Land the Fan (disabled)

src/compiler/linkage.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_LINKAGE_H_
+#define V8_COMPILER_LINKAGE_H_
+
+#include "src/v8.h"
+
+#include "src/code-stubs.h"
+#include "src/compiler/frame.h"
+#include "src/compiler/machine-operator.h"
+#include "src/compiler/node.h"
+#include "src/compiler/operator.h"
+#include "src/zone.h"
+
+namespace v8 {
+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(MachineRepresentation rep, int location)
+      : rep_(rep), location_(location) {}
+
+  inline MachineRepresentation representation() const { return rep_; }
+
+  static const int16_t ANY_REGISTER = 32767;
+
+ private:
+  friend class CallDescriptor;
+  friend class OperandGenerator;
+  MachineRepresentation rep_;
+  int16_t location_;  // >= 0 implies register, otherwise stack slot.
+};
+
+
+class CallDescriptor : 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 };
+
+  enum DeoptimizationSupport { kCanDeoptimize, kCannotDeoptimize };
+
+  CallDescriptor(Kind kind, int8_t return_count, int16_t parameter_count,
+                 int16_t input_count, LinkageLocation* locations,
+                 Operator::Property properties, RegList callee_saved_registers,
+                 DeoptimizationSupport deoptimization_support,
+                 const char* debug_name = "")
+      : kind_(kind),
+        return_count_(return_count),
+        parameter_count_(parameter_count),
+        input_count_(input_count),
+        locations_(locations),
+        properties_(properties),
+        callee_saved_registers_(callee_saved_registers),
+        deoptimization_support_(deoptimization_support),
+        debug_name_(debug_name) {}
+  // 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 JavaScript parameters to this call, including receiver,
+  // but not the context.
+  int ParameterCount() const { return parameter_count_; }
+
+  int InputCount() const { return input_count_; }
+
+  bool CanLazilyDeoptimize() const {
+    return deoptimization_support_ == kCanDeoptimize;
+  }
+
+  LinkageLocation GetReturnLocation(int index) {
+    ASSERT(index < return_count_);
+    return locations_[0 + index];  // return locations start at 0.
+  }
+
+  LinkageLocation GetInputLocation(int index) {
+    ASSERT(index < input_count_ + 1);  // input_count + 1 is the context.
+    return locations_[return_count_ + index];  // inputs start after returns.
+  }
+
+  // Operator properties describe how this call can be optimized, if at all.
+  Operator::Property properties() const { return properties_; }
+
+  // Get the callee-saved registers, if any, across this call.
+  RegList CalleeSavedRegisters() { return callee_saved_registers_; }
+
+  const char* debug_name() const { return debug_name_; }
+
+ private:
+  friend class Linkage;
+
+  Kind kind_;
+  int8_t return_count_;
+  int16_t parameter_count_;
+  int16_t input_count_;
+  LinkageLocation* locations_;
+  Operator::Property properties_;
+  RegList callee_saved_registers_;
+  DeoptimizationSupport deoptimization_support_;
+  const char* debug_name_;
+};
+
+OStream& operator<<(OStream& os, const CallDescriptor& d);
+OStream& operator<<(OStream& os, const CallDescriptor::Kind& k);
+
+// Defines the linkage for a compilation, including the calling conventions
+// for incoming parameters and return value(s) as well as the outgoing calling
+// convention for any kind of call. Linkage is generally architecture-specific.
+//
+// Can be used to translate {arg_index} (i.e. index of the call node input) as
+// well as {param_index} (i.e. as stored in parameter nodes) into an operator
+// representing the architecture-specific location. The following call node
+// layouts are supported (where {n} is the number value inputs):
+//
+//                  #0          #1     #2     #3     [...]             #n
+// Call[CodeStub]   code,       arg 1, arg 2, arg 3, [...],            context
+// Call[JSFunction] function,   rcvr,  arg 1, arg 2, [...],            context
+// Call[Runtime]    CEntryStub, arg 1, arg 2, arg 3, [...], fun, #arg, context
+class Linkage : public ZoneObject {
+ public:
+  explicit Linkage(CompilationInfo* info);
+  explicit Linkage(CompilationInfo* info, CallDescriptor* incoming)
+      : info_(info), incoming_(incoming) {}
+
+  // The call descriptor for this compilation unit describes the locations
+  // of incoming parameters and the outgoing return value(s).
+  CallDescriptor* GetIncomingDescriptor() { return incoming_; }
+  CallDescriptor* GetJSCallDescriptor(int parameter_count);
+  static CallDescriptor* GetJSCallDescriptor(int parameter_count, Zone* zone);
+  CallDescriptor* GetRuntimeCallDescriptor(
+      Runtime::FunctionId function, int parameter_count,
+      Operator::Property properties,
+      CallDescriptor::DeoptimizationSupport can_deoptimize =
+          CallDescriptor::kCannotDeoptimize);
+  static CallDescriptor* GetRuntimeCallDescriptor(
+      Runtime::FunctionId function, int parameter_count,
+      Operator::Property properties,
+      CallDescriptor::DeoptimizationSupport can_deoptimize, Zone* zone);
+
+  CallDescriptor* GetStubCallDescriptor(CodeStubInterfaceDescriptor* descriptor,
+                                        int stack_parameter_count = 0);
+
+  // Creates a call descriptor for simplified C calls that is appropriate
+  // 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, MachineRepresentation return_type,
+      const MachineRepresentation* param_types);
+
+  // Get the location of an (incoming) parameter to this function.
+  LinkageLocation GetParameterLocation(int index) {
+    return incoming_->GetInputLocation(index + 1);
+  }
+
+  // Get the location where this function should place its return value.
+  LinkageLocation GetReturnLocation() {
+    return incoming_->GetReturnLocation(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
+  // caller's frame. The {extra} parameter indicates an additional offset from
+  // the frame offset, e.g. to index into part of a double slot.
+  FrameOffset GetFrameOffset(int spill_slot, Frame* frame, int extra = 0);
+
+  CompilationInfo* info() const { return info_; }
+
+ private:
+  CompilationInfo* info_;
+  CallDescriptor* incoming_;
+};
+}
+}
+}  // namespace v8::internal::compiler
+
+#endif  // V8_COMPILER_LINKAGE_H_