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mergepoints.cc Go to the documentation of this file. // $Id: mergepoints.cc,v 1.9 2003/08/07 23:14:26 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" #include <algorithm> #include "mergepoints.h" // --- find_merge_points : Essentially, perform an interprocedural // version of dominance frontiers. Look for a dominance frontier in // the current procedure; if there is none, move up to the calling // procedure. void mergePoints::find_merge_points(basicblockLocation * where, mergepoint_list & merge_points) { basicblockLocation * cur = where; procLocation * proc_loc; procNode * cur_proc; bool found = false; // --- Move up the call stack until we find a dominance frontier while ( cur && ! found ) { // --- Check to see if the given proc has a dominance frontier entry. proc_loc = cur->proc_location(); cur_proc = proc_loc->proc(); procedureInfo * info = Procedures->lookup(cur_proc); DFPreds * dfs = info->dominance_frontiers(); basicblock_set_map_map_p p = dfs->find(cur->block()); if (p != dfs->end()) { // --- Found one: get the list of DF blocks and make sure it's // not empty. basicblock_set_map & df = (*p).second; if ( ! df.empty()) { found = true; // --- Put each entry on the list for (basicblock_set_map_p q = df.begin(); q != df.end(); ++q) { basicblockNode * bb = (*q).first; basicblock_set & preds = (*q).second; basicblockLocation * bblock = proc_loc->lookup_block(bb); merge_points.push_back(mergepoint_pair(bblock, preds)); } } } if (proc_loc->stmt_location()) cur = proc_loc->stmt_location()->block_location(); else cur = 0; } } // --- Add a block to the list of blocks that need to be merged at // the given merge point. void mergePoints::add_block_to_merge_point(mergepoint_pair & merge_point, memoryBlock * block) { basicblockLocation * merge_location = merge_point.first; // --- Look up the merge point mergepoint_map_p existing = find(merge_location); if (existing == end()) { // --- Not there; start a new entry memoryblock_set empty; pair< basicblockLocation *, memoryblock_set > new_entry(merge_location, empty); pair< mergepoint_map_p, bool > result = insert(new_entry); existing = result.first; } // --- Add the object to the list, skipping over it if it is not in // the scope of the given merge point (i.e., don't create a merge // point for a local variable outside it's potential scope). memoryblock_set & objects = (*existing).second; if (block->in_scope(merge_location)) objects.insert(block); if (pointerOptions::Verbose) cout << " - Merge " << block->name() << " at " << * merge_location << endl; } // --- Find the set of objects to be merged at a particular basic // block entry point. memoryblock_set * mergePoints::lookup_merge_point(basicblockLocation * merge_location) { if (pointerOptions::Verbose) { cout << " Lookup merge: " << *merge_location << endl; } mergepoint_map_p p = find(merge_location); if (p == end()) { if (pointerOptions::Verbose) cout << " None found." << endl; return 0; } else { if (pointerOptions::Verbose) { memoryblock_set & objects = (*p).second; for (memoryblock_set_cp q = objects.begin(); q != objects.end(); ++q) cout << " Merge: " << (*q)->name() << endl; } return &((*p).second); } } // --- Print some statistics void mergePoints::stats() { cout << "CLASS: mergePoints" << endl; cout << " Total number of merge points: " << size() << endl; }

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