Precise shift right result type derivation for all int32 input ranges.

src/compiler/typer.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_TYPER_H_
 #define V8_COMPILER_TYPER_H_
 
 #include "src/compiler/graph.h"
 #include "src/types.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Forward declarations.
 class LazyTypeCache;
 
 
+struct IntType {
+  int32_t min;
+  int32_t max;
+  IntType(int32_t min, int32_t max) : min(min), max(max) {}
+};
+
+IntType JSShiftRightIntType(IntType lhs, IntType rhs);
+
+
 class Typer {
  public:
   Typer(Isolate* isolate, Graph* graph, MaybeHandle<Context> context);
   ~Typer();
 
   void Run();
 
   Graph* graph() { return graph_; }
   MaybeHandle<Context> context() { return context_; }
   Zone* zone() { return graph_->zone(); }
@@ skipping 34 matching lines @@
   LazyTypeCache* cache_;
 
   DISALLOW_COPY_AND_ASSIGN(Typer);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_TYPER_H_