common: Add aligned memory allocator.

src/common/aligned_memory.cpp

+//
+// Copyright 2017 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// aligned_memory: An aligned memory allocator. Based on Chrome's base/memory/aligned_memory.
+//
+
+#include "common/aligned_memory.h"
+
+#include "common/debug.h"
+
+#if defined(COMPILER_MSVC)
+#include <malloc.h>
+#else
+#include <stdlib.h>
+#endif
+
+namespace angle
+{
+
+void *AlignedAlloc(size_t size, size_t alignment)
+{
+    ASSERT(size > 0);
+    ASSERT((alignment & (alignment - 1)) == 0);
+    ASSERT((alignment % sizeof(void *)) == 0);
+    void *ptr = nullptr;
+#if defined(_MSC_VER)
+    ptr = _aligned_malloc(size, alignment);
+// Android technically supports posix_memalign(), but does not expose it in
+// the current version of the library headers used by Chrome.  Luckily,
+// memalign() on Android returns pointers which can safely be used with
+// free(), so we can use it instead.  Issue filed to document this:
+// http://code.google.com/p/android/issues/detail?id=35391
+#elif defined(ANGLE_PLATFORM_ANDROID)
+    ptr = memalign(alignment, size);
+#else
+    if (posix_memalign(&ptr, alignment, size))
+        ptr = nullptr;
+#endif
+    // Since aligned allocations may fail for non-memory related reasons, force a
+    // crash if we encounter a failed allocation.
+    if (!ptr)
+    {
+        ERR() << "If you crashed here, your aligned allocation is incorrect: "
+              << "size=" << size << ", alignment=" << alignment;
+        ASSERT(false);
+    }
+    // Sanity check alignment just to be safe.
+    ASSERT((reinterpret_cast<uintptr_t>(ptr) & (alignment - 1)) == 0);
+    return ptr;
+}
+
+void AlignedFree(void *ptr)
+{
+#if defined(_MSC_VER)
+    _aligned_free(ptr);
+#else
+    free(ptr);
+#endif
+}
+
+}  // namespace angle

src/common/aligned_memory.h

+//
+// Copyright 2017 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// aligned_memory: An aligned memory allocator. Based on Chrome's base/memory/aligned_memory.
+//
+
+#ifndef COMMON_ALIGNED_MEMORY_H_
+#define COMMON_ALIGNED_MEMORY_H_
+
+#include <cstddef>
+
+namespace angle
+{
+
+// This can be replaced with std::aligned_malloc when we have C++17.
+void *AlignedAlloc(size_t size, size_t alignment);
+void AlignedFree(void *ptr);
+
+}  // namespace angle
+
+#endif  // COMMON_ALIGNED_MEMORY_H_

src/common/aligned_memory_unittest.cpp

+//
+// Copyright 2017 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// aligned_memory_unittests: Tests for the aligned memory allocator.
+//   Tests copied from Chrome: src/base/memory/aligned_memory_unittests.cc.
+//
+
+#include "common/aligned_memory.h"
+
+#include <memory>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+#define EXPECT_ALIGNED(ptr, align) EXPECT_EQ(0u, reinterpret_cast<uintptr_t>(ptr) & (align - 1))
+
+namespace angle
+{
+
+// Test that dynamic allocation works as expected.
+TEST(AlignedMemoryTest, DynamicAllocation)
+{
+    void *p = AlignedAlloc(8, 8);
+    EXPECT_TRUE(p);
+    EXPECT_ALIGNED(p, 8);
+    AlignedFree(p);
+
+    p = AlignedAlloc(8, 16);
+    EXPECT_TRUE(p);
+    EXPECT_ALIGNED(p, 16);
+    AlignedFree(p);
+
+    p = AlignedAlloc(8, 256);
+    EXPECT_TRUE(p);
+    EXPECT_ALIGNED(p, 256);
+    AlignedFree(p);
+
+    p = AlignedAlloc(8, 4096);
+    EXPECT_TRUE(p);
+    EXPECT_ALIGNED(p, 4096);
+    AlignedFree(p);
+}
+
+}  // namespace base
\ No newline at end of file

src/libGLESv2.gypi

@@ -14,6 +14,8 @@
             'common/MemoryBuffer.cpp',
             'common/MemoryBuffer.h',
             'common/Optional.h',
+            'common/aligned_memory.cpp',
+            'common/aligned_memory.h',
             'common/angleutils.cpp',
             'common/angleutils.h',
             'common/bitset_utils.h',

src/tests/angle_unittests.gypi

@@ -15,6 +15,7 @@
         'angle_unittests_sources':
         [
             '<(angle_path)/src/common/Optional_unittest.cpp',
+            '<(angle_path)/src/common/aligned_memory_unittest.cpp',
             '<(angle_path)/src/common/angleutils_unittest.cpp',
             '<(angle_path)/src/common/bitset_utils_unittest.cpp',
             '<(angle_path)/src/common/mathutil_unittest.cpp',