From: Michael Beck Date: Thu, 24 Feb 2005 15:02:09 +0000 (+0000) Subject: typos fixed X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=1a38f36ddb4614591fc9162fc956b17e7e3b6d3b;p=libfirm typos fixed added more docu added hooks for statistics handle special case: both operands of a mux are identical [r5244] --- diff --git a/ir/opt/ifconv.c b/ir/opt/ifconv.c index c100a79f7..1abf8fcf6 100644 --- a/ir/opt/ifconv.c +++ b/ir/opt/ifconv.c @@ -27,6 +27,7 @@ #include "set.h" #include "bitset.h" #include "bitfiddle.h" +#include "irhooks.h" #define MAX_DEPTH 20 @@ -234,43 +235,52 @@ static opt_if_conv_info_t default_info = { static firm_dbg_module_t *dbg; /** - * A simple check for sde effects upton an opcode of a ir node. + * 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. */ static INLINE int has_side_effects(const ir_node *irn) { - opcode opc = get_irn_opcode(irn); + ir_op *op = get_irn_op(irn); - if(opc == iro_Cmp) + 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 +}; + /** - * Decdies, if a given expression and its subexpressions + * 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 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 */ static int _can_move_to(ir_node *expr, ir_node *dest_block, int depth, int max_depth) { int i, n; - int res = 1; + 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 = 0; + res = TO_DEEP; goto end; } @@ -280,34 +290,34 @@ static int _can_move_to(ir_node *expr, ir_node *dest_block, int depth, int max_d * has side effects or anything else. It is executed on each * path the destination block is reached. */ - if(block_dominates(expr_block, dest_block)) + if (block_dominates(expr_block, dest_block)) goto end; /* * We cannot move phis! */ - if(is_Phi(expr)) { - res = 0; + if (is_Phi(expr)) { + res = PHI_FOUND; goto end; } /* - * This should be superflous and could be converted into a assertion. + * 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. */ - if(!block_dominates(dest_block, expr_block)) { - res = 0; + if (! block_dominates(dest_block, expr_block)) { + res = IF_RESULT_SIDE_EFFECT; goto end; } /* * Surely, if the expression does not have a data mode, it is not - * movable. Perhaps onw should also test the floating property of + * movable. Perhaps one should also test the floating property of * the opcode/node. */ - if(has_side_effects(expr)) { - res = 0; + if (has_side_effects(expr)) { + res = IF_RESULT_SIDE_EFFECT; goto end; } @@ -316,13 +326,14 @@ static int _can_move_to(ir_node *expr, ir_node *dest_block, int depth, int max_d * 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) { + 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; + + res = _can_move_to(op, dest_block, new_depth, max_depth); + + if (res != SUCCESS) goto end; - } } end: @@ -338,17 +349,24 @@ end: * 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 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. + * @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 + */ static void move_to(ir_node *expr, ir_node *dest_block) { int i, n; @@ -358,15 +376,18 @@ static void move_to(ir_node *expr, ir_node *dest_block) * If we reached the dominator, we are done. * We will never put code through the dominator */ - if(block_dominates(expr_block, dest_block)) + if (block_dominates(expr_block, dest_block)) return; - for(i = 0, n = get_irn_arity(expr); i < n; ++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); } +/** + * return the common dominator of two blocks + */ static INLINE ir_node *common_idom(ir_node *b1, ir_node *b2) { if(block_dominates(b1, b2)) @@ -376,18 +397,17 @@ static INLINE ir_node *common_idom(ir_node *b1, ir_node *b2) else { ir_node *p; - for(p = b1; !block_dominates(p, b2); p = get_Block_idom(p)); + for (p = get_Block_idom(b1); !block_dominates(p, b2); p = get_Block_idom(p)); return p; } } - /** * 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 queueing this cond + 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; @@ -410,6 +430,9 @@ typedef struct _cond_t { } cases[2]; } cond_t; +/** + * retrieve the conditional information from a Cond node + */ static INLINE cond_t *get_cond(ir_node *irn, set *cond_set) { cond_t templ; @@ -481,15 +504,15 @@ static int cond_cmp(const void *a, const void *b, size_t size) * blocks in which phis are located. */ typedef struct _cond_info_t { - struct list_head list; /**< Used to list all of these structs per method. */ + 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. */ + 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. */ + set *cond_set; /**< A set of all dominating reachable Conds. */ } cond_info_t; /** @@ -499,7 +522,7 @@ 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 saw_switch_cond = 0; + int saw_select_cond = 0; block = get_nodes_block(irn); @@ -507,7 +530,7 @@ static void _find_conds(ir_node *irn, long visited_nr, * 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) { + if (block_dominates(dominator, block) && get_Block_block_visited(block) < visited_nr) { cond_t *res = masked_by; int i, n; @@ -526,7 +549,7 @@ static void _find_conds(ir_node *irn, long visited_nr, int is_modeb_cond = get_irn_opcode(cond) == iro_Cond && get_irn_mode(get_Cond_selector(cond)) == mode_b; - saw_switch_cond = !is_modeb_cond; + saw_select_cond = !is_modeb_cond; /* Check, if the pred of the proj is a Cond * with a Projb as selector. @@ -573,7 +596,6 @@ static void _find_conds(ir_node *irn, long visited_nr, * root list of the conf trees. */ else { - DBG((dbg, LEVEL_2, "%Ddeleting from list: %n, res: %n\n", depth, masked_by->cond, res->cond)); assert(res->cases[proj].pos < 0); list_del_init(&masked_by->list); } @@ -585,7 +607,7 @@ static void _find_conds(ir_node *irn, long visited_nr, } } - if(get_Block_block_visited(block) < visited_nr && !saw_switch_cond) { + if(get_Block_block_visited(block) < visited_nr && !saw_select_cond) { set_Block_block_visited(block, visited_nr); @@ -610,9 +632,10 @@ static void _find_conds(ir_node *irn, long visited_nr, * 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. + * + * @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) { @@ -621,7 +644,6 @@ static INLINE void find_conds(ir_node *irn, cond_info_t *ci) 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); @@ -644,7 +666,7 @@ static INLINE void find_conds(ir_node *irn, cond_info_t *ci) 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) { - int i; + 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]; @@ -660,8 +682,8 @@ static ir_node *make_mux_on_demand(ir_node *phi, ir_node *dom, cond_t *cond, 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 + * 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) { @@ -683,30 +705,61 @@ static ir_node *make_mux_on_demand(ir_node *phi, ir_node *dom, cond_t *cond, /* * Move the operands to the dominator block if the cond - * made sense. Some conds found are not suitable for making a mux + * 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])); - - *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]); + 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]); + } } + 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; } @@ -831,7 +884,7 @@ static void annotate_cond_info_post(ir_node *irn, void *data) */ list_add(&cwi->cond_info_head, &ci->list); - DBG((dbg, LEVEL_2, "searching conds at %n(%n)\n", irn, block)); + DBG((dbg, LEVEL_2, "searching conds at %n\n", irn)); /* * Fill the set with conds we find on the way from @@ -934,7 +987,7 @@ void opt_if_conv(ir_graph *irg, opt_if_conv_info_t *params) /* Init the debug stuff. */ dbg = firm_dbg_register("firm.opt.ifconv"); #if 0 - firm_dbg_set_mask(dbg, LEVEL_1 | LEVEL_2 | LEVEL_3); + firm_dbg_set_mask(dbg, LEVEL_1); #endif /* Ensure, that the dominators are computed. */