Convert Linkage to use MachineSignature.

src/compiler/linkage.h

Index: src/compiler/linkage.h
diff --git a/src/compiler/linkage.h b/src/compiler/linkage.h
index f0f14e3c89edcb3f2cf62f380b1cba768ac4dfe7..e742af824cee9c5f810e764b7095bec0a07e1927 100644
--- a/src/compiler/linkage.h
+++ b/src/compiler/linkage.h
@@ -18,29 +18,32 @@ namespace internal {
 namespace compiler {
 
 // Describes the location for a parameter or a return value to a call.
-// TODO(titzer): replace with Radium locations when they are ready.
 class LinkageLocation {
  public:
-  LinkageLocation(MachineType rep, int location)
-      : rep_(rep), location_(location) {}
-
-  inline MachineType representation() const { return rep_; }
+  explicit LinkageLocation(int location) : location_(location) {}
 
   static const int16_t ANY_REGISTER = 32767;
 
+  static LinkageLocation AnyRegister() { return LinkageLocation(ANY_REGISTER); }
+
  private:
   friend class CallDescriptor;
   friend class OperandGenerator;
-  MachineType rep_;
   int16_t location_;  // >= 0 implies register, otherwise stack slot.
 };
 
+typedef Signature<LinkageLocation> LocationSignature;
 
+// Describes a call to various parts of the compiler. Every call has the notion
+// of a "target", which is the first input to the call.
 class CallDescriptor FINAL : public ZoneObject {
  public:
-  // Describes whether the first parameter is a code object, a JSFunction,
-  // or an address--all of which require different machine sequences to call.
-  enum Kind { kCallCodeObject, kCallJSFunction, kCallAddress };
+  // Describes the kind of this call, which determines the target.
+  enum Kind {
+    kCallCodeObject,  // target is a Code object
+    kCallJSFunction,  // target is a JSFunction object
+    kCallAddress      // target is a machine pointer
+  };
 
   enum Flag {
     // TODO(jarin) kLazyDeoptimization and kNeedsFrameState should be unified.
@@ -52,56 +55,74 @@ class CallDescriptor FINAL : public ZoneObject {
   };
   typedef base::Flags<Flag> Flags;
 
-  CallDescriptor(Kind kind, int8_t return_count, int16_t parameter_count,
-                 int16_t input_count, LinkageLocation* locations,
-                 Operator::Properties properties,
+  CallDescriptor(Kind kind, MachineType target_type, LinkageLocation target_loc,
+                 MachineSignature* machine_sig, LocationSignature* location_sig,
+                 size_t js_param_count, Operator::Properties properties,
                  RegList callee_saved_registers, Flags flags,
                  const char* debug_name = "")
       : kind_(kind),
-        return_count_(return_count),
-        parameter_count_(parameter_count),
-        input_count_(input_count),
-        locations_(locations),
+        target_type_(target_type),
+        target_loc_(target_loc),
+        machine_sig_(machine_sig),
+        location_sig_(location_sig),
+        js_param_count_(js_param_count),
         properties_(properties),
         callee_saved_registers_(callee_saved_registers),
         flags_(flags),
-        debug_name_(debug_name) {}
+        debug_name_(debug_name) {
+    DCHECK(machine_sig->return_count() == location_sig->return_count());
+    DCHECK(machine_sig->parameter_count() == location_sig->parameter_count());
+  }
+
   // Returns the kind of this call.
   Kind kind() const { return kind_; }
 
   // Returns {true} if this descriptor is a call to a JSFunction.
   bool IsJSFunctionCall() const { return kind_ == kCallJSFunction; }
 
-  // The number of return values from this call, usually 0 or 1.
-  int ReturnCount() const { return return_count_; }
+  // The number of return values from this call.
+  size_t ReturnCount() const { return machine_sig_->return_count(); }
 
-  // The number of JavaScript parameters to this call, including receiver,
-  // but not the context.
-  int ParameterCount() const { return parameter_count_; }
+  // The number of JavaScript parameters to this call, including the receiver
+  // object.
+  size_t JSParameterCount() const { return js_param_count_; }
 
-  int InputCount() const { return input_count_; }
+  // The total number of inputs to this call, which includes the target,
+  // receiver, context, etc.
+  // TODO(titzer): this should input the framestate input too.
+  size_t InputCount() const { return 1 + machine_sig_->parameter_count(); }
 
-  int FrameStateCount() const { return NeedsFrameState() ? 1 : 0; }
+  size_t FrameStateCount() const { return NeedsFrameState() ? 1 : 0; }
 
   Flags flags() const { return flags_; }
 
   bool NeedsFrameState() const { return flags() & kNeedsFrameState; }
 
-  LinkageLocation GetReturnLocation(int index) {
-    DCHECK(index < return_count_);
-    return locations_[0 + index];  // return locations start at 0.
+  LinkageLocation GetReturnLocation(size_t index) const {
+    return location_sig_->GetReturn(index);
   }
 
-  LinkageLocation GetInputLocation(int index) {
-    DCHECK(index < input_count_ + 1);  // input_count + 1 is the context.
-    return locations_[return_count_ + index];  // inputs start after returns.
+  LinkageLocation GetInputLocation(size_t index) const {
+    if (index == 0) return target_loc_;
+    return location_sig_->GetParam(index - 1);
+  }
+
+  const MachineSignature* GetMachineSignature() const { return machine_sig_; }
+
+  MachineType GetReturnType(size_t index) const {
+    return machine_sig_->GetReturn(index);
+  }
+
+  MachineType GetInputType(size_t index) const {
+    if (index == 0) return target_type_;
+    return machine_sig_->GetParam(index - 1);
   }
 
   // Operator properties describe how this call can be optimized, if at all.
   Operator::Properties properties() const { return properties_; }
 
   // Get the callee-saved registers, if any, across this call.
-  RegList CalleeSavedRegisters() { return callee_saved_registers_; }
+  RegList CalleeSavedRegisters() const { return callee_saved_registers_; }
 
   const char* debug_name() const { return debug_name_; }
 
@@ -109,10 +130,11 @@ class CallDescriptor FINAL : public ZoneObject {
   friend class Linkage;
 
   Kind kind_;
-  int8_t return_count_;
-  int16_t parameter_count_;
-  int16_t input_count_;
-  LinkageLocation* locations_;
+  MachineType target_type_;
+  LinkageLocation target_loc_;
+  MachineSignature* machine_sig_;
+  LocationSignature* location_sig_;
+  size_t js_param_count_;
   Operator::Properties properties_;
   RegList callee_saved_registers_;
   Flags flags_;
@@ -166,13 +188,17 @@ class Linkage : public ZoneObject {
   // for the host platform. This simplified calling convention only supports
   // integers and pointers of one word size each, i.e. no floating point,
   // structs, pointers to members, etc.
-  static CallDescriptor* GetSimplifiedCDescriptor(
-      Zone* zone, int num_params, MachineType return_type,
-      const MachineType* param_types);
+  static CallDescriptor* GetSimplifiedCDescriptor(Zone* zone,
+                                                  MachineSignature* sig);
 
   // Get the location of an (incoming) parameter to this function.
   LinkageLocation GetParameterLocation(int index) {
-    return incoming_->GetInputLocation(index + 1);
+    return incoming_->GetInputLocation(index + 1);  // + 1 to skip target.
+  }
+
+  // Get the machine type of an (incoming) parameter to this function.
+  MachineType GetParameterType(int index) {
+    return incoming_->GetInputType(index + 1);  // + 1 to skip target.
   }
 
   // Get the location where this function should place its return value.
@@ -180,6 +206,9 @@ class Linkage : public ZoneObject {
     return incoming_->GetReturnLocation(0);
   }
 
+  // Get the machine type of this function's return value.
+  MachineType GetReturnType() { return incoming_->GetReturnType(0); }
+
   // Get the frame offset for a given spill slot. The location depends on the
   // calling convention and the specific frame layout, and may thus be
   // architecture-specific. Negative spill slots indicate arguments on the