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OMRCFGSimplifier.cpp
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OMRCFGSimplifier.cpp
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/*******************************************************************************
* Copyright (c) 2000, 2020 IBM Corp. and others
*
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which accompanies this
* distribution and is available at http://eclipse.org/legal/epl-2.0
* or the Apache License, Version 2.0 which accompanies this distribution
* and is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License, v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
*******************************************************************************/
#include "optimizer/CFGSimplifier.hpp"
#include <algorithm>
#include <stddef.h>
#include "codegen/CodeGenerator.hpp"
#include "compile/Compilation.hpp"
#include "env/StackMemoryRegion.hpp"
#include "env/TRMemory.hpp"
#include "il/Block.hpp"
#include "il/ILOpCodes.hpp"
#include "il/ILOps.hpp"
#include "il/Node.hpp"
#include "il/Node_inlines.hpp"
#include "il/StaticSymbol.hpp"
#include "il/Symbol.hpp"
#include "il/SymbolReference.hpp"
#include "il/TreeTop.hpp"
#include "il/TreeTop_inlines.hpp"
#include "infra/Assert.hpp"
#include "infra/Cfg.hpp"
#include "infra/List.hpp"
#include "infra/CfgEdge.hpp"
#include "infra/CfgNode.hpp"
#include "optimizer/Optimization.hpp"
#include "optimizer/Optimization_inlines.hpp"
#include "optimizer/Optimizer.hpp"
#include "optimizer/TransformUtil.hpp"
#include "ras/DebugCounter.hpp"
#include "infra/Checklist.hpp"
// Set to 0 to disable the special-case pattern matching using the
// s390 condition code.
#define ALLOW_SIMPLIFY_COND_CODE_BOOLEAN_STORE 1
#define OPT_DETAILS "O^O CFG SIMPLIFICATION: "
TR::Optimization* OMR::CFGSimplifier::create(TR::OptimizationManager *manager)
{
return new (manager->allocator()) TR::CFGSimplifier(manager);
}
OMR::CFGSimplifier::CFGSimplifier(TR::OptimizationManager *manager)
: TR::Optimization(manager)
{}
int32_t OMR::CFGSimplifier::perform()
{
if (trace())
traceMsg(comp(), "Starting CFG Simplification\n");
bool anySuccess = false;
{
TR::StackMemoryRegion stackMemoryRegion(*trMemory());
_cfg = comp()->getFlowGraph();
if (_cfg != NULL)
{
for (TR::CFGNode *cfgNode = _cfg->getFirstNode(); cfgNode; cfgNode = cfgNode->getNext())
{
_block = toBlock(cfgNode);
anySuccess |= simplify();
}
}
// Any transformations invalidate use/def and value number information
//
if (anySuccess)
{
optimizer()->setUseDefInfo(NULL);
optimizer()->setValueNumberInfo(NULL);
}
} // stackMemoryRegion scope
if (trace())
{
traceMsg(comp(), "\nEnding CFG Simplification\n");
comp()->dumpMethodTrees("\nTrees after CFG Simplification\n");
}
return 1; // actual cost
}
bool OMR::CFGSimplifier::simplify()
{
// Can't simplify the entry or exit blocks
//
if (_block->getEntry() == NULL)
return false;
// Find the first two successors
//
_succ1 = _succ2 = NULL;
_next2 = NULL;
if (_block->getSuccessors().empty())
{
_next1 = NULL;
}
else
{
_succ1 = _block->getSuccessors().front();
_next1 = toBlock(_succ1->getTo());
if (_block->getSuccessors().size() > 1)
{
_succ2 = *(++(_block->getSuccessors().begin()));
_next2 = toBlock(_succ2->getTo());
}
}
return simplifyIfStructure();
}
bool OMR::CFGSimplifier::simplifyIfStructure()
{
if (trace())
traceMsg(comp(), "Attempting if simpliciaton on block_%d\n", _block->getNumber());
// There must be exactly two successors, and they must be real blocks
//
if (_next1 == NULL || _next2 == NULL)
return false;
if (_succ2 == NULL)
return false;
if (_block->getSuccessors().size() > 2)
return false;
if (_next1->getEntry() == NULL || _next2->getEntry() == NULL)
return false;
// The successors must have only this block as their predecessor, and must
// have a common successor.
//
bool needToDuplicateTree = false;
if (_next1->getPredecessors().empty())
return false;
if (!(_next1->getPredecessors().front()->getFrom() == _block && (_next1->getPredecessors().size() == 1)))
needToDuplicateTree = true;
if (_next2->getPredecessors().empty())
return false;
if (!(_next2->getPredecessors().front()->getFrom() == _block && (_next2->getPredecessors().size() == 1)))
needToDuplicateTree = true;
// This block must end in a compare-and-branch which can be converted to a
// boolean compare, or a branch using the condition code.
//
TR::TreeTop *compareTreeTop = getLastRealTreetop(_block);
TR::Node *compareNode = compareTreeTop->getNode();
if (!compareNode->getOpCode().isIf())
return false;
if (compareNode->isNopableInlineGuard())
//don't simplify nopable guards
return false;
// ... and so one of the successors must be the fall-through successor. Make
// _next1 be the fall-through successor.
//
TR::Block *b = getFallThroughBlock(_block);
if (b != _next1)
{
TR_ASSERT(b == _next2, "CFG Simplifier");
_next2 = _next1;
_next1 = b;
}
return simplifyIfPatterns(needToDuplicateTree);
}
bool OMR::CFGSimplifier::simplifyIfPatterns(bool needToDuplicateTree)
{
return simplifyBooleanStore(needToDuplicateTree)
|| simplifyNullToException(needToDuplicateTree)
|| simplifySimpleStore(needToDuplicateTree)
|| simplifyCondStoreSequence(needToDuplicateTree)
|| simplifyInstanceOfTestToCheckcast(needToDuplicateTree)
|| simplifyBoundCheckWithThrowException(needToDuplicateTree)
;
}
bool OMR::CFGSimplifier::hasExceptionPoint(TR::Block *block, TR::TreeTop *end)
{
if (!block->getExceptionSuccessors().empty())
return true;
for (TR::TreeTop *itr = block->getEntry(); itr && itr != end; itr = itr->getNextTreeTop())
{
if (itr->getNode()->exceptionsRaised() != 0)
return true;
}
return false;
}
bool OMR::CFGSimplifier::simplifyInstanceOfTestToCheckcast(bool needToDuplicateTree)
{
static char *disableSimplifyInstanceOfTestToCheckcast = feGetEnv("TR_disableSimplifyInstanceOfTestToCheckcast");
if (disableSimplifyInstanceOfTestToCheckcast != NULL)
return false;
if (comp()->getOSRMode() == TR::involuntaryOSR)
return false;
if (_block->isCatchBlock())
return false;
if (trace())
traceMsg(comp(), "Start simplifyInstanceOfTestToCheckcast block_%d\n", _block->getNumber());
// This block must end in an ifacmpeq or ifacmpne against aconst NULL
TR::TreeTop *compareTreeTop = getLastRealTreetop(_block);
TR::Node *compareNode = compareTreeTop->getNode();
if (compareNode->getOpCodeValue() != TR::ificmpeq
&& compareNode->getOpCodeValue() != TR::ificmpne)
return false;
if (trace())
traceMsg(comp(), " Found an ificmp[eq/ne] n%dn\n", compareNode->getGlobalIndex());
if (compareNode->getSecondChild()->getOpCodeValue() != TR::iconst
|| compareNode->getSecondChild()->getInt() != 0)
return false;
if (trace())
traceMsg(comp(), " Found an ificmp[eq/ne] against zero n%dn\n", compareNode->getGlobalIndex());
if (compareNode->getFirstChild()->getOpCodeValue() != TR::instanceof)
return false;
if (trace())
traceMsg(comp(), " Found an ificmp[eq/ne] of an instanceof against 0 n%dn\n", compareNode->getGlobalIndex());
if (compareNode->getFirstChild()->getSecondChild()->getOpCodeValue() != TR::loadaddr)
return false;
if (trace())
traceMsg(comp(), " Found an ificmp[eq/new] of an instanceof a constant class against zero n%dn\n", compareNode->getGlobalIndex());
TR::Block *throwBlock = NULL, *fallthroughBlock = NULL;
if (compareNode->getOpCodeValue() == TR::ificmpeq)
{
if (_next2->getLastRealTreeTop()->getNode()->getNumChildren() != 1
|| _next2->getLastRealTreeTop()->getNode()->getFirstChild()->getOpCodeValue() != TR::athrow)
return false;
if (trace())
traceMsg(comp(), " Found an ificmpeq of an instanceof against zero which throws on taken size\n");
throwBlock = _next2;
fallthroughBlock = _next1;
} else {
if (_next1->getLastRealTreeTop()->getNode()->getNumChildren() != 1
|| _next1->getLastRealTreeTop()->getNode()->getFirstChild()->getOpCodeValue() != TR::athrow)
return false;
if (trace())
traceMsg(comp(), " Found an ificmpne of an instance of against zero which throws on the fallthrough path\n");
throwBlock = _next1;
fallthroughBlock = _next2;
}
if (!performTransformation(comp(), "%sReplace ificmp of instanceof with throw failure with checkcastAndNULLCHK in block_%d\n", OPT_DETAILS, _block->getNumber()))
return false;
_cfg->invalidateStructure();
TR::Node *objNode = compareNode->getFirstChild()->getFirstChild();
TR::Node *classNode = compareNode->getFirstChild()->getSecondChild();
TR::Block *catchBlock = TR::Block::createEmptyBlock(compareNode, comp(), throwBlock->getFrequency());
catchBlock->setHandlerInfo(0, comp()->getInlineDepth(), 0, comp()->getCurrentMethod(), comp());
TR::Node *gotoNode = TR::Node::create(compareNode, TR::Goto, 0);
gotoNode->setBranchDestination(throwBlock->getEntry());
catchBlock->append(TR::TreeTop::create(comp(), gotoNode));
TR::TreeTop *lastTree = comp()->findLastTree();
catchBlock->getExit()->join(lastTree->getNextTreeTop());
lastTree->join(catchBlock->getEntry());
TR::Node *checkcastAndNULLCHKNode = TR::Node::createWithSymRef(compareNode->getFirstChild(), TR::checkcastAndNULLCHK, 2, comp()->getSymRefTab()->findOrCreateCheckCastSymbolRef(comp()->getMethodSymbol()));
TR_Pair<TR_ByteCodeInfo, TR::Node> *bcInfo = new (trHeapMemory()) TR_Pair<TR_ByteCodeInfo, TR::Node> (&compareNode->getFirstChild()->getByteCodeInfo(), checkcastAndNULLCHKNode);
comp()->getCheckcastNullChkInfo().push_front(bcInfo);
checkcastAndNULLCHKNode->setAndIncChild(0, objNode);
checkcastAndNULLCHKNode->setAndIncChild(1, classNode);
if (trace())
traceMsg(comp(), "Remove compareTreeTop n%dn\n", compareTreeTop->getNode()->getGlobalIndex());
TR::TransformUtil::removeTree(comp(), compareTreeTop);
TR::TreeTop *checkcastAndNULLCHKTree = TR::TreeTop::create(comp(), checkcastAndNULLCHKNode);
if (trace())
traceMsg(comp(), "Create checkcastAndNULLCHK Node n%dn\n", checkcastAndNULLCHKNode->getGlobalIndex());
_block->append(checkcastAndNULLCHKTree);
if (hasExceptionPoint(_block, checkcastAndNULLCHKTree))
_block = _block->split(checkcastAndNULLCHKTree, _cfg, true, false);
_cfg->addNode(catchBlock);
_cfg->addExceptionEdge(_block, catchBlock);
_cfg->addEdge(catchBlock, throwBlock);
_cfg->removeEdge(_block, throwBlock);
if (_block->getNextBlock() != fallthroughBlock) {
TR::Node *gotoNode = TR::Node::create(checkcastAndNULLCHKNode, TR::Goto, 0);
gotoNode->setBranchDestination(fallthroughBlock->getEntry());
_block->append(TR::TreeTop::create(comp(), gotoNode));
}
if (trace())
traceMsg(comp(), "End simplifyInstanceOfTestToCheckcast.\n");
TR::DebugCounter::incStaticDebugCounter(comp(), TR::DebugCounter::debugCounterName(comp(), "cfgSimpCheckcast/(%s)", comp()->signature()));
return true;
}
// Looks for one of the patterns of the form:
// Pattern-1:
// ificmplt (i, 0) --------
// | (FallThrough) |
// ificmplt (i, length) ======
// | | |
// throw <-------------- |
// |
// return <=================
//
// Pattern-2:
// ificmplt (i, 0) -----------
// | (FallThrough) |
// ificmpge (i, length) ------|
// | |
// return |
// |
// throw <------------------
//
// Pattern-3:
// ificmpge (i, 0) -----------
// | (FallThrough) |
// --> throw |
// | |
// - ificmpge (i, length) <-----
// |
// return
//
// That can be generated from the typical bound check code,
// if (i < 0 || i >= length)
// throw Exception();
// return i;
//
// Or,
// if (i>=0 && i < length)
// return i;
// throw Exception();
//
// And tries to simplify them by replacing the ifcmp[lt/ge] blocks with a BNDCHK such that it becomes
//
//
// Simplification:
// BNDCHK (i, length) ----(exp edge) ------
// | |
// return |
// |
// goto <---------------------------------
// |
// throw Exception()
// Or,
//
// Simplification:
// BNDCHK (i, length) ----(exp edge) ------
// | |
// goto ================= |
// | |
// goto <---------------------------------
// | |
// throw Exception() |
// |
// return <==============
//
// Return "true" if any transformations were made.
//
bool OMR::CFGSimplifier::simplifyBoundCheckWithThrowException(bool needToDuplicateTree)
{
static char *disableSimplifyBoundCheckWithThrowException = feGetEnv("TR_disableSimplifyBoundCheckWithThrowException");
if (disableSimplifyBoundCheckWithThrowException != NULL)
return false;
if (trace())
traceMsg(comp(), "Start simplifyBoundCheckWithThrowException\n");
TR::TreeTop * treeTop = getLastRealTreetop(_block);
if (!treeTop)
return false;
TR::Node *compareNode = treeTop->getNode();
TR::ILOpCodes opCode = compareNode->getOpCodeValue();
if (opCode != TR::ificmplt && opCode != TR::ificmpge)
{
if (trace())
traceMsg(comp(), " Abort simplifyBoundCheckWithThrowException : pattern not matched\n");
return false;
}
bool isCompareLT = opCode == TR::ificmplt;
bool patternMatched = false;
TR::Block *throwBlock = NULL;
TR::Block *nextCompareBlock = NULL;
TR::Node *firstChildBndChk = NULL;
TR::Node *secondChildBndChk = NULL;
TR::Node *firstChild = compareNode->getFirstChild();
TR::Node *secondChild = compareNode->getSecondChild();
TR::SymbolReference *firstSymRef = NULL;
if (firstChild->getOpCodeValue() == TR::iload)
{
firstSymRef = firstChild->getSymbolReference();
if (secondChild->getOpCodeValue() == TR::iconst && secondChild->getConstValue() == 0)
{
patternMatched = true;
throwBlock = isCompareLT ? compareNode->getBranchDestination()->getNode()->getBlock() : _block->getNextBlock();
nextCompareBlock = isCompareLT ? _block->getNextBlock() : compareNode->getBranchDestination()->getNode()->getBlock();
firstChildBndChk = firstChild;
}
else if (secondChild->getOpCode().isIntegralLoadVar() || secondChild->getOpCode().isLoadIndirect())
{
patternMatched = true;
throwBlock = isCompareLT ? _block->getNextBlock() : compareNode->getBranchDestination()->getNode()->getBlock();
nextCompareBlock = isCompareLT ? compareNode->getBranchDestination()->getNode()->getBlock() : _block->getNextBlock();
secondChildBndChk = secondChild;
}
}
if (!patternMatched)
return false;
if (trace())
traceMsg(comp(), " Matched with first %s in block_%d\n", isCompareLT ? "ificmplt" : "ificmpge",
_block->getNumber());
if (nextCompareBlock->getFirstRealTreeTop() != nextCompareBlock->getLastRealTreeTop())
{
if (trace())
traceMsg(comp(), " Abort simplifyBoundCheckWithThrowException : pattern not matched\n");
return false;
}
TR::Node *secondCompareNode = nextCompareBlock->getLastRealTreeTop()->getNode();
if (secondCompareNode->getOpCodeValue() != TR::ificmplt && secondCompareNode->getOpCodeValue() != TR::ificmpge)
{
if (trace())
traceMsg(comp(), " Abort simplifyBoundCheckWithThrowException : The second compare block does not contain ificmplt or ificmpge\n");
return false;
}
bool firstNodeRequiresDuplicate = false;
bool secondNodeRequiresDuplicate = false;
bool isLastBlockRetBlock = true;
patternMatched = false;
TR::Block *retBlock = NULL;
TR::Block *secondThrowBlock = NULL;
bool isSecondCompareLT = secondCompareNode->getOpCodeValue() == TR::ificmplt;
firstChild = secondCompareNode->getFirstChild();
secondChild = secondCompareNode->getSecondChild();
TR::SymbolReference *secondSymRef = NULL;
if (firstChild->getOpCodeValue() == TR::iload)
{
secondSymRef = firstChild->getSymbolReference();
if (secondChild->getOpCodeValue() == TR::iconst && secondChild->getConstValue() == 0)
{
patternMatched = true;
secondThrowBlock = isSecondCompareLT ? secondCompareNode->getBranchDestination()->getNode()->getBlock() : nextCompareBlock->getNextBlock();
retBlock = isSecondCompareLT ? nextCompareBlock->getNextBlock() : secondCompareNode->getBranchDestination()->getNode()->getBlock();
isLastBlockRetBlock = !isSecondCompareLT;
firstChildBndChk = firstChild;
firstNodeRequiresDuplicate = true;
}
else if (secondChild->getOpCode().isIntegralLoadVar() || secondChild->getOpCode().isLoadIndirect())
{
patternMatched = true;
secondThrowBlock = isSecondCompareLT ? nextCompareBlock->getNextBlock() : secondCompareNode->getBranchDestination()->getNode()->getBlock();
retBlock = isSecondCompareLT ? secondCompareNode->getBranchDestination()->getNode()->getBlock() : nextCompareBlock->getNextBlock();
isLastBlockRetBlock = isSecondCompareLT;
secondChildBndChk = secondChild;
secondNodeRequiresDuplicate = true;
}
}
if (!patternMatched || !firstChildBndChk || !secondChildBndChk || throwBlock != secondThrowBlock)
{
if (trace())
traceMsg(comp(), "Abort simplifyBoundCheckWithThrowException : %s\n", !patternMatched ? "Pattern did not matched" :
(!firstChildBndChk ? "None of the ificmp matches (param < 0) or (param >= 0)" :
(!secondChildBndChk ? "None of the ificmp matches (param < limit) or (param >= limit)" :
"Each of the branch jumps to different throw block")));
return false;
}
if (!firstSymRef || firstSymRef != secondSymRef)
{
if (trace())
traceMsg(comp(), "Abort simplifyBoundCheckWithThrowException : compare nodes uses different variables, pattern not matched\n");
return false;
}
if (trace())
traceMsg(comp(), " Matched with second %s in block_%d\n", isSecondCompareLT ? "ificmplt" : "ificmpge",
nextCompareBlock->getNumber());
TR::Node *throwNode = throwBlock->getLastRealTreeTop()->getNode();
if (throwNode->getNumChildren() < 1 || throwNode->getFirstChild()->getOpCodeValue() != TR::athrow)
{
if (trace())
traceMsg(comp(), "Abort simplifyBoundCheckWithThrowException : %s\n", throwNode->getNumChildren() < 1 ? "Expected throwNode does not contain children" :
"The throwNode does not contain throw, pattern not matched");
return false;
}
if (!performTransformation(comp(), "%sReplace %s n%dn [%p] followed by a %s n%dn [%p] that throws (block_%d) with a BNDCHK to a catch which goes to block_%d\n",
OPT_DETAILS, isCompareLT ? "ificmplt" : "ificmpge",
compareNode->getGlobalIndex(), compareNode, isSecondCompareLT ? "ificmplt" : "ificmpge",
secondCompareNode->getGlobalIndex(), secondCompareNode, throwBlock->getNumber(), throwBlock->getNumber()))
return false;
_cfg->invalidateStructure();
TR::Block *compareBlock = _block;
if (hasExceptionPoint(compareBlock, treeTop))
compareBlock = compareBlock->split(treeTop, _cfg, true, false);
TR::Node *bndChkNode = TR::Node::createWithSymRef(TR::BNDCHK, 2, 2,
secondNodeRequiresDuplicate ? secondChildBndChk->duplicateTree(true) : secondChildBndChk,
firstNodeRequiresDuplicate ? firstChildBndChk->duplicateTree(true) : firstChildBndChk,
comp()->getSymRefTab()->findOrCreateArrayBoundsCheckSymbolRef(comp()->getMethodSymbol()));
bndChkNode = compareBlock->append(TR::TreeTop::create(comp(), bndChkNode))->getNode();
TR::Block *catchBlock = TR::Block::createEmptyBlock(bndChkNode, comp(), throwBlock->getFrequency());
catchBlock->setHandlerInfo(0, comp()->getInlineDepth(), 0, comp()->getCurrentMethod(), comp());
TR::Node *gotoNode = TR::Node::create(bndChkNode, TR::Goto, 0);
gotoNode->setBranchDestination(throwBlock->getEntry());
catchBlock->append(TR::TreeTop::create(comp(), gotoNode));
TR::TreeTop *swapTree = throwBlock->getExit()->getNextTreeTop();
throwBlock->getExit()->join(catchBlock->getEntry());
catchBlock->getExit()->join(swapTree);
ncount_t replacedNodeId = compareNode->getGlobalIndex();
TR::TransformUtil::removeTree(comp(), treeTop);
if (trace())
{
traceMsg(comp(), " Replaced %s n%dn with BNDCHK n%dn\n", isCompareLT ? "ificmplt" : "ificmpge",
replacedNodeId, bndChkNode->getGlobalIndex());
traceMsg(comp(), " Added a new goto node n%dn that branches to throw block (block_%d)\n",
gotoNode->getGlobalIndex(), throwBlock->getNumber());
}
TR::Block *jmpBlock = NULL;
if (isLastBlockRetBlock)
{
jmpBlock = TR::Block::createEmptyBlock(_block->getLastRealTreeTop()->getNode(), comp(), retBlock->getFrequency());
jmpBlock->setHandlerInfo(0, comp()->getInlineDepth(), 0, comp()->getCurrentMethod(), comp());
TR::Node *jmpNode = TR::Node::create(_block->getLastRealTreeTop()->getNode(), TR::Goto, 0);
jmpNode->setBranchDestination(retBlock->getEntry());
jmpBlock->append(TR::TreeTop::create(comp(), jmpNode));
compareBlock->getExit()->join(jmpBlock->getEntry());
jmpBlock->getExit()->join(nextCompareBlock->getEntry());
if (trace())
traceMsg(comp(), " Added a new goto node n%dn that branches to return block (block_%d)\n",
jmpNode->getGlobalIndex(), retBlock->getNumber());
}
TR::TransformUtil::removeTree(comp(), nextCompareBlock->getLastRealTreeTop());
TR::TransformUtil::removeTree(comp(), nextCompareBlock->getEntry());
TR::TransformUtil::removeTree(comp(), nextCompareBlock->getExit());
if (trace())
traceMsg(comp(), " Removed %s block (block_%d) which either branches to throw block (block_%d) or normal block (block_%d)\n",
isSecondCompareLT ? "ificmplt" : "ificmpge", nextCompareBlock->getNumber(), throwBlock->getNumber(), retBlock->getNumber());
_cfg->addNode(catchBlock);
_cfg->addExceptionEdge(compareBlock, catchBlock);
_cfg->addEdge(catchBlock, throwBlock);
if (isLastBlockRetBlock)
{
_cfg->addNode(jmpBlock);
_cfg->addEdge(compareBlock, jmpBlock);
_cfg->addEdge(jmpBlock, retBlock);
}
else
{
_cfg->addEdge(compareBlock, retBlock);
}
_cfg->removeEdge(compareBlock, throwBlock);
_cfg->removeEdge(compareBlock, nextCompareBlock);
_cfg->removeEdge(nextCompareBlock, retBlock);
_cfg->removeEdge(nextCompareBlock, throwBlock);
_cfg->removeNode(nextCompareBlock);
nextCompareBlock->removeFromCFG(comp());
if (trace())
{
traceMsg(comp(), " Updated CFG\n");
traceMsg(comp(), "End simplifyBoundCheckWithThrowException\n");
}
return true;
}
static bool containsIndirectOperationImpl(TR::Node *node, TR::NodeChecklist *visited, int32_t depth)
{
if (visited->contains(node))
return false;
if (depth == 0)
return true;
visited->add(node);
if (!(node->getOpCode().isArithmetic() && !node->getOpCode().isDiv())
&& !node->getOpCode().isLoadVarDirect()
&& !node->getOpCode().isSelect()
&& !node->getOpCode().isLoadConst())
return true;
if (node->getOpCode().hasSymbolReference()
&& !node->getSymbolReference()->getSymbol()->isAutoOrParm())
return true;
for (int i = 0; i < node->getNumChildren(); ++i)
{
if (containsIndirectOperationImpl(node->getChild(i), visited, depth-1))
return true;
}
return false;
}
static bool containsIndirectOperation(TR::Compilation *comp, TR::TreeTop *treetop)
{
TR::NodeChecklist visited(comp);
return containsIndirectOperationImpl(treetop->getNode()->getFirstChild(), &visited, 3);
}
bool OMR::CFGSimplifier::simplifyCondStoreSequence(bool needToDuplicateTree)
{
static char *enableSimplifyCondStoreSequence = feGetEnv("TR_enableSimplifyCondStoreSequence");
if (enableSimplifyCondStoreSequence == NULL)
return false;
if (!(comp()->cg()->getSupportsSelect()))
return false;
if (trace())
traceMsg(comp(), "Start simplifyCondStoreSequence block_%d\n", _block->getNumber());
TR::TreeTop *compareTree = _block->getLastRealTreeTop();
TR::Node *compareNode = compareTree->getNode();
bool triangle2 = _next2->getSuccessors().size() == 1
&& _next2->getExceptionSuccessors().size() == 0
&& toBlock(_next2->getSuccessors().front()->getTo()) == _next1;
bool triangle1 = _next1->getSuccessors().size () == 1
&& _next1->getExceptionSuccessors().size() == 0
&& toBlock(_next1->getSuccessors().front()->getTo()) == _next2;
if (trace())
{
traceMsg(comp(), " block%d triangle1: %d triangle2: %d\n", _block->getNumber(), triangle1, triangle2);
}
if (!triangle1 || triangle2) { return false; }
TR::Block *toCheck = triangle1 ? _next1 : _next2;
TR::TreeTop *treeCursor = toCheck->getEntry()->getNextTreeTop();
int32_t count = 0;
while (treeCursor->getNode()->getOpCode().isStoreDirect()
&& !treeCursor->getNode()->getOpCode().isWrtBar()
&& !containsIndirectOperation(comp(), treeCursor))
{
if (treeCursor->getNode()->getFirstChild()->isInternalPointer())
return false;
if (trace())
traceMsg(comp(), " Store value is not internal pointer\n");
if (!treeCursor->getNode()->getDataType().isIntegral()
&& !treeCursor->getNode()->getDataType().isAddress())
return false;
if (trace())
traceMsg(comp(), " Store node n%dn data type checks out\n", treeCursor->getNode()->getGlobalIndex());
if (!treeCursor->getNode()->getSymbolReference()->getSymbol()->isAutoOrParm())
return false;
if (trace())
traceMsg(comp(), " Store node n%dn symRef checks out\n", treeCursor->getNode()->getGlobalIndex());
treeCursor = treeCursor->getNextTreeTop();
count++;
}
if (treeCursor->getNode()->getOpCodeValue() != TR::BBEnd || count < 2)
return false;
if (!performTransformation(comp(), "%sReplace conditional stores in block_%d with stores of appropriate select at nodes\n", OPT_DETAILS, toCheck->getNumber()))
return false;
_cfg->invalidateStructure();
TR::Node *condition = TR::Node::create(compareNode, compareNode->getOpCode().convertIfCmpToCmp(), 2,
compareNode->getFirstChild(),
compareNode->getSecondChild());
treeCursor = toCheck->getEntry()->getNextTreeTop();
while (treeCursor->getNode()->getOpCode().isStoreDirect()
&& !treeCursor->getNode()->getOpCode().isWrtBar())
{
TR::Node *storeNode = treeCursor->getNode();
TR::Node *trueValue = triangle1 ? TR::Node::createWithSymRef(comp()->il.opCodeForDirectLoad(storeNode->getDataType()), 0, storeNode->getSymbolReference()) : (needToDuplicateTree ? storeNode->getFirstChild()->duplicateTree() : storeNode->getFirstChild());
TR::Node *falseValue = triangle1 ? (needToDuplicateTree ? storeNode->getFirstChild()->duplicateTree() : storeNode->getFirstChild()) : TR::Node::createWithSymRef(comp()->il.opCodeForDirectLoad(storeNode->getDataType()), 0, storeNode->getSymbolReference());
TR::Node *select = TR::Node::create(storeNode, comp()->il.opCodeForSelect(storeNode->getDataType()), 3);
if (trace())
traceMsg(comp(), "Created select node n%dn\n", select->getGlobalIndex());
select->setAndIncChild(0, condition);
select->setAndIncChild(1, trueValue);
select->setAndIncChild(2, falseValue);
TR::TreeTop *insTree = TR::TreeTop::create(comp(), TR::Node::createWithSymRef(storeNode, storeNode->getOpCodeValue(), 1, select, storeNode->getSymbolReference()));
if (storeNode->getOpCodeValue() == TR::astore && storeNode->isHeapificationStore())
insTree->getNode()->setHeapificationStore(true);
compareTree->insertBefore(insTree);
treeCursor = treeCursor->getNextTreeTop();
}
if (triangle1) {
_cfg->removeEdge(_block, _next1);
if (_block->getNextBlock() != _next2)
{
TR::Node *gotoNode = TR::Node::create(compareNode, TR::Goto, 0);
gotoNode->setBranchDestination(_next2->getEntry());
_block->append(TR::TreeTop::create(comp(), gotoNode));
}
} else {
_cfg->removeEdge(_block, _next2);
if (_block->getNextBlock() != _next2)
{
TR::Node *gotoNode = TR::Node::create(compareNode, TR::Goto, 0);
gotoNode->setBranchDestination(_next1->getEntry());
_block->append(TR::TreeTop::create(comp(), gotoNode));
}
}
TR::TransformUtil::removeTree(comp(), compareTree);
if (trace())
traceMsg(comp(), "End simplifyCondStoreSequence.\n");
TR::DebugCounter::incStaticDebugCounter(comp(), TR::DebugCounter::debugCounterName(comp(), "cfgSimpMovSeq/%d/(%s)", count, comp()->signature()));
return true;
}
bool OMR::CFGSimplifier::simplifySimpleStore(bool needToDuplicateTree)
{
static char *enableSimplifySimpleStore = feGetEnv("TR_enableSimplifySimpleStore");
if (enableSimplifySimpleStore == NULL)
return false;
if (!(comp()->cg()->getSupportsSelect()))
return false;
if (trace())
traceMsg(comp(), "Start simplifySimpleStore block_%d\n", _block->getNumber());
TR::TreeTop *compareTree = _block->getLastRealTreeTop();
TR::Node *compareNode = compareTree->getNode();
bool triangle2 = _next2->getSuccessors().size() == 1
&& _next2->getExceptionSuccessors().size() == 0
&& toBlock(_next2->getSuccessors().front()->getTo()) == _next1;
bool triangle1 = _next1->getSuccessors().size () == 1
&& _next1->getExceptionSuccessors().size() == 0
&& toBlock(_next1->getSuccessors().front()->getTo()) == _next2;
bool diamond = _next2->getSuccessors().size() == 1
&& _next2->getExceptionSuccessors().size() == 0
&& _next1->getSuccessors().size() == 1
&& _next1->getExceptionSuccessors().size() == 0
&& toBlock(_next1->getSuccessors().front()->getTo()) == toBlock(_next2->getSuccessors().front()->getTo());
if (trace())
{
traceMsg(comp(), " block%d triangle1: %d triangle2: %d diamond: %d\n", _block->getNumber(), triangle1, triangle2, diamond);
}
static char *disableSimplifySimpleStoreTriangle = feGetEnv("TR_disableSimplifySimpleStoreTriangle");
if ((triangle1 || triangle2) && disableSimplifySimpleStoreTriangle != NULL)
return false;
static char *disableSimplifySimpleStoreDiamond = feGetEnv("TR_disableSimplifySimpleStoreDiamond");
if ((diamond) && disableSimplifySimpleStoreDiamond != NULL)
return false;
if (!triangle1 && !triangle2 && !diamond)
return false;
if (trace())
traceMsg(comp(), " compareTree has correctType\n");
TR::TreeTop *treeCursor = NULL;
TR::Node *trueValue = NULL, *falseValue = NULL, *storeNode = NULL;
bool isHeapificationStore = false;
if (triangle2 || diamond)
{
treeCursor =_next2->getEntry()->getNextTreeTop();
if (!treeCursor->getNode()->getOpCode().isStoreDirect()
|| treeCursor->getNode()->getOpCode().isWrtBar()
|| containsIndirectOperation(comp(), treeCursor))
return false;
if (trace())
traceMsg(comp(), " Take side has an appropriate store as the first tree\n");
trueValue = treeCursor->getNode()->getFirstChild();
if (treeCursor->getNode()->getFirstChild()->isInternalPointer())
return false;
if (trace())
traceMsg(comp(), " Value on taken side is not internal pointer\n");
storeNode = treeCursor->getNode();
isHeapificationStore = storeNode->getOpCodeValue() == TR::astore && storeNode->isHeapificationStore();
if (treeCursor->getNextTreeTop()->getNode()->getOpCodeValue() != TR::BBEnd
&& treeCursor->getNextTreeTop()->getNode()->getOpCodeValue() != TR::Goto)
return false;
trueValue = treeCursor->getNode()->getFirstChild();
if (trace())
traceMsg(comp(), " Taken side checks out\n");
}
if (triangle1 || diamond)
{
treeCursor = _next1->getEntry()->getNextTreeTop();
if (!treeCursor->getNode()->getOpCode().isStoreDirect()
|| treeCursor->getNode()->getOpCode().isWrtBar()
|| containsIndirectOperation(comp(), treeCursor))
return false;
if (trace())
traceMsg(comp(), " Fallthrough side has an appropriate store as the first tree\n");
if (treeCursor->getNode()->getFirstChild()->isInternalPointer())
return false;
if (trace())
traceMsg(comp(), " Value on fallthrough side is not internal pointer\n");
if (storeNode != NULL
&& treeCursor->getNode()->getSymbolReference()->getReferenceNumber() != storeNode->getSymbolReference()->getReferenceNumber())
return false;
storeNode = treeCursor->getNode();
isHeapificationStore = storeNode->getOpCodeValue() == TR::astore && ((diamond && isHeapificationStore && storeNode->isHeapificationStore()) || (!diamond && storeNode->isHeapificationStore()));
if (trace())
traceMsg(comp(), " Fallthrough side is storing to the same symeref\n");
traceMsg(comp(), "Next tree n%dn\n", treeCursor->getNextTreeTop()->getNode()->getGlobalIndex());
if (treeCursor->getNextTreeTop()->getNode()->getOpCodeValue() != TR::BBEnd
&& treeCursor->getNextTreeTop()->getNode()->getOpCodeValue() != TR::Goto)
return false;
falseValue = treeCursor->getNode()->getFirstChild();
if (trace())
traceMsg(comp(), " Fallthrough checks out\n");
}
if (!storeNode->getDataType().isIntegral()
&& !storeNode->getDataType().isAddress())
return false;
if (trace())
traceMsg(comp(), " StoreNode data type checks out\n");
if (!diamond && !storeNode->getSymbolReference()->getSymbol()->isAutoOrParm())
return false;
if (trace())
traceMsg(comp(), " StoreNode symRef checks out\n");
if (!performTransformation(comp(), "%sReplace conditional store with store of an appropriate select at node [%p]\n", OPT_DETAILS, compareNode))
return false;
_cfg->invalidateStructure();
TR::Node *select = TR::Node::create(storeNode, comp()->il.opCodeForSelect(storeNode->getDataType()), 3);
select->setAndIncChild(0,
TR::Node::create(compareNode, compareNode->getOpCode().convertIfCmpToCmp(), 2,
compareNode->getFirstChild(),
compareNode->getSecondChild()));
select->setAndIncChild(1,
trueValue ? (needToDuplicateTree ? trueValue->duplicateTree() : trueValue) : TR::Node::createWithSymRef(comp()->il.opCodeForDirectLoad(storeNode->getDataType()), 0, storeNode->getSymbolReference()));
select->setAndIncChild(2,
falseValue ? (needToDuplicateTree? falseValue->duplicateTree() : falseValue) : TR::Node::createWithSymRef(comp()->il.opCodeForDirectLoad(storeNode->getDataType()), 0, storeNode->getSymbolReference()));
TR::TreeTop *cmov = TR::TreeTop::create(comp(), TR::Node::createWithSymRef(storeNode, storeNode->getOpCodeValue(), 1, select, storeNode->getSymbolReference()));
compareTree->insertBefore(cmov);
if (isHeapificationStore)
cmov->getNode()->setHeapificationStore(true);
if (trace())
traceMsg(comp(), "End simplifySimpleStore. New select node is n%dn\n", select->getGlobalIndex());
TR::Block *dest;
if (diamond) {
dest = toBlock(_next1->getSuccessors().front()->getTo());
_cfg->addEdge(_block, dest);
_cfg->removeEdge(_block, _next1);
_cfg->removeEdge(_block, _next2);
} else if (triangle2) {
dest = _next1;
_cfg->removeEdge(_block, _next2);
} else if (triangle1) {
dest = _next2;
_cfg->removeEdge(_block, _next1);
}
if (_block->getNextBlock() != dest)
{
TR::Node *gotoNode = TR::Node::create(compareNode, TR::Goto, 0);
gotoNode->setBranchDestination(dest->getEntry());
_block->append(TR::TreeTop::create(comp(), gotoNode));
}
TR::TransformUtil::removeTree(comp(), compareTree);
TR::DebugCounter::incStaticDebugCounter(comp(), TR::DebugCounter::debugCounterName(comp(), "cfgSimpCMOV/%s/(%s)", (diamond ? "diamond" : (triangle1 ? "triangle1" : "triangle2")), comp()->signature()));
return true;
}
bool OMR::CFGSimplifier::simplifyNullToException(bool needToDuplicateTree)
{
static char *disableSimplifyExplicitNULLTest = feGetEnv("TR_disableSimplifyExplicitNULLTest");
static char *disableSimplifyNullToException = feGetEnv("TR_disableSimplifyNullToException");
if (disableSimplifyExplicitNULLTest != NULL || disableSimplifyNullToException != NULL)
return false;
if (comp()->getOSRMode() == TR::involuntaryOSR)
return false;
if (trace())
traceMsg(comp(), "Start simplifyNullToException\n");
// This block must end in an ifacmpeq or ifacmpne against aconst NULL
TR::TreeTop *compareTreeTop = getLastRealTreetop(_block);
TR::Node *compareNode = compareTreeTop->getNode();
if (compareNode->getOpCodeValue() != TR::ifacmpeq
&& compareNode->getOpCodeValue() != TR::ifacmpne)
return false;
if (trace())
traceMsg(comp(), " Found an ifacmp[eq/ne] n%dn\n", compareNode->getGlobalIndex());
if (compareNode->getSecondChild()->getOpCodeValue() != TR::aconst
|| compareNode->getSecondChild()->getAddress() != 0)
return false;
// _next1 is fall through so grab the block where the value is NULL
TR::Block *nullBlock = compareNode->getOpCodeValue() == TR::ifacmpeq ? _next2 : _next1;
if (trace())
traceMsg(comp(), " Matched nullBlock %d\n", nullBlock->getNumber());
// we want code sequence ending in a throw (any throw will do)
TR::Node *lastRootNode = nullBlock->getLastRealTreeTop()->getNode();
if (lastRootNode->getNumChildren() < 1
|| lastRootNode->getFirstChild()->getOpCodeValue() != TR::athrow)
return false;
if (!performTransformation(comp(), "%sReplace ifacmpeq/ifacmpne of NULL node n%dn [%p] to a blcok ending in throw with a NULLCHK to a catch which goes to block_%d\n", OPT_DETAILS, compareNode->getGlobalIndex(), compareNode, nullBlock->getNumber()))
return false;