X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firgmod.c;h=ec7cc6d42f517c61e06d872539c488cdcd1f4daa;hb=5f8ddee6b08c8040c0a304a347d65045c1141d52;hp=fde51ce975403cbb821b2bbaf383a9b280cacb09;hpb=efbeaff549fcc6015da255ed4d453a95937ff0fd;p=libfirm diff --git a/ir/ir/irgmod.c b/ir/ir/irgmod.c index fde51ce97..ec7cc6d42 100644 --- a/ir/ir/irgmod.c +++ b/ir/ir/irgmod.c @@ -1,3 +1,4 @@ + /* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe ** All rights reserved. ** @@ -6,275 +7,15 @@ ** irgmod: ir graph modification */ +# include "irnode_t.h" +# include "irgraph_t.h" # include "irgmod.h" -# include "iropt.h" - -/* ir_node * */ -/* arg_access (ir_mode *mode, long proj) */ -/* { */ -/* return new_r_Proj (current_ir_graph, current_ir_graph->start, */ -/* current_ir_graph->args, mode, proj); */ -/* } */ - - -/* these two functions are used in phi_merge, but defined in ircons.c */ -inline ir_node * get_r_value_internal (ir_node *block, - int pos, ir_mode *mode); -inline ir_node * new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode, - ir_node **in, int ins); - -/** This function computes the predecessors for a 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, or even a pointer - to a deallocated Phi node on top of the obstack! - This function is called with an in-array of proper size. **/ -static inline ir_node * -phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins) -{ - ir_node *prevBlock, *res; - 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 <= ins; ++i) { - assert (block->in[i]); - prevBlock = block->in[i]->in[0]; /* go past control flow op to prev block */ - assert (prevBlock); - nin[i-1] = get_r_value_internal (prevBlock, pos, mode); - } - - /* After collecting all predecessors into the array nin 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. If the value - passes two different control flow edges without being defined, and - this is the second path treated, a pointer to the node that will be - allocated for the first path (recurstion) is returned. We already - know the address of this node, as it is the next node to be allocated - and will be placed on top of the obstack. (The obstack is a _stack_!) */ - res = new_r_Phi_in (current_ir_graph, block, mode, nin, ins); - - /* Now we now the value "pos" and can enter it in the array with - all known local variables. Attention: this might be a pointer to - a node, that later will be allocated!!! See new_r_Phi_in. - If this is called in mature, after some set_value in the same block, - the proper value must not be overwritten: - The call order - get_value (makes Phi0, put's it into graph_arr) - set_value (overwrites Phi0 in graph_arr) - mature_block (upgrades Phi0, puts it again into graph_arr, overwriting - the proper value.) - fails. */ - if (!block->attr.block.graph_arr[pos]) { - block->attr.block.graph_arr[pos] = res; - } else { - // printf(" value already computed by %s\n", - // id_to_str(block->attr.block.graph_arr[pos]->op->name)); - } - - return res; -} - - -/* this function is used in get_r_value_internal, but defined in ircons.c */ -inline ir_node * new_r_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode); - - -/* This function returns the last definition of a variable. In case - this variable was last defined in a previous block, Phi nodes are - inserted. If the part of the firm graph containing the definition - is not yet constructed, a dummy Phi node is returned. */ -inline 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 (field - "link") of the containing block to be completed when this block is - matured. (Comlpletion will add a new Phi and turn the Phi0 into a 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 optimizes 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 without knowing the result yet. - There is no simple check for the second subcase. Therefore we check - for a second visit and treat all such cases as the second subcase. - Anyways, the basic situation is the same: we reached a block - on two paths without finding a definition of the value: No Phi - nodes are needed on both paths. - We return this information "Two paths, no Phi needed" by a very tricky - implementation that relies on the fact that an obstack is a stack and - will return a node with the same address on different allocations. - Look also at phi_merge and get_r_phi_in to understand this. - */ - - /* case 4 -- already visited. */ - if (block->visit == ir_visited) return NULL; - - /* visited the first time */ - block->visit = ir_visited; - - /* Get the local valid value */ - res = block->attr.block.graph_arr[pos]; - - /* case 2 -- If the value is actually computed, return it. */ - if (res) { return res;}; - - if (block->attr.block.matured) { /* case 3 */ - - /* The Phi has the same amount of ins as the corresponding block. */ - int ins = get_irn_arity(block); // ARR_LEN (block->in)-1; - ir_node **nin; - NEW_ARR_A (ir_node *, nin, ins); - - /* Phi merge collects the predecessors and then creates a node. */ - res = phi_merge (block, pos, mode, nin, ins); - - } 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. (There is also an obsolete Phi0 opcode.) The Phi0 is then added - to the list of Phi0 nodes in this block to be matured by mature_block - 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_r_Phi0 (current_ir_graph, block, mode); - res->attr.phi0_pos = pos; - res->link = block->link; - block->link = res; - } - - /* If we get here, the frontend missed a use-before-definition error */ - if (!res) { - /* Error Message */ - printf("Error: no value set\n"); - assert (mode->code >= irm_f && mode->code <= irm_p); - res = new_r_Const (current_ir_graph, block, mode, - tarval_mode_null[mode->code]); - } - - /* The local valid value is available now. */ - block->attr.block.graph_arr[pos] = res; - - return res; -} - - -/* add an adge to a jmp node */ -void -add_in_edge (ir_node *block, ir_node *jmp) -{ - if (block->attr.block.matured) { - printf("Error: Block already matured!\n"); - } - else { - assert (jmp != NULL); - ARR_APP1 (ir_node *, block->in, jmp); - } -} - - -/****************************/ -/* parameter administration */ - -/* get a value from the parameter array from the current block by its index */ -ir_node * -get_value (int pos, ir_mode *mode) -{ - ++ir_visited; - return get_r_value_internal (current_ir_graph->current_block, pos + 1, mode); -} - - -/* set a value at position pos in the parameter array from the current block */ -inline void -set_value (int pos, ir_node *value) -{ - current_ir_graph->current_block->attr.block.graph_arr[pos + 1] = value; -} - - -/* get the current store */ -inline ir_node * -get_store (void) -{ - /* GL: one could call get_value instead */ - ++ir_visited; - return get_r_value_internal (current_ir_graph->current_block, 0, mode_M); -} - - -/* set the current store */ -inline void -set_store (ir_node *store) -{ - /* GL: one could call set_value instead */ - current_ir_graph->current_block->attr.block.graph_arr[0] = store; -} - -/** Finalize a Block node, when all control flows are known. */ -/** Acceptable parameters are only Block nodes. */ -void -mature_block (ir_node *block) -{ - - int ins; - ir_node *n, **nin; - ir_node *next; - - assert (get_irn_opcode(block) == iro_Block); - - if (!get_Block_matured(block)) { - - /* turn the dynamic in-array into a static one. */ - ins = ARR_LEN (block->in)-1; - NEW_ARR_A (ir_node *, nin, ins); - - /* GL, 7.2.2000. seems to be not complete. added this: but does'nt work.* - memcpy (nin, block->in, sizeof (ir_node *) * ins); - block->in = nin; - */ - - /* Traverse a chain of Phi nodes attached to this block and mature these, too. **/ - for (n = block->link; n; n=next) { - ir_visited++; - next = n->link; - exchange (n, phi_merge (block, n->attr.phi0_pos, n->mode, nin, ins)); - } - - block->attr.block.matured = 1; - - block = optimize_in_place(block); - ir_vrfy(block); - } - -} - -/* changing the current block */ -void -switch_block (ir_node *target) -{ - current_ir_graph->current_block = target; -} - +# include "array.h" +/* Turns a node into a "useless" Tuple. The Tuple just forms a tuple + from several inputs. + This is useful if a node returning a tuple is removed, but the Projs + extracting values from the tuple are not available. */ void turn_into_tuple (ir_node *node, int arity) { @@ -283,14 +24,13 @@ turn_into_tuple (ir_node *node, int arity) if (get_irn_arity(node) == arity) { /* keep old array */ } else { - /* allocate new array, remove old one. */ - /* !!!??? free old in_array */ + /* Allocate new array, don't free old in_array, it's on the obstack. */ + ir_node *block = get_nodes_Block(node); node->in = NEW_ARR_D (ir_node *, current_ir_graph->obst, arity+1); + set_nodes_Block(node, block); } } - - /* Insert irnode `new' in place of irnode `old' Since `new' may be bigger than `old' replace `old' by an op_Id which is smaller than everything */