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fornode.cc Go to the documentation of this file. // $Id: fornode.cc,v 1.3 2003/08/07 23:13:04 pnav Exp $ // ---------------------------------------------------------------------- // // C-Breeze // C Compiler Framework // // Copyright (c) 2000 University of Texas at Austin // // Samuel Z. Guyer // Daniel A. Jimenez // Calvin Lin // // Permission is hereby granted, free of charge, to any person // obtaining a copy of this software and associated documentation // files (the "Software"), to deal in the Software without // restriction, including without limitation the rights to use, copy, // modify, merge, publish, distribute, sublicense, and/or sell copies // of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be // included in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND // NONINFRINGEMENT. IN NO EVENT SHALL THE UNIVERSITY OF TEXAS AT // AUSTIN BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF // OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. // // We acknowledge the C-to-C Translator from MIT Laboratory for // Computer Science for inspiring parts of the C-Breeze design. // // ---------------------------------------------------------------------- #include "c_breeze.h" // -------------------------------------------------------------------- // Constructors // -------------------------------------------------------------------- forNode::forNode(exprNode * init, exprNode * cond, exprNode * next, stmtNode * body, const Coord coord) : loopNode(For, cond, body, coord), _init(init), _next(next) {} // ------------------------------------------------------------ // Walker // ------------------------------------------------------------ void forNode::visit(Visitor * the_visitor) { the_visitor->at_for(this); } void forNode::walk(Walker & the_walker) { Walker::Order ord = the_walker.order(); if (ord == Walker::Preorder || ord == Walker::Both) the_walker.at_for(this, Walker::Preorder); if (the_walker.depth() == Walker::Subtree) { // -- Visit the children if (init()) init()->walk(the_walker); if (cond()) cond()->walk(the_walker); if (next()) next()->walk(the_walker); if (body()) body()->walk(the_walker); } if (ord == Walker::Postorder || ord == Walker::Both) the_walker.at_for(this, Walker::Postorder); } // ------------------------------------------------------------ // Dataflow // ------------------------------------------------------------ void forNode::dataflow(FlowVal * v, FlowProblem & fp) { if (fp.forward()) { fp.flow_for(v, this, FlowProblem::Entry); if (init()) if (fp.basicblocks()) { fp.flow_basicblock(v, init(), FlowProblem::Entry); fp.flow_basicblock(v, init(), FlowProblem::Exit); } else init()->dataflow(v, fp); // -- Get the values from the previous loop iteration v->meet(at_loop_head()); if (cond()) if (fp.basicblocks()) { fp.flow_basicblock(v, cond(), FlowProblem::Entry); fp.flow_basicblock(v, cond(), FlowProblem::Exit); } else cond()->dataflow(v, fp); // -- Dataflow the loop body (collect break values in at_exit and // continue values in at_loop_tail) FlowVal * bv = v->clone(); if (body()) body()->dataflow(bv, fp); // -- Get the collected continue values bv->meet(at_loop_tail()); if (next()) if (fp.basicblocks()) { fp.flow_basicblock(v, next(), FlowProblem::Entry); fp.flow_basicblock(v, next(), FlowProblem::Exit); } else next()->dataflow(v, fp); // -- Transfer values at the end of the loop to the loop head at_loop_head()->meet_and_diff(bv, fp); delete bv; // -- If there is no condition, then flow cannot go directly from // the cond to the exit. if (! cond()) v->to_top(); // -- Get the collected break values v->meet(at_exit()); fp.flow_for(v, this, FlowProblem::Exit); } else { fp.flow_for(v, this, FlowProblem::Exit); // -- at_exit holds the values need by breaks at_exit()->meet_and_diff(v, fp); // -- Dataflow the loop FlowVal * bv = at_loop_head()->clone(); if (next()) if (fp.basicblocks()) { fp.flow_basicblock(v, next(), FlowProblem::Exit); fp.flow_basicblock(v, next(), FlowProblem::Entry); } else next()->dataflow(v, fp); // -- Save the loop_tail values needed by continue and break at_loop_tail()->meet_and_diff(bv, fp); // -- Dataflow the body (breaks and continues read values from // at_exit and at_loop_end, respectively). if (body()) body()->dataflow(bv, fp); // -- If there is no condition, then flow cannot go directly from // the cond to the exit. if (! cond()) v->to_top(); // -- Merge in the loop body values v->meet(bv); delete bv; if (cond()) if (fp.basicblocks()) { fp.flow_basicblock(v, cond(), FlowProblem::Exit); fp.flow_basicblock(v, cond(), FlowProblem::Entry); } else cond()->dataflow(v, fp); // -- Save the values for the next loop iteration at_loop_head()->meet_and_diff(v, fp); if (init()) if (fp.basicblocks()) { fp.flow_basicblock(v, init(), FlowProblem::Exit); fp.flow_basicblock(v, init(), FlowProblem::Entry); } else init()->dataflow(v, fp); fp.flow_for(v, this, FlowProblem::Entry); } } // ------------------------------------------------------------ // Output // ------------------------------------------------------------ void forNode::output_stmt(output_context & ct, Node * parent) { ct << "for " << '('; if (init()) init()->output(ct, this); ct.space(); ct << ';'; ct.space(); if (cond()) cond()->output(ct, this); ct.space(); ct << ';'; ct.space(); if (next()) next()->output(ct, this); ct.space(); ct << ')'; ct.space(); if (body()) body()->output(ct, this); else ct << ';'; } // ------------------------------------------------------------ // Changer // ------------------------------------------------------------ Node * forNode::change(Changer & the_changer, bool redispatch) { Changer::Order ord = the_changer.order(); forNode * the_for = this; if ((ord == Changer::Preorder || ord == Changer::Both) && ! redispatch) the_for = (forNode *) the_changer.at_for(the_for, Changer::Preorder); if (the_for) { if (the_for != this) return the_for->change(the_changer, true); exprNode * old_init = the_for->init(); if (old_init) { exprNode * new_init = (exprNode *) old_init->change(the_changer); if (old_init != new_init) { //if (the_changer.delete_old()) //delete old_init; the_for->init(new_init); } } exprNode * old_cond = the_for->cond(); if (old_cond) { exprNode * new_cond = (exprNode *) old_cond->change(the_changer); if (old_cond != new_cond) { //if (the_changer.delete_old()) //delete old_cond; the_for->cond(new_cond); } } exprNode * old_next = the_for->next(); if (old_next) { exprNode * new_next = (exprNode *) old_next->change(the_changer); if (old_next != new_next) { //if (the_changer.delete_old()) //delete old_next; the_for->next(new_next); } } blockNode * old_body = the_for->body(); if (old_body) { blockNode * new_body = (blockNode *) old_body->change(the_changer); if (old_body != new_body) { //if (the_changer.delete_old()) //delete old_body; the_for->body(new_body); } } } if ((ord == Changer::Postorder || ord == Changer::Both) && ! redispatch) the_for = (forNode *) the_changer.at_for(the_for, Changer::Postorder); return the_for; } // ------------------------------------------------------------ // Destructor // ------------------------------------------------------------ forNode::~forNode() { //delete _init; //delete _next; }

Generated on August 27, 2003
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