--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/utilities/align.hpp Wed Jul 05 11:33:17 2017 +0200
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_UTILITIES_ALIGN_HPP
+#define SHARE_VM_UTILITIES_ALIGN_HPP
+
+#include "utilities/globalDefinitions.hpp"
+
+// Signed variants of alignment helpers. There are two versions of each, a macro
+// for use in places like enum definitions that require compile-time constant
+// expressions and a function for all other places so as to get type checking.
+
+// Using '(what) & ~align_mask(alignment)' to align 'what' down is broken when
+// 'alignment' is an unsigned int and 'what' is a wider type. The & operation
+// will widen the inverted mask, and not sign extend it, leading to a mask with
+// zeros in the most significant bits. The use of align_mask_widened() solves
+// this problem.
+#define align_mask(alignment) ((alignment) - 1)
+#define widen_to_type_of(what, type_carrier) (true ? (what) : (type_carrier))
+#define align_mask_widened(alignment, type_carrier) widen_to_type_of(align_mask(alignment), (type_carrier))
+
+#define align_down_(size, alignment) ((size) & ~align_mask_widened((alignment), (size)))
+
+#define align_up_(size, alignment) (align_down_((size) + align_mask(alignment), (alignment)))
+
+#define is_aligned_(size, alignment) ((size) == (align_up_((size), (alignment))))
+
+// Temporary declaration until this file has been restructured.
+template <typename T>
+bool is_power_of_2_t(T x) {
+ return (x != T(0)) && ((x & (x - 1)) == T(0));
+}
+
+// Helpers to align sizes and check for alignment
+
+template <typename T, typename A>
+inline T align_up(T size, A alignment) {
+ assert(is_power_of_2_t(alignment), "must be a power of 2: " UINT64_FORMAT, (uint64_t)alignment);
+
+ T ret = align_up_(size, alignment);
+ assert(is_aligned_(ret, alignment), "must be aligned: " UINT64_FORMAT, (uint64_t)ret);
+
+ return ret;
+}
+
+template <typename T, typename A>
+inline T align_down(T size, A alignment) {
+ assert(is_power_of_2_t(alignment), "must be a power of 2: " UINT64_FORMAT, (uint64_t)alignment);
+
+ T ret = align_down_(size, alignment);
+ assert(is_aligned_(ret, alignment), "must be aligned: " UINT64_FORMAT, (uint64_t)ret);
+
+ return ret;
+}
+
+template <typename T, typename A>
+inline bool is_aligned(T size, A alignment) {
+ assert(is_power_of_2_t(alignment), "must be a power of 2: " UINT64_FORMAT, (uint64_t)alignment);
+
+ return is_aligned_(size, alignment);
+}
+
+// Align down with a lower bound. If the aligning results in 0, return 'alignment'.
+template <typename T, typename A>
+inline T align_down_bounded(T size, A alignment) {
+ A aligned_size = align_down(size, alignment);
+ return aligned_size > 0 ? aligned_size : alignment;
+}
+
+// Helpers to align pointers and check for alignment.
+
+template <typename T, typename A>
+inline T* align_up(T* ptr, A alignment) {
+ return (T*)align_up((uintptr_t)ptr, alignment);
+}
+
+template <typename T, typename A>
+inline T* align_down(T* ptr, A alignment) {
+ return (T*)align_down((uintptr_t)ptr, alignment);
+}
+
+template <typename T, typename A>
+inline bool is_aligned(T* ptr, A alignment) {
+ return is_aligned((uintptr_t)ptr, alignment);
+}
+
+// Align metaspace objects by rounding up to natural word boundary
+template <typename T>
+inline T align_metadata_size(T size) {
+ return align_up(size, 1);
+}
+
+// Align objects in the Java Heap by rounding up their size, in HeapWord units.
+template <typename T>
+inline T align_object_size(T word_size) {
+ return align_up(word_size, MinObjAlignment);
+}
+
+inline bool is_object_aligned(size_t word_size) {
+ return is_aligned(word_size, MinObjAlignment);
+}
+
+inline bool is_object_aligned(const void* addr) {
+ return is_aligned(addr, MinObjAlignmentInBytes);
+}
+
+// Pad out certain offsets to jlong alignment, in HeapWord units.
+template <typename T>
+inline T align_object_offset(T offset) {
+ return align_up(offset, HeapWordsPerLong);
+}
+
+// Clamp an address to be within a specific page
+// 1. If addr is on the page it is returned as is
+// 2. If addr is above the page_address the start of the *next* page will be returned
+// 3. Otherwise, if addr is below the page_address the start of the page will be returned
+template <typename T>
+inline T* clamp_address_in_page(T* addr, T* page_address, size_t page_size) {
+ if (align_down(addr, page_size) == align_down(page_address, page_size)) {
+ // address is in the specified page, just return it as is
+ return addr;
+ } else if (addr > page_address) {
+ // address is above specified page, return start of next page
+ return align_down(page_address, page_size) + page_size;
+ } else {
+ // address is below specified page, return start of page
+ return align_down(page_address, page_size);
+ }
+}
+
+#endif // SHARE_VM_UTILITIES_ALIGN_HPP