[turbofan] Call frequencies for JSCallFunction and JSCallConstruct.

src/compiler/ast-graph-builder.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_AST_GRAPH_BUILDER_H_
 #define V8_COMPILER_AST_GRAPH_BUILDER_H_
 
 #include "src/ast/ast.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/liveness-analyzer.h"
@@ skipping 246 matching lines @@
   Node** EnsureInputBufferSize(int size);
 
   // Named and keyed loads require a VectorSlotPair for successful lowering.
   VectorSlotPair CreateVectorSlotPair(FeedbackVectorSlot slot) const;
 
   // Determine which contexts need to be checked for extension objects that
   // might shadow the optimistic declaration of dynamic lookup variables.
   uint32_t ComputeBitsetForDynamicGlobal(Variable* variable);
   uint32_t ComputeBitsetForDynamicContext(Variable* variable);
 
+  // Computes the frequency for JSCallFunction and JSCallConstruct nodes.
+  float ComputeCallFrequency(FeedbackVectorSlot slot) const;

[Jarin, 2016/09/12 13:10:01]

Why not double?

[Benedikt Meurer, 2016/09/13 17:45:07]

Because space. float fits perfectly for the two operators (fills the 32bit gap
on 64bit architectures) and offers more than enough precision for us.

+
   // ===========================================================================
   // The following build methods all generate graph fragments and return one
   // resulting node. The operand stack height remains the same, variables and
   // other dependencies tracked by the environment might be mutated though.
 
   // Builders to create local function, script and block contexts.
   Node* BuildLocalActivationContext(Node* context);
   Node* BuildLocalFunctionContext(Scope* scope);
   Node* BuildLocalScriptContext(Scope* scope);
   Node* BuildLocalBlockContext(Scope* scope);
@@ skipping 327 matching lines @@
 
   // Prepare environment to be used as loop header.
   void PrepareForLoop(BitVector* assigned, bool is_osr = false);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_AST_GRAPH_BUILDER_H_