Move backend specific files to separate directories.

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
new file mode 100644
index 0000000000000000000000000000000000000000..365c1ad7f2e305cc0bd880eeb46bd9b4ffbc2edb
--- /dev/null
+++ b/src/arm/macro-assembler-arm.cc
@@ -0,0 +1,941 @@
+// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "v8.h"
+
+#include "bootstrapper.h"
+#include "codegen-inl.h"
+#include "debug.h"
+#include "runtime.h"
+
+namespace v8 { namespace internal {
+
+// Give alias names to registers
+Register cp = {  8 };  // JavaScript context pointer
+Register pp = { 10 };  // parameter pointer
+
+
+MacroAssembler::MacroAssembler(void* buffer, int size)
+    : Assembler(buffer, size),
+      unresolved_(0),
+      generating_stub_(false),
+      allow_stub_calls_(true),
+      code_object_(Heap::undefined_value()) {
+}
+
+
+// We always generate arm code, never thumb code, even if V8 is compiled to
+// thumb, so we require inter-working support
+#if defined(__thumb__) && !defined(__THUMB_INTERWORK__)
+#error "flag -mthumb-interwork missing"
+#endif
+
+
+// We do not support thumb inter-working with an arm architecture not supporting
+// the blx instruction (below v5t)
+#if defined(__THUMB_INTERWORK__)
+#if !defined(__ARM_ARCH_5T__) && !defined(__ARM_ARCH_5TE__)
+// add tests for other versions above v5t as required
+#error "for thumb inter-working we require architecture v5t or above"
+#endif
+#endif
+
+
+// Using blx may yield better code, so use it when required or when available
+#if defined(__THUMB_INTERWORK__) || defined(__ARM_ARCH_5__)
+#define USE_BLX 1
+#endif
+
+// Using bx does not yield better code, so use it only when required
+#if defined(__THUMB_INTERWORK__)
+#define USE_BX 1
+#endif
+
+
+void MacroAssembler::Jump(Register target, Condition cond) {
+#if USE_BX
+  bx(target, cond);
+#else
+  mov(pc, Operand(target), LeaveCC, cond);
+#endif
+}
+
+
+void MacroAssembler::Jump(intptr_t target, RelocInfo::Mode rmode,
+                          Condition cond) {
+#if USE_BX
+  mov(ip, Operand(target, rmode), LeaveCC, cond);
+  bx(ip, cond);
+#else
+  mov(pc, Operand(target, rmode), LeaveCC, cond);
+#endif
+}
+
+
+void MacroAssembler::Jump(byte* target, RelocInfo::Mode rmode,
+                          Condition cond) {
+  ASSERT(!RelocInfo::IsCodeTarget(rmode));
+  Jump(reinterpret_cast<intptr_t>(target), rmode, cond);
+}
+
+
+void MacroAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
+                          Condition cond) {
+  ASSERT(RelocInfo::IsCodeTarget(rmode));
+  // 'code' is always generated ARM code, never THUMB code
+  Jump(reinterpret_cast<intptr_t>(code.location()), rmode, cond);
+}
+
+
+void MacroAssembler::Call(Register target, Condition cond) {
+#if USE_BLX
+  blx(target, cond);
+#else
+  // set lr for return at current pc + 8
+  mov(lr, Operand(pc), LeaveCC, cond);
+  mov(pc, Operand(target), LeaveCC, cond);
+#endif
+}
+
+
+void MacroAssembler::Call(intptr_t target, RelocInfo::Mode rmode,
+                          Condition cond) {
+#if !defined(__arm__)
+  if (rmode == RelocInfo::RUNTIME_ENTRY) {
+    mov(r2, Operand(target, rmode), LeaveCC, cond);
+    // Set lr for return at current pc + 8.
+    mov(lr, Operand(pc), LeaveCC, cond);
+    // Emit a ldr<cond> pc, [pc + offset of target in constant pool].
+    // Notify the simulator of the transition to C code.
+    swi(assembler::arm::call_rt_r2);
+  } else {
+    // set lr for return at current pc + 8
+    mov(lr, Operand(pc), LeaveCC, cond);
+    // emit a ldr<cond> pc, [pc + offset of target in constant pool]
+    mov(pc, Operand(target, rmode), LeaveCC, cond);
+  }
+#else
+  // Set lr for return at current pc + 8.
+  mov(lr, Operand(pc), LeaveCC, cond);
+  // Emit a ldr<cond> pc, [pc + offset of target in constant pool].
+  mov(pc, Operand(target, rmode), LeaveCC, cond);
+#endif  // !defined(__arm__)
+  // If USE_BLX is defined, we could emit a 'mov ip, target', followed by a
+  // 'blx ip'; however, the code would not be shorter than the above sequence
+  // and the target address of the call would be referenced by the first
+  // instruction rather than the second one, which would make it harder to patch
+  // (two instructions before the return address, instead of one).
+  ASSERT(kTargetAddrToReturnAddrDist == sizeof(Instr));
+}
+
+
+void MacroAssembler::Call(byte* target, RelocInfo::Mode rmode,
+                          Condition cond) {
+  ASSERT(!RelocInfo::IsCodeTarget(rmode));
+  Call(reinterpret_cast<intptr_t>(target), rmode, cond);
+}
+
+
+void MacroAssembler::Call(Handle<Code> code, RelocInfo::Mode rmode,
+                          Condition cond) {
+  ASSERT(RelocInfo::IsCodeTarget(rmode));
+  // 'code' is always generated ARM code, never THUMB code
+  Call(reinterpret_cast<intptr_t>(code.location()), rmode, cond);
+}
+
+
+void MacroAssembler::Ret(Condition cond) {
+#if USE_BX
+  bx(lr, cond);
+#else
+  mov(pc, Operand(lr), LeaveCC, cond);
+#endif
+}
+
+
+void MacroAssembler::SmiJumpTable(Register index, Vector<Label*> targets) {
+  // Empty the const pool.
+  CheckConstPool(true, true);
+  add(pc, pc, Operand(index,
+                      LSL,
+                      assembler::arm::Instr::kInstrSizeLog2 - kSmiTagSize));
+  BlockConstPoolBefore(pc_offset() + (targets.length() + 1) * sizeof(Instr));
+  nop();  // Jump table alignment.
+  for (int i = 0; i < targets.length(); i++) {
+    b(targets[i]);
+  }
+}
+
+
+// Will clobber 4 registers: object, offset, scratch, ip.  The
+// register 'object' contains a heap object pointer.  The heap object
+// tag is shifted away.
+void MacroAssembler::RecordWrite(Register object, Register offset,
+                                 Register scratch) {
+  // This is how much we shift the remembered set bit offset to get the
+  // offset of the word in the remembered set.  We divide by kBitsPerInt (32,
+  // shift right 5) and then multiply by kIntSize (4, shift left 2).
+  const int kRSetWordShift = 3;
+
+  Label fast, done;
+
+  // First, test that the object is not in the new space.  We cannot set
+  // remembered set bits in the new space.
+  // object: heap object pointer (with tag)
+  // offset: offset to store location from the object
+  and_(scratch, object, Operand(Heap::NewSpaceMask()));
+  cmp(scratch, Operand(ExternalReference::new_space_start()));
+  b(eq, &done);
+
+  // Compute the bit offset in the remembered set.
+  // object: heap object pointer (with tag)
+  // offset: offset to store location from the object
+  mov(ip, Operand(Page::kPageAlignmentMask));  // load mask only once
+  and_(scratch, object, Operand(ip));  // offset into page of the object
+  add(offset, scratch, Operand(offset));  // add offset into the object
+  mov(offset, Operand(offset, LSR, kObjectAlignmentBits));
+
+  // Compute the page address from the heap object pointer.
+  // object: heap object pointer (with tag)
+  // offset: bit offset of store position in the remembered set
+  bic(object, object, Operand(ip));
+
+  // If the bit offset lies beyond the normal remembered set range, it is in
+  // the extra remembered set area of a large object.
+  // object: page start
+  // offset: bit offset of store position in the remembered set
+  cmp(offset, Operand(Page::kPageSize / kPointerSize));
+  b(lt, &fast);
+
+  // Adjust the bit offset to be relative to the start of the extra
+  // remembered set and the start address to be the address of the extra
+  // remembered set.
+  sub(offset, offset, Operand(Page::kPageSize / kPointerSize));
+  // Load the array length into 'scratch' and multiply by four to get the
+  // size in bytes of the elements.
+  ldr(scratch, MemOperand(object, Page::kObjectStartOffset
+                                  + FixedArray::kLengthOffset));
+  mov(scratch, Operand(scratch, LSL, kObjectAlignmentBits));
+  // Add the page header (including remembered set), array header, and array
+  // body size to the page address.
+  add(object, object, Operand(Page::kObjectStartOffset
+                              + Array::kHeaderSize));
+  add(object, object, Operand(scratch));
+
+  bind(&fast);
+  // Get address of the rset word.
+  // object: start of the remembered set (page start for the fast case)
+  // offset: bit offset of store position in the remembered set
+  bic(scratch, offset, Operand(kBitsPerInt - 1));  // clear the bit offset
+  add(object, object, Operand(scratch, LSR, kRSetWordShift));
+  // Get bit offset in the rset word.
+  // object: address of remembered set word
+  // offset: bit offset of store position
+  and_(offset, offset, Operand(kBitsPerInt - 1));
+
+  ldr(scratch, MemOperand(object));
+  mov(ip, Operand(1));
+  orr(scratch, scratch, Operand(ip, LSL, offset));
+  str(scratch, MemOperand(object));
+
+  bind(&done);
+}
+
+
+void MacroAssembler::EnterFrame(StackFrame::Type type) {
+  // r0-r3: preserved
+  stm(db_w, sp, cp.bit() | fp.bit() | lr.bit());
+  mov(ip, Operand(Smi::FromInt(type)));
+  push(ip);
+  mov(ip, Operand(CodeObject()));
+  push(ip);
+  add(fp, sp, Operand(3 * kPointerSize));  // Adjust FP to point to saved FP.
+}
+
+
+void MacroAssembler::LeaveFrame(StackFrame::Type type) {
+  // r0: preserved
+  // r1: preserved
+  // r2: preserved
+
+  // Drop the execution stack down to the frame pointer and restore
+  // the caller frame pointer and return address.
+  mov(sp, fp);
+  ldm(ia_w, sp, fp.bit() | lr.bit());
+}
+
+
+void MacroAssembler::EnterExitFrame(StackFrame::Type type) {
+  ASSERT(type == StackFrame::EXIT || type == StackFrame::EXIT_DEBUG);
+  // Compute parameter pointer before making changes and save it as ip
+  // register so that it is restored as sp register on exit, thereby
+  // popping the args.
+
+  // ip = sp + kPointerSize * #args;
+  add(ip, sp, Operand(r0, LSL, kPointerSizeLog2));
+
+  // Push in reverse order: caller_fp, sp_on_exit, and caller_pc.
+  stm(db_w, sp, fp.bit() | ip.bit() | lr.bit());
+  mov(fp, Operand(sp));  // setup new frame pointer
+
+  // Push debug marker.
+  mov(ip, Operand(type == StackFrame::EXIT_DEBUG ? 1 : 0));
+  push(ip);
+
+  // Save the frame pointer and the context in top.
+  mov(ip, Operand(ExternalReference(Top::k_c_entry_fp_address)));
+  str(fp, MemOperand(ip));
+  mov(ip, Operand(ExternalReference(Top::k_context_address)));
+  str(cp, MemOperand(ip));
+
+  // Setup argc and the builtin function in callee-saved registers.
+  mov(r4, Operand(r0));
+  mov(r5, Operand(r1));
+
+  // Compute the argv pointer and keep it in a callee-saved register.
+  add(r6, fp, Operand(r4, LSL, kPointerSizeLog2));
+  add(r6, r6, Operand(ExitFrameConstants::kPPDisplacement - kPointerSize));
+
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  // Save the state of all registers to the stack from the memory
+  // location. This is needed to allow nested break points.
+  if (type == StackFrame::EXIT_DEBUG) {
+    // Use sp as base to push.
+    CopyRegistersFromMemoryToStack(sp, kJSCallerSaved);
+  }
+#endif
+}
+
+
+void MacroAssembler::LeaveExitFrame(StackFrame::Type type) {
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  // Restore the memory copy of the registers by digging them out from
+  // the stack. This is needed to allow nested break points.
+  if (type == StackFrame::EXIT_DEBUG) {
+    // This code intentionally clobbers r2 and r3.
+    const int kCallerSavedSize = kNumJSCallerSaved * kPointerSize;
+    const int kOffset = ExitFrameConstants::kDebugMarkOffset - kCallerSavedSize;
+    add(r3, fp, Operand(kOffset));
+    CopyRegistersFromStackToMemory(r3, r2, kJSCallerSaved);
+  }
+#endif
+
+  // Clear top frame.
+  mov(r3, Operand(0));
+  mov(ip, Operand(ExternalReference(Top::k_c_entry_fp_address)));
+  str(r3, MemOperand(ip));
+
+  // Restore current context from top and clear it in debug mode.
+  mov(ip, Operand(ExternalReference(Top::k_context_address)));
+  ldr(cp, MemOperand(ip));
+#ifdef DEBUG
+  str(r3, MemOperand(ip));
+#endif
+
+  // Pop the arguments, restore registers, and return.
+  mov(sp, Operand(fp));  // respect ABI stack constraint
+  ldm(ia, sp, fp.bit() | sp.bit() | pc.bit());
+}
+
+
+void MacroAssembler::InvokePrologue(const ParameterCount& expected,
+                                    const ParameterCount& actual,
+                                    Handle<Code> code_constant,
+                                    Register code_reg,
+                                    Label* done,
+                                    InvokeFlag flag) {
+  bool definitely_matches = false;
+  Label regular_invoke;
+
+  // Check whether the expected and actual arguments count match. If not,
+  // setup registers according to contract with ArgumentsAdaptorTrampoline:
+  //  r0: actual arguments count
+  //  r1: function (passed through to callee)
+  //  r2: expected arguments count
+  //  r3: callee code entry
+
+  // The code below is made a lot easier because the calling code already sets
+  // up actual and expected registers according to the contract if values are
+  // passed in registers.
+  ASSERT(actual.is_immediate() || actual.reg().is(r0));
+  ASSERT(expected.is_immediate() || expected.reg().is(r2));
+  ASSERT((!code_constant.is_null() && code_reg.is(no_reg)) || code_reg.is(r3));
+
+  if (expected.is_immediate()) {
+    ASSERT(actual.is_immediate());
+    if (expected.immediate() == actual.immediate()) {
+      definitely_matches = true;
+    } else {
+      mov(r0, Operand(actual.immediate()));
+      const int sentinel = SharedFunctionInfo::kDontAdaptArgumentsSentinel;
+      if (expected.immediate() == sentinel) {
+        // Don't worry about adapting arguments for builtins that
+        // don't want that done. Skip adaption code by making it look
+        // like we have a match between expected and actual number of
+        // arguments.
+        definitely_matches = true;
+      } else {
+        mov(r2, Operand(expected.immediate()));
+      }
+    }
+  } else {
+    if (actual.is_immediate()) {
+      cmp(expected.reg(), Operand(actual.immediate()));
+      b(eq, &regular_invoke);
+      mov(r0, Operand(actual.immediate()));
+    } else {
+      cmp(expected.reg(), Operand(actual.reg()));
+      b(eq, &regular_invoke);
+    }
+  }
+
+  if (!definitely_matches) {
+    if (!code_constant.is_null()) {
+      mov(r3, Operand(code_constant));
+      add(r3, r3, Operand(Code::kHeaderSize - kHeapObjectTag));
+    }
+
+    Handle<Code> adaptor =
+        Handle<Code>(Builtins::builtin(Builtins::ArgumentsAdaptorTrampoline));
+    if (flag == CALL_FUNCTION) {
+      Call(adaptor, RelocInfo::CODE_TARGET);
+      b(done);
+    } else {
+      Jump(adaptor, RelocInfo::CODE_TARGET);
+    }
+    bind(&regular_invoke);
+  }
+}
+
+
+void MacroAssembler::InvokeCode(Register code,
+                                const ParameterCount& expected,
+                                const ParameterCount& actual,
+                                InvokeFlag flag) {
+  Label done;
+
+  InvokePrologue(expected, actual, Handle<Code>::null(), code, &done, flag);
+  if (flag == CALL_FUNCTION) {
+    Call(code);
+  } else {
+    ASSERT(flag == JUMP_FUNCTION);
+    Jump(code);
+  }
+
+  // Continue here if InvokePrologue does handle the invocation due to
+  // mismatched parameter counts.
+  bind(&done);
+}
+
+
+void MacroAssembler::InvokeCode(Handle<Code> code,
+                                const ParameterCount& expected,
+                                const ParameterCount& actual,
+                                RelocInfo::Mode rmode,
+                                InvokeFlag flag) {
+  Label done;
+
+  InvokePrologue(expected, actual, code, no_reg, &done, flag);
+  if (flag == CALL_FUNCTION) {
+    Call(code, rmode);
+  } else {
+    Jump(code, rmode);
+  }
+
+  // Continue here if InvokePrologue does handle the invocation due to
+  // mismatched parameter counts.
+  bind(&done);
+}
+
+
+void MacroAssembler::InvokeFunction(Register fun,
+                                    const ParameterCount& actual,
+                                    InvokeFlag flag) {
+  // Contract with called JS functions requires that function is passed in r1.
+  ASSERT(fun.is(r1));
+
+  Register expected_reg = r2;
+  Register code_reg = r3;
+
+  ldr(code_reg, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
+  ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
+  ldr(expected_reg,
+      FieldMemOperand(code_reg,
+                      SharedFunctionInfo::kFormalParameterCountOffset));
+  ldr(code_reg,
+      MemOperand(code_reg, SharedFunctionInfo::kCodeOffset - kHeapObjectTag));
+  add(code_reg, code_reg, Operand(Code::kHeaderSize - kHeapObjectTag));
+
+  ParameterCount expected(expected_reg);
+  InvokeCode(code_reg, expected, actual, flag);
+}
+
+
+#ifdef ENABLE_DEBUGGER_SUPPORT
+void MacroAssembler::SaveRegistersToMemory(RegList regs) {
+  ASSERT((regs & ~kJSCallerSaved) == 0);
+  // Copy the content of registers to memory location.
+  for (int i = 0; i < kNumJSCallerSaved; i++) {
+    int r = JSCallerSavedCode(i);
+    if ((regs & (1 << r)) != 0) {
+      Register reg = { r };
+      mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
+      str(reg, MemOperand(ip));
+    }
+  }
+}
+
+
+void MacroAssembler::RestoreRegistersFromMemory(RegList regs) {
+  ASSERT((regs & ~kJSCallerSaved) == 0);
+  // Copy the content of memory location to registers.
+  for (int i = kNumJSCallerSaved; --i >= 0;) {
+    int r = JSCallerSavedCode(i);
+    if ((regs & (1 << r)) != 0) {
+      Register reg = { r };
+      mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
+      ldr(reg, MemOperand(ip));
+    }
+  }
+}
+
+
+void MacroAssembler::CopyRegistersFromMemoryToStack(Register base,
+                                                    RegList regs) {
+  ASSERT((regs & ~kJSCallerSaved) == 0);
+  // Copy the content of the memory location to the stack and adjust base.
+  for (int i = kNumJSCallerSaved; --i >= 0;) {
+    int r = JSCallerSavedCode(i);
+    if ((regs & (1 << r)) != 0) {
+      mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
+      ldr(ip, MemOperand(ip));
+      str(ip, MemOperand(base, 4, NegPreIndex));
+    }
+  }
+}
+
+
+void MacroAssembler::CopyRegistersFromStackToMemory(Register base,
+                                                    Register scratch,
+                                                    RegList regs) {
+  ASSERT((regs & ~kJSCallerSaved) == 0);
+  // Copy the content of the stack to the memory location and adjust base.
+  for (int i = 0; i < kNumJSCallerSaved; i++) {
+    int r = JSCallerSavedCode(i);
+    if ((regs & (1 << r)) != 0) {
+      mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
+      ldr(scratch, MemOperand(base, 4, PostIndex));
+      str(scratch, MemOperand(ip));
+    }
+  }
+}
+#endif
+
+void MacroAssembler::PushTryHandler(CodeLocation try_location,
+                                    HandlerType type) {
+  ASSERT(StackHandlerConstants::kSize == 6 * kPointerSize);  // adjust this code
+  // The pc (return address) is passed in register lr.
+  if (try_location == IN_JAVASCRIPT) {
+    stm(db_w, sp, pp.bit() | fp.bit() | lr.bit());
+    if (type == TRY_CATCH_HANDLER) {
+      mov(r3, Operand(StackHandler::TRY_CATCH));
+    } else {
+      mov(r3, Operand(StackHandler::TRY_FINALLY));
+    }
+    push(r3);  // state
+    mov(r3, Operand(ExternalReference(Top::k_handler_address)));
+    ldr(r1, MemOperand(r3));
+    push(r1);  // next sp
+    str(sp, MemOperand(r3));  // chain handler
+    mov(r0, Operand(Smi::FromInt(StackHandler::kCodeNotPresent)));  // new TOS
+    push(r0);
+  } else {
+    // Must preserve r0-r4, r5-r7 are available.
+    ASSERT(try_location == IN_JS_ENTRY);
+    // The parameter pointer is meaningless here and fp does not point to a JS
+    // frame. So we save NULL for both pp and fp. We expect the code throwing an
+    // exception to check fp before dereferencing it to restore the context.
+    mov(pp, Operand(0));  // set pp to NULL
+    mov(ip, Operand(0));  // to save a NULL fp
+    stm(db_w, sp, pp.bit() | ip.bit() | lr.bit());
+    mov(r6, Operand(StackHandler::ENTRY));
+    push(r6);  // state
+    mov(r7, Operand(ExternalReference(Top::k_handler_address)));
+    ldr(r6, MemOperand(r7));
+    push(r6);  // next sp
+    str(sp, MemOperand(r7));  // chain handler
+    mov(r5, Operand(Smi::FromInt(StackHandler::kCodeNotPresent)));  // new TOS
+    push(r5);  // flush TOS
+  }
+}
+
+
+Register MacroAssembler::CheckMaps(JSObject* object, Register object_reg,
+                                   JSObject* holder, Register holder_reg,
+                                   Register scratch,
+                                   Label* miss) {
+  // Make sure there's no overlap between scratch and the other
+  // registers.
+  ASSERT(!scratch.is(object_reg) && !scratch.is(holder_reg));
+
+  // Keep track of the current object in register reg.
+  Register reg = object_reg;
+  int depth = 1;
+
+  // Check the maps in the prototype chain.
+  // Traverse the prototype chain from the object and do map checks.
+  while (object != holder) {
+    depth++;
+
+    // Only global objects and objects that do not require access
+    // checks are allowed in stubs.
+    ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
+
+    // Get the map of the current object.
+    ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
+    cmp(scratch, Operand(Handle<Map>(object->map())));
+
+    // Branch on the result of the map check.
+    b(ne, miss);
+
+    // Check access rights to the global object.  This has to happen
+    // after the map check so that we know that the object is
+    // actually a global object.
+    if (object->IsJSGlobalProxy()) {
+      CheckAccessGlobalProxy(reg, scratch, miss);
+      // Restore scratch register to be the map of the object.  In the
+      // new space case below, we load the prototype from the map in
+      // the scratch register.
+      ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
+    }
+
+    reg = holder_reg;  // from now the object is in holder_reg
+    JSObject* prototype = JSObject::cast(object->GetPrototype());
+    if (Heap::InNewSpace(prototype)) {
+      // The prototype is in new space; we cannot store a reference
+      // to it in the code. Load it from the map.
+      ldr(reg, FieldMemOperand(scratch, Map::kPrototypeOffset));
+    } else {
+      // The prototype is in old space; load it directly.
+      mov(reg, Operand(Handle<JSObject>(prototype)));
+    }
+
+    // Go to the next object in the prototype chain.
+    object = prototype;
+  }
+
+  // Check the holder map.
+  ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
+  cmp(scratch, Operand(Handle<Map>(object->map())));
+  b(ne, miss);
+
+  // Log the check depth.
+  LOG(IntEvent("check-maps-depth", depth));
+
+  // Perform security check for access to the global object and return
+  // the holder register.
+  ASSERT(object == holder);
+  ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
+  if (object->IsJSGlobalProxy()) {
+    CheckAccessGlobalProxy(reg, scratch, miss);
+  }
+  return reg;
+}
+
+
+void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
+                                            Register scratch,
+                                            Label* miss) {
+  Label same_contexts;
+
+  ASSERT(!holder_reg.is(scratch));
+  ASSERT(!holder_reg.is(ip));
+  ASSERT(!scratch.is(ip));
+
+  // Load current lexical context from the stack frame.
+  ldr(scratch, MemOperand(fp, StandardFrameConstants::kContextOffset));
+  // In debug mode, make sure the lexical context is set.
+#ifdef DEBUG
+  cmp(scratch, Operand(0));
+  Check(ne, "we should not have an empty lexical context");
+#endif
+
+  // Load the global context of the current context.
+  int offset = Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
+  ldr(scratch, FieldMemOperand(scratch, offset));
+  ldr(scratch, FieldMemOperand(scratch, GlobalObject::kGlobalContextOffset));
+
+  // Check the context is a global context.
+  if (FLAG_debug_code) {
+    // TODO(119): avoid push(holder_reg)/pop(holder_reg)
+    // Cannot use ip as a temporary in this verification code. Due to the fact
+    // that ip is clobbered as part of cmp with an object Operand.
+    push(holder_reg);  // Temporarily save holder on the stack.
+    // Read the first word and compare to the global_context_map.
+    ldr(holder_reg, FieldMemOperand(scratch, HeapObject::kMapOffset));
+    cmp(holder_reg, Operand(Factory::global_context_map()));
+    Check(eq, "JSGlobalObject::global_context should be a global context.");
+    pop(holder_reg);  // Restore holder.
+  }
+
+  // Check if both contexts are the same.
+  ldr(ip, FieldMemOperand(holder_reg, JSGlobalProxy::kContextOffset));
+  cmp(scratch, Operand(ip));
+  b(eq, &same_contexts);
+
+  // Check the context is a global context.
+  if (FLAG_debug_code) {
+    // TODO(119): avoid push(holder_reg)/pop(holder_reg)
+    // Cannot use ip as a temporary in this verification code. Due to the fact
+    // that ip is clobbered as part of cmp with an object Operand.
+    push(holder_reg);  // Temporarily save holder on the stack.
+    mov(holder_reg, ip);  // Move ip to its holding place.
+    cmp(holder_reg, Operand(Factory::null_value()));
+    Check(ne, "JSGlobalProxy::context() should not be null.");
+
+    ldr(holder_reg, FieldMemOperand(holder_reg, HeapObject::kMapOffset));
+    cmp(holder_reg, Operand(Factory::global_context_map()));
+    Check(eq, "JSGlobalObject::global_context should be a global context.");
+    // Restore ip is not needed. ip is reloaded below.
+    pop(holder_reg);  // Restore holder.
+    // Restore ip to holder's context.
+    ldr(ip, FieldMemOperand(holder_reg, JSGlobalProxy::kContextOffset));
+  }
+
+  // Check that the security token in the calling global object is
+  // compatible with the security token in the receiving global
+  // object.
+  int token_offset = Context::kHeaderSize +
+                     Context::SECURITY_TOKEN_INDEX * kPointerSize;
+
+  ldr(scratch, FieldMemOperand(scratch, token_offset));
+  ldr(ip, FieldMemOperand(ip, token_offset));
+  cmp(scratch, Operand(ip));
+  b(ne, miss);
+
+  bind(&same_contexts);
+}
+
+
+void MacroAssembler::CallStub(CodeStub* stub) {
+  ASSERT(allow_stub_calls());  // stub calls are not allowed in some stubs
+  Call(stub->GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
+void MacroAssembler::StubReturn(int argc) {
+  ASSERT(argc >= 1 && generating_stub());
+  if (argc > 1)
+    add(sp, sp, Operand((argc - 1) * kPointerSize));
+  Ret();
+}
+
+
+void MacroAssembler::IllegalOperation(int num_arguments) {
+  if (num_arguments > 0) {
+    add(sp, sp, Operand(num_arguments * kPointerSize));
+  }
+  mov(r0, Operand(Factory::undefined_value()));
+}
+
+
+void MacroAssembler::CallRuntime(Runtime::Function* f, int num_arguments) {
+  // All parameters are on the stack.  r0 has the return value after call.
+
+  // If the expected number of arguments of the runtime function is
+  // constant, we check that the actual number of arguments match the
+  // expectation.
+  if (f->nargs >= 0 && f->nargs != num_arguments) {
+    IllegalOperation(num_arguments);
+    return;
+  }
+
+  Runtime::FunctionId function_id =
+      static_cast<Runtime::FunctionId>(f->stub_id);
+  RuntimeStub stub(function_id, num_arguments);
+  CallStub(&stub);
+}
+
+
+void MacroAssembler::CallRuntime(Runtime::FunctionId fid, int num_arguments) {
+  CallRuntime(Runtime::FunctionForId(fid), num_arguments);
+}
+
+
+void MacroAssembler::TailCallRuntime(const ExternalReference& ext,
+                                     int num_arguments) {
+  // TODO(1236192): Most runtime routines don't need the number of
+  // arguments passed in because it is constant. At some point we
+  // should remove this need and make the runtime routine entry code
+  // smarter.
+  mov(r0, Operand(num_arguments));
+  JumpToBuiltin(ext);
+}
+
+
+void MacroAssembler::JumpToBuiltin(const ExternalReference& builtin) {
+#if defined(__thumb__)
+  // Thumb mode builtin.
+  ASSERT((reinterpret_cast<intptr_t>(builtin.address()) & 1) == 1);
+#endif
+  mov(r1, Operand(builtin));
+  CEntryStub stub;
+  Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
+Handle<Code> MacroAssembler::ResolveBuiltin(Builtins::JavaScript id,
+                                            bool* resolved) {
+  // Contract with compiled functions is that the function is passed in r1.
+  int builtins_offset =
+      JSBuiltinsObject::kJSBuiltinsOffset + (id * kPointerSize);
+  ldr(r1, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  ldr(r1, FieldMemOperand(r1, GlobalObject::kBuiltinsOffset));
+  ldr(r1, FieldMemOperand(r1, builtins_offset));
+
+  return Builtins::GetCode(id, resolved);
+}
+
+
+void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
+                                   InvokeJSFlags flags) {
+  bool resolved;
+  Handle<Code> code = ResolveBuiltin(id, &resolved);
+
+  if (flags == CALL_JS) {
+    Call(code, RelocInfo::CODE_TARGET);
+  } else {
+    ASSERT(flags == JUMP_JS);
+    Jump(code, RelocInfo::CODE_TARGET);
+  }
+
+  if (!resolved) {
+    const char* name = Builtins::GetName(id);
+    int argc = Builtins::GetArgumentsCount(id);
+    uint32_t flags =
+        Bootstrapper::FixupFlagsArgumentsCount::encode(argc) |
+        Bootstrapper::FixupFlagsIsPCRelative::encode(true) |
+        Bootstrapper::FixupFlagsUseCodeObject::encode(false);
+    Unresolved entry = { pc_offset() - sizeof(Instr), flags, name };
+    unresolved_.Add(entry);
+  }
+}
+
+
+void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
+  bool resolved;
+  Handle<Code> code = ResolveBuiltin(id, &resolved);
+
+  mov(target, Operand(code));
+  if (!resolved) {
+    const char* name = Builtins::GetName(id);
+    int argc = Builtins::GetArgumentsCount(id);
+    uint32_t flags =
+        Bootstrapper::FixupFlagsArgumentsCount::encode(argc) |
+        Bootstrapper::FixupFlagsIsPCRelative::encode(true) |
+        Bootstrapper::FixupFlagsUseCodeObject::encode(true);
+    Unresolved entry = { pc_offset() - sizeof(Instr), flags, name };
+    unresolved_.Add(entry);
+  }
+
+  add(target, target, Operand(Code::kHeaderSize - kHeapObjectTag));
+}
+
+
+void MacroAssembler::SetCounter(StatsCounter* counter, int value,
+                                Register scratch1, Register scratch2) {
+  if (FLAG_native_code_counters && counter->Enabled()) {
+    mov(scratch1, Operand(value));
+    mov(scratch2, Operand(ExternalReference(counter)));
+    str(scratch1, MemOperand(scratch2));
+  }
+}
+
+
+void MacroAssembler::IncrementCounter(StatsCounter* counter, int value,
+                                      Register scratch1, Register scratch2) {
+  ASSERT(value > 0);
+  if (FLAG_native_code_counters && counter->Enabled()) {
+    mov(scratch2, Operand(ExternalReference(counter)));
+    ldr(scratch1, MemOperand(scratch2));
+    add(scratch1, scratch1, Operand(value));
+    str(scratch1, MemOperand(scratch2));
+  }
+}
+
+
+void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
+                                      Register scratch1, Register scratch2) {
+  ASSERT(value > 0);
+  if (FLAG_native_code_counters && counter->Enabled()) {
+    mov(scratch2, Operand(ExternalReference(counter)));
+    ldr(scratch1, MemOperand(scratch2));
+    sub(scratch1, scratch1, Operand(value));
+    str(scratch1, MemOperand(scratch2));
+  }
+}
+
+
+void MacroAssembler::Assert(Condition cc, const char* msg) {
+  if (FLAG_debug_code)
+    Check(cc, msg);
+}
+
+
+void MacroAssembler::Check(Condition cc, const char* msg) {
+  Label L;
+  b(cc, &L);
+  Abort(msg);
+  // will not return here
+  bind(&L);
+}
+
+
+void MacroAssembler::Abort(const char* msg) {
+  // We want to pass the msg string like a smi to avoid GC
+  // problems, however msg is not guaranteed to be aligned
+  // properly. Instead, we pass an aligned pointer that is
+  // a proper v8 smi, but also pass the alignment difference
+  // from the real pointer as a smi.
+  intptr_t p1 = reinterpret_cast<intptr_t>(msg);
+  intptr_t p0 = (p1 & ~kSmiTagMask) + kSmiTag;
+  ASSERT(reinterpret_cast<Object*>(p0)->IsSmi());
+#ifdef DEBUG
+  if (msg != NULL) {
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
+#endif
+  mov(r0, Operand(p0));
+  push(r0);
+  mov(r0, Operand(Smi::FromInt(p1 - p0)));
+  push(r0);
+  CallRuntime(Runtime::kAbort, 2);
+  // will not return here
+}
+
+} }  // namespace v8::internal