VM: Cache instructions entry point in RawFunction/RawCode.

runtime/vm/stub_code_arm64.cc

 // Copyright (c) 2014, 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_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 326 matching lines @@
   // Setup space on stack for return value and preserve arguments descriptor.
   __ Push(R4);
   __ PushObject(Object::null_object());
   __ CallRuntime(kPatchStaticCallRuntimeEntry, 0);
   // Get Code object result and restore arguments descriptor array.
   __ Pop(R0);
   __ Pop(R4);
   // Remove the stub frame.
   __ LeaveStubFrame();
   // Jump to the dart function.
-  __ LoadFieldFromOffset(R0, R0, Code::instructions_offset());
-  __ AddImmediate(R0, R0, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R0, R0, Code::entry_point_offset());
   __ br(R0);
 }
 
 
 // Called from a static call only when an invalid code has been entered
 // (invalid because its function was optimized or deoptimized).
 // R4: arguments descriptor array.
 void StubCode::GenerateFixCallersTargetStub(Assembler* assembler) {
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
   // Setup space on stack for return value and preserve arguments descriptor.
   __ Push(R4);
   __ PushObject(Object::null_object());
   __ CallRuntime(kFixCallersTargetRuntimeEntry, 0);
   // Get Code object result and restore arguments descriptor array.
   __ Pop(R0);
   __ Pop(R4);
   // Remove the stub frame.
   __ LeaveStubFrame();
   // Jump to the dart function.
-  __ LoadFieldFromOffset(R0, R0, Code::instructions_offset());
-  __ AddImmediate(R0, R0, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R0, R0, Code::entry_point_offset());
   __ br(R0);
 }
 
 
 // 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);
   // Get Code object result.
   __ Pop(R0);
   // Remove the stub frame.
   __ LeaveStubFrame();
   // Jump to the dart function.
-  __ LoadFieldFromOffset(R0, R0, Code::instructions_offset());
-  __ AddImmediate(R0, R0, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R0, R0, Code::entry_point_offset());
   __ br(R0);
 }
 
 
 // Input parameters:
 //   R2: smi-tagged argument count, may be zero.
 //   FP[kParamEndSlotFromFp + 1]: last argument.
 static void PushArgumentsArray(Assembler* assembler) {
   // Allocate array to store arguments of caller.
   __ LoadObject(R1, Object::null_object());
@@ skipping 201 matching lines @@
 
   __ LeaveStubFrame();
 
   if (!FLAG_lazy_dispatchers) {
     Label call_target_function;
     GenerateDispatcherCode(assembler, &call_target_function);
     __ Bind(&call_target_function);
   }
 
   // Tail-call to target function.
-  __ LoadFieldFromOffset(R2, R0, Function::instructions_offset());
-  __ AddImmediate(R2, R2, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
   __ br(R2);
 }
 
 
 // Called for inline allocation of arrays.
 // Input parameters:
 //   LR: return address.
 //   R2: array length as Smi.
 //   R1: array element type (either NULL or an instantiated type).
 // NOTE: R2 cannot be clobbered here as the caller relies on it being saved.
@@ skipping 911 matching lines @@
     __ LoadFromOffset(R1, R6, count_offset);
     __ adds(R1, R1, Operand(Smi::RawValue(1)));
     __ LoadImmediate(R2, Smi::RawValue(Smi::kMaxValue));
     __ csel(R1, R2, R1, VS);  // Overflow.
     __ StoreToOffset(R1, R6, count_offset);
   }
 
   __ Comment("Call target");
   __ Bind(&call_target_function);
   // R0: target function.
-  __ LoadFieldFromOffset(R2, R0, Function::instructions_offset());
-  __ AddImmediate(
-      R2, R2, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
   if (range_collection_mode == kCollectRanges) {
     __ ldr(R1, Address(SP, 0 * kWordSize));
     if (num_args == 2) {
       __ ldr(R3, Address(SP, 1 * kWordSize));
     }
     __ EnterStubFrame();
     __ Push(R5);
     if (num_args == 2) {
       __ Push(R3);
     }
@@ skipping 153 matching lines @@
     __ LoadImmediate(R2, Smi::RawValue(Smi::kMaxValue));
     __ csel(R1, R2, R1, VS);  // Overflow.
     __ StoreToOffset(R1, R6, count_offset);
   }
 
   // Load arguments descriptor into R4.
   __ LoadFieldFromOffset(R4, R5, ICData::arguments_descriptor_offset());
 
   // Get function and call it, if possible.
   __ LoadFromOffset(R0, R6, target_offset);
-  __ LoadFieldFromOffset(R2, R0, Function::instructions_offset());
-
-  // R0: function.
-  // R2: target instructons.
-  __ AddImmediate(
-      R2, R2, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
   __ br(R2);
 
   if (FLAG_support_debugger) {
     __ Bind(&stepping);
     __ EnterStubFrame();
     __ Push(R5);  // Preserve IC data.
     __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
     __ Pop(R5);
     __ LeaveStubFrame();
     __ b(&done_stepping);
@@ skipping 26 matching lines @@
   __ EnterStubFrame();
   __ Push(R5);  // Save IC Data.
   __ Push(R4);  // Save arg. desc.
   __ Push(R0);  // Pass function.
   __ CallRuntime(kCompileFunctionRuntimeEntry, 1);
   __ Pop(R0);  // Restore argument.
   __ Pop(R4);  // Restore arg desc.
   __ Pop(R5);  // Restore IC Data.
   __ LeaveStubFrame();
 
-  __ LoadFieldFromOffset(R2, R0, Function::instructions_offset());
-  __ AddImmediate(
-      R2, R2, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R2, R0, Function::entry_point_offset());
   __ br(R2);
 }
 
 
 // R5: Contains an ICData.
 void StubCode::GenerateICCallBreakpointStub(Assembler* assembler) {
   __ EnterStubFrame();
   __ Push(R5);
   __ PushObject(Object::null_object());  // Space for result.
   __ CallRuntime(kBreakpointRuntimeHandlerRuntimeEntry, 0);
@@ skipping 182 matching lines @@
 void StubCode::GenerateOptimizeFunctionStub(Assembler* assembler) {
   __ EnterStubFrame();
   __ Push(R4);
   // Setup space on stack for the return value.
   __ PushObject(Object::null_object());
   __ Push(R6);
   __ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry, 1);
   __ Pop(R0);  // Discard argument.
   __ Pop(R0);  // Get Code object
   __ Pop(R4);  // Restore argument descriptor.
-  __ LoadFieldFromOffset(R0, R0, Code::instructions_offset());
-  __ AddImmediate(R0, R0, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R0, R0, Code::entry_point_offset());
   __ LeaveStubFrame();
   __ br(R0);
   __ brk(0);
 }
 
 
 // Does identical check (object references are equal or not equal) with special
 // checks for boxed numbers.
 // Left and right are pushed on stack.
 // Return Zero condition flag set if equal.
@@ skipping 130 matching lines @@
   __ CompareRegisters(R4, R0);
   __ b(&update, NE);
 
   __ 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.
   __ add(TMP, R2, Operand(R3, LSL, 3));
   __ LoadFieldFromOffset(R0, TMP, base + kWordSize);
-  __ LoadFieldFromOffset(R1, R0, Function::instructions_offset());
-  // TODO(srdjan): Evaluate performance impact of moving the instruction below
-  // to the call site, instead of having it here.
-  __ AddImmediate(target, R1, Instructions::HeaderSize() - kHeapObjectTag);
+  __ LoadFieldFromOffset(R1, R0, Function::entry_point_offset());
 }
 
 
 // Called from megamorphic calls.
 //  R0: receiver.
 //  R1: lookup cache.
 // Result:
 //  R1: entry point.
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
   EmitMegamorphicLookup(assembler, R0, R1, R1);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64