[crankshaft] Added checks to tail call instructions that we don't have to restore caller doubles.

src/crankshaft/x64/lithium-codegen-x64.cc

 // Copyright 2013 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/crankshaft/x64/lithium-codegen-x64.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 3116 matching lines @@
                               ARGUMENTS_DONT_CONTAIN_RECEIVER);
   __ Push(args.GetArgumentOperand(0));
   __ decl(length);
   __ j(not_zero, &loop);
 
   // Invoke the function.
   __ bind(&invoke);
 
   InvokeFlag flag = CALL_FUNCTION;
   if (instr->hydrogen()->tail_call_mode() == TailCallMode::kAllow) {
+    DCHECK(!info()->saves_caller_doubles());
     // TODO(ishell): drop current frame before pushing arguments to the stack.
     flag = JUMP_FUNCTION;
     ParameterCount actual(rax);
     // It is safe to use rbx, rcx and r8 as scratch registers here given that
     // 1) we are not going to return to caller function anyway,
     // 2) rbx (expected number of arguments) will be initialized below.
     PrepareForTailCall(actual, rbx, rcx, r8);
   }
 
   DCHECK(instr->HasPointerMap());
@@ skipping 533 matching lines @@
 
 void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
   HInvokeFunction* hinstr = instr->hydrogen();
   DCHECK(ToRegister(instr->context()).is(rsi));
   DCHECK(ToRegister(instr->function()).is(rdi));
   DCHECK(instr->HasPointerMap());
 
   bool is_tail_call = hinstr->tail_call_mode() == TailCallMode::kAllow;
 
   if (is_tail_call) {
+    DCHECK(!info()->saves_caller_doubles());
     ParameterCount actual(instr->arity());
     // It is safe to use rbx, rcx and r8 as scratch registers here given that
     // 1) we are not going to return to caller function anyway,
     // 2) rbx (expected number of arguments) will be initialized below.
     PrepareForTailCall(actual, rbx, rcx, r8);
   }
 
   Handle<JSFunction> known_function = hinstr->known_function();
   if (known_function.is_null()) {
     LPointerMap* pointers = instr->pointer_map();
@@ skipping 1881 matching lines @@
   __ movp(Operand(rbp, StandardFrameConstants::kContextOffset), context);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64