/* * Copyright (C) 2017 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "config.h" #include "AirFixSpillsAfterTerminals.h" #if ENABLE(B3_JIT) #include "AirBlockInsertionSet.h" #include "AirCode.h" #include "AirInsertionSet.h" #include "AirInstInlines.h" #include "AirTmpInlines.h" namespace JSC { namespace B3 { namespace Air { void fixSpillsAfterTerminals(Code& code) { // Because there may be terminals that produce values, IRC may // want to spill those terminals. It'll happen to spill it after // the terminal. If we left the graph in this state, it'd be invalid // because a terminal must be the last instruction in a block. // We fix that here. BlockInsertionSet blockInsertionSet(code); InsertionSet insertionSet(code); for (BasicBlock* block : code) { unsigned terminalIndex = block->size(); bool foundTerminal = false; while (terminalIndex--) { if (block->at(terminalIndex).isTerminal()) { foundTerminal = true; break; } } ASSERT_UNUSED(foundTerminal, foundTerminal); if (terminalIndex == block->size() - 1) continue; // There must be instructions after the terminal because it's not the last instruction. ASSERT(terminalIndex < block->size() - 1); Vector<Inst, 1> instsToMove; for (unsigned i = terminalIndex + 1; i < block->size(); i++) instsToMove.append(block->at(i)); RELEASE_ASSERT(instsToMove.size()); for (FrequentedBlock& frequentedSuccessor : block->successors()) { BasicBlock* successor = frequentedSuccessor.block(); // If successor's only predecessor is block, we can plant the spill inside // the successor. Otherwise, we must split the critical edge and create // a new block for the spill. if (successor->numPredecessors() == 1) { insertionSet.insertInsts(0, instsToMove); insertionSet.execute(successor); } else { BasicBlock* newBlock = blockInsertionSet.insertBefore(successor, successor->frequency()); for (const Inst& inst : instsToMove) newBlock->appendInst(inst); newBlock->appendInst(Inst(Jump, instsToMove.last().origin)); newBlock->successors().append(successor); frequentedSuccessor.block() = newBlock; } } block->resize(terminalIndex + 1); } if (blockInsertionSet.execute()) code.resetReachability(); } } } } // namespace JSC::B3::Air #endif // ENABLE(B3_JIT)