UNREACHABLE();
}
+
+ZoneList<Expression*>* VarUseMap::Lookup(Variable* var) {
+ HashMap::Entry* entry = HashMap::Lookup(var, var->name()->Hash(), true);
+ if (entry->value == NULL) {
+ entry->value = new ZoneList<Expression*>(1);
+ }
+ return reinterpret_cast<ZoneList<Expression*>*>(entry->value);
+}
+
+
+void LivenessAnalyzer::Analyze(FunctionLiteral* fun) {
+ // Process the function body.
+ VisitStatements(fun->body());
+
+ // All variables are implicitly defined at the function start.
+ // Record a definition of all variables live at function entry.
+ for (HashMap::Entry* p = live_vars_.Start();
+ p != NULL;
+ p = live_vars_.Next(p)) {
+ Variable* var = reinterpret_cast<Variable*>(p->key);
+ RecordDef(var, fun);
+ }
+}
+
+
+void LivenessAnalyzer::VisitStatements(ZoneList<Statement*>* stmts) {
+ // Visit statements right-to-left.
+ for (int i = stmts->length() - 1; i >= 0; i--) {
+ Visit(stmts->at(i));
+ }
+}
+
+
+void LivenessAnalyzer::RecordUse(Variable* var, Expression* expr) {
+ ASSERT(var->is_global() || var->is_this());
+ ZoneList<Expression*>* uses = live_vars_.Lookup(var);
+ uses->Add(expr);
+}
+
+
+void LivenessAnalyzer::RecordDef(Variable* var, Expression* expr) {
+ ASSERT(var->is_global() || var->is_this());
+
+ // We do not support other expressions that can define variables.
+ ASSERT(expr->AsFunctionLiteral() != NULL);
+
+ // Add the variable to the list of defined variables.
+ if (expr->defined_vars() == NULL) {
+ expr->set_defined_vars(new ZoneList<DefinitionInfo*>(1));
+ }
+ DefinitionInfo* def = new DefinitionInfo();
+ expr->AsFunctionLiteral()->defined_vars()->Add(def);
+
+ // Compute the last use of the definition. The variable uses are
+ // inserted in reversed evaluation order. The first element
+ // in the list of live uses is the last use.
+ ZoneList<Expression*>* uses = live_vars_.Lookup(var);
+ while (uses->length() > 0) {
+ Expression* use_site = uses->RemoveLast();
+ use_site->set_var_def(def);
+ if (uses->length() == 0) {
+ def->set_last_use(use_site);
+ }
+ }
+}
+
+
+// Visitor functions for live variable analysis.
+void LivenessAnalyzer::VisitDeclaration(Declaration* decl) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitBlock(Block* stmt) {
+ VisitStatements(stmt->statements());
+}
+
+
+void LivenessAnalyzer::VisitExpressionStatement(
+ ExpressionStatement* stmt) {
+ Visit(stmt->expression());
+}
+
+
+void LivenessAnalyzer::VisitEmptyStatement(EmptyStatement* stmt) {
+ // Do nothing.
+}
+
+
+void LivenessAnalyzer::VisitIfStatement(IfStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitContinueStatement(ContinueStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitBreakStatement(BreakStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitReturnStatement(ReturnStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitWithEnterStatement(
+ WithEnterStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitWithExitStatement(WithExitStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitSwitchStatement(SwitchStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitDoWhileStatement(DoWhileStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitWhileStatement(WhileStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitForStatement(ForStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitForInStatement(ForInStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitTryCatchStatement(TryCatchStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitTryFinallyStatement(
+ TryFinallyStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitDebuggerStatement(
+ DebuggerStatement* stmt) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitFunctionLiteral(FunctionLiteral* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitFunctionBoilerplateLiteral(
+ FunctionBoilerplateLiteral* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitConditional(Conditional* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitSlot(Slot* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitVariableProxy(VariableProxy* expr) {
+ Variable* var = expr->var();
+ ASSERT(var->is_global());
+ ASSERT(!var->is_this());
+ RecordUse(var, expr);
+}
+
+
+void LivenessAnalyzer::VisitLiteral(Literal* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitRegExpLiteral(RegExpLiteral* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitObjectLiteral(ObjectLiteral* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitArrayLiteral(ArrayLiteral* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitCatchExtensionObject(
+ CatchExtensionObject* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitAssignment(Assignment* expr) {
+ Property* prop = expr->target()->AsProperty();
+ ASSERT(prop != NULL);
+ ASSERT(prop->key()->IsPropertyName());
+ VariableProxy* proxy = prop->obj()->AsVariableProxy();
+ ASSERT(proxy != NULL && proxy->var()->is_this());
+
+ // Record use of this at the assignment node. Assignments to
+ // this-properties are treated like unary operations.
+ RecordUse(proxy->var(), expr);
+
+ // Visit right-hand side.
+ Visit(expr->value());
+}
+
+
+void LivenessAnalyzer::VisitThrow(Throw* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitProperty(Property* expr) {
+ ASSERT(expr->key()->IsPropertyName());
+ VariableProxy* proxy = expr->obj()->AsVariableProxy();
+ ASSERT(proxy != NULL && proxy->var()->is_this());
+ RecordUse(proxy->var(), expr);
+}
+
+
+void LivenessAnalyzer::VisitCall(Call* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitCallNew(CallNew* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitCallRuntime(CallRuntime* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitUnaryOperation(UnaryOperation* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitCountOperation(CountOperation* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitBinaryOperation(BinaryOperation* expr) {
+ // Visit child nodes in reverse evaluation order.
+ Visit(expr->right());
+ Visit(expr->left());
+}
+
+
+void LivenessAnalyzer::VisitCompareOperation(CompareOperation* expr) {
+ UNREACHABLE();
+}
+
+
+void LivenessAnalyzer::VisitThisFunction(ThisFunction* expr) {
+ UNREACHABLE();
+}
+
+
} } // namespace v8::internal
};
+class VarUseMap : public HashMap {
+ public:
+ VarUseMap() : HashMap(VarMatch) {}
+
+ ZoneList<Expression*>* Lookup(Variable* var);
+
+ private:
+ static bool VarMatch(void* key1, void* key2) { return key1 == key2; }
+};
+
+
+class DefinitionInfo : public ZoneObject {
+ public:
+ explicit DefinitionInfo() : last_use_(NULL) {}
+
+ Expression* last_use() { return last_use_; }
+ void set_last_use(Expression* expr) { last_use_ = expr; }
+
+ private:
+ Expression* last_use_;
+ Register location_;
+};
+
+
+class LivenessAnalyzer : public AstVisitor {
+ public:
+ LivenessAnalyzer() {}
+
+ void Analyze(FunctionLiteral* fun);
+
+ private:
+ void VisitStatements(ZoneList<Statement*>* stmts);
+
+ void RecordUse(Variable* var, Expression* expr);
+ void RecordDef(Variable* var, Expression* expr);
+
+
+ // AST node visit functions.
+#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
+ AST_NODE_LIST(DECLARE_VISIT)
+#undef DECLARE_VISIT
+
+ // Map for tracking the live variables.
+ VarUseMap live_vars_;
+
+ DISALLOW_COPY_AND_ASSIGN(LivenessAnalyzer);
+};
+
+
} } // namespace v8::internal
+
#endif // V8_DATAFLOW_H_
AstLabeler labeler;
labeler.Label(info);
+ LivenessAnalyzer analyzer;
+ analyzer.Analyze(info->function());
+
CodeGenerator::MakeCodePrologue(info);
const int kInitialBufferSize = 4 * KB;
Comment cmnt(masm(), ";; Global");
if (FLAG_print_ir) {
SmartPointer<char> name = expr->name()->ToCString();
- PrintF("%d: t%d = Global(%s)\n", expr->num(), expr->num(), *name);
+ PrintF("%d: t%d = Global(%s) // last_use = %d\n", expr->num(),
+ expr->num(), *name, expr->var_def()->last_use()->num());
}
EmitGlobalVariableLoad(cell);
}
SmartPointer<char> name_string = name->ToCString();
PrintF("%d: ", expr->num());
if (!destination().is(no_reg)) PrintF("t%d = ", expr->num());
- PrintF("Store(this, \"%s\", t%d)\n", *name_string, expr->value()->num());
+ PrintF("Store(this, \"%s\", t%d) // last_use(this) = %d\n", *name_string,
+ expr->value()->num(),
+ expr->var_def()->last_use()->num());
}
EmitThisPropertyStore(name);
Comment cmnt(masm(), ";; Load from this");
if (FLAG_print_ir) {
SmartPointer<char> name_string = name->ToCString();
- PrintF("%d: t%d = Load(this, \"%s\")\n",
- expr->num(), expr->num(), *name_string);
+ PrintF("%d: t%d = Load(this, \"%s\") // last_use(this) = %d\n",
+ expr->num(), expr->num(), *name_string,
+ expr->var_def()->last_use()->num());
}
EmitThisPropertyLoad(name);
}
--- /dev/null
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * 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.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "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 THE COPYRIGHT
+// OWNER 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.
+
+// Flags: --fast-compiler
+
+var a = 1;
+var b = 2;
+var c = 4;
+
+function f() { this.x = this.x | a | b | c | a | c; }
+
+var o = {x:0, g:f}
+
+o.g();
+
+assertEquals(7, o.x);
projects / platform / upstream / v8.git / commitdiff