[turbofan] Add liveness analysis to the BytecodeGraphBuilder.

This is analogous to the variable liveness analysis we do in the AstGraphBuilder, but on the bytecode registers.

BUG=

Review-Url: https://codereview.chromium.org/2307863002
Cr-Commit-Position: refs/heads/master@{#39248}

src/compiler/bytecode-graph-builder.h

@@ -8,6 +8,8 @@
 #include "src/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/bytecode-loop-analysis.h"
 #include "src/compiler/js-graph.h"
+#include "src/compiler/liveness-analyzer.h"
+#include "src/compiler/state-values-utils.h"
 #include "src/compiler/type-hint-analyzer.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-flags.h"
@@ -115,6 +117,10 @@ class BytecodeGraphBuilder {
                                     interpreter::Register first_arg,
                                     size_t arity);
 
+  // Computes register liveness and replaces dead ones in frame states with the
+  // undefined values.
+  void ClearNonLiveSlotsInFrameStates();
+
   void BuildCreateLiteral(const Operator* op);
   void BuildCreateArguments(CreateArgumentsType type);
   Node* BuildLoadContextSlot();
@@ -231,6 +237,12 @@ class BytecodeGraphBuilder {
     loop_analysis_ = loop_analysis;
   }
 
+  LivenessAnalyzer* liveness_analyzer() { return &liveness_analyzer_; }
+
+  bool IsLivenessAnalysisEnabled() const {
+    return this->is_liveness_analysis_enabled_;
+  }
+
 #define DECLARE_VISIT_BYTECODE(name, ...) void Visit##name();
   BYTECODE_LIST(DECLARE_VISIT_BYTECODE)
 #undef DECLARE_VISIT_BYTECODE
@@ -268,6 +280,13 @@ class BytecodeGraphBuilder {
   // Control nodes that exit the function body.
   ZoneVector<Node*> exit_controls_;
 
+  bool const is_liveness_analysis_enabled_;
+
+  StateValuesCache state_values_cache_;
+
+  // Analyzer of register liveness.
+  LivenessAnalyzer liveness_analyzer_;
+
   static int const kBinaryOperationHintIndex = 1;
   static int const kCountOperationHintIndex = 0;
   static int const kBinaryOperationSmiHintIndex = 2;

test/cctest/cctest.status

@@ -482,11 +482,6 @@
   # BUG(4751). Flaky with Ignition.
   'test-cpu-profiler/JsNativeJsSample': [SKIP],
 
-  # TODO(bmeurer): TurboFan embeds strong references to all kinds of objects
-  # via deoptimization data (Crankshaft also does this, but lack proper test
-  # coverage).
-  'test-heap/ObjectsInOptimizedCodeAreWeak': [FAIL],
-
   # TurboFan cpu profiler result is different.
   'test-cpu-profiler/DeoptAtFirstLevelInlinedSource': [FAIL],
   'test-cpu-profiler/DeoptAtSecondLevelInlinedSource': [FAIL],