Patchable AllocateArray stub, like instance allocation stubs.

runtime/vm/stub_code_arm.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_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 394 matching lines @@
   __ Pop(R0);
   // Remove the stub frame.
   __ LeaveStubFrame();
   // Jump to the dart function.
   __ ldr(R0, FieldAddress(R0, Code::instructions_offset()));
   __ AddImmediate(R0, R0, Instructions::HeaderSize() - kHeapObjectTag);
   __ bx(R0);
 }
 
 
+// Called from array allocate instruction when the allocation stub has been
+// disabled.
+// R1: element type (preserved).
+// R2: length (preserved).
+void StubCode::GenerateFixAllocateArrayStubTargetStub(Assembler* assembler) {
+  __ EnterStubFrame();
+  // Setup space on stack for return value and preserve length, element type.
+  __ LoadImmediate(R0, reinterpret_cast<intptr_t>(Object::null()));
+  __ PushList((1 << R0) | (1 << R1) | (1 << R2));
+  __ CallRuntime(kFixAllocationStubTargetRuntimeEntry, 0);
+  // Get Code object result and restore length, element type.
+  __ PopList((1 << R0) | (1 << R1) | (1 << R2));
+  // Remove the stub frame.
+  __ LeaveStubFrame();
+  // Jump to the dart function.
+  __ ldr(R0, FieldAddress(R0, Code::instructions_offset()));
+  __ AddImmediate(R0, R0, Instructions::HeaderSize() - kHeapObjectTag);
+  __ bx(R0);
+}
+
+
 // Input parameters:
 //   R2: smi-tagged argument count, may be zero.
 //   FP[kParamEndSlotFromFp + 1]: last argument.
 static void PushArgumentsArray(Assembler* assembler) {
   StubCode* stub_code = Isolate::Current()->stub_code();
   // Allocate array to store arguments of caller.
   __ LoadImmediate(R1, reinterpret_cast<intptr_t>(Object::null()));
   // R1: null element type for raw Array.
   // R2: smi-tagged argument count, may be zero.
-  __ BranchLink(&stub_code->AllocateArrayLabel());
+  const Code& array_stub = Code::Handle(stub_code->GetAllocateArrayStub());
+  const ExternalLabel array_label(array_stub.EntryPoint());
+  __ BranchLink(&array_label);
   // R0: newly allocated array.
   // R2: smi-tagged argument count, may be zero (was preserved by the stub).
   __ Push(R0);  // Array is in R0 and on top of stack.
   __ add(R1, FP, Operand(R2, LSL, 1));
   __ AddImmediate(R1, kParamEndSlotFromFp * kWordSize);
   __ AddImmediate(R3, R0, Array::data_offset() - kHeapObjectTag);
   // R1: address of first argument on stack.
   // R3: address of first argument in array.
   Label loop;
   __ Bind(&loop);
@@ skipping 165 matching lines @@
   __ bx(R2);
 }
 
 
 // Called for inline allocation of arrays.
 // Input parameters:
 //   LR: return address.
 //   R1: array element type (either NULL or an instantiated type).
 //   R2: array length as Smi (must be preserved).
 // The newly allocated object is returned in R0.
-void StubCode::GenerateAllocateArrayStub(Assembler* assembler) {
+void StubCode::GeneratePatchableAllocateArrayStub(Assembler* assembler,
+    uword* entry_patch_offset, uword* patch_code_pc_offset) {
+  *entry_patch_offset = assembler->CodeSize();
   Label slow_case;
 
   // Compute the size to be allocated, it is based on the array length
   // and is computed as:
   // RoundedAllocationSize((array_length * kwordSize) + sizeof(RawArray)).
   __ MoveRegister(R3, R2);   // Array length.
 
   // Check that length is a positive Smi.
   __ tst(R3, Operand(kSmiTagMask));
   __ b(&slow_case, NE);
@@ skipping 95 matching lines @@
   __ LoadImmediate(IP, reinterpret_cast<intptr_t>(Object::null()));
   // Setup space on stack for return value.
   // Push array length as Smi and element type.
   __ PushList((1 << R1) | (1 << R2) | (1 << IP));
   __ CallRuntime(kAllocateArrayRuntimeEntry, 2);
   // Pop arguments; result is popped in IP.
   __ PopList((1 << R1) | (1 << R2) | (1 << IP));  // R2 is restored.
   __ mov(R0, Operand(IP));
   __ LeaveStubFrame();
   __ Ret();
+  *patch_code_pc_offset = assembler->CodeSize();
+  StubCode* stub_code = Isolate::Current()->stub_code();
+  __ BranchPatchable(&stub_code->FixAllocateArrayStubTargetLabel());
 }
 
 
 // Called when invoking Dart code from C++ (VM code).
 // Input parameters:
 //   LR : points to return address.
 //   R0 : entrypoint of the Dart function to call.
 //   R1 : arguments descriptor array.
 //   R2 : arguments array.
 //   R3 : new context containing the current isolate pointer.
@@ skipping 1238 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM