VM: Optimized context allocation on all platforms.

runtime/vm/assembler_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/cpu.h"
 #include "vm/longjump.h"
@@ skipping 3163 matching lines @@
     ASSERT(cls.id() != kIllegalCid);
     tags = RawObject::ClassIdTag::update(cls.id(), tags);
     LoadImmediate(IP, tags);
     str(IP, FieldAddress(instance_reg, Object::tags_offset()));
   } else {
     b(failure);
   }
 }
 
 
+void Assembler::TryAllocateArray(intptr_t cid,
+                                 intptr_t instance_size,
+                                 Label* failure,
+                                 Register instance,
+                                 Register end_address,
+                                 Register temp1,
+                                 Register temp2) {

[srdjan, 2014/08/11 21:42:34]

Guard with FLAG_inline_alloc

[Florian Schneider, 2014/08/13 14:56:11]

Done.

+  Isolate* isolate = Isolate::Current();
+  Heap* heap = isolate->heap();
+  LoadImmediate(temp1, heap->TopAddress());
+  ldr(instance, Address(temp1, 0));  // Potential new object start.
+  AddImmediate(end_address, instance, instance_size);
+  b(failure, VS);
+
+  // Check if the allocation fits into the remaining space.
+  // instance: potential new object start.
+  // end_address: potential next object start.
+  LoadImmediate(temp2, heap->EndAddress());
+  ldr(temp2, Address(temp2, 0));
+  cmp(end_address, Operand(temp2));
+  b(failure, CS);
+
+  // Successfully allocated the object(s), now update top to point to
+  // next object start and initialize the object.
+  str(end_address, Address(temp1, 0));
+  add(instance, instance, Operand(kHeapObjectTag));
+  LoadImmediate(temp2, instance_size);
+  UpdateAllocationStatsWithSize(cid, temp2, temp1);
+
+  // Initialize the tags.
+  // instance: new object start as a tagged pointer.
+  uword tags = 0;
+  tags = RawObject::ClassIdTag::update(cid, tags);
+  tags = RawObject::SizeTag::update(instance_size, tags);
+  LoadImmediate(temp2, tags);
+  str(temp2, FieldAddress(instance, Array::tags_offset()));  // Store tags.
+}
+
+
 void Assembler::Stop(const char* message) {
   if (FLAG_print_stop_message) {
     StubCode* stub_code = Isolate::Current()->stub_code();
     PushList((1 << R0) | (1 << IP) | (1 << LR));  // Preserve R0, IP, LR.
     LoadImmediate(R0, reinterpret_cast<int32_t>(message));
     // PrintStopMessage() preserves all registers.
     BranchLink(&stub_code->PrintStopMessageLabel());  // Passing message in R0.
     PopList((1 << R0) | (1 << IP) | (1 << LR));  // Restore R0, IP, LR.
   }
   // Emit the message address before the svc instruction, so that we can
@@ skipping 130 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfFpuRegisters));
   return fpu_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM