VM: Cache instructions entry point in RawFunction/RawCode.

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 265 matching lines @@
   __ EnterStubFrame();
   __ pushq(R10);  // Preserve arguments descriptor array.
   // Setup space on stack for return value.
   __ PushObject(Object::null_object());
   __ CallRuntime(kPatchStaticCallRuntimeEntry, 0);
   __ popq(RAX);  // Get Code object result.
   __ popq(R10);  // Restore arguments descriptor array.
   // Remove the stub frame as we are about to jump to the dart function.
   __ LeaveStubFrame();
 
-  __ movq(RBX, FieldAddress(RAX, Code::instructions_offset()));
-  __ addq(RBX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RBX, FieldAddress(RAX, Code::entry_point_offset()));
   __ jmp(RBX);
 }
 
 
 // Called from a static call only when an invalid code has been entered
 // (invalid because its function was optimized or deoptimized).
 // R10: arguments descriptor array.
 void StubCode::GenerateFixCallersTargetStub(Assembler* assembler) {
   __ EnterStubFrame();
   __ pushq(R10);  // Preserve arguments descriptor array.
   // Setup space on stack for return value.
   __ PushObject(Object::null_object());
   __ CallRuntime(kFixCallersTargetRuntimeEntry, 0);
   __ popq(RAX);  // Get Code object.
   __ popq(R10);  // Restore arguments descriptor array.
-  __ movq(RAX, FieldAddress(RAX, Code::instructions_offset()));
-  __ addq(RAX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RAX, FieldAddress(RAX, Code::entry_point_offset()));
   __ LeaveStubFrame();
   __ jmp(RAX);
   __ int3();
 }
 
 
 // Called from object allocate instruction when the allocation stub has been
 // disabled.
 void StubCode::GenerateFixAllocationStubTargetStub(Assembler* assembler) {
   __ EnterStubFrame();
   // Setup space on stack for return value.
   __ PushObject(Object::null_object());
   __ CallRuntime(kFixAllocationStubTargetRuntimeEntry, 0);
   __ popq(RAX);  // Get Code object.
-  __ movq(RAX, FieldAddress(RAX, Code::instructions_offset()));
-  __ addq(RAX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RAX, FieldAddress(RAX, Code::entry_point_offset()));
   __ LeaveStubFrame();
   __ jmp(RAX);
   __ int3();
 }
 
 
 // Input parameters:
 //   R10: smi-tagged argument count, may be zero.
 //   RBP[kParamEndSlotFromFp + 1]: last argument.
 static void PushArgumentsArray(Assembler* assembler) {
@@ skipping 219 matching lines @@
   __ popq(R10);  // Restore arguments descriptor.
   __ popq(RBX);  // Restore IC data.
   __ LeaveStubFrame();
 
   if (!FLAG_lazy_dispatchers) {
     Label call_target_function;
     GenerateDispatcherCode(assembler, &call_target_function);
     __ Bind(&call_target_function);
   }
 
-  __ movq(RCX, FieldAddress(RAX, Function::instructions_offset()));
-  __ addq(RCX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RCX, FieldAddress(RAX, Function::entry_point_offset()));
   __ jmp(RCX);
 }
 
 
 // Called for inline allocation of arrays.
 // Input parameters:
 //   R10 : Array length as Smi.
 //   RBX : array element type (either NULL or an instantiated type).
 // NOTE: R10 cannot be clobbered here as the caller relies on it being saved.
 // The newly allocated object is returned in RAX.
@@ skipping 913 matching lines @@
     __ addq(R8, Immediate(Smi::RawValue(1)));
     __ movq(R13, Immediate(Smi::RawValue(Smi::kMaxValue)));
     __ cmovnoq(R13, R8);
     __ StoreIntoSmiField(Address(R12, count_offset), R13);
   }
 
   __ Comment("Call target");
   __ Bind(&call_target_function);
   // RAX: Target function.
   Label is_compiled;
-  __ movq(RCX, FieldAddress(RAX, Function::instructions_offset()));
-  __ addq(RCX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RCX, FieldAddress(RAX, Function::entry_point_offset()));
   if (range_collection_mode == kCollectRanges) {
     __ movq(R8, Address(RSP, + 1 * kWordSize));
     if (num_args == 2) {
       __ movq(R13, Address(RSP, + 2 * kWordSize));
     }
     __ EnterStubFrame();
     __ pushq(RBX);
     if (num_args == 2) {
       __ pushq(R13);
     }
@@ skipping 178 matching lines @@
     __ movq(R13, Immediate(Smi::RawValue(Smi::kMaxValue)));
     __ cmovnoq(R13, R8);
     __ StoreIntoSmiField(Address(R12, count_offset), R13);
   }
 
   // Load arguments descriptor into R10.
   __ movq(R10, FieldAddress(RBX, ICData::arguments_descriptor_offset()));
 
   // Get function and call it, if possible.
   __ movq(RAX, Address(R12, target_offset));
-  __ movq(RCX, FieldAddress(RAX, Function::instructions_offset()));
-  // RCX: Target instructions.
-  __ addq(RCX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RCX, FieldAddress(RAX, Function::entry_point_offset()));
   __ jmp(RCX);
 
   if (FLAG_support_debugger) {
     __ Bind(&stepping);
     __ EnterStubFrame();
     __ pushq(RBX);  // Preserve IC data object.
     __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
     __ popq(RBX);
     __ LeaveStubFrame();
     __ jmp(&done_stepping, Assembler::kNearJump);
@@ skipping 30 matching lines @@
   __ EnterStubFrame();
   __ pushq(R10);  // Preserve arguments descriptor array.
   __ pushq(RBX);  // Preserve IC data object.
   __ pushq(RAX);  // Pass function.
   __ CallRuntime(kCompileFunctionRuntimeEntry, 1);
   __ popq(RAX);  // Restore function.
   __ popq(RBX);  // Restore IC data array.
   __ popq(R10);  // Restore arguments descriptor array.
   __ LeaveStubFrame();
 
-  __ movq(RAX, FieldAddress(RAX, Function::instructions_offset()));
-  __ addq(RAX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RAX, FieldAddress(RAX, Function::entry_point_offset()));
   __ jmp(RAX);
 }
 
 
 // RBX: Contains an ICData.
 // TOS(0): return address (Dart code).
 void StubCode::GenerateICCallBreakpointStub(Assembler* assembler) {
   __ EnterStubFrame();
   // Preserve IC data.
   __ pushq(RBX);
@@ skipping 206 matching lines @@
 void StubCode::GenerateOptimizeFunctionStub(Assembler* assembler) {
   __ EnterStubFrame();
   __ LoadObject(R12, Object::null_object());
   __ pushq(R10);
   __ pushq(R12);  // Setup space on stack for return value.
   __ pushq(RDI);
   __ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry, 1);
   __ popq(RAX);  // Disard argument.
   __ popq(RAX);  // Get Code object.
   __ popq(R10);  // Restore argument descriptor.
-  __ movq(RAX, FieldAddress(RAX, Code::instructions_offset()));
-  __ addq(RAX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(RAX, FieldAddress(RAX, Code::entry_point_offset()));
   __ LeaveStubFrame();
   __ jmp(RAX);
   __ int3();
 }
 
 
 // Does identical check (object references are equal or not equal) with special
 // checks for boxed numbers.
 // Left and right are pushed on stack.
 // Return ZF set.
@@ skipping 129 matching lines @@
   __ j(ZERO, &call_target_function, Assembler::kNearJump);
   __ cmpq(RDX, RAX);
   __ j(NOT_EQUAL, &update, Assembler::kNearJump);
 
   __ Bind(&call_target_function);
   // Call the target found in the cache.  For a class id match, this is a
   // proper target for the given name and arguments descriptor.  If the
   // illegal class id was found, the target is a cache miss handler that can
   // be invoked as a normal Dart function.
   __ movq(RAX, FieldAddress(RDI, RCX, TIMES_8, base + kWordSize));
-  __ movq(target, FieldAddress(RAX, Function::instructions_offset()));
-  // TODO(srdjan): Evaluate performance impact of moving the instruction below
-  // to the call site, instead of having it here.
-  __ AddImmediate(
-      target, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
+  __ movq(target, FieldAddress(RAX, Function::entry_point_offset()));
 }
 
 
 // Called from megamorphic calls.
 //  RDI: receiver.
 //  RBX: lookup cache.
 // Result:
 //  RCX: entry point.
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
   EmitMegamorphicLookup(assembler, RDI, RBX, RCX);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64