[base] Align the address hint in VirtualMemory.

BUG=chromium:739644

Change-Id: I6c7d0f48c959826dd2a8587d7a321be4387ef39f
Reviewed-on: https://chromium-review.googlesource.com/586529Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46936}

src/base/macros.h

@@ -321,4 +321,11 @@ constexpr inline T RoundUp(T x) {
   return RoundDown<m, T>(static_cast<T>(x + m - 1));
 }
 
+inline void* AlignedAddress(void* address, size_t alignment) {
+  // The alignment must be a power of two.
+  DCHECK_EQ(alignment & (alignment - 1), 0u);
+  return reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(address) &
+                                 ~static_cast<uintptr_t>(alignment - 1));
+}
+
 #endif   // V8_BASE_MACROS_H_

src/base/platform/platform-aix.cc

@@ -138,6 +138,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
+  hint = AlignedAddress(hint, alignment);
   size_t request_size =
       RoundUp(size + alignment, static_cast<intptr_t>(OS::AllocateAlignment()));
   void* reservation = mmap(hint, request_size, PROT_NONE,

src/base/platform/platform-cygwin.cc

@@ -161,6 +161,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
+  hint = AlignedAddress(hint, alignment);
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));

src/base/platform/platform-freebsd.cc

@@ -116,6 +116,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
+  hint = AlignedAddress(hint, alignment);
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));

src/base/platform/platform-linux.cc

@@ -202,6 +202,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
+  hint = AlignedAddress(hint, alignment);
   size_t request_size =
       RoundUp(size + alignment, static_cast<intptr_t>(OS::AllocateAlignment()));
   void* reservation =

src/base/platform/platform-macos.cc

@@ -105,6 +105,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
+  hint = AlignedAddress(hint, alignment);
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));
   void* reservation =

src/base/platform/platform-openbsd.cc

@@ -147,6 +147,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
+  hint = AlignedAddress(hint, alignment);
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));
   void* reservation =

src/base/platform/platform-qnx.cc

@@ -173,6 +173,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
+  hint = AlignedAddress(hint, alignment);
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));
   void* reservation =

src/base/platform/platform-solaris.cc

@@ -92,6 +92,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
+  hint = AlignedAddress(hint, alignment);
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));
   void* reservation =

src/base/platform/platform-win32.cc

@@ -1214,6 +1214,7 @@ VirtualMemory::VirtualMemory(size_t size, void* hint)
 VirtualMemory::VirtualMemory(size_t size, size_t alignment, void* hint)
     : address_(NULL), size_(0) {
   DCHECK((alignment % OS::AllocateAlignment()) == 0);
+  hint = AlignedAddress(hint, alignment);
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));
   void* address = ReserveRegion(request_size, hint);

test/unittests/BUILD.gn

@@ -29,6 +29,7 @@ v8_executable("unittests") {
     "base/ieee754-unittest.cc",
     "base/iterator-unittest.cc",
     "base/logging-unittest.cc",
+    "base/macros-unittest.cc",
     "base/ostreams-unittest.cc",
     "base/platform/condition-variable-unittest.cc",
     "base/platform/mutex-unittest.cc",

test/unittests/base/macros-unittest.cc

+// Copyright 2017 the V8 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.
+
+#include "src/base/macros.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace v8 {
+namespace base {
+
+TEST(AlignedAddressTest, AlignedAddress) {
+  EXPECT_EQ(reinterpret_cast<void*>(0xFFFF0),
+            AlignedAddress(reinterpret_cast<void*>(0xFFFF0), 16));
+  EXPECT_EQ(reinterpret_cast<void*>(0xFFFF0),
+            AlignedAddress(reinterpret_cast<void*>(0xFFFF2), 16));
+  EXPECT_EQ(reinterpret_cast<void*>(0xFFFF0),
+            AlignedAddress(reinterpret_cast<void*>(0xFFFF2), 16));
+  EXPECT_EQ(reinterpret_cast<void*>(0xFFFF0),
+            AlignedAddress(reinterpret_cast<void*>(0xFFFFF), 16));
+  EXPECT_EQ(reinterpret_cast<void*>(0x0),
+            AlignedAddress(reinterpret_cast<void*>(0xFFFFF), 0x100000));
+}
+
+}  // namespace base
+}  // namespace v8

test/unittests/unittests.gyp

@@ -25,6 +25,7 @@
       'base/functional-unittest.cc',
       'base/ieee754-unittest.cc',
       'base/logging-unittest.cc',
+      'base/macros-unittest.cc',
       'base/iterator-unittest.cc',
       'base/ostreams-unittest.cc',
       'base/platform/condition-variable-unittest.cc',