Revert "VM: New calling convention for generated code."

runtime/vm/assembler_x64.cc

Index: runtime/vm/assembler_x64.cc
diff --git a/runtime/vm/assembler_x64.cc b/runtime/vm/assembler_x64.cc
index e39d8b21aecfb658f2ee652343ffeb8c386218f4..523f29f9ca8fdc3cc7229e3fe75c955c6445f283 100644
--- a/runtime/vm/assembler_x64.cc
+++ b/runtime/vm/assembler_x64.cc
@@ -93,25 +93,20 @@ void Assembler::call(const ExternalLabel* label) {
 
 void Assembler::CallPatchable(const StubEntry& stub_entry) {
   ASSERT(constant_pool_allowed());
-  const Code& target = Code::Handle(stub_entry.code());
   intptr_t call_start = buffer_.GetPosition();
   const int32_t offset = ObjectPool::element_offset(
-      object_pool_wrapper_.FindObject(target, kPatchable));
-  LoadWordFromPoolOffset(CODE_REG, offset - kHeapObjectTag);
-  movq(TMP, FieldAddress(CODE_REG, Code::entry_point_offset()));
-  call(TMP);
+      object_pool_wrapper_.FindExternalLabel(&stub_entry.label(), kPatchable));
+  call(Address::AddressBaseImm32(PP, offset - kHeapObjectTag));
   ASSERT((buffer_.GetPosition() - call_start) == kCallExternalLabelSize);
 }
 
 
 void Assembler::Call(const StubEntry& stub_entry) {
   ASSERT(constant_pool_allowed());
-  const Code& target = Code::Handle(stub_entry.code());
   const int32_t offset = ObjectPool::element_offset(
-      object_pool_wrapper_.FindObject(target, kNotPatchable));
-  LoadWordFromPoolOffset(CODE_REG, offset - kHeapObjectTag);
-  movq(TMP, FieldAddress(CODE_REG, Code::entry_point_offset()));
-  call(TMP);
+      object_pool_wrapper_.FindExternalLabel(&stub_entry.label(),
+                                             kNotPatchable));
+  call(Address::AddressBaseImm32(PP, offset - kHeapObjectTag));
 }
 
 
@@ -2548,12 +2543,11 @@ void Assembler::j(Condition condition, Label* label, bool near) {
 }
 
 
-void Assembler::J(Condition condition,
-                  const StubEntry& stub_entry,
+void Assembler::J(Condition condition, const StubEntry& stub_entry,
                   Register pp) {
   Label no_jump;
   // Negate condition.
-  j(static_cast<Condition>(condition ^ 1), &no_jump, kNearJump);
+  j(static_cast<Condition>(condition ^ 1), &no_jump, Assembler::kNearJump);
   Jmp(stub_entry, pp);
   Bind(&no_jump);
 }
@@ -2614,25 +2608,28 @@ void Assembler::jmp(const ExternalLabel* label) {
 }
 
 
+void Assembler::jmp(const StubEntry& stub_entry) {
+  jmp(&stub_entry.label());
+}
+
+
 void Assembler::JmpPatchable(const StubEntry& stub_entry, Register pp) {
   ASSERT((pp != PP) || constant_pool_allowed());
-  const Code& target = Code::Handle(stub_entry.code());
+  intptr_t call_start = buffer_.GetPosition();
   const int32_t offset = ObjectPool::element_offset(
-      object_pool_wrapper_.FindObject(target, kPatchable));
-  movq(CODE_REG, Address::AddressBaseImm32(pp, offset - kHeapObjectTag));
-  movq(TMP, FieldAddress(CODE_REG, Code::entry_point_offset()));
-  jmp(TMP);
+      object_pool_wrapper_.FindExternalLabel(&stub_entry.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 StubEntry& stub_entry, Register pp) {
   ASSERT((pp != PP) || constant_pool_allowed());
-  const Code& target = Code::Handle(stub_entry.code());
   const int32_t offset = ObjectPool::element_offset(
-      object_pool_wrapper_.FindObject(target, kNotPatchable));
-  movq(CODE_REG, FieldAddress(pp, offset));
-  movq(TMP, FieldAddress(CODE_REG, Code::entry_point_offset()));
-  jmp(TMP);
+      object_pool_wrapper_.FindExternalLabel(&stub_entry.label(),
+                                             kNotPatchable));
+  jmp(Address(pp, offset - kHeapObjectTag));
 }
 
 
@@ -3080,12 +3077,8 @@ void Assembler::StoreIntoObject(Register object,
   if (object != RDX) {
     movq(RDX, object);
   }
-  pushq(CODE_REG);
-  movq(CODE_REG, Address(THR, Thread::update_store_buffer_code_offset()));
   movq(TMP, Address(THR, Thread::update_store_buffer_entry_point_offset()));
   call(TMP);
-
-  popq(CODE_REG);
   if (value != RDX) popq(RDX);
   Bind(&done);
 }
@@ -3386,30 +3379,27 @@ void Assembler::CallRuntime(const RuntimeEntry& entry,
 }
 
 
-void Assembler::RestoreCodePointer() {
-  movq(CODE_REG, Address(RBP, kPcMarkerSlotFromFp * kWordSize));
-}
-
-
 void Assembler::LoadPoolPointer(Register pp) {
   // Load new pool pointer.
-  CheckCodePointer();
-  movq(pp, FieldAddress(CODE_REG, Code::object_pool_offset()));
+  const intptr_t kRIPRelativeMovqSize = 7;
+  const intptr_t entry_to_rip_offset = CodeSize() + kRIPRelativeMovqSize;
+  const intptr_t object_pool_pc_dist =
+      Instructions::HeaderSize() - Instructions::object_pool_offset();
+  movq(pp, Address::AddressRIPRelative(
+      -entry_to_rip_offset - object_pool_pc_dist));
+  ASSERT(CodeSize() == entry_to_rip_offset);
   set_constant_pool_allowed(pp == PP);
 }
 
 
-void Assembler::EnterDartFrame(intptr_t frame_size, Register new_pp) {
-  CheckCodePointer();
+void Assembler::EnterDartFrame(intptr_t frame_size,
+                               Register new_pp,
+                               Register pc_marker_override) {
   ASSERT(!constant_pool_allowed());
   EnterFrame(0);
-  pushq(CODE_REG);
+  pushq(pc_marker_override);
   pushq(PP);
-  if (new_pp == kNoRegister) {
-    LoadPoolPointer(PP);
-  } else {
-    movq(PP, new_pp);
-  }
+  movq(PP, new_pp);
   set_constant_pool_allowed(true);
   if (frame_size != 0) {
     subq(RSP, Immediate(frame_size));
@@ -3417,57 +3407,30 @@ void Assembler::EnterDartFrame(intptr_t frame_size, Register new_pp) {
 }
 
 
-void Assembler::LeaveDartFrame(RestorePP restore_pp) {
+void Assembler::LeaveDartFrame() {
+  set_constant_pool_allowed(false);
   // Restore caller's PP register that was pushed in EnterDartFrame.
-  if (restore_pp == kRestoreCallerPP) {
-    movq(PP, Address(RBP, (kSavedCallerPpSlotFromFp * kWordSize)));
-    set_constant_pool_allowed(false);
-  }
+  movq(PP, Address(RBP, (kSavedCallerPpSlotFromFp * kWordSize)));
   LeaveFrame();
 }
 
 
-void Assembler::CheckCodePointer() {
-#ifdef DEBUG
-  Label cid_ok, instructions_ok;
-  pushq(RAX);
-  LoadClassId(RAX, CODE_REG);
-  cmpq(RAX, Immediate(kCodeCid));
-  j(EQUAL, &cid_ok);
-  int3();
-  Bind(&cid_ok);
-  {
-    const intptr_t kRIPRelativeLeaqSize = 7;
-    const intptr_t header_to_entry_offset =
-        (Instructions::HeaderSize() - kHeapObjectTag);
-    const intptr_t header_to_rip_offset =
-        CodeSize() + kRIPRelativeLeaqSize + header_to_entry_offset;
-    leaq(RAX, Address::AddressRIPRelative(-header_to_rip_offset));
-    ASSERT(CodeSize() == (header_to_rip_offset - header_to_entry_offset));
-  }
-  cmpq(RAX, FieldAddress(CODE_REG, Code::saved_instructions_offset()));
-  j(EQUAL, &instructions_ok);
-  int3();
-  Bind(&instructions_ok);
-  popq(RAX);
-#endif
-}
-
-
 // On entry to a function compiled for OSR, the caller's frame pointer, the
 // stack locals, and any copied parameters are already in place.  The frame
 // pointer is already set up.  The PC marker is not correct for the
 // optimized function and there may be extra space for spill slots to
 // allocate.
-void Assembler::EnterOsrFrame(intptr_t extra_size) {
+void Assembler::EnterOsrFrame(intptr_t extra_size,
+                              Register new_pp,
+                              Register pc_marker_override) {
   ASSERT(!constant_pool_allowed());
   if (prologue_offset_ == -1) {
     Comment("PrologueOffset = %" Pd "", CodeSize());
     prologue_offset_ = CodeSize();
   }
-  RestoreCodePointer();
-  LoadPoolPointer();
-
+  movq(Address(RBP, kPcMarkerSlotFromFp * kWordSize), pc_marker_override);
+  movq(PP, new_pp);
+  set_constant_pool_allowed(true);
   if (extra_size != 0) {
     subq(RSP, Immediate(extra_size));
   }
@@ -3475,7 +3438,11 @@ void Assembler::EnterOsrFrame(intptr_t extra_size) {
 
 
 void Assembler::EnterStubFrame() {
-  EnterDartFrame(0, kNoRegister);
+  set_constant_pool_allowed(false);
+  EnterFrame(0);
+  pushq(Immediate(0));  // Push 0 in the saved PC area for stub frames.
+  pushq(PP);  // Save caller's pool pointer
+  LoadPoolPointer();
 }