Object pool with support for untagged entries.

runtime/vm/assembler_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"  // NOLINT
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
@@ skipping 15 matching lines @@
       prologue_offset_(-1),
       comments_(),
       allow_constant_pool_(true) {
   // Far branching mode is only needed and implemented for MIPS and ARM.
   ASSERT(!use_far_branches);
   Isolate* isolate = Isolate::Current();
   if (isolate != Dart::vm_isolate()) {
     // These objects and labels need to be accessible through every pool-pointer
     // at the same index.
     intptr_t index =
-        object_pool_.AddObject(Object::null_object(), kNotPatchable);
+        object_pool_.AddObject(Object::null_object());

[srdjan, 2015/06/09 21:49:47]

On one line?

[Florian Schneider, 2015/06/10 08:26:17]

Done.

     ASSERT(index == 0);
 
-    index = object_pool_.AddObject(Bool::True(), kNotPatchable);
+    index = object_pool_.AddObject(Bool::True());
     ASSERT(index == 1);
 
-    index = object_pool_.AddObject(Bool::False(), kNotPatchable);
+    index = object_pool_.AddObject(Bool::False());
     ASSERT(index == 2);
 
     const Smi& vacant = Smi::Handle(Smi::New(0xfa >> kSmiTagShift));
     StubCode* stub_code = isolate->stub_code();
     if (stub_code->UpdateStoreBuffer_entry() != NULL) {
       object_pool_.AddExternalLabel(&stub_code->UpdateStoreBufferLabel(),
                                     kNotPatchable);
     } else {
-      object_pool_.AddObject(vacant, kNotPatchable);
+      object_pool_.AddObject(vacant);
     }
 
     if (stub_code->CallToRuntime_entry() != NULL) {
       object_pool_.AddExternalLabel(&stub_code->CallToRuntimeLabel(),
                                     kNotPatchable);
     } else {
-      object_pool_.AddObject(vacant, kNotPatchable);
+      object_pool_.AddObject(vacant);
     }
   }
 }
 
 
 void Assembler::InitializeMemoryWithBreakpoints(uword data, intptr_t length) {
   memset(reinterpret_cast<void*>(data), Instr::kBreakPointInstruction, length);
 }
 
 
@@ skipping 19 matching lines @@
   static const int kSize = 5;
   EmitUint8(0xE8);
   EmitLabel(label, kSize);
 }
 
 
 void Assembler::LoadExternalLabel(Register dst,
                                   const ExternalLabel* label,
                                   Patchability patchable,
                                   Register pp) {
-  const int32_t offset =
-      Array::element_offset(object_pool_.FindExternalLabel(label, patchable));
+  const int32_t offset = ObjectPool::element_offset(
+      object_pool_.FindExternalLabel(label, patchable));
   LoadWordFromPoolOffset(dst, pp, offset - kHeapObjectTag);
 }
 
 
 void Assembler::call(const ExternalLabel* label) {
   {  // Encode movq(TMP, Immediate(label->address())), but always as imm64.
     AssemblerBuffer::EnsureCapacity ensured(&buffer_);
     EmitRegisterREX(TMP, REX_W);
     EmitUint8(0xB8 | (TMP & 7));
     EmitInt64(label->address());
   }
   call(TMP);
 }
 
 
 void Assembler::CallPatchable(const ExternalLabel* label) {
   ASSERT(allow_constant_pool());
   intptr_t call_start = buffer_.GetPosition();
-  const int32_t offset =
-      Array::element_offset(object_pool_.FindExternalLabel(label, kPatchable));
+  const int32_t offset = ObjectPool::element_offset(
+      object_pool_.FindExternalLabel(label, kPatchable));
   call(Address::AddressBaseImm32(PP, offset - kHeapObjectTag));
   ASSERT((buffer_.GetPosition() - call_start) == kCallExternalLabelSize);
 }
 
 
 void Assembler::Call(const ExternalLabel* label, Register pp) {
   if (Isolate::Current() == Dart::vm_isolate()) {
     call(label);
   } else {
-    const int32_t offset = Array::element_offset(
+    const int32_t offset = ObjectPool::element_offset(
         object_pool_.FindExternalLabel(label, kNotPatchable));
     call(Address::AddressBaseImm32(pp, offset - kHeapObjectTag));
   }
 }
 
 
 void Assembler::pushq(Register reg) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitRegisterREX(reg, REX_NONE);
   EmitUint8(0x50 | (reg & 7));
@@ skipping 2460 matching lines @@
     EmitUint8(0xB8 | (TMP & 7));
     EmitInt64(label->address());
   }
   jmp(TMP);
 }
 
 
 void Assembler::JmpPatchable(const ExternalLabel* label, Register pp) {
   ASSERT(allow_constant_pool());
   intptr_t call_start = buffer_.GetPosition();
-  const int32_t offset =
-      Array::element_offset(object_pool_.FindExternalLabel(label, kPatchable));
+  const int32_t offset = ObjectPool::element_offset(
+      object_pool_.FindExternalLabel(label, kPatchable));
   // Patchable jumps always use a 32-bit immediate encoding.
   jmp(Address::AddressBaseImm32(pp, offset - kHeapObjectTag));
   ASSERT((buffer_.GetPosition() - call_start) == JumpPattern::kLengthInBytes);
 }
 
 
 void Assembler::Jmp(const ExternalLabel* label, Register pp) {
-  const int32_t offset = Array::element_offset(
+  const int32_t offset = ObjectPool::element_offset(
       object_pool_.FindExternalLabel(label, kNotPatchable));
   jmp(Address(pp, offset - kHeapObjectTag));
 }
 
 
 void Assembler::lock() {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xF0);
 }
 
@@ skipping 180 matching lines @@
 
 
 void Assembler::LoadIsolate(Register dst) {
   movq(dst, Address(THR, Thread::isolate_offset()));
 }
 
 
 void Assembler::LoadObject(Register dst, const Object& object, Register pp) {
   if (CanLoadFromObjectPool(object)) {
     const int32_t offset =
-        Array::element_offset(object_pool_.FindObject(object, kNotPatchable));
+        ObjectPool::element_offset(object_pool_.FindObject(object));
     LoadWordFromPoolOffset(dst, pp, offset - kHeapObjectTag);
   } else {
     ASSERT((Isolate::Current() == Dart::vm_isolate()) ||
            object.IsSmi() ||
            object.InVMHeap());
     LoadImmediate(dst, Immediate(reinterpret_cast<int64_t>(object.raw())), pp);
   }
 }
 
 
@@ skipping 14 matching lines @@
     pushq(TMP);
   } else {
     PushImmediate(Immediate(reinterpret_cast<int64_t>(object.raw())), pp);
   }
 }
 
 
 void Assembler::CompareObject(Register reg, const Object& object, Register pp) {
   if (CanLoadFromObjectPool(object)) {
     const int32_t offset =
-        Array::element_offset(object_pool_.FindObject(object, kNotPatchable));
+        ObjectPool::element_offset(object_pool_.FindObject(object));
     cmpq(reg, Address(pp, offset-kHeapObjectTag));
   } else {
     CompareImmediate(
         reg, Immediate(reinterpret_cast<int64_t>(object.raw())), pp);
   }
 }
 
 
 intptr_t Assembler::FindImmediate(int64_t imm) {
   ASSERT(Isolate::Current() != Dart::vm_isolate());
-  const Smi& smi = Smi::Handle(reinterpret_cast<RawSmi*>(imm));
-  return object_pool_.FindObject(smi, kNotPatchable);
+  return object_pool_.FindImmediate(imm);
 }
 
 
 bool Assembler::CanLoadImmediateFromPool(const Immediate& imm, Register pp) {
   if (!allow_constant_pool()) {
     return false;
   }
   return !imm.is_int32() &&
          (pp != kNoRegister) &&
          (Isolate::Current() != Dart::vm_isolate());
 }
 
 
 void Assembler::LoadImmediate(Register reg, const Immediate& imm, Register pp) {
   if (CanLoadImmediateFromPool(imm, pp)) {
     // It's a 64-bit constant and we're not in the VM isolate, so load from
     // object pool.
-    int64_t val = imm.value();
-    // Save the bits that must be masked-off for the SmiTag
-    int64_t val_smi_tag = val & kSmiTagMask;
-    val &= ~kSmiTagMask;  // Mask off the tag bits.
-    const int32_t offset = Array::element_offset(FindImmediate(val));
+    int32_t offset = ObjectPool::element_offset(FindImmediate(imm.value()));
     LoadWordFromPoolOffset(reg, pp, offset - kHeapObjectTag);
-    if (val_smi_tag != 0) {
-      // Add back the tag bits.
-      orq(reg, Immediate(val_smi_tag));
-    }
   } else {
     movq(reg, imm);
   }
 }
 
 
 void Assembler::MoveImmediate(const Address& dst, const Immediate& imm,
                               Register pp) {
   if (CanLoadImmediateFromPool(imm, pp)) {
     LoadImmediate(TMP, imm, pp);
@@ skipping 1003 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64