Provide a tagged allocation top pointer.

test/cctest/test-macro-assembler-mips.cc

Index: test/cctest/test-macro-assembler-mips.cc
diff --git a/test/cctest/test-macro-assembler-mips.cc b/test/cctest/test-macro-assembler-mips.cc
index 5408061c3c9c1172459b5e78dbaac32bf18848c0..4aeeab0275a6a02c7f33e3961986b02e3dfc2f36 100644
--- a/test/cctest/test-macro-assembler-mips.cc
+++ b/test/cctest/test-macro-assembler-mips.cc
@@ -34,7 +34,7 @@
 #include "src/mips/simulator-mips.h"
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
-
+#include "test/cctest/heap/heap-utils.h"
 
 using namespace v8::internal;
 
@@ -413,12 +413,12 @@ static const std::vector<int32_t> cvt_trunc_int32_test_values() {
   for (std::vector<ctype>::iterator var = var##_vec.begin(); \
        var != var##_vec.end(); ++var)
 
-#define FOR_INPUTS2(ctype, itype, var, var2, test_vector)  \
+#define FOR_INPUTS2(ctype, itype, var, vat1, test_vector)  \
   std::vector<ctype> var##_vec = test_vector();            \
   std::vector<ctype>::iterator var;                        \
-  std::vector<ctype>::reverse_iterator var2;               \
-  for (var = var##_vec.begin(), var2 = var##_vec.rbegin(); \
-       var != var##_vec.end(); ++var, ++var2)
+  std::vector<ctype>::reverse_iterator vat1;               \
+  for (var = var##_vec.begin(), vat1 = var##_vec.rbegin(); \
+       var != var##_vec.end(); ++var, ++vat1)
 
 #define FOR_ENUM_INPUTS(var, type, test_vector) \
   FOR_INPUTS(enum type, type, var, test_vector)
@@ -428,8 +428,8 @@ static const std::vector<int32_t> cvt_trunc_int32_test_values() {
   FOR_INPUTS(uint32_t, uint32, var, test_vector)
 #define FOR_INT32_INPUTS(var, test_vector) \
   FOR_INPUTS(int32_t, int32, var, test_vector)
-#define FOR_INT32_INPUTS2(var, var2, test_vector) \
-  FOR_INPUTS2(int32_t, int32, var, var2, test_vector)
+#define FOR_INT32_INPUTS2(var, vat1, test_vector) \
+  FOR_INPUTS2(int32_t, int32, var, vat1, test_vector)
 
 #define FOR_UINT64_INPUTS(var, test_vector) \
   FOR_INPUTS(uint64_t, uint32, var, test_vector)
@@ -1168,4 +1168,112 @@ TEST(Uldc1) {
   }
 }
 
+template <typename Fun>
+void AssembleFunction(Isolate* isolate, size_t actual_size, byte* buffer,
+                      Fun f) {
+  MacroAssembler assembler(isolate, buffer, static_cast<int>(actual_size),
+                           v8::internal::CodeObjectRequired::kYes);
+  MacroAssembler* masm = &assembler;
+  f(masm);
+  __ jr(ra);
+
+  CodeDesc desc;
+  masm->GetCode(&desc);
+}
+
+TEST(AllocateMacrosNoGCRequired) {
+  typedef intptr_t (*F0)();
+  // Allocate an executable page of memory.
+  CcTest::InitializeVM();
+  size_t actual_size;
+  byte* buffer = static_cast<byte*>(v8::base::OS::Allocate(
+      Assembler::kMinimalBufferSize, &actual_size, true));
+  CHECK(buffer);
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope handles(isolate);
+
+  AllocationFlags const kDoubleAligned =
+      static_cast<AllocationFlags>(DOUBLE_ALIGNMENT);
+  AllocationFlags const kNoAllocationFlags =
+      static_cast<AllocationFlags>(NO_ALLOCATION_FLAGS);
+
+#define CHECK_TAGGED(result) CHECK_EQ(result& kHeapObjectTag, 1);
+#define CHECK_DOUBLE_ALIGNED(result)                                   \
+  do {                                                                 \
+    CHECK_TAGGED((result));                                            \
+    CHECK_EQ((result)&kDoubleAlignmentMaskTagged, 0);                  \
+    /* Check that the filler was written in the correct place */       \
+    CHECK_EQ(*reinterpret_cast<v8::internal::Map***>(                  \
+                 (result) - (kHeapObjectTag + kPointerSize)),          \
+             isolate->factory()->one_pointer_filler_map().location()); \
+  } while (false)
+
+  heap::GcAndSweep(isolate->heap(), AllocationSpace::NEW_SPACE);
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ Allocate(kPointerSize, v0, t0, t1, &gc_required, kNoAllocationFlags);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(kNoReason);
+      __ bind(&success);
+    });
+    F0 f = FUNCTION_CAST<F0>(buffer);
+    intptr_t test_result = reinterpret_cast<intptr_t>(
+        CALL_GENERATED_CODE(isolate, f, 0, 0, 0, 0, 0));
+    CHECK_TAGGED(test_result);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ Allocate(kDoubleSize, v0, t0, t1, &gc_required, kDoubleAligned);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(kNoReason);
+      __ bind(&success);
+    });
+    heap::MakeSureNewSpaceTopIsNotDoubleAligned(isolate->heap());
+    F0 f = FUNCTION_CAST<F0>(buffer);
+    intptr_t test_result = reinterpret_cast<intptr_t>(
+        CALL_GENERATED_CODE(isolate, f, 0, 0, 0, 0, 0));
+    CHECK_DOUBLE_ALIGNED(test_result);
+  }
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ li(a0, Operand(kPointerSize));
+      __ Allocate(a0, v0, t0, t1, &gc_required, kNoAllocationFlags);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(kNoReason);
+      __ bind(&success);
+    });
+    F0 f = FUNCTION_CAST<F0>(buffer);
+    intptr_t test_result = reinterpret_cast<intptr_t>(
+        CALL_GENERATED_CODE(isolate, f, 0, 0, 0, 0, 0));
+    CHECK_TAGGED(test_result);
+  }
+
+  {
+    AssembleFunction(isolate, actual_size, buffer, [](MacroAssembler* masm) {
+      Label gc_required, success;
+      __ li(a0, Operand(kDoubleSize));
+      __ Allocate(a0, v0, t0, t1, &gc_required, kDoubleAligned);
+      __ jmp(&success);
+      __ bind(&gc_required);
+      __ Abort(kNoReason);
+      __ bind(&success);
+    });
+    heap::MakeSureNewSpaceTopIsNotDoubleAligned(isolate->heap());
+    F0 f = FUNCTION_CAST<F0>(buffer);
+    intptr_t test_result = reinterpret_cast<intptr_t>(
+        CALL_GENERATED_CODE(isolate, f, 0, 0, 0, 0, 0));
+    CHECK_DOUBLE_ALIGNED(test_result);
+  }
+
+#undef CHECK_TAGGED
+#undef CHECK_DOUBLE_ALIGNED
+}
+
 #undef __