Patchable AllocateArray stub, like instance allocation stubs.

runtime/vm/stub_code_mips.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_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 440 matching lines @@
 
   // Jump to the dart function.
   __ lw(T0, FieldAddress(T0, Code::instructions_offset()));
   __ AddImmediate(T0, T0, Instructions::HeaderSize() - kHeapObjectTag);
 
   // Remove the stub frame.
   __ LeaveStubFrameAndReturn(T0);
 }
 
 
+// Called from array allocate instruction when the allocation stub has been
+// disabled.
+// A0: element type (preserved).
+// A1: length (preserved).
+void StubCode::GenerateFixAllocateArrayStubTargetStub(Assembler* assembler) {
+  __ TraceSimMsg("FixAllocationStubTarget");
+  __ EnterStubFrame();
+  // Setup space on stack for return value.
+  __ addiu(SP, SP, Immediate(-3 * kWordSize));
+  __ sw(A0, Address(SP, 2 * kWordSize));
+  __ sw(A1, Address(SP, 1 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 0 * kWordSize));
+  __ CallRuntime(kFixAllocationStubTargetRuntimeEntry, 0);
+  // Get Code object result.
+  __ lw(T0, Address(SP, 0 * kWordSize));
+  __ lw(A1, Address(SP, 1 * kWordSize));
+  __ lw(A0, Address(SP, 2 * kWordSize));
+  __ addiu(SP, SP, Immediate(3 * kWordSize));
+
+  // Jump to the dart function.
+  __ lw(T0, FieldAddress(T0, Code::instructions_offset()));
+  __ AddImmediate(T0, T0, Instructions::HeaderSize() - kHeapObjectTag);
+
+  // Remove the stub frame.
+  __ LeaveStubFrameAndReturn(T0);
+}
+
+
 // Input parameters:
 //   A1: Smi-tagged argument count, may be zero.
 //   FP[kParamEndSlotFromFp + 1]: Last argument.
 static void PushArgumentsArray(Assembler* assembler) {
   StubCode* stub_code = Isolate::Current()->stub_code();
   __ TraceSimMsg("PushArgumentsArray");
   // Allocate array to store arguments of caller.
   __ LoadImmediate(A0, reinterpret_cast<intptr_t>(Object::null()));
   // A0: Null element type for raw Array.
   // A1: 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);
   __ TraceSimMsg("PushArgumentsArray return");
   // V0: newly allocated array.
   // A1: Smi-tagged argument count, may be zero (was preserved by the stub).
   __ Push(V0);  // Array is in V0 and on top of stack.
   __ sll(T1, A1, 1);
   __ addu(T1, FP, T1);
   __ AddImmediate(T1, kParamEndSlotFromFp * kWordSize);
   // T1: address of first argument on stack.
   // T2: address of first argument in array.
 
@@ skipping 198 matching lines @@
 }
 
 
 // Called for inline allocation of arrays.
 // Input parameters:
 //   RA: return address.
 //   A1: Array length as Smi (must be preserved).
 //   A0: array element type (either NULL or an instantiated type).
 // NOTE: A1 cannot be clobbered here as the caller relies on it being saved.
 // The newly allocated object is returned in V0.
-void StubCode::GenerateAllocateArrayStub(Assembler* assembler) {
+void StubCode::GeneratePatchableAllocateArrayStub(Assembler* assembler,
+    uword* entry_patch_offset, uword* patch_code_pc_offset) {
   __ TraceSimMsg("AllocateArrayStub");
+  *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)).
   __ mov(T3, A1);  // Array length.
 
   // Check that length is a positive Smi.
   __ andi(CMPRES1, T3, Immediate(kSmiTagMask));
   __ bne(CMPRES1, ZR, &slow_case);
@@ skipping 108 matching lines @@
   __ sw(A0, Address(SP, 0 * kWordSize));
   __ CallRuntime(kAllocateArrayRuntimeEntry, 2);
   __ TraceSimMsg("AllocateArrayStub return");
   // Pop arguments; result is popped in IP.
   __ lw(V0, Address(SP, 2 * kWordSize));
   __ lw(A1, Address(SP, 1 * kWordSize));
   __ lw(A0, Address(SP, 0 * kWordSize));
   __ addiu(SP, SP, Immediate(3 * kWordSize));
 
   __ LeaveStubFrameAndReturn();
+  *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:
 //   RA : points to return address.
 //   A0 : entrypoint of the Dart function to call.
 //   A1 : arguments descriptor array.
 //   A2 : arguments array.
 //   A3 : new context containing the current isolate pointer.
@@ skipping 1399 matching lines @@
   const Register right = T0;
   __ lw(left, Address(SP, 1 * kWordSize));
   __ lw(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp1, temp2);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS