diff options
| -rw-r--r-- | src/qml/compiler/qv4ssa.cpp | 66 |
1 files changed, 58 insertions, 8 deletions
diff --git a/src/qml/compiler/qv4ssa.cpp b/src/qml/compiler/qv4ssa.cpp index f14205519d..7113dc7c26 100644 --- a/src/qml/compiler/qv4ssa.cpp +++ b/src/qml/compiler/qv4ssa.cpp @@ -409,7 +409,7 @@ class DominatorTree { typedef int BasicBlockIndex; enum { InvalidBasicBlockIndex = -1 }; - const QVector<BasicBlock *> nodes; + QVector<BasicBlock *> nodes; int N; std::vector<int> dfnum; // BasicBlock index -> dfnum std::vector<int> vertex; @@ -705,19 +705,57 @@ public: return nodes[idom[bb->index]]; } + void dumpImmediateDominators() const + { + qDebug() << "Immediate dominators for" << idom.size() << "nodes:"; + for (size_t i = 0, ei = idom.size(); i != ei; ++i) + if (idom[i] == InvalidBasicBlockIndex) + qDebug("\tnone -> L%d", int(i)); + else + qDebug("\tL%d -> L%d", idom[i], int(i)); + } + void updateImmediateDominator(BasicBlock *bb, BasicBlock *newDominator) { - idom[bb->index] = newDominator->index; + Q_ASSERT(bb->index >= 0); + + int blockIndex; + if (static_cast<std::vector<BasicBlockIndex>::size_type>(bb->index) >= idom.size()) { + // This is a new block, probably introduced by edge splitting. So, we'll have to grow + // the array before inserting the immediate dominator. + nodes.append(bb); + idom.resize(nodes.size(), InvalidBasicBlockIndex); + blockIndex = nodes.size() - 1; + } else { + blockIndex = getBlockIndex(bb); + } + + idom[blockIndex] = getBlockIndex(newDominator); } bool dominates(BasicBlock *dominator, BasicBlock *dominated) const { // The index of the basic blocks might have changed, or the nodes array might have changed, - // or the block got deleted, so get the index from our copy of the array. - return dominates(nodes.indexOf(dominator), nodes.indexOf(dominated)); + // so get the index from our copy of the array. + return dominates(getBlockIndex(dominator), getBlockIndex(dominated)); } private: + int getBlockIndex(BasicBlock *bb) const { + if (!bb) + return InvalidBasicBlockIndex; + + if (bb->index >= 0 && bb->index < nodes.size()) { + if (nodes.at(bb->index) == bb) + return bb->index; + } + + return nodes.indexOf(bb); + } + bool dominates(BasicBlockIndex dominator, BasicBlockIndex dominated) const { + // dominator can be Invalid when the dominated block has no dominator (i.e. the start node) + Q_ASSERT(dominated != InvalidBasicBlockIndex); + for (BasicBlockIndex it = dominated; it != InvalidBasicBlockIndex; it = idom[it]) { if (it == dominator) return true; @@ -2471,7 +2509,7 @@ protected: } }; -void splitCriticalEdges(Function *f) +void splitCriticalEdges(Function *f, DominatorTree &df) { for (int i = 0, ei = f->basicBlocks.size(); i != ei; ++i) { BasicBlock *bb = f->basicBlocks[i]; @@ -2518,6 +2556,9 @@ void splitCriticalEdges(Function *f) } else { Q_ASSERT(!"Unknown terminator!"); } + + // Set the immediate dominator of the new block to inBB + df.updateImmediateDominator(newBB, inBB); } } } @@ -2667,6 +2708,12 @@ public: showMeTheCode(function); schedule(function->basicBlocks.first()); +#if defined(SHOW_SSA) + qDebug() << "Block sequence:"; + foreach (BasicBlock *bb, sequence) + qDebug("\tL%d", bb->index); +#endif // SHOW_SSA + Q_ASSERT(function->basicBlocks.size() == sequence.size()); function->basicBlocks = sequence; return loopsStartEnd; @@ -3660,9 +3707,6 @@ void Optimizer::run(QQmlEnginePrivate *qmlEngine) if (!function->hasTry && !function->hasWith && !function->module->debugMode && doSSA) { // qout << "SSA for " << (function->name ? qPrintable(*function->name) : "<anonymous>") << endl; -// qout << "Starting edge splitting..." << endl; - splitCriticalEdges(function); -// showMeTheCode(function); // Calculate the dominator tree: DominatorTree df(function->basicBlocks); @@ -3690,6 +3734,11 @@ void Optimizer::run(QQmlEnginePrivate *qmlEngine) TypePropagation(defUses).run(function); // showMeTheCode(function); + // Transform the CFG into edge-split SSA. +// qout << "Starting edge splitting..." << endl; + splitCriticalEdges(function, df); +// showMeTheCode(function); + static bool doOpt = qgetenv("QV4_NO_OPT").isEmpty(); if (doOpt) { // qout << "Running SSA optimization..." << endl; @@ -3709,6 +3758,7 @@ void Optimizer::run(QQmlEnginePrivate *qmlEngine) // showMeTheCode(function); // qout << "Doing block scheduling..." << endl; +// df.dumpImmediateDominators(); startEndLoops = BlockScheduler(function, df).go(); // showMeTheCode(function); |