ARM: Add literal pool blocking to position critical code.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
===================================================================
--- src/arm/lithium-codegen-arm.cc	(revision 11662)
+++ src/arm/lithium-codegen-arm.cc	(working copy)
@@ -571,6 +571,9 @@
                                LInstruction* instr,
                                SafepointMode safepoint_mode) {
   ASSERT(instr != NULL);
+  // Block literal pool emission to ensure nop indicating no inlined smi code
+  // is in the correct position.
+  Assembler::BlockConstPoolScope block_const_pool(masm());
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
   __ Call(code, mode);
@@ -1684,6 +1687,9 @@
   ASSERT(ToRegister(instr->result()).is(r0));
 
   BinaryOpStub stub(instr->op(), NO_OVERWRITE);
+  // Block literal pool emission to ensure nop indicating no inlined smi code
+  // is in the correct position.
+  Assembler::BlockConstPoolScope block_const_pool(masm());
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   __ nop();  // Signals no inlined code.
 }
@@ -2315,20 +2321,25 @@
   Label cache_miss;
   Register map = temp;
   __ ldr(map, FieldMemOperand(object, HeapObject::kMapOffset));
-  __ bind(deferred->map_check());  // Label for calculating code patching.
-  // We use Factory::the_hole_value() on purpose instead of loading from the
-  // root array to force relocation to be able to later patch with
-  // the cached map.
-  Handle<JSGlobalPropertyCell> cell =
-      factory()->NewJSGlobalPropertyCell(factory()->the_hole_value());
-  __ mov(ip, Operand(Handle<Object>(cell)));
-  __ ldr(ip, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
-  __ cmp(map, Operand(ip));
-  __ b(ne, &cache_miss);
-  // We use Factory::the_hole_value() on purpose instead of loading from the
-  // root array to force relocation to be able to later patch
-  // with true or false.
-  __ mov(result, Operand(factory()->the_hole_value()));
+  {
+    // Block constant pool emission to ensure the positions of instructions are
+    // as expected by the patcher. See InstanceofStub::Generate().
+    Assembler::BlockConstPoolScope block_const_pool(masm());
+    __ bind(deferred->map_check());  // Label for calculating code patching.
+    // We use Factory::the_hole_value() on purpose instead of loading from the
+    // root array to force relocation to be able to later patch with
+    // the cached map.
+    Handle<JSGlobalPropertyCell> cell =
+        factory()->NewJSGlobalPropertyCell(factory()->the_hole_value());
+    __ mov(ip, Operand(Handle<Object>(cell)));
+    __ ldr(ip, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
+    __ cmp(map, Operand(ip));
+    __ b(ne, &cache_miss);
+    // We use Factory::the_hole_value() on purpose instead of loading from the
+    // root array to force relocation to be able to later patch
+    // with true or false.
+    __ mov(result, Operand(factory()->the_hole_value()));
+  }
   __ b(&done);
 
   // The inlined call site cache did not match. Check null and string before
@@ -5139,6 +5150,8 @@
   int current_pc = masm()->pc_offset();
   int patch_size = Deoptimizer::patch_size();
   if (current_pc < last_lazy_deopt_pc_ + patch_size) {
+    // Block literal pool emission for duration of padding.
+    Assembler::BlockConstPoolScope block_const_pool(masm());
     int padding_size = last_lazy_deopt_pc_ + patch_size - current_pc;
     ASSERT_EQ(0, padding_size % Assembler::kInstrSize);
     while (padding_size > 0) {