X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Fircons.c;h=19d883311fa89901c8a31a32c41b8be8fc32ea1c;hb=5bc78d88ae1e64522c533088db47bebd38de3d28;hp=9299df330af08ac09da988d8af9d88b1c8e63fed;hpb=7efd3927d376d522192fab481fe61ef9070cd604;p=libfirm diff --git a/ir/ir/ircons.c b/ir/ir/ircons.c index 9299df330..19d883311 100644 --- a/ir/ir/ircons.c +++ b/ir/ir/ircons.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved. + * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved. * * This file is part of libFirm. * @@ -172,219 +172,97 @@ ir_node *new_r_ASM(ir_node *block, return new_rd_ASM(NULL, block, arity, in, inputs, n_outs, outputs, n_clobber, clobber, text); } -/* ***********************************************************************/ -/* Methods necessary for automatic Phi node creation */ -/* - ir_node *phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins) - ir_node *get_r_value_internal (ir_node *block, int pos, ir_mode *mode); - ir_node *new_rd_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode) - ir_node *new_rd_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode, ir_node **in, int ins) - - Call Graph: ( A ---> B == A "calls" B) - - get_value mature_immBlock - | | - | | - | | - | ---> phi_merge - | / / \ - | / / \ - \|/ / |/_ \ - get_r_value_internal | - | | - | | - \|/ \|/ - new_rd_Phi0 new_rd_Phi_in - -* *************************************************************************** */ - /** Creates a Phi node with 0 predecessors. */ -static inline ir_node *new_rd_Phi0(ir_node *block, ir_mode *mode) +static inline ir_node *new_rd_Phi0(dbg_info *dbgi, ir_node *block, + ir_mode *mode, int pos) { ir_graph *irg = get_irn_irg(block); - ir_node *res = new_ir_node(NULL, irg, block, op_Phi, mode, 0, NULL); + ir_node *res = new_ir_node(dbgi, irg, block, op_Phi, mode, 0, NULL); + res->attr.phi.u.pos = pos; irn_verify_irg(res, irg); return res; } -/** - * Internal constructor of a Phi node by a phi_merge operation. - * - * @param block the block in which the Phi will be constructed - * @param mode the mod eof the Phi node - * @param in the input array of the phi node - * @param n_in number of elements in the input array - * @param phi0 in non-NULL: the Phi0 node in the same block that represents - * the value for which the new Phi is constructed - */ -static ir_node *new_rd_Phi_in(ir_node *block, ir_mode *mode, - int n_in, ir_node **in, ir_node *phi0) -{ - int i; - ir_node *res, *known; - ir_graph *irg = get_irn_irg(block); - - /* Allocate a new node on the obstack. The allocation copies the in - array. */ - res = new_ir_node(NULL, irg, block, op_Phi, mode, n_in, in); - res->attr.phi.u.backedge = new_backedge_arr(irg->obst, n_in); - - /* This loop checks whether the Phi has more than one predecessor. - If so, it is a real Phi node and we break the loop. Else the - Phi node merges the same definition on several paths and therefore - is not needed. - Note: We MUST consider Bad nodes, else we might get data flow cycles in dead loops! */ - known = res; - for (i = n_in - 1; i >= 0; --i) { - assert(in[i]); - - in[i] = skip_Id(in[i]); /* increases the number of freed Phis. */ +static ir_node *get_r_value_internal(ir_node *block, int pos, ir_mode *mode); - /* Optimize self referencing Phis: We can't detect them yet properly, as - they still refer to the Phi0 they will replace. So replace right now. */ - if (phi0 && in[i] == phi0) - in[i] = res; +static void try_remove_unnecessary_phi(ir_node *phi) +{ + ir_node *phi_value = NULL; + int arity = get_irn_arity(phi); + int i; - if (in[i] == res || in[i] == known) + /* see if all inputs are either pointing to a single value or + * are self references */ + for (i = 0; i < arity; ++i) { + ir_node *in = get_irn_n(phi, i); + if (in == phi) continue; - - if (known == res) - known = in[i]; - else - break; + if (in == phi_value) + continue; + /** found a different value from the one we already found, can't remove + * the phi (yet) */ + if (phi_value != NULL) + return; + phi_value = in; } + if (phi_value == NULL) + return; - /* i < 0: there is at most one predecessor, we don't need a phi node. */ - if (i < 0) { - if (res != known) { - edges_node_deleted(res, irg); - obstack_free(irg->obst, res); - if (is_Phi(known)) { - /* If pred is a phi node we want to optimize it: If loops are matured in a bad - order, an enclosing Phi know may get superfluous. */ - res = optimize_in_place_2(known); - if (res != known) - exchange(known, res); - } - else - res = known; - } else { - /* A undefined value, e.g., in unreachable code. */ - res = new_r_Bad(irg); - } - } else { - res = optimize_node(res); /* This is necessary to add the node to the hash table for cse. */ - irn_verify_irg(res, irg); - /* Memory Phis in endless loops must be kept alive. - As we can't distinguish these easily we keep all of them alive. */ - if (is_Phi(res) && mode == mode_M) - add_End_keepalive(get_irg_end(irg), res); - } + /* if we're here then all phi inputs have been either phi_value + * or self-references, we can replace the phi by phi_value. + * We do this with an Id-node */ + exchange(phi, phi_value); - return res; + /* recursively check phi_value, because it could be that we were the last + * phi-node in a loop-body. Then our arguments is an unnecessary phi in + * the loop header which can be eliminated now */ + if (is_Phi(phi_value)) { + try_remove_unnecessary_phi(phi_value); + } } -static ir_node *get_r_value_internal(ir_node *block, int pos, ir_mode *mode); - /** * Computes the predecessors for the real phi node, and then * allocates and returns this node. The routine called to allocate the * node might optimize it away and return a real value. * This function must be called with an in-array of proper size. */ -static ir_node *phi_merge(ir_node *block, int pos, ir_mode *mode, - int n_ins, ir_node **ins) +static ir_node *set_phi_arguments(ir_node *phi, int pos) { - ir_graph *irg = get_irn_irg(block); - ir_node *prevBlock, *res, *phi0, *phi0_all; - int i; - - /* If this block has no value at pos create a Phi0 and remember it - in graph_arr to break recursions. - Else we may not set graph_arr as there a later value is remembered. */ - phi0 = NULL; - if (block->attr.block.graph_arr[pos] == NULL) { - - if (block == get_irg_start_block(irg)) { - /* Collapsing to Bad tarvals is no good idea. - So we call a user-supplied routine here that deals with this - case as appropriate for the given language. Sorrily the only - help we can give here is the position. - - Even if all variables are defined before use, it can happen that - we get to the start block, if a Cond has been replaced by a tuple - (bad, jmp). In this case we call the function needlessly, - eventually generating an non existent error. - However, this SHOULD NOT HAPPEN, as bad control flow nodes are - intercepted before recurring. - */ - if (default_initialize_local_variable != NULL) { - ir_node *rem = get_r_cur_block(irg); - - set_r_cur_block(irg, block); - block->attr.block.graph_arr[pos] = default_initialize_local_variable(irg, mode, pos - 1); - set_r_cur_block(irg, rem); - } else { - block->attr.block.graph_arr[pos] = new_r_Unknown(irg, mode); - } - return block->attr.block.graph_arr[pos]; - } else { - phi0 = new_rd_Phi0(block, mode); - block->attr.block.graph_arr[pos] = phi0; - } - } + ir_node *block = get_nodes_block(phi); + ir_graph *irg = get_irn_irg(block); + int arity = get_irn_arity(block); + ir_node **in = ALLOCAN(ir_node*, arity); + ir_mode *mode = get_irn_mode(phi); + int i; /* This loop goes to all predecessor blocks of the block the Phi node is in and there finds the operands of the Phi node by calling get_r_value_internal. */ - for (i = 1; i <= n_ins; ++i) { - ir_node *cf_pred = block->in[i]; - ir_node *prevCfOp = skip_Proj(cf_pred); - assert(prevCfOp); - if (is_Bad(prevCfOp)) { - /* In case a Cond has been optimized we would get right to the start block - with an invalid definition. */ - ins[i-1] = new_r_Bad(irg); - continue; - } - prevBlock = prevCfOp->in[0]; /* go past control flow op to prev block */ - assert(prevBlock); - if (!is_Bad(prevBlock)) { - ins[i-1] = get_r_value_internal(prevBlock, pos, mode); + for (i = 0; i < arity; ++i) { + ir_node *cfgpred = get_Block_cfgpred_block(block, i); + ir_node *value; + if (is_Bad(cfgpred)) { + value = new_r_Bad(irg); } else { - ins[i-1] = new_r_Bad(irg); + value = get_r_value_internal(cfgpred, pos, mode); } + in[i] = value; } - /* We want to pass the Phi0 node to the constructor: this finds additional - optimization possibilities. - The Phi0 node either is allocated in this function, or it comes from - a former call to get_r_value_internal(). In this case we may not yet - exchange phi0, as this is done in mature_immBlock(). */ - if (phi0 == NULL) { - phi0_all = block->attr.block.graph_arr[pos]; - if (! is_Phi0(phi0_all) || - get_irn_arity(phi0_all) != 0 || - get_nodes_block(phi0_all) != block) - phi0_all = NULL; - } else { - phi0_all = phi0; - } + phi->attr.phi.u.backedge = new_backedge_arr(irg->obst, arity); + set_irn_in(phi, arity, in); + set_irn_op(phi, op_Phi); - /* After collecting all predecessors into the array ins a new Phi node - with these predecessors is created. This constructor contains an - optimization: If all predecessors of the Phi node are identical it - returns the only operand instead of a new Phi node. */ - res = new_rd_Phi_in(block, mode, n_ins, ins, phi0_all); - - /* In case we allocated a Phi0 node at the beginning of this procedure, - we need to exchange this Phi0 with the real Phi. */ - if (phi0 != NULL) { - exchange(phi0, res); - block->attr.block.graph_arr[pos] = res; - } + irn_verify_irg(phi, irg); - return res; + /* Memory Phis in endless loops must be kept alive. + As we can't distinguish these easily we keep all of them alive. */ + if (is_Phi(phi) && mode == mode_M) + add_End_keepalive(get_irg_end(irg), phi); + + try_remove_unnecessary_phi(phi); + return phi; } /** @@ -399,82 +277,48 @@ static ir_node *phi_merge(ir_node *block, int pos, ir_mode *mode, */ static ir_node *get_r_value_internal(ir_node *block, int pos, ir_mode *mode) { - ir_node *res; - /* There are 4 cases to treat. - - 1. The block is not mature and we visit it the first time. We can not - create a proper Phi node, therefore a Phi0, i.e., a Phi without - predecessors is returned. This node is added to the linked list (block - attribute "phis") of the containing block to be completed when this block is - matured. (Completion will add a new Phi and turn the Phi0 into an Id - node.) - - 2. The value is already known in this block, graph_arr[pos] is set and we - visit the block the first time. We can return the value without - creating any new nodes. - - 3. The block is mature and we visit it the first time. A Phi node needs - to be created (phi_merge). If the Phi is not needed, as all it's - operands are the same value reaching the block through different - paths, it's optimized away and the value itself is returned. - - 4. The block is mature, and we visit it the second time. Now two - subcases are possible: - * The value was computed completely the last time we were here. This - is the case if there is no loop. We can return the proper value. - * The recursion that visited this node and set the flag did not - return yet. We are computing a value in a loop and need to - break the recursion. This case only happens if we visited - the same block with phi_merge before, which inserted a Phi0. - So we return the Phi0. - */ - - /* case 4 -- already visited. */ - if (irn_visited(block)) { - /* As phi_merge allocates a Phi0 this value is always defined. Here - is the critical difference of the two algorithms. */ - assert(block->attr.block.graph_arr[pos]); - return block->attr.block.graph_arr[pos]; - } - - /* visited the first time */ - mark_irn_visited(block); - - /* Get the local valid value */ - res = block->attr.block.graph_arr[pos]; - - /* case 2 -- If the value is actually computed, return it. */ + ir_node *res = block->attr.block.graph_arr[pos]; if (res != NULL) return res; - if (block->attr.block.is_matured) { /* case 3 */ - - /* The Phi has the same amount of ins as the corresponding block. */ - int n_in = get_irn_arity(block); - ir_node **in; - NEW_ARR_A(ir_node *, in, n_in); - - /* Phi merge collects the predecessors and then creates a node. */ - res = phi_merge(block, pos, mode, n_in, in); - } else { /* case 1 */ - /* The block is not mature, we don't know how many in's are needed. A Phi - with zero predecessors is created. Such a Phi node is called Phi0 - node. The Phi0 is then added to the list of Phi0 nodes in this block - to be matured by mature_immBlock later. - The Phi0 has to remember the pos of it's internal value. If the real - Phi is computed, pos is used to update the array with the local - values. */ - res = new_rd_Phi0(block, mode); - res->attr.phi.u.pos = pos; + /* in a matured block we can immediately determine the phi arguments */ + if (block->attr.block.is_matured) { + int arity = get_irn_arity(block); + /* no predecessors: use unknown value */ + if (arity == 0 && block == get_irg_start_block(get_irn_irg(block))) { + ir_graph *irg = get_irn_irg(block); + if (default_initialize_local_variable != NULL) { + ir_node *rem = get_r_cur_block(irg); + set_r_cur_block(irg, block); + res = default_initialize_local_variable(irg, mode, pos - 1); + set_r_cur_block(irg, rem); + } else { + res = new_r_Unknown(irg, mode); + } + /* one predecessor just use its value */ + } else if (arity == 1) { + ir_node *cfgpred = get_Block_cfgpred_block(block, 0); + if (is_Bad(cfgpred)) { + res = cfgpred; + } else { + res = get_r_value_internal(cfgpred, pos, mode); + } + /* multiple predecessors construct Phi */ + } else { + res = new_rd_Phi0(NULL, block, mode, pos); + /* enter phi0 into our variable value table to break cycles + * arising from set_phi_arguments */ + block->attr.block.graph_arr[pos] = res; + res = set_phi_arguments(res, pos); + } + } else { + /* in case of immature block we have to keep a Phi0 */ + res = new_rd_Phi0(NULL, block, mode, pos); + /* enqueue phi so we can set arguments once the block matures */ res->attr.phi.next = block->attr.block.phis; block->attr.block.phis = res; } - - assert(is_ir_node(res) && "phi_merge() failed to construct a definition"); - - /* The local valid value is available now. */ block->attr.block.graph_arr[pos] = res; - return res; } @@ -486,29 +330,31 @@ static ir_node *get_r_value_internal(ir_node *block, int pos, ir_mode *mode) */ void mature_immBlock(ir_node *block) { - int ins; - ir_node *n, **nin; - ir_node *next; + size_t n_preds; + ir_node *next; + ir_node *phi; ir_graph *irg; assert(is_Block(block)); if (get_Block_matured(block)) return; - irg = get_irn_irg(block); - ins = ARR_LEN(block->in) - 1; + irg = get_irn_irg(block); + n_preds = ARR_LEN(block->in) - 1; /* Fix block parameters */ - block->attr.block.backedge = new_backedge_arr(irg->obst, ins); - - /* An array for building the Phi nodes. */ - NEW_ARR_A(ir_node *, nin, ins); + block->attr.block.backedge = new_backedge_arr(irg->obst, n_preds); /* Traverse a chain of Phi nodes attached to this block and mature these, too. */ - for (n = block->attr.block.phis; n; n = next) { - inc_irg_visited(irg); - next = n->attr.phi.next; - exchange(n, phi_merge(block, n->attr.phi.u.pos, n->mode, ins, nin)); + for (phi = block->attr.block.phis; phi != NULL; phi = next) { + ir_node *new_value; + int pos = phi->attr.phi.u.pos; + + next = phi->attr.phi.next; + new_value = set_phi_arguments(phi, pos); + if (block->attr.block.graph_arr[pos] == phi) { + block->attr.block.graph_arr[pos] = new_value; + } } block->attr.block.is_matured = 1; @@ -611,9 +457,9 @@ ir_node *new_rd_DivRL(dbg_info *dbgi, ir_node *block, ir_node * irn_mem, ir_node in[2] = irn_right; res = new_ir_node(dbgi, irg, block, op_Div, mode_T, 3, in); - res->attr.divmod.resmode = resmode; - res->attr.divmod.no_remainder = 1; - res->attr.divmod.exc.pin_state = pin_state; + res->attr.div.resmode = resmode; + res->attr.div.no_remainder = 1; + res->attr.div.exc.pin_state = pin_state; res = optimize_node(res); irn_verify_irg(res, irg); return res; @@ -697,11 +543,13 @@ void add_immBlock_pred(ir_node *block, ir_node *jmp) void set_cur_block(ir_node *target) { + assert(target == NULL || current_ir_graph == get_irn_irg(target)); current_ir_graph->current_block = target; } void set_r_cur_block(ir_graph *irg, ir_node *target) { + assert(target == NULL || irg == get_irn_irg(target)); irg->current_block = target; } @@ -718,8 +566,6 @@ ir_node *get_cur_block(void) ir_node *get_r_value(ir_graph *irg, int pos, ir_mode *mode) { assert(get_irg_phase_state(irg) == phase_building); - inc_irg_visited(irg); - assert(pos >= 0); return get_r_value_internal(irg->current_block, pos + 1, mode); @@ -801,12 +647,13 @@ void set_value(int pos, ir_node *value) int r_find_value(ir_graph *irg, ir_node *value) { - int i; + size_t i; ir_node *bl = irg->current_block; - for (i = ARR_LEN(bl->attr.block.graph_arr) - 1; i >= 1; --i) - if (bl->attr.block.graph_arr[i] == value) + for (i = ARR_LEN(bl->attr.block.graph_arr); i > 1;) { + if (bl->attr.block.graph_arr[--i] == value) return i - 1; + } return -1; } @@ -818,7 +665,6 @@ int find_value(ir_node *value) ir_node *get_r_store(ir_graph *irg) { assert(get_irg_phase_state(irg) == phase_building); - inc_irg_visited(irg); return get_r_value_internal(irg->current_block, 0, mode_M); } @@ -870,14 +716,10 @@ void set_store(ir_node *store) set_r_store(current_ir_graph, store); } -void r_keep_alive(ir_graph *irg, ir_node *ka) -{ - add_End_keepalive(get_irg_end(irg), ka); -} - void keep_alive(ir_node *ka) { - r_keep_alive(current_ir_graph, ka); + ir_graph *irg = get_irn_irg(ka); + add_End_keepalive(get_irg_end(irg), ka); } void ir_set_uninitialized_local_variable_func( @@ -893,8 +735,8 @@ void irg_finalize_cons(ir_graph *irg) void irp_finalize_cons(void) { - int i; - for (i = get_irp_n_irgs() - 1; i >= 0; --i) { + size_t i, n; + for (i = 0, n = get_irp_n_irgs(); i < n; ++i) { irg_finalize_cons(get_irp_irg(i)); } irp->phase_state = phase_high;