Remove isolate pointer from context objects.

runtime/vm/stub_code_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/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 27 matching lines @@
   const intptr_t isolate_offset = NativeArguments::isolate_offset();
   const intptr_t argc_tag_offset = NativeArguments::argc_tag_offset();
   const intptr_t argv_offset = NativeArguments::argv_offset();
   const intptr_t retval_offset = NativeArguments::retval_offset();
   const intptr_t exitframe_last_param_slot_from_fp = 2;
 
   __ mov(IP, Operand(0));
   __ Push(IP);  // Push 0 for the PC marker.
   __ EnterFrame((1 << FP) | (1 << LR), 0);
 
-  // Load current Isolate pointer from Context structure into R0.
-  __ ldr(R0, FieldAddress(CTX, Context::isolate_offset()));
+  __ LoadIsolate(R0);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to Dart VM C++ code.
   __ StoreToOffset(kWord, SP, R0, Isolate::top_exit_frame_info_offset());
 
   // Save current Context pointer into Isolate structure.
   __ StoreToOffset(kWord, CTX, R0, Isolate::top_context_offset());
 
   // Cache Isolate pointer into CTX while executing runtime code.
   __ mov(CTX, Operand(R0));
@@ skipping 92 matching lines @@
 void StubCode::GenerateCallNativeCFunctionStub(Assembler* assembler) {
   const intptr_t isolate_offset = NativeArguments::isolate_offset();
   const intptr_t argc_tag_offset = NativeArguments::argc_tag_offset();
   const intptr_t argv_offset = NativeArguments::argv_offset();
   const intptr_t retval_offset = NativeArguments::retval_offset();
 
   __ mov(IP, Operand(0));
   __ Push(IP);  // Push 0 for the PC marker.
   __ EnterFrame((1 << FP) | (1 << LR), 0);
 
-  // Load current Isolate pointer from Context structure into R0.
-  __ ldr(R0, FieldAddress(CTX, Context::isolate_offset()));
+  __ LoadIsolate(R0);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
   __ StoreToOffset(kWord, SP, R0, Isolate::top_exit_frame_info_offset());
 
   // Save current Context pointer into Isolate structure.
   __ StoreToOffset(kWord, CTX, R0, Isolate::top_context_offset());
 
   // Cache Isolate pointer into CTX while executing native code.
   __ mov(CTX, Operand(R0));
@@ skipping 86 matching lines @@
 void StubCode::GenerateCallBootstrapCFunctionStub(Assembler* assembler) {
   const intptr_t isolate_offset = NativeArguments::isolate_offset();
   const intptr_t argc_tag_offset = NativeArguments::argc_tag_offset();
   const intptr_t argv_offset = NativeArguments::argv_offset();
   const intptr_t retval_offset = NativeArguments::retval_offset();
 
   __ mov(IP, Operand(0));
   __ Push(IP);  // Push 0 for the PC marker.
   __ EnterFrame((1 << FP) | (1 << LR), 0);
 
-  // Load current Isolate pointer from Context structure into R0.
-  __ ldr(R0, FieldAddress(CTX, Context::isolate_offset()));
+  __ LoadIsolate(R0);
 
   // Save exit frame information to enable stack walking as we are about
   // to transition to native code.
   __ StoreToOffset(kWord, SP, R0, Isolate::top_exit_frame_info_offset());
 
   // Save current Context pointer into Isolate structure.
   __ StoreToOffset(kWord, CTX, R0, Isolate::top_context_offset());
 
   // Cache Isolate pointer into CTX while executing native code.
   __ mov(CTX, Operand(R0));
@@ skipping 526 matching lines @@
 
   // The new Context structure contains a pointer to the current Isolate
   // 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.
   __ ldr(CTX, Address(R3, VMHandles::kOffsetOfRawPtrInHandle));
 
-  // Load Isolate pointer into temporary register R8.
   __ LoadIsolate(R8);
 
   // Save the current VMTag on the stack.
   ASSERT(kSavedVMTagSlotFromEntryFp == -25);
   __ LoadFromOffset(kWord, R5, R8, Isolate::vm_tag_offset());
   __ Push(R5);
 
   // Mark that the isolate is executing Dart code.
   __ LoadImmediate(R5, VMTag::kDartTagId);
   __ StoreToOffset(kWord, R5, R8, Isolate::vm_tag_offset());
@@ skipping 152 matching lines @@
     __ orr(R3, R3, Operand(IP));
     __ str(R3, FieldAddress(R0, Context::tags_offset()));
 
     // Setup up number of context variables field.
     // R0: new object.
     // R1: number of context variables as integer value (not object).
     // R2: object size.
     // R4: allocation stats address.
     __ str(R1, FieldAddress(R0, Context::num_variables_offset()));
 
-    // Setup isolate field.
-    // Load Isolate pointer into R3.
-    // R0: new object.
-    // R1: number of context variables.
-    // R2: object size.
-    // R4: allocation stats address.
-    __ LoadIsolate(R3);
-    // R3: isolate, not an object.
-    __ str(R3, FieldAddress(R0, Context::isolate_offset()));
-
     // Setup the parent field.
     // R0: new object.
     // R1: number of context variables.
     // R2: object size.
     // R4: allocation stats address.
     __ LoadImmediate(R3, reinterpret_cast<intptr_t>(Object::null()));
     __ str(R3, FieldAddress(R0, Context::parent_offset()));
 
     // Initialize the context variables.
     // R0: new object.
@@ skipping 743 matching lines @@
   __ LeaveStubFrame();
   __ bx(R0);
 }
 
 
 // Called only from unoptimized code. All relevant registers have been saved.
 void StubCode::GenerateDebugStepCheckStub(
     Assembler* assembler) {
   // Check single stepping.
   Label stepping, done_stepping;
-  __ ldr(R1, FieldAddress(CTX, Context::isolate_offset()));
+  __ LoadIsolate(R1);
   __ ldrb(R1, Address(R1, Isolate::single_step_offset()));
   __ CompareImmediate(R1, 0);
   __ b(&stepping, NE);
   __ Bind(&done_stepping);
   __ Ret();
 
   __ Bind(&stepping);
   __ EnterStubFrame();
   __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
   __ LeaveStubFrame();
@@ skipping 239 matching lines @@
 
 // Called only from unoptimized code. All relevant registers have been saved.
 // LR: return address.
 // SP + 4: left operand.
 // SP + 0: right operand.
 // Return Zero condition flag set if equal.
 void StubCode::GenerateUnoptimizedIdenticalWithNumberCheckStub(
     Assembler* assembler) {
   // Check single stepping.
   Label stepping, done_stepping;
-  __ ldr(R1, FieldAddress(CTX, Context::isolate_offset()));
+  __ LoadIsolate(R1);
   __ ldrb(R1, Address(R1, Isolate::single_step_offset()));
   __ CompareImmediate(R1, 0);
   __ b(&stepping, NE);
   __ Bind(&done_stepping);
 
   const Register temp = R2;
   const Register left = R1;
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
@@ skipping 20 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM