VM: Use current isolate as immediate in per-isolate stubs.

runtime/vm/stub_code_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"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 727 matching lines @@
   // structure. Cache the Context pointer in the CTX register so that it is
   // available in generated code and calls to Isolate::Current() need not be
   // done. The assumption is that this register will never be clobbered by
   // compiled or runtime stub code.
 
   // Cache the new Context pointer into CTX while executing Dart code.
   __ movq(CTX, Address(kNewContextReg, VMHandles::kOffsetOfRawPtrInHandle));
 
   const Register kIsolateReg = RBX;
 
-  // Load Isolate pointer from Context structure into R8.
-  __ movq(kIsolateReg, FieldAddress(CTX, Context::isolate_offset()));
+  // Load Isolate pointer into kIsolateReg.
+  __ movq(kIsolateReg, Immediate(Isolate::CurrentAddress()));
 
   // Save the current VMTag on the stack.
   __ movq(RAX, Address(kIsolateReg, Isolate::vm_tag_offset()));
   __ pushq(RAX);
 #if defined(DEBUG)
   {
     Label ok;
     __ leaq(RAX, Address(RBP, kSavedVMTagSlotFromEntryFp * kWordSize));
     __ cmpq(RAX, RSP);
     __ j(EQUAL, &ok);
@@ skipping 81 matching lines @@
   __ movq(CTX, Address(CTX, VMHandles::kOffsetOfRawPtrInHandle));
 
   // Read the saved arguments descriptor array to obtain the number of passed
   // arguments.
   __ movq(kArgDescReg, Address(RBP, kArgumentsDescOffset));
   __ movq(R10, Address(kArgDescReg, VMHandles::kOffsetOfRawPtrInHandle));
   __ movq(RDX, FieldAddress(R10, ArgumentsDescriptor::count_offset()));
   // Get rid of arguments pushed on the stack.
   __ leaq(RSP, Address(RSP, RDX, TIMES_4, 0));  // RDX is a Smi.
 
-  // Load Isolate pointer from Context structure into CTX. Drop Context.
-  __ movq(kIsolateReg, FieldAddress(CTX, Context::isolate_offset()));
-
+  __ movq(kIsolateReg, Immediate(Isolate::CurrentAddress()));
   // Restore the saved Context pointer into the Isolate structure.
-  __ popq(RDX);
-  __ movq(Address(kIsolateReg, Isolate::top_context_offset()), RDX);
+  __ popq(Address(kIsolateReg, Isolate::top_context_offset()));
 
   // Restore the saved top exit frame info back into the Isolate structure.
-  __ popq(RDX);
-  __ movq(Address(kIsolateReg, Isolate::top_exit_frame_info_offset()), RDX);
+  __ popq(Address(kIsolateReg, Isolate::top_exit_frame_info_offset()));
 
   // Restore the current VMTag from the stack.
-  __ popq(RDX);
-  __ movq(Address(kIsolateReg, Isolate::vm_tag_offset()), RDX);
+  __ popq(Address(kIsolateReg, Isolate::vm_tag_offset()));
 
   // Restore C++ ABI callee-saved registers.
   __ PopRegisters(CallingConventions::kCalleeSaveCpuRegisters,
                   CallingConventions::kCalleeSaveXmmRegisters);
 
   // Restore the frame pointer.
   __ LeaveFrame();
 
   __ ret();
 }
 
 
 // Called for inline allocation of contexts.
 // Input:
 // R10: number of context variables.
 // Output:
 // RAX: new allocated RawContext object.
 void StubCode::GenerateAllocateContextStub(Assembler* assembler) {
   __ LoadObject(R12, Object::null_object(), PP);
   if (FLAG_inline_alloc) {
     const Class& context_class = Class::ZoneHandle(Object::context_class());
     Label slow_case;
-    Heap* heap = Isolate::Current()->heap();
+    Isolate* isolate = Isolate::Current();
+    Heap* heap = isolate->heap();
     // First compute the rounded instance size.
     // R10: number of context variables.
     intptr_t fixed_size = (sizeof(RawContext) + kObjectAlignment - 1);
     __ leaq(R13, Address(R10, TIMES_8, fixed_size));
     __ andq(R13, Immediate(-kObjectAlignment));
 
     // Now allocate the object.
     // R10: number of context variables.
     __ movq(RAX, Immediate(heap->TopAddress()));
     __ movq(RAX, Address(RAX, 0));
@@ skipping 46 matching lines @@
              Immediate(RawObject::ClassIdTag::encode(context_class.id())));
       __ movq(FieldAddress(RAX, Context::tags_offset()), R13);  // Tags.
     }
 
     // Setup up number of context variables field.
     // RAX: new object.
     // R10: number of context variables as integer value (not object).
     __ movq(FieldAddress(RAX, Context::num_variables_offset()), R10);
 
     // Setup isolate field.
-    // Load Isolate pointer from Context structure into R13.
     // RAX: new object.
     // R10: number of context variables.
-    __ movq(R13, FieldAddress(CTX, Context::isolate_offset()));
     // R13: Isolate, not an object.
-    __ movq(FieldAddress(RAX, Context::isolate_offset()), R13);
+    __ movq(FieldAddress(RAX, Context::isolate_offset()),
+            Immediate(Isolate::CurrentAddress()));
 
     // Setup the parent field.
     // RAX: new object.
     // R10: number of context variables.
     __ movq(FieldAddress(RAX, Context::parent_offset()), R12);
 
     // Initialize the context variables.
     // RAX: new object.
     // R10: number of context variables.
     {
@@ skipping 49 matching lines @@
   __ testq(RCX, Immediate(1 << RawObject::kRememberedBit));
   __ j(EQUAL, &add_to_buffer, Assembler::kNearJump);
   __ popq(RCX);
   __ popq(RDX);
   __ ret();
 
   __ Bind(&add_to_buffer);
   __ orq(RCX, Immediate(1 << RawObject::kRememberedBit));
   __ movq(FieldAddress(RAX, Object::tags_offset()), RCX);
 
-  // Load the isolate out of the context.
+  // Load the isolate.
   // RAX: Address being stored
-  __ movq(RDX, FieldAddress(CTX, Context::isolate_offset()));
+  __ movq(RDX, Immediate(Isolate::CurrentAddress()));
 
   // Load the StoreBuffer block out of the isolate. Then load top_ out of the
   // StoreBufferBlock and add the address to the pointers_.
   // RAX: Address being stored
   // RDX: Isolate
   __ movq(RDX, Address(RDX, Isolate::store_buffer_offset()));
   __ movl(RCX, Address(RDX, StoreBufferBlock::top_offset()));
   __ movq(Address(RDX, RCX, TIMES_8, StoreBufferBlock::pointers_offset()), RAX);
 
   // Increment top_ and check for overflow.
   // RCX: top_
   // RDX: StoreBufferBlock
   Label L;
   __ incq(RCX);
   __ movl(Address(RDX, StoreBufferBlock::top_offset()), RCX);
   __ cmpl(RCX, Immediate(StoreBufferBlock::kSize));
   // Restore values.
   __ popq(RCX);
   __ popq(RDX);
   __ j(EQUAL, &L, Assembler::kNearJump);
   __ ret();
 
   // Handle overflow: Call the runtime leaf function.
   __ Bind(&L);
   // Setup frame, push callee-saved registers.
   __ EnterCallRuntimeFrame(0);
-  __ movq(CallingConventions::kArg1Reg,
-          FieldAddress(CTX, Context::isolate_offset()));
+  __ movq(CallingConventions::kArg1Reg, Immediate(Isolate::CurrentAddress()));
   __ CallRuntime(kStoreBufferBlockProcessRuntimeEntry, 1);
   __ LeaveCallRuntimeFrame();
   __ ret();
 }
 
 
 // Called for inline allocation of objects.
 // Input parameters:
 //   RSP + 8 : type arguments object (only if class is parameterized).
 //   RSP : points to return address.
@@ skipping 282 matching lines @@
     __ movl(RCX, FieldAddress(RBX, ICData::state_bits_offset()));
     ASSERT(ICData::NumArgsTestedShift() == 0);  // No shift needed.
     __ andq(RCX, Immediate(ICData::NumArgsTestedMask()));
     __ cmpq(RCX, Immediate(num_args));
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ Stop("Incorrect stub for IC data");
     __ Bind(&ok);
   }
 #endif  // DEBUG
 
+  // Check single stepping.
   Label stepping, done_stepping;
-  // Check single stepping.
-  __ movq(RAX, FieldAddress(CTX, Context::isolate_offset()));
+  __ movq(RAX, Immediate(Isolate::CurrentAddress()));
   __ cmpb(Address(RAX, Isolate::single_step_offset()), Immediate(0));
   __ j(NOT_EQUAL, &stepping);
   __ Bind(&done_stepping);
 
   if (kind != Token::kILLEGAL) {
     Label not_smi_or_overflow;
     EmitFastSmiOp(assembler, kind, num_args, &not_smi_or_overflow);
     __ Bind(&not_smi_or_overflow);
   }
 
@@ skipping 210 matching lines @@
     __ andq(RCX, Immediate(ICData::NumArgsTestedMask()));
     __ cmpq(RCX, Immediate(0));
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ Stop("Incorrect IC data for unoptimized static call");
     __ Bind(&ok);
   }
 #endif  // DEBUG
 
   // Check single stepping.
   Label stepping, done_stepping;
-  __ movq(RAX, FieldAddress(CTX, Context::isolate_offset()));
+  __ movq(RAX, Immediate(Isolate::CurrentAddress()));
   __ movzxb(RAX, Address(RAX, Isolate::single_step_offset()));
   __ cmpq(RAX, Immediate(0));
   __ j(NOT_EQUAL, &stepping, Assembler::kNearJump);
   __ Bind(&done_stepping);
 
   // RBX: IC data object (preserved).
   __ movq(R12, FieldAddress(RBX, ICData::ic_data_offset()));
   // R12: ic_data_array with entries: target functions and count.
   __ leaq(R12, FieldAddress(R12, Array::data_offset()));
   // R12: points directly to the first ic data array element.
@@ skipping 421 matching lines @@
 
   __ movq(left, Address(RSP, 2 * kWordSize));
   __ movq(right, Address(RSP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64