[turbofan]: Implement tail calls with more callee than caller parameters

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/base/flags.h"
 #include "src/compiler/frame.h"
 #include "src/compiler/machine-type.h"
@@ skipping 39 matching lines @@
     DCHECK(slot < 0);
     return LinkageLocation(STACK_SLOT, slot);
   }
 
   static LinkageLocation ForCalleeFrameSlot(int32_t slot) {
     // TODO(titzer): bailout instead of crashing here.
     DCHECK(slot >= 0 && slot < LinkageLocation::MAX_STACK_SLOT);
     return LinkageLocation(STACK_SLOT, slot);
   }
 
+  static LinkageLocation ForSavedCallerReturnAddress() {
+    return ForCalleeFrameSlot((StandardFrameConstants::kCallerPCOffset -
+                               StandardFrameConstants::kCallerPCOffset) /
+                              kPointerSize);
+  }
+
+  static LinkageLocation ForSavedCallerFramePtr() {
+    return ForCalleeFrameSlot((StandardFrameConstants::kCallerPCOffset -
+                               StandardFrameConstants::kCallerFPOffset) /
+                              kPointerSize);
+  }
+
+  static LinkageLocation ForSavedCallerConstantPool() {
+    DCHECK(FLAG_enable_embedded_constant_pool);

[Benedikt Meurer, 2015/11/20 10:06:43]

This use of FLAG_something worries me. Can we somehow make that into a global
constant, because disabling that at runtime will not work anyway.

[danno, 2015/11/20 14:43:23]

Done.

+    return ForCalleeFrameSlot((StandardFrameConstants::kCallerPCOffset -
+                               StandardFrameConstants::kConstantPoolOffset) /
+                              kPointerSize);
+  }
+
   static LinkageLocation ConvertToTailCallerLocation(
       LinkageLocation caller_location, int stack_param_delta) {
     if (!caller_location.IsRegister()) {
       return LinkageLocation(STACK_SLOT,
                              caller_location.GetLocation() + stack_param_delta);
     }
     return caller_location;
   }
 
  private:
@@ skipping 289 matching lines @@
   CallDescriptor* const incoming_;
 
   DISALLOW_COPY_AND_ASSIGN(Linkage);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_LINKAGE_H_