Provide a tagged allocation top pointer.

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

 // Copyright 2013 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
@@ skipping 16 matching lines @@
 
 #include <stdlib.h>
 #include <iostream>  // NOLINT(readability/streams)
 
 #include "src/base/utils/random-number-generator.h"
 #include "src/macro-assembler.h"
 #include "src/mips/macro-assembler-mips.h"
 #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;
 
 typedef void* (*F)(int x, int y, int p2, int p3, int p4);
 typedef Object* (*F1)(int x, int p1, int p2, int p3, int p4);
 typedef Object* (*F3)(void* p, int p1, int p2, int p3, int p4);
 
 #define __ masm->
 
 
@@ skipping 358 matching lines @@
       static_cast<int32_t>(0xffffffff)};
   return std::vector<int32_t>(&kValues[0], &kValues[arraysize(kValues)]);
 }
 
 // Helper macros that can be used in FOR_INT32_INPUTS(i) { ... *i ... }
 #define FOR_INPUTS(ctype, itype, var, test_vector)           \
   std::vector<ctype> var##_vec = test_vector();              \
   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)
 #define FOR_STRUCT_INPUTS(var, type, test_vector) \
   FOR_INPUTS(struct type, type, var, test_vector)
 #define FOR_UINT32_INPUTS(var, test_vector) \
   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)
 
 template <typename RET_TYPE, typename IN_TYPE, typename Func>
 RET_TYPE run_Cvt(IN_TYPE x, Func GenerateConvertInstructionFunc) {
   typedef RET_TYPE (*F_CVT)(IN_TYPE x0, int x1, int x2, int x3, int x4);
 
   Isolate* isolate = CcTest::i_isolate();
   HandleScope scope(isolate);
@@ skipping 718 matching lines @@
                            [](MacroAssembler* masm, int32_t in_offset,
                               int32_t out_offset) {
                              __ Uldc1(f0, MemOperand(a0, in_offset), t0);
                              __ Usdc1(f0, MemOperand(a0, out_offset), t0);
                            }));
       }
     }
   }
 }
 
+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 __