selector(cond), phi, i, j)) continue; + + DB((dbg, LEVEL_1, "Found Cond %+F with proj %+F and %+F\n", + cond, projx0, projx1 + )); + + prepare_path(block, i, dependency); + prepare_path(block, j, dependency); + arity = get_irn_arity(block); + + sel = get_Cond_selector(cond); + + mux_block = get_nodes_block(cond); + cond_dbg = get_irn_dbg_info(cond); + do { + ir_node* val_i = get_irn_n(phi, i); + ir_node* val_j = get_irn_n(phi, j); + ir_node* mux; + ir_node* next_phi; + + if (val_i == val_j) { + mux = val_i; + DB((dbg, LEVEL_2, "Generating no Mux, because both values are equal\n")); + } else { + ir_node *t, *f; + + /* Something is very fishy if two predecessors of a PhiM point into + * one block, but not at the same memory node + */ + assert(get_irn_mode(phi) != mode_M); + if (get_Proj_proj(projx0) == pn_Cond_true) { + t = val_i; + f = val_j; + } else { + t = val_j; + f = val_i; + } + + mux = new_rd_Mux(cond_dbg, current_ir_graph, mux_block, sel, f, t, get_irn_mode(phi)); + DB((dbg, LEVEL_2, "Generating %+F for %+F\n", mux, phi)); + } + + next_phi = get_Phi_next(phi); + + if (arity == 2) { + exchange(phi, mux); + } else { + rewire(phi, i, j, mux); + } + + phi = next_phi; + } while (phi != NULL); + + exchange(get_nodes_block(get_irn_n(block, i)), mux_block); + exchange(get_nodes_block(get_irn_n(block, j)), mux_block); + + if (arity == 2) { + unsigned mark; +#if 1 + DB((dbg, LEVEL_1, "Welding block %+F and %+F\n", block, mux_block)); + /* copy the block-info from the Mux-block to the block before merging */ + + mark = get_Block_mark(mux_block) | get_Block_mark(block); + set_Block_mark(block, mark); + set_Block_phis(block, get_Block_phis(mux_block)); + + set_irn_in(block, get_irn_arity(mux_block), get_irn_in(mux_block) + 1); + exchange_cdep(mux_block, block); + exchange(mux_block, block); +#else + DB((dbg, LEVEL_1, "Welding block %+F to %+F\n", block, mux_block)); + mark = get_Block_mark(mux_block) | get_Block_mark(block); + /* mark both block just to be sure, should be enough to mark mux_block */ + set_Block_mark(mux_block, mark); + exchange(block, mux_block); +#endif + return; + } else { + rewire(block, i, j, new_r_Jmp(current_ir_graph, mux_block)); + goto restart; + } + } + } + } } /** - * Compare two conds for use in a firm set. - * Two cond_t's are equal, if they designate the same cond node. - * @param a A cond_t. - * @param b Another one. - * @param size Not used. - * @return 0 (!) if they are equal, != 0 otherwise. + * Block walker: clear block mark and Phi list */ -static int cond_cmp(const void *a, const void *b, size_t size) +static void init_block_link(ir_node *block, void *env) { - const cond_t *x = a; - const cond_t *y = b; - return x->cond != y->cond; + (void)env; + set_Block_mark(block, 0); + set_Block_phis(block, NULL); } -/** - * Information about conds which can be made to muxes. - * Instances of this struct are attached to the link field of - * blocks in which phis are located. - */ -typedef struct _cond_info_t { - struct list_head list; /**< Used to list all of these structs per class. */ - - struct list_head roots; /**< A list of non-depending conds. Two conds are - independent, if yot can not reach the one from the - other (all conds in this list have to dominate the - block this struct is attached to. */ - - set *cond_set; /**< A set of all dominating reachable conds. */ -} cond_info_t; /** - * @see find_conds. + * Daisy-chain all phis in a block + * If a non-movable node is encountered set the has_pinned flag in its block. */ -static void _find_conds(ir_node *irn, long visited_nr, - ir_node *dominator, cond_t *masked_by, int pos, int depth, cond_info_t *ci) -{ - ir_node *block; - int is_modeb_cond = 0; - - block = get_nodes_block(irn); - - /* - * Only check this block if it is dominated by the specified - * dominator or it has not been visited yet. - */ - if(block_dominates(dominator, block) && get_Block_block_visited(block) < visited_nr) { - cond_t *res = NULL; - int i, n; - - /* check, if we're on a ProjX - * - * Further, the ProjX/Cond block must dominate the base block - * (the block with the phi in it), otherwise, the Cond - * is not affecting the phi so that a mux can be inserted. - */ - if(is_Proj(irn) && get_irn_mode(irn) == mode_X) { - - int proj = get_Proj_proj(irn); - ir_node *cond = get_Proj_pred(irn); - - /* true, if the mode is a mode_b cond _NO_ switch cond */ - is_modeb_cond = get_irn_opcode(cond) == iro_Cond - && get_irn_mode(get_Cond_selector(cond)) == mode_b; - - /* Check, if the pred of the proj is a Cond - * with a Projb as selector. - */ - if(is_modeb_cond) { - cond_t c; - - memset(&c, 0, sizeof(c)); - c.cond = cond; - c.is_new = 1; - c.cases[0].pos = -1; - c.cases[1].pos = -1; - - /* get or insert the cond info into the set. */ - res = set_insert(ci->cond_set, &c, sizeof(c), HASH_PTR(cond)); - - if(res->is_new) { - res->is_new = 0; - INIT_LIST_HEAD(&res->list); - } - - if(!res->in_list) { - res->in_list = 1; - list_add(&res->list, &ci->roots); - } - - /* - * Set masked by (either NULL or another cond node. - * If this cond is truly masked by another one, set - * the position of the actually investigated branch - * to -1. Since the cond is masked by another one, - * there could be more ways from the start block - * to this branch, so we choose -1. - */ - res->cases[proj].masked_by = masked_by; - - if(!masked_by) - res->cases[proj].pos = pos; - - /* - * Since the masked_by nodes masks a cond, remove it from the - * root list of the conf trees. - */ - else if(!list_empty(&masked_by->list)) { - list_del_init(&masked_by->list); - } - - DBG((dbg, LEVEL_2, "%{firm:indent}found cond %n (%s branch) " - "for pos %d in block %n reached by %n\n", - depth, cond, get_Proj_proj(irn) ? "true" : "false", pos, - block, masked_by ? masked_by->cond : NULL)); - } - } - - if(get_Block_block_visited(block) < visited_nr) { +static void collect_phis(ir_node *node, void *env) { + (void) env; - set_Block_block_visited(block, visited_nr); + if (is_Phi(node)) { + ir_node *block = get_nodes_block(node); - /* Search recursively from this cond. */ - for(i = 0, n = get_irn_arity(block); i < n; ++i) { - ir_node *pred = get_irn_n(block, i); + add_Block_phi(block, node); + } else { + if (is_no_Block(node) && get_irn_pinned(node) == op_pin_state_pinned) { + /* + * Ignore control flow nodes, these will be removed. + * This ignores Raise. That is surely bad. FIXME. + */ + if (!is_cfop(node)) { + ir_node *block = get_nodes_block(node); - /* - * If the depth is 0 (the first recursion), we set the pos to - * the current viewed predecessor, else we adopt the position - * as given by the caller. We also increase the depth for the - * recursively called functions. - */ - _find_conds(pred, visited_nr, dominator, res, pos, depth + 1, ci); + DB((dbg, LEVEL_2, "Node %+F in block %+F is unmovable\n", node, block)); + set_Block_mark(block, 1); } } } } - -/** - * A convenience function for _find_conds. - * It sets some parameters needed for recursion to appropriate start - * values. Always use this function. - * @param irn The node to start looking for conds from. This might - * be the phi node we are investigating. - * @param conds The set to record the found conds in. - */ -static INLINE void find_conds(ir_node *irn, cond_info_t *ci) +static void optimise_muxs_0(ir_node* mux, void* env) { - int i, n; - long visited_nr; - ir_node *block = get_nodes_block(irn); - ir_node *dom = get_Block_idom(block); + ir_node* t; + ir_node* f; + (void) env; - for(i = 0, n = get_irn_arity(block); i < n; ++i) { - ir_node *pred = get_irn_n(block, i); + if (!is_Mux(mux)) return; - inc_irg_block_visited(current_ir_graph); - visited_nr = get_irg_block_visited(current_ir_graph); - set_Block_block_visited(block, visited_nr); - DBG((dbg, LEVEL_2, "find conds at pred %d (%n) and idom %n\n", i, pred, dom)); - _find_conds(pred, visited_nr, dom, NULL, i, 0, ci); - } -} + t = get_Mux_true(mux); + f = get_Mux_false(mux); + DB((dbg, LEVEL_3, "Simplify %+F T=%+F F=%+F\n", mux, t, f)); -/** - * Make the mux for a given cond. - * @param phi The phi node which shall be replaced by a mux. - * @param dom The block where the muxes shall be placed. - * @param cond The cond information. - * @return The mux node made for this cond. - */ -static ir_node *make_mux_on_demand(ir_node *phi, ir_node *dom, cond_t *cond, - int max_depth, ir_node **mux, bitset_t *positions) -{ - int i; - ir_node *projb = get_Cond_selector(cond->cond); - ir_node *bl = get_nodes_block(cond->cond); - ir_node *operands[2]; - int set[2]; - - DBG((dbg, LEVEL_2, "%n\n", cond->cond)); - for(i = 0; i < 2; ++i) { - cond_t *masked_by = cond->cases[i].masked_by; - int pos = cond->cases[i].pos; - - operands[i] = NULL; - set[i] = -1; - - /* - * If this cond branch is masked by another cond, make the mux - * for that cond first, since the mux for this cond takes - * it as an operand. - */ - if(masked_by) { - assert(pos < 0); - operands[i] = make_mux_on_demand(phi, dom, masked_by, max_depth, mux, positions); - } - - /* - * If this cond branch is not masked by another cond, take - * the corresponding phi operand as an operand to the mux. - */ - else if(pos >= 0) { - operands[i] = get_irn_n(phi, pos); - set[i] = pos; - } + if (is_Unknown(t)) { + DB((dbg, LEVEL_3, "Replace Mux with unknown operand by %+F\n", f)); + exchange(mux, f); + return; } - - /* - * Move the operands to the dominator block if the cond - * made sense. Some conds found are not suitable for making a mux - * out of them, since one of their branches cannot be reached from - * the phi block. In that case we do not make a mux and return NULL. - */ - if(operands[0] && operands[1] - && can_move_to(operands[0], bl, max_depth) - && can_move_to(operands[1], bl, max_depth)) { - - move_to(operands[0], bl); - move_to(operands[1], bl); - - /* Make the mux. */ - *mux = new_r_Mux(current_ir_graph, bl, projb, - operands[0], operands[1], get_irn_mode(operands[0])); - - DBG((dbg, LEVEL_2, "\t%n(%n, %n, %n)[%d, %d]\n", - *mux, projb, operands[0], operands[1], set[0], set[1])); - - for(i = 0; i < 2; ++i) - if(set[i] >= 0) - bitset_set(positions, set[i]); + if (is_Unknown(f)) { + DB((dbg, LEVEL_3, "Replace Mux with unknown operand by %+F\n", t)); + exchange(mux, t); + return; } - return *mux; -} - -typedef struct _phi_info_t { - struct list_head list; - cond_info_t *cond_info; - ir_node *irn; -} phi_info_t; - - -/** - * Examine a phi node if it can be replaced by some muxes. - * @param irn A phi node. - * @param info Parameters for the if conversion algorithm. - */ -static void check_out_phi(phi_info_t *phi_info, opt_if_conv_info_t *info) -{ - int max_depth = info->max_depth; - ir_node *irn = phi_info->irn; - ir_node *block, *nw; - cond_info_t *cond_info = phi_info->cond_info; - cond_t *cond; - int i, arity; - bitset_t *positions; - - block = get_nodes_block(irn); - arity = get_irn_arity(irn); - positions = bitset_alloca(arity); - - assert(is_Phi(irn)); - assert(get_irn_arity(irn) == get_irn_arity(block)); - assert(arity > 0); - - DBG((dbg, LEVEL_2, "phi candidate: %n\n", irn)); - - list_for_each_entry(cond_t, cond, &cond_info->roots, list) { - ir_node *cidom = block; - ir_node *mux = NULL; - cond_t *p, *head = NULL; - long pos; - - bitset_clear_all(positions); - - DBG((dbg, LEVEL_2, "\tcond root: %n\n", cond->cond)); - /* - * Link all conds which are in the subtree of - * the current cond in the list together. - */ - walk_conds(cond, link_conds, NULL, &head); - - cidom = block; - for(p = head; p; p = p->link) { - for(i = 0; i < 2; ++i) { - int pos = p->cases[i].pos; - if(pos != -1) - cidom = common_idom(cidom, get_nodes_block(get_irn_n(block, pos))); - } + if (is_Mux(t)) { + ir_graph* irg = current_ir_graph; + ir_node* block = get_nodes_block(mux); + ir_mode* mode = get_irn_mode(mux); + ir_node* c0 = get_Mux_sel(mux); + ir_node* c1 = get_Mux_sel(t); + ir_node* t1 = get_Mux_true(t); + ir_node* f1 = get_Mux_false(t); + if (f == f1) { + /* Mux(c0, Mux(c1, x, y), y) -> typical if (c0 && c1) x else y */ + ir_node* and_ = new_r_And(irg, block, c0, c1, mode_b); + ir_node* new_mux = new_r_Mux(irg, block, and_, f1, t1, mode); + exchange(mux, new_mux); + } else if (f == t1) { + /* Mux(c0, Mux(c1, x, y), x) */ + ir_node* not_c1 = new_r_Not(irg, block, c1, mode_b); + ir_node* and_ = new_r_And(irg, block, c0, not_c1, mode_b); + ir_node* new_mux = new_r_Mux(irg, block, and_, t1, f1, mode); + exchange(mux, new_mux); } - - DBG((dbg, LEVEL_2, "\tcommon idom: %n\n", cidom)); - make_mux_on_demand(irn, cidom, cond, max_depth, &mux, positions); - - if(mux) { - bitset_foreach(positions, pos) { - set_irn_n(irn, (int) pos, mux); - } + } else if (is_Mux(f)) { + ir_graph* irg = current_ir_graph; + ir_node* block = get_nodes_block(mux); + ir_mode* mode = get_irn_mode(mux); + ir_node* c0 = get_Mux_sel(mux); + ir_node* c1 = get_Mux_sel(f); + ir_node* t1 = get_Mux_true(f); + ir_node* f1 = get_Mux_false(f); + if (t == t1) { + /* Mux(c0, x, Mux(c1, x, y)) -> typical if (c0 || c1) x else y */ + ir_node* or_ = new_r_Or(irg, block, c0, c1, mode_b); + ir_node* new_mux = new_r_Mux(irg, block, or_, f1, t1, mode); + exchange(mux, new_mux); + } else if (t == f1) { + /* Mux(c0, x, Mux(c1, y, x)) */ + ir_node* not_c1 = new_r_Not(irg, block, c1, mode_b); + ir_node* or_ = new_r_Or(irg, block, c0, not_c1, mode_b); + ir_node* new_mux = new_r_Mux(irg, block, or_, t1, f1, mode); + exchange(mux, new_mux); } } - - /* - * optimize the phi away. This can anable further runs of this - * function. Look at _can_move. phis cannot be moved there. - */ - nw = optimize_in_place_2(irn); - if(nw != irn) - exchange(irn, nw); } -typedef struct _cond_walk_info_t { - struct obstack *obst; - struct list_head cond_info_head; - struct list_head phi_head; -} cond_walk_info_t; - -static void annotate_cond_info_pre(ir_node *irn, void *data) +static void optimise_muxs_1(ir_node* mux, void* env) { - set_irn_link(irn, NULL); -} + ir_node* t; + ir_node* f; + ir_mode* mode; -static void annotate_cond_info_post(ir_node *irn, void *data) -{ - cond_walk_info_t *cwi = data; - - /* - * Check, if the node is a phi - * we then compute a set of conds which are reachable from this - * phi's block up to its dominator. - * The set is attached to the blocks link field. - */ - if(is_Phi(irn) && mode_is_datab(get_irn_mode(irn))) { - ir_node *block = get_nodes_block(irn); - - cond_info_t *ci = get_irn_link(block); - - /* If the set is not yet computed, do it now. */ - if(!ci) { - ci = obstack_alloc(cwi->obst, sizeof(*ci)); - ci->cond_set = new_set(cond_cmp, log2_ceil(get_irn_arity(block))); - INIT_LIST_HEAD(&ci->roots); - INIT_LIST_HEAD(&ci->list); + (void) env; - /* - * Add this cond info to the list of all cond infos - * in this graph. This is just done to free the - * set easier afterwards (we save an irg_walk_graph). - */ - list_add(&cwi->cond_info_head, &ci->list); + if (!is_Mux(mux)) return; - DBG((dbg, LEVEL_2, "searching conds at %n\n", irn)); + t = get_Mux_true(mux); + f = get_Mux_false(mux); - /* - * Fill the set with conds we find on the way from - * the block to its dominator. - */ - find_conds(irn, ci); + DB((dbg, LEVEL_3, "Simplify %+F T=%+F F=%+F\n", mux, t, f)); - /* - * If there where no suitable conds, delete the set - * immediately and reset the set pointer to NULL - */ - if(set_count(ci->cond_set) == 0) { - del_set(ci->cond_set); - list_del(&ci->list); - obstack_free(cwi->obst, ci); - ci = NULL; - } - } - - else - DBG((dbg, LEVEL_2, "conds already computed for %n\n", irn)); - - set_irn_link(block, ci); + mode = get_irn_mode(mux); - if(ci) { - phi_info_t *pi = obstack_alloc(cwi->obst, sizeof(*pi)); - pi->irn = irn; - pi->cond_info = ci; - INIT_LIST_HEAD(&pi->list); - list_add(&pi->list, &cwi->phi_head); + if (is_Const(t) && is_Const(f) && (mode_is_int(mode))) { + ir_node* block = get_nodes_block(mux); + ir_node* c = get_Mux_sel(mux); + tarval* tv_t = get_Const_tarval(t); + tarval* tv_f = get_Const_tarval(f); + if (tarval_is_one(tv_t) && tarval_is_null(tv_f)) { + ir_node* conv = new_r_Conv(current_ir_graph, block, c, mode); + exchange(mux, conv); + } else if (tarval_is_null(tv_t) && tarval_is_one(tv_f)) { + ir_node* not_ = new_r_Not(current_ir_graph, block, c, mode_b); + ir_node* conv = new_r_Conv(current_ir_graph, block, not_, mode); + exchange(mux, conv); } - } } -static void dump_conds(cond_t *cond, void *env) -{ - int i; - FILE *f = env; - - ir_fprintf(f, "node:{title:\"n%p\" label:\"%n(%d, %d)\n%n\"}\n", - cond, cond->cond, cond->cases[0].pos, cond->cases[1].pos, - get_nodes_block(cond->cond)); - - for(i = 0; i < 2; ++i) - if(cond->cases[i].masked_by) - ir_fprintf(f, "edge:{sourcename:\"n%p\" targetname:\"n%p\" label:\"%d\"}\n", - cond, cond->cases[i].masked_by, i); -} - -static void vcg_dump_conds(ir_graph *irg, cond_walk_info_t *cwi) -{ - char buf[512]; - FILE *f; - - snprintf(buf, sizeof(buf), "%s-conds.vcg", get_entity_name(get_irg_entity(irg))); - - if((f = fopen(buf, "wt")) != NULL) { - cond_info_t *ci; - phi_info_t *phi; - cond_t *cond; - - ir_fprintf(f, "graph:{\ndisplay_edge_labels:yes\n"); - list_for_each_entry(cond_info_t, ci, &cwi->cond_info_head, list) { - ir_fprintf(f, "node:{title:\"n%p\" label:\"cond info\"}\n", ci); - list_for_each_entry(cond_t, cond, &ci->roots, list) { - walk_conds(cond, NULL, dump_conds, f); - ir_fprintf(f, "edge:{sourcename:\"n%p\" targetname:\"n%p\"}\n", ci, cond); - } - } - - list_for_each_entry(phi_info_t, phi, &cwi->phi_head, list) { - ir_fprintf(f, "node:{title:\"n%p\" label:\"%n\n%n\"}\n", - phi->irn, phi->irn, get_nodes_block(phi->irn)); - ir_fprintf(f, "edge:{sourcename:\"n%p\" targetname:\"n%p\"}\n", phi->irn, phi->cond_info); - } - fprintf(f, "}\n"); - } -} -#if 0 -/** - * Free the sets which are put at some blocks. - */ -static void free_sets(ir_node *irn, void *data) +void opt_if_conv(ir_graph *irg, const ir_settings_if_conv_t *params) { - if(is_Block(irn) && get_irn_link(irn)) { - set *conds = get_irn_link(irn); - del_set(conds); - } -} -#endif + ir_settings_if_conv_t p; -void opt_if_conv(ir_graph *irg, opt_if_conv_info_t *params) -{ - struct obstack obst; - phi_info_t *phi_info; - cond_info_t *cond_info; - cond_walk_info_t cwi; + /* get the parameters */ + p = (params != NULL ? *params : default_info); - opt_if_conv_info_t *p = params ? params : &default_info; + FIRM_DBG_REGISTER(dbg, "firm.opt.ifconv"); - if(!get_opt_if_conversion()) - return; + DB((dbg, LEVEL_1, "Running if-conversion on %+F\n", irg)); - obstack_init(&obst); + normalize_one_return(irg); + remove_critical_cf_edges(irg); - cwi.obst = &obst; - INIT_LIST_HEAD(&cwi.cond_info_head); - INIT_LIST_HEAD(&cwi.phi_head); + compute_cdep(irg); + assure_doms(irg); - /* Init the debug stuff. */ - dbg = firm_dbg_register("firm.opt.ifconv"); -#if 0 - firm_dbg_set_mask(dbg, LEVEL_1 | LEVEL_2 | LEVEL_3); -#endif + ir_reserve_resources(irg, IR_RESOURCE_BLOCK_MARK); - /* Ensure, that the dominators are computed. */ - compute_doms(irg); + irg_block_walk_graph(irg, init_block_link, NULL, NULL); + irg_walk_graph(irg, collect_phis, NULL, NULL); + irg_block_walk_graph(irg, NULL, if_conv_walker, &p); - DBG((dbg, LEVEL_2, "if conversion for irg %s(%p)\n", - get_entity_name(get_irg_entity(irg)), irg)); + ir_free_resources(irg, IR_RESOURCE_BLOCK_MARK); - /* - * Collect information about the conds pu the phis on an obstack. - * It is important that phi nodes which are 'higher' (with a - * lower dfs pre order) are in front of the obstack. Since they are - * possibly turned in to muxes this can enable the optimization - * of 'lower' ones. - */ - irg_walk_graph(irg, annotate_cond_info_pre, annotate_cond_info_post, &cwi); + local_optimize_graph(irg); -#if 0 - vcg_dump_conds(irg, &cwi); + irg_walk_graph(irg, NULL, optimise_muxs_0, NULL); +#if 1 + irg_walk_graph(irg, NULL, optimise_muxs_1, NULL); #endif - /* Process each suitable phi found. */ - list_for_each_entry(phi_info_t, phi_info, &cwi.phi_head, list) { - DBG((dbg, LEVEL_4, "phi node %n\n", phi_info->irn)); - check_out_phi(phi_info, p); - } - - list_for_each_entry(cond_info_t, cond_info, &cwi.cond_info_head, list) { - del_set(cond_info->cond_set); - } + /* TODO: graph might be changed, handle more graceful */ + set_irg_outs_inconsistent(irg); + set_irg_extblk_inconsistent(irg); + set_irg_loopinfo_inconsistent(irg); + free_dom(irg); - obstack_free(&obst, NULL); + free_cdep(irg); }