X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fifconv.c;h=1173ca4dface98173e0342ddda5a477abead8aae;hb=cd4e22d1a782b4782d85c83c7390561bb3afa5ed;hp=1abf8fcf68fa9a1c97f621497e1682656bc107f0;hpb=1a38f36ddb4614591fc9162fc956b17e7e3b6d3b;p=libfirm diff --git a/ir/opt/ifconv.c b/ir/opt/ifconv.c index 1abf8fcf6..1173ca4df 100644 --- a/ir/opt/ifconv.c +++ b/ir/opt/ifconv.c @@ -1,1025 +1,664 @@ -/** - * If conversion. - * Make Mux nodes from Conds where it its possible. - * @author Sebastian Hack - * @date 4.2.2005 - * $Id$ +/* + * 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. */ -#include -#include -#include - -#include "irgraph_t.h" -#include "irnode_t.h" -#include "iropt_t.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 "debug.h" -#include "obst.h" -#include "set.h" -#include "bitset.h" -#include "bitfiddle.h" -#include "irhooks.h" - -#define MAX_DEPTH 20 - /* - * Mux optimization routines. + * @file ir/opt/ifconv.c + * @brief If conversion + * @author Christoph Mallon + * @version $Id$ */ -#if 0 -static ir_node *local_optimize_mux(ir_node *mux) -{ - 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; -} +#ifdef HAVE_CONFIG_H +#include "config.h" #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. - */ -static tarval *get_value_or(ir_node *cnst, tarval *or) -{ - return get_irn_op(cnst) == op_Const ? get_Const_tarval(cnst) : or; -} - - -/** - * 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. - */ -static ir_node *optimize_mux_chain(ir_node *mux) -{ - 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); - - if(tarval_cmp(tarval_and(tva, tvd), tvd) == pn_Cmp_Eq - && tarval_cmp(tarval_and(tvb, tvd), tvd) == pn_Cmp_Eq) { +#include - ops[i] = new_Const(mode, minus_one); - res = new_r_And(current_ir_graph, get_nodes_block(mux), - mux, child_mux, mode); - break; - } - } - } +#include "obst.h" +#include "irnode_t.h" +#include "cdep.h" +#include "ircons.h" +#include "ifconv.h" +#include "irdom.h" +#include "irgmod.h" +#include "irgopt.h" +#include "irgwalk.h" +#include "irtools.h" +#include "return.h" +#include "array.h" +#include "xmalloc.h" + +// debug +#include "irdump.h" +#include "debug.h" - /* recursively optimize nested muxes. */ - set_irn_n(mux, 1, optimize_mux_chain(ops[0])); - set_irn_n(mux, 2, optimize_mux_chain(ops[1])); +DEBUG_ONLY(firm_dbg_module_t *dbg); - return res; +/** allow every Psi to be created. */ +static int default_allow_ifconv(ir_node *sel, ir_node* phi_list, int i, int j) +{ + return 1; } - -/*********************************************************** - * The If conversion itself. - ***********************************************************/ - /** * Default options. */ -static opt_if_conv_info_t default_info = { - MAX_DEPTH +static const opt_if_conv_info_t default_info = { + 0, /* doesn't matter for Psi */ + default_allow_ifconv }; -/** The debugging module. */ -static firm_dbg_module_t *dbg; - /** - * A simple check for side effects upto 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. + * Additional block info. */ -static INLINE int has_side_effects(const ir_node *irn) -{ - ir_op *op = get_irn_op(irn); +typedef struct block_info { + ir_node *phi; /**< head of the Phi list */ + int has_pinned; /**< set if the block contains instructions that cannot be moved */ +} block_info; - if (op == op_Cmp) - return 0; - - return !mode_is_datab(get_irn_mode(irn)); -} - -enum failure_reason_t { - SUCCESS = IF_RESULT_SUCCESS, - TO_DEEP = IF_RESULT_TOO_DEEP, - SIDE_EFFECTS = IF_RESULT_SIDE_EFFECT, - PHI_FOUND = IF_RESULT_SIDE_EFFECT_PHI -}; +#define get_block_blockinfo(block) ((block_info *)get_irn_link(block)) /** - * Decides, 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. - * - * @return a failure reason + * Returns non-zero if a Block can be emptied. */ -static int _can_move_to(ir_node *expr, ir_node *dest_block, int depth, int max_depth) +static int can_empty_block(ir_node *block) { - int i, n; - int res = SUCCESS; - 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 = TO_DEEP; - goto end; - } + return !get_block_blockinfo(block)->has_pinned; +} - /* - * 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 = PHI_FOUND; - goto end; - } +static ir_node* walk_to_projx(ir_node* start, const ir_node* dependency) +{ + int arity; + int i; - /* - * This should be superfluous 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. + /* No need to find the conditional block if this block cannot be emptied and + * therefore not moved */ - if (! block_dominates(dest_block, expr_block)) { - res = IF_RESULT_SIDE_EFFECT; - goto end; - } + if (!can_empty_block(start)) return NULL; - /* - * Surely, if the expression does not have a data mode, it is not - * movable. Perhaps one should also test the floating property of - * the opcode/node. - */ - if (has_side_effects(expr)) { - res = IF_RESULT_SIDE_EFFECT; - goto end; - } + 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); - /* - * 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 (pred_block == dependency) { + if (is_Proj(pred)) { + assert(get_irn_mode(pred) == mode_X); + return pred; + } + return NULL; + } - res = _can_move_to(op, dest_block, new_depth, max_depth); + if (is_Proj(pred)) { + assert(get_irn_mode(pred) == mode_X); + return NULL; + } - if (res != SUCCESS) - goto end; + if (is_cdep_on(pred_block, dependency)) { + return walk_to_projx(pred_block, dependency); + } } - -end: - DBG((dbg, LEVEL_3, "\t\t\t%Dcan move to %n: %d\n", depth, expr, res)); - - return res; + return NULL; } -/** - * 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 return a failure reason - */ -static INLINE int can_move_to(ir_node *expr, ir_node *dest_block, int max_depth) -{ - return _can_move_to(expr, dest_block, 0, max_depth); -} /** - * move a DAG given by a root node expr into a new block - * - * @param expr the root of a dag - * @param dest_block the destination block + * 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 void move_to(ir_node *expr, ir_node *dest_block) +static ir_node* copy_to(ir_node* node, ir_node* src_block, int i) { - int i, n; - ir_node *expr_block = get_nodes_block(expr); + ir_node* dst_block; + ir_node* copy; + int arity; + int j; - /* - * If we reached the dominator, we are done. - * We will never put code through the dominator - */ - if (block_dominates(expr_block, dest_block)) - return; + if (get_nodes_block(node) != src_block) return node; + if (get_irn_op(node) == op_Phi) return get_irn_n(node, i); - 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); -} + copy = exact_copy(node); + dst_block = get_nodes_block(get_irn_n(src_block, i)); + set_nodes_block(copy, dst_block); -/** - * return the common dominator of two blocks - */ -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; + DB((dbg, LEVEL_1, "Copying node %+F to block %+F, copy is %+F\n", + node, dst_block, copy)); - for (p = get_Block_idom(b1); !block_dominates(p, b2); p = get_Block_idom(p)); - return p; + 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))); } + return copy; } -/** - * Information about a cond node. - */ -typedef struct _cond_t { - ir_node *cond; /**< The cond node. */ - struct list_head list; /**< List head which is used for queuing this cond - into the cond bunch it belongs to. */ - unsigned is_new : 1; - unsigned totally_covers : 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; /** - * retrieve the conditional information from a Cond node + * Remove predecessors i and j from node and add predecessor new_pred */ -static INLINE cond_t *get_cond(ir_node *irn, set *cond_set) +static void rewire(ir_node* node, int i, int j, ir_node* new_pred) { - cond_t templ; - - templ.cond = irn; - return set_find(cond_set, &templ, sizeof(templ), HASH_PTR(templ.cond)); + 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); } -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) +/** + * Remove the jth predecessors from the ith predecessor of block and add it to block + */ +static void split_block(ir_node* block, int i, int j) { - int i; - - if(cond->visited_nr >= visited_nr) - return; - - cond->visited_nr = visited_nr; - - if(pre) - pre(cond, env); - - for(i = 0; i < 2; ++i) { - cond_t *c = cond->cases[i].masked_by; + 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; + 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_blockinfo(block)->phi; phi != NULL; phi = get_irn_link(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); + } - if(c) - _walk_conds(c, pre, post, visited_nr, env); + 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_blockinfo(pred_block)->phi; phi != NULL; phi = get_irn_link(phi)) { + 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); + if (new_pred_arity > 1) { + set_irn_in(phi, new_pred_arity, pred_ins); + } else { + exchange(phi, pred_ins[0]); + } } - if(post) - post(cond, env); + 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])); + } } -static long cond_visited_nr = 0; -static void walk_conds(cond_t *cond, cond_walker_t *pre, cond_walker_t *post, void *env) +static void prepare_path(ir_node* block, int i, const ir_node* dependency) { - _walk_conds(cond, pre, post, ++cond_visited_nr, env); -} + ir_node* pred = get_nodes_block(get_irn_n(block, i)); + int pred_arity; + int j; -static void link_conds(cond_t *cond, void *env) -{ - cond_t **ptr = (cond_t **) env; + DB((dbg, LEVEL_1, "Preparing predecessor %d of %+F\n", i, block)); - cond->link = *ptr; - *ptr = cond; -} + 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)); -/** - * 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. - */ -static int cond_cmp(const void *a, const void *b, size_t size) -{ - const cond_t *x = a; - const cond_t *y = b; - return x->cond != y->cond; + if (is_cdep_on(pred_pred, dependency)) { + prepare_path(pred, j, dependency); + split_block(block, i, j); + break; + } + } } -/** - * 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 it's not possible not reach one from the - other (all Conds in this list have to dominate the - block this struct is attached to). */ - - ir_node *first_phi; /**< The first phi node this cond info was made for. */ - set *cond_set; /**< A set of all dominating reachable Conds. */ -} cond_info_t; - -/** - * @see find_conds. - */ -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) +static void if_conv_walker(ir_node* block, void* env) { - ir_node *block; - int saw_select_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 = masked_by; - 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 */ - int is_modeb_cond = get_irn_opcode(cond) == iro_Cond - && get_irn_mode(get_Cond_selector(cond)) == mode_b; - - saw_select_cond = !is_modeb_cond; - - /* 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 this cond is already masked by the masked_by cond - * return immediately, since we don't have anything to add. - */ - if(masked_by && res->cases[proj].masked_by == masked_by) + int arity; + int i; + opt_if_conv_info_t *opt_info = env; + + /* Bail out, if there are no Phis at all */ + if (get_block_blockinfo(block)->phi == NULL) return; + +restart: + arity = get_irn_arity(block); + for (i = 0; i < arity; ++i) { + ir_node* pred; + cdep* cdep; + + pred = get_nodes_block(get_irn_n(block, i)); + for (cdep = find_cdep(pred); cdep != NULL; cdep = cdep->next) { + const ir_node* dependency = cdep->node; + ir_node* projx0 = walk_to_projx(pred, dependency); + ir_node* cond; + int j; + + if (projx0 == NULL) continue; + + cond = get_Proj_pred(projx0); + if (get_irn_op(cond) != op_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* conds[1]; + ir_node* vals[2]; + ir_node* psi = NULL; + ir_node* psi_block; + ir_node* phi; + + pred = get_nodes_block(get_irn_n(block, j)); + + if (!is_cdep_on(pred, dependency)) continue; + + projx1 = walk_to_projx(pred, dependency); + + if (projx1 == NULL) continue; + + phi = get_block_blockinfo(block)->phi; + 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); + + conds[0] = get_Cond_selector(cond); + + psi_block = get_nodes_block(cond); + do { + ir_node* val_i = get_irn_n(phi, i); + ir_node* val_j = get_irn_n(phi, j); + + if (val_i == val_j) { + psi = val_i; + DB((dbg, LEVEL_2, "Generating no psi, because both values are equal\n")); + } else { + /* 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) { + vals[0] = val_i; + vals[1] = val_j; + } else { + vals[0] = val_j; + vals[1] = val_i; + } + + psi = new_r_Psi( + current_ir_graph, psi_block, 1, conds, vals, get_irn_mode(phi) + ); + DB((dbg, LEVEL_2, "Generating %+F for %+F\n", psi, phi)); + } + + if (arity == 2) { + exchange(phi, psi); + } else { + rewire(phi, i, j, psi); + } + + phi = get_irn_link(phi); + } while (phi != NULL); + + exchange(get_nodes_block(get_irn_n(block, i)), psi_block); + exchange(get_nodes_block(get_irn_n(block, j)), psi_block); + + if (arity == 2) { +#if 1 + DB((dbg, LEVEL_1, "Welding block %+F and %+F\n", block, psi_block)); + /* copy the block-info from the Psi-block to the block before merging */ + get_block_blockinfo(psi_block)->has_pinned |= get_block_blockinfo(block)->has_pinned; + set_irn_link(block, get_irn_link(psi_block)); + + set_irn_in(block, get_irn_arity(psi_block), get_irn_in(psi_block) + 1); + exchange_cdep(psi_block, block); + exchange(psi_block, block); +#else + DB((dbg, LEVEL_1, "Welding block %+F to %+F\n", block, psi_block)); + get_block_blockinfo(psi_block)->has_pinned |= get_block_blockinfo(block)->has_pinned; + exchange(block, psi_block); +#endif return; - - if(res->is_new) { - res->is_new = 0; - 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 { - assert(res->cases[proj].pos < 0); - list_del_init(&masked_by->list); + } else { + rewire(block, i, j, new_r_Jmp(current_ir_graph, psi_block)); + goto restart; } - - DBG((dbg, LEVEL_2, "%D%n (%s branch) " - "for pos %d in block %n reached by %n\n", - depth, cond, proj ? "true" : "false", pos, - block, masked_by ? masked_by->cond : NULL)); - } - } - - if(get_Block_block_visited(block) < visited_nr && !saw_select_cond) { - - set_Block_block_visited(block, visited_nr); - - /* Search recursively from this cond. */ - for(i = 0, n = get_irn_arity(block); i < n; ++i) { - ir_node *pred = get_irn_n(block, i); - - /* - * 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 + (res != masked_by), ci); } } } } - /** - * 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. + * Block walker: add additional data */ -static INLINE void find_conds(ir_node *irn, cond_info_t *ci) +static void init_block_link(ir_node *block, void *env) { - int i, n; - long visited_nr; - ir_node *block = get_nodes_block(irn); - ir_node *dom = get_Block_idom(block); - - for(i = 0, n = get_irn_arity(block); i < n; ++i) { - ir_node *pred = get_irn_n(block, i); + struct obstack *obst = env; + block_info *bi = obstack_alloc(obst, sizeof(*bi)); - 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); - } + bi->phi = NULL; + bi->has_pinned = 0; + set_irn_link(block, bi); } + /** - * 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. + * Daisy-chain all phis in a block + * If a non-movable node is encountered set the has_pinned flag */ -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 *muxes_made, long visited_nr) +static void collect_phis(ir_node *node, void *env) { - int i, can_move[2]; - ir_node *projb = get_Cond_selector(cond->cond); - ir_node *bl = get_nodes_block(cond->cond); - ir_node *operands[2]; - int set[2]; - - cond->visited_nr = visited_nr; - 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); - DBG((dbg, LEVEL_2, "\tmasked by: %n\n", masked_by->cond)); - if(masked_by->visited_nr < visited_nr) - operands[i] = make_mux_on_demand(phi, dom, masked_by, max_depth, mux, positions, muxes_made, visited_nr); - } + if (is_Phi(node)) { + ir_node *block = get_nodes_block(node); + block_info *bi = get_block_blockinfo(block); - /* - * 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; - } + set_irn_link(node, bi->phi); + bi->phi = 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); + block_info *bi = get_block_blockinfo(block); - /* - * 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]) { - if (operands[0] == operands[1]) { - /* there is no gain in using mux in this case, as - it will be optimized away. We will NOT move the - content of the blocks either - */ - for (i = 0; i < 2; ++i) - if(set[i] >= 0) - bitset_set(positions, set[i]); - - *mux = operands[0]; - return *mux; - } - - can_move[0] = can_move_to(operands[0], bl, max_depth); - can_move[1] = can_move_to(operands[1], bl, max_depth); - - if (can_move[0] == SUCCESS && can_move[1] == SUCCESS) { - 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])); - - *muxes_made += 1; - - 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]); - - /* we have done one */ - hook_if_conversion(current_ir_graph, phi, set[i], *mux, IF_RESULT_SUCCESS); - } - } - else { - if(can_move[0] != SUCCESS) - hook_if_conversion(current_ir_graph, phi, set[0], NULL, can_move[0]); - if(can_move[1] != SUCCESS) - hook_if_conversion(current_ir_graph, phi, set[1], NULL, can_move[1]); - } + DB((dbg, LEVEL_2, "Node %+F in block %+F is unmovable\n", node, block)); + bi->has_pinned = 1; + } + } } - else { - if(operands[0] != SUCCESS) - hook_if_conversion(current_ir_graph, phi, set[0], NULL, IF_RESULT_BAD_CF); - if(operands[1] != SUCCESS) - hook_if_conversion(current_ir_graph, phi, set[1], NULL, IF_RESULT_BAD_CF); - } - - 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. +/* + * Transform multiple cascaded Psis into one Psi */ -static int check_out_phi(phi_info_t *phi_info, opt_if_conv_info_t *info) +static ir_node* fold_psi(ir_node* psi) { - 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; - int muxes_made = 0; - 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))); - } + int arity = get_Psi_n_conds(psi); + int new_arity = 0; + int i; + ir_node* n; + ir_node** conds; + ir_node** vals; + int j; + int k; + int a; + ir_node* new_psi; + + for (i = 0; i < arity; ++i) { + n = get_Psi_val(psi, i); + if (get_irn_op(n) == op_Psi) { + new_arity += get_Psi_n_conds(n) + 1; + } else { + ++new_arity; } + } + n = get_Psi_default(psi); + if (get_irn_op(n) == op_Psi) { + new_arity += get_Psi_n_conds(n); + } - DBG((dbg, LEVEL_2, "\tcommon idom: %n\n", cidom)); - make_mux_on_demand(irn, cidom, cond, max_depth, &mux, positions, &muxes_made, ++cond_visited_nr); - - if(mux) { - bitset_foreach(positions, pos) - set_irn_n(irn, (int) pos, mux); + if (arity == new_arity) return psi; // no attached Psis found + DB((dbg, LEVEL_1, "Folding %+F from %d to %d conds\n", psi, arity, new_arity)); + + NEW_ARR_A(ir_node *, conds, new_arity); + NEW_ARR_A(ir_node *, vals, new_arity + 1); + j = 0; + for (i = 0; i < arity; ++i) { + ir_node* c = get_Psi_cond(psi, i); + + n = get_Psi_val(psi, i); + if (get_irn_op(n) == op_Psi) { + a = get_Psi_n_conds(n); + for (k = 0; k < a; ++k) { + conds[j] = new_r_And( + current_ir_graph, get_nodes_block(psi), + c, get_Psi_cond(n, k), mode_b + ); + vals[j] = get_Psi_val(n, k); + ++j; + } + conds[j] = c; + vals[j] = get_Psi_default(n); + } else { + conds[j] = c; + vals[j] = n; } + ++j; } - - /* - * 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); - - return muxes_made; + n = get_Psi_default(psi); + if (get_irn_op(n) == op_Psi) { + a = get_Psi_n_conds(n); + for (k = 0; k < a; ++k) { + conds[j] = get_Psi_cond(n, k); + vals[j] = get_Psi_val(n, k); + ++j; + } + vals[j] = get_Psi_default(n); + } else { + vals[j] = n; + } + assert(j == new_arity); + new_psi = new_r_Psi( + current_ir_graph, get_nodes_block(psi), + new_arity, conds, vals, get_irn_mode(psi) + ); + DB((dbg, LEVEL_1, "Folded %+F into new %+F\n", psi, new_psi)); + exchange(psi, new_psi); + return new_psi; } -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) -{ - set_irn_link(irn, NULL); -} - -static void annotate_cond_info_post(ir_node *irn, void *data) +/* + * Merge consecutive psi inputs if the data inputs are the same + */ +static ir_node* meld_psi(ir_node* psi) { - 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))); - ci->first_phi = irn; - - INIT_LIST_HEAD(&ci->roots); - INIT_LIST_HEAD(&ci->list); - - /* - * 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); - - DBG((dbg, LEVEL_2, "searching conds at %n\n", irn)); - - /* - * Fill the set with conds we find on the way from - * the block to its dominator. - */ - find_conds(irn, ci); - - /* - * 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; - } + int arity = get_Psi_n_conds(psi); + int new_arity; + ir_node** conds; + ir_node** vals; + ir_node* cond; + ir_node* val; + int i; + int j; + ir_node* new_psi; + + new_arity = 1; + val = get_Psi_val(psi, 0); + DB((dbg, LEVEL_1, "Pred 0 of %+F is %+F\n", psi, val)); + for (i = 1; i < arity; ++i) { + ir_node* v = get_Psi_val(psi, i); + DB((dbg, LEVEL_1, "Pred %2d of %+F is %+F\n", i, psi, v)); + if (val != v) { + val = v; + ++new_arity; } + } + DB((dbg, LEVEL_1, "Default of %+F is %+F\n", psi, get_Psi_default(psi))); + if (val == get_Psi_default(psi)) --new_arity; - else - DBG((dbg, LEVEL_2, "conds already computed for %n (look at %n)\n", irn, ci->first_phi)); + DB((dbg, LEVEL_1, "Melding Psi %+F from %d conds to %d\n", psi, arity, new_arity)); - set_irn_link(block, ci); + if (new_arity == arity) return psi; - 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 all data inputs of the Psi are equal, exchange the Psi with that value */ + if (new_arity == 0) { + exchange(psi, val); + return val; + } + NEW_ARR_A(ir_node *, conds, new_arity); + NEW_ARR_A(ir_node *, vals, new_arity + 1); + cond = get_Psi_cond(psi, 0); + val = get_Psi_val(psi, 0); + j = 0; + for (i = 1; i < arity; ++i) { + ir_node* v = get_Psi_val(psi, i); + + if (v == val) { + cond = new_r_Or( + current_ir_graph, get_nodes_block(psi), + cond, get_Psi_cond(psi, i), mode_b + ); + } else { + conds[j] = cond; + vals[j] = val; + ++j; + val = v; + } } + if (val != get_Psi_default(psi)) { + conds[j] = cond; + vals[j] = val; + ++j; + } + vals[j] = get_Psi_default(psi); + assert(j == new_arity); + new_psi = new_r_Psi( + current_ir_graph, get_nodes_block(psi), + new_arity, conds, vals, get_irn_mode(psi) + ); + DB((dbg, LEVEL_1, "Molded %+F into %+F\n", psi, new_psi)); + exchange(psi, new_psi); + return new_psi; } -static void dump_conds(cond_t *cond, void *env) + +/** + * Split a Psi with multiple conditions into multiple Psis with one condtition + * each + */ +static ir_node* split_psi(ir_node* psi) { + int arity = get_Psi_n_conds(psi); + ir_mode* mode; + ir_node* block; + ir_node* rval; 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); + if (arity == 1) return psi; + + mode = get_irn_mode(psi); + block = get_nodes_block(psi); + rval = get_Psi_default(psi); + for (i = arity - 1; i >= 0; --i) { + ir_node* conds[1]; + ir_node* vals[2]; + + conds[0] = get_Psi_cond(psi, i); + vals[0] = get_Psi_val(psi, i); + vals[1] = rval; + rval = new_r_Psi( + current_ir_graph, block, 1, conds, vals, mode + ); + } + exchange(psi, rval); + return rval; } -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"); - } +static void optimise_psis(ir_node* node, void* env) +{ + if (get_irn_op(node) != op_Psi) return; +#if 1 + node = fold_psi(node); +#endif +#if 1 + node = meld_psi(node); +#endif +#if 1 + node = split_psi(node); +#endif } -void opt_if_conv(ir_graph *irg, opt_if_conv_info_t *params) + +void opt_if_conv(ir_graph *irg, const opt_if_conv_info_t *params) { - int muxes_made = 0; struct obstack obst; - phi_info_t *phi_info; - cond_info_t *cond_info; - cond_walk_info_t cwi; - - opt_if_conv_info_t *p = params ? params : &default_info; + opt_if_conv_info_t p; - if(!get_opt_if_conversion()) + if (! get_opt_if_conversion()) return; - obstack_init(&obst); - - cwi.obst = &obst; - INIT_LIST_HEAD(&cwi.cond_info_head); - INIT_LIST_HEAD(&cwi.phi_head); - - /* Init the debug stuff. */ - dbg = firm_dbg_register("firm.opt.ifconv"); -#if 0 - firm_dbg_set_mask(dbg, LEVEL_1); -#endif + /* get the parameters */ + p = (params != NULL ? *params : default_info); - /* Ensure, that the dominators are computed. */ - compute_doms(irg); + FIRM_DBG_REGISTER(dbg, "firm.opt.ifconv"); - DBG((dbg, LEVEL_1, "if conversion for irg %s(%p)\n", - get_entity_name(get_irg_entity(irg)), irg)); + DB((dbg, LEVEL_1, "Running if-conversion on %+F\n", irg)); - /* - * 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); + normalize_one_return(irg); + remove_critical_cf_edges(irg); -#if 0 - vcg_dump_conds(irg, &cwi); -#endif + compute_cdep(irg); + assure_doms(irg); - /* Process each suitable phi found. */ - list_for_each_entry(phi_info_t, phi_info, &cwi.phi_head, list) { - DBG((dbg, LEVEL_2, "phi node %n\n", phi_info->irn)); - muxes_made += check_out_phi(phi_info, p); - } + obstack_init(&obst); + irg_block_walk_graph(irg, init_block_link, NULL, &obst); + irg_walk_graph(irg, collect_phis, NULL, NULL); + irg_block_walk_graph(irg, NULL, if_conv_walker, &p); - list_for_each_entry(cond_info_t, cond_info, &cwi.cond_info_head, list) { - del_set(cond_info->cond_set); - } + local_optimize_graph(irg); - DBG((dbg, LEVEL_1, "muxes made: %d\n", muxes_made)); + irg_walk_graph(irg, NULL, optimise_psis, NULL); obstack_free(&obst, NULL); + + free_dom(irg); + free_cdep(irg); }