[Isolates] Merge 6500:6700 from bleeding_edge to isolates.

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
===================================================================
--- src/arm/macro-assembler-arm.cc	(revision 7006)
+++ src/arm/macro-assembler-arm.cc	(working copy)
@@ -485,11 +485,21 @@
   PopSafepointRegisters();
 }
 
+void MacroAssembler::StoreToSafepointRegistersAndDoublesSlot(Register reg) {
+  str(reg, SafepointRegistersAndDoublesSlot(reg));
+}
+
+
 void MacroAssembler::StoreToSafepointRegisterSlot(Register reg) {
   str(reg, SafepointRegisterSlot(reg));
 }
 
 
+void MacroAssembler::LoadFromSafepointRegisterSlot(Register reg) {
+  ldr(reg, SafepointRegisterSlot(reg));
+}
+
+
 int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
   // The registers are pushed starting with the highest encoding,
   // which means that lowest encodings are closest to the stack pointer.
@@ -503,6 +513,14 @@
 }
 
 
+MemOperand MacroAssembler::SafepointRegistersAndDoublesSlot(Register reg) {
+  // General purpose registers are pushed last on the stack.
+  int doubles_size = DwVfpRegister::kNumAllocatableRegisters * kDoubleSize;
+  int register_offset = SafepointRegisterStackIndex(reg.code()) * kPointerSize;
+  return MemOperand(sp, doubles_size + register_offset);
+}
+
+
 void MacroAssembler::Ldrd(Register dst1, Register dst2,
                           const MemOperand& src, Condition cond) {
   ASSERT(src.rm().is(no_reg));
@@ -614,11 +632,7 @@
 }
 
 
-void MacroAssembler::EnterExitFrame(bool save_doubles) {
-  // Compute the argv pointer in a callee-saved register.
-  add(r6, sp, Operand(r0, LSL, kPointerSizeLog2));
-  sub(r6, r6, Operand(kPointerSize));
-
+void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space) {
   // Setup the frame structure on the stack.
   ASSERT_EQ(2 * kPointerSize, ExitFrameConstants::kCallerSPDisplacement);
   ASSERT_EQ(1 * kPointerSize, ExitFrameConstants::kCallerPCOffset);
@@ -640,10 +654,6 @@
   mov(ip, Operand(ExternalReference(Isolate::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));
-
   // Optionally save all double registers.
   if (save_doubles) {
     sub(sp, sp, Operand(DwVfpRegister::kNumRegisters * kDoubleSize));
@@ -657,10 +667,10 @@
     // since the sp slot and code slot were pushed after the fp.
   }
 
-  // Reserve place for the return address and align the frame preparing for
-  // calling the runtime function.
+  // Reserve place for the return address and stack space and align the frame
+  // preparing for calling the runtime function.
   const int frame_alignment = MacroAssembler::ActivationFrameAlignment();
-  sub(sp, sp, Operand(kPointerSize));
+  sub(sp, sp, Operand((stack_space + 1) * kPointerSize));
   if (frame_alignment > 0) {
     ASSERT(IsPowerOf2(frame_alignment));
     and_(sp, sp, Operand(-frame_alignment));
@@ -1141,7 +1151,8 @@
 
   // Calculate new top and bail out if new space is exhausted. Use result
   // to calculate the new top.
-  add(scratch2, result, Operand(obj_size_reg));
+  add(scratch2, result, Operand(obj_size_reg), SetCC);
+  b(cs, gc_required);
   cmp(scratch2, Operand(ip));
   b(hi, gc_required);
   str(scratch2, MemOperand(topaddr));
@@ -1220,10 +1231,11 @@
   // to calculate the new top. Object size may be in words so a shift is
   // required to get the number of bytes.
   if ((flags & SIZE_IN_WORDS) != 0) {
-    add(scratch2, result, Operand(object_size, LSL, kPointerSizeLog2));
+    add(scratch2, result, Operand(object_size, LSL, kPointerSizeLog2), SetCC);
   } else {
-    add(scratch2, result, Operand(object_size));
+    add(scratch2, result, Operand(object_size), SetCC);
   }
+  b(cs, gc_required);
   cmp(scratch2, Operand(ip));
   b(hi, gc_required);
 
@@ -1458,17 +1470,115 @@
 
 
 void MacroAssembler::CallStub(CodeStub* stub, Condition cond) {
-  ASSERT(allow_stub_calls());  // stub calls are not allowed in some stubs
+  ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
   Call(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
 }
 
 
 void MacroAssembler::TailCallStub(CodeStub* stub, Condition cond) {
-  ASSERT(allow_stub_calls());  // stub calls are not allowed in some stubs
+  ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
   Jump(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
 }
 
 
+MaybeObject* MacroAssembler::TryTailCallStub(CodeStub* stub, Condition cond) {
+  ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
+  Object* result;
+  { MaybeObject* maybe_result = stub->TryGetCode();
+    if (!maybe_result->ToObject(&result)) return maybe_result;
+  }
+  Jump(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
+  return result;
+}
+
+
+static int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
+  return ref0.address() - ref1.address();
+}
+
+
+MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
+    ApiFunction* function, int stack_space) {
+  ExternalReference next_address =
+      ExternalReference::handle_scope_next_address();
+  const int kNextOffset = 0;
+  const int kLimitOffset = AddressOffset(
+      ExternalReference::handle_scope_limit_address(),
+      next_address);
+  const int kLevelOffset = AddressOffset(
+      ExternalReference::handle_scope_level_address(),
+      next_address);
+
+  // Allocate HandleScope in callee-save registers.
+  mov(r7, Operand(next_address));
+  ldr(r4, MemOperand(r7, kNextOffset));
+  ldr(r5, MemOperand(r7, kLimitOffset));
+  ldr(r6, MemOperand(r7, kLevelOffset));
+  add(r6, r6, Operand(1));
+  str(r6, MemOperand(r7, kLevelOffset));
+
+  // Native call returns to the DirectCEntry stub which redirects to the
+  // return address pushed on stack (could have moved after GC).
+  // DirectCEntry stub itself is generated early and never moves.
+  DirectCEntryStub stub;
+  stub.GenerateCall(this, function);
+
+  Label promote_scheduled_exception;
+  Label delete_allocated_handles;
+  Label leave_exit_frame;
+
+  // If result is non-zero, dereference to get the result value
+  // otherwise set it to undefined.
+  cmp(r0, Operand(0));
+  LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
+  ldr(r0, MemOperand(r0), ne);
+
+  // No more valid handles (the result handle was the last one). Restore
+  // previous handle scope.
+  str(r4, MemOperand(r7, kNextOffset));
+  if (FLAG_debug_code) {
+    ldr(r1, MemOperand(r7, kLevelOffset));
+    cmp(r1, r6);
+    Check(eq, "Unexpected level after return from api call");
+  }
+  sub(r6, r6, Operand(1));
+  str(r6, MemOperand(r7, kLevelOffset));
+  ldr(ip, MemOperand(r7, kLimitOffset));
+  cmp(r5, ip);
+  b(ne, &delete_allocated_handles);
+
+  // Check if the function scheduled an exception.
+  bind(&leave_exit_frame);
+  LoadRoot(r4, Heap::kTheHoleValueRootIndex);
+  mov(ip, Operand(ExternalReference::scheduled_exception_address()));
+  ldr(r5, MemOperand(ip));
+  cmp(r4, r5);
+  b(ne, &promote_scheduled_exception);
+
+  // LeaveExitFrame expects unwind space to be in r4.
+  mov(r4, Operand(stack_space));
+  LeaveExitFrame(false);
+
+  bind(&promote_scheduled_exception);
+  MaybeObject* result = TryTailCallExternalReference(
+      ExternalReference(Runtime::kPromoteScheduledException), 0, 1);
+  if (result->IsFailure()) {
+    return result;
+  }
+
+  // HandleScope limit has changed. Delete allocated extensions.
+  bind(&delete_allocated_handles);
+  str(r5, MemOperand(r7, kLimitOffset));
+  mov(r4, r0);
+  PrepareCallCFunction(0, r5);
+  CallCFunction(ExternalReference::delete_handle_scope_extensions(), 0);
+  mov(r0, r4);
+  jmp(&leave_exit_frame);
+
+  return result;
+}
+
+
 void MacroAssembler::IllegalOperation(int num_arguments) {
   if (num_arguments > 0) {
     add(sp, sp, Operand(num_arguments * kPointerSize));
@@ -1560,13 +1670,14 @@
                                     Register dest,
                                     Register scratch,
                                     Register scratch2,
+                                    DwVfpRegister double_scratch,
                                     Label *not_int32) {
   if (Isolate::Current()->cpu_features()->IsSupported(VFP3)) {
     CpuFeatures::Scope scope(VFP3);
     sub(scratch, source, Operand(kHeapObjectTag));
-    vldr(d0, scratch, HeapNumber::kValueOffset);
-    vcvt_s32_f64(s0, d0);
-    vmov(dest, s0);
+    vldr(double_scratch, scratch, HeapNumber::kValueOffset);
+    vcvt_s32_f64(double_scratch.low(), double_scratch);
+    vmov(dest, double_scratch.low());
     // Signed vcvt instruction will saturate to the minimum (0x80000000) or
     // maximun (0x7fffffff) signed 32bits integer when the double is out of
     // range. When substracting one, the minimum signed integer becomes the
@@ -1723,6 +1834,17 @@
 }
 
 
+MaybeObject* MacroAssembler::TryTailCallExternalReference(
+    const ExternalReference& ext, int num_arguments, int result_size) {
+  // 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));
+  return TryJumpToExternalReference(ext);
+}
+
+
 void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
                                      int num_arguments,
                                      int result_size) {
@@ -1741,6 +1863,18 @@
 }
 
 
+MaybeObject* MacroAssembler::TryJumpToExternalReference(
+    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(1);
+  return TryTailCallStub(&stub);
+}
+
+
 void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                    InvokeJSFlags flags,
                                    PostCallGenerator* post_call_generator) {
@@ -1938,6 +2072,17 @@
 }
 
 
+void MacroAssembler::JumpIfNotPowerOfTwoOrZero(
+    Register reg,
+    Register scratch,
+    Label* not_power_of_two_or_zero) {
+  sub(scratch, reg, Operand(1), SetCC);
+  b(mi, not_power_of_two_or_zero);
+  tst(scratch, reg);
+  b(ne, not_power_of_two_or_zero);
+}
+
+
 void MacroAssembler::JumpIfNotBothSmi(Register reg1,
                                       Register reg2,
                                       Label* on_not_both_smi) {
@@ -1972,6 +2117,16 @@
 }
 
 
+void MacroAssembler::AbortIfNotRootValue(Register src,
+                                         Heap::RootListIndex root_value_index,
+                                         const char* message) {
+  ASSERT(!src.is(ip));
+  LoadRoot(ip, root_value_index);
+  cmp(src, ip);
+  Assert(eq, message);
+}
+
+
 void MacroAssembler::JumpIfNotHeapNumber(Register object,
                                          Register heap_number_map,
                                          Register scratch,
@@ -2086,7 +2241,7 @@
 void MacroAssembler::CountLeadingZeros(Register zeros,   // Answer.
                                        Register source,  // Input.
                                        Register scratch) {
-  ASSERT(!zeros.is(source) || !source.is(zeros));
+  ASSERT(!zeros.is(source) || !source.is(scratch));
   ASSERT(!zeros.is(scratch));
   ASSERT(!scratch.is(ip));
   ASSERT(!source.is(ip));