| /* |
| * Copyright (c) 2006, 2016, 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. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "runtime/sharedRuntime.hpp" |
| #include "utilities/align.hpp" |
| #include "utilities/copy.hpp" |
| |
| |
| // Copy bytes; larger units are filled atomically if everything is aligned. |
| void Copy::conjoint_memory_atomic(void* from, void* to, size_t size) { |
| address src = (address) from; |
| address dst = (address) to; |
| uintptr_t bits = (uintptr_t) src | (uintptr_t) dst | (uintptr_t) size; |
| |
| // (Note: We could improve performance by ignoring the low bits of size, |
| // and putting a short cleanup loop after each bulk copy loop. |
| // There are plenty of other ways to make this faster also, |
| // and it's a slippery slope. For now, let's keep this code simple |
| // since the simplicity helps clarify the atomicity semantics of |
| // this operation. There are also CPU-specific assembly versions |
| // which may or may not want to include such optimizations.) |
| |
| if (bits % sizeof(jlong) == 0) { |
| Copy::conjoint_jlongs_atomic((jlong*) src, (jlong*) dst, size / sizeof(jlong)); |
| } else if (bits % sizeof(jint) == 0) { |
| Copy::conjoint_jints_atomic((jint*) src, (jint*) dst, size / sizeof(jint)); |
| } else if (bits % sizeof(jshort) == 0) { |
| Copy::conjoint_jshorts_atomic((jshort*) src, (jshort*) dst, size / sizeof(jshort)); |
| } else { |
| // Not aligned, so no need to be atomic. |
| Copy::conjoint_jbytes((void*) src, (void*) dst, size); |
| } |
| } |
| |
| class CopySwap : AllStatic { |
| public: |
| /** |
| * Copy and optionally byte swap elements |
| * |
| * <swap> - true if elements should be byte swapped |
| * |
| * @param src address of source |
| * @param dst address of destination |
| * @param byte_count number of bytes to copy |
| * @param elem_size size of the elements to copy-swap |
| */ |
| template<bool swap> |
| static void conjoint_swap_if_needed(const void* src, void* dst, size_t byte_count, size_t elem_size) { |
| assert(src != NULL, "address must not be NULL"); |
| assert(dst != NULL, "address must not be NULL"); |
| assert(elem_size == 2 || elem_size == 4 || elem_size == 8, |
| "incorrect element size: " SIZE_FORMAT, elem_size); |
| assert(is_aligned(byte_count, elem_size), |
| "byte_count " SIZE_FORMAT " must be multiple of element size " SIZE_FORMAT, byte_count, elem_size); |
| |
| address src_end = (address)src + byte_count; |
| |
| if (dst <= src || dst >= src_end) { |
| do_conjoint_swap<RIGHT,swap>(src, dst, byte_count, elem_size); |
| } else { |
| do_conjoint_swap<LEFT,swap>(src, dst, byte_count, elem_size); |
| } |
| } |
| |
| private: |
| /** |
| * Byte swap a 16-bit value |
| */ |
| static uint16_t byte_swap(uint16_t x) { |
| return (x << 8) | (x >> 8); |
| } |
| |
| /** |
| * Byte swap a 32-bit value |
| */ |
| static uint32_t byte_swap(uint32_t x) { |
| uint16_t lo = (uint16_t)x; |
| uint16_t hi = (uint16_t)(x >> 16); |
| |
| return ((uint32_t)byte_swap(lo) << 16) | (uint32_t)byte_swap(hi); |
| } |
| |
| /** |
| * Byte swap a 64-bit value |
| */ |
| static uint64_t byte_swap(uint64_t x) { |
| uint32_t lo = (uint32_t)x; |
| uint32_t hi = (uint32_t)(x >> 32); |
| |
| return ((uint64_t)byte_swap(lo) << 32) | (uint64_t)byte_swap(hi); |
| } |
| |
| enum CopyDirection { |
| RIGHT, // lower -> higher address |
| LEFT // higher -> lower address |
| }; |
| |
| /** |
| * Copy and byte swap elements |
| * |
| * <T> - type of element to copy |
| * <D> - copy direction |
| * <is_src_aligned> - true if src argument is aligned to element size |
| * <is_dst_aligned> - true if dst argument is aligned to element size |
| * |
| * @param src address of source |
| * @param dst address of destination |
| * @param byte_count number of bytes to copy |
| */ |
| template <typename T, CopyDirection D, bool swap, bool is_src_aligned, bool is_dst_aligned> |
| static void do_conjoint_swap(const void* src, void* dst, size_t byte_count) { |
| const char* cur_src; |
| char* cur_dst; |
| |
| switch (D) { |
| case RIGHT: |
| cur_src = (const char*)src; |
| cur_dst = (char*)dst; |
| break; |
| case LEFT: |
| cur_src = (const char*)src + byte_count - sizeof(T); |
| cur_dst = (char*)dst + byte_count - sizeof(T); |
| break; |
| } |
| |
| for (size_t i = 0; i < byte_count / sizeof(T); i++) { |
| T tmp; |
| |
| if (is_src_aligned) { |
| tmp = *(T*)cur_src; |
| } else { |
| memcpy(&tmp, cur_src, sizeof(T)); |
| } |
| |
| if (swap) { |
| tmp = byte_swap(tmp); |
| } |
| |
| if (is_dst_aligned) { |
| *(T*)cur_dst = tmp; |
| } else { |
| memcpy(cur_dst, &tmp, sizeof(T)); |
| } |
| |
| switch (D) { |
| case RIGHT: |
| cur_src += sizeof(T); |
| cur_dst += sizeof(T); |
| break; |
| case LEFT: |
| cur_src -= sizeof(T); |
| cur_dst -= sizeof(T); |
| break; |
| } |
| } |
| } |
| |
| /** |
| * Copy and byte swap elements |
| * |
| * <T> - type of element to copy |
| * <D> - copy direction |
| * <swap> - true if elements should be byte swapped |
| * |
| * @param src address of source |
| * @param dst address of destination |
| * @param byte_count number of bytes to copy |
| */ |
| template <typename T, CopyDirection direction, bool swap> |
| static void do_conjoint_swap(const void* src, void* dst, size_t byte_count) { |
| if (is_aligned(src, sizeof(T))) { |
| if (is_aligned(dst, sizeof(T))) { |
| do_conjoint_swap<T,direction,swap,true,true>(src, dst, byte_count); |
| } else { |
| do_conjoint_swap<T,direction,swap,true,false>(src, dst, byte_count); |
| } |
| } else { |
| if (is_aligned(dst, sizeof(T))) { |
| do_conjoint_swap<T,direction,swap,false,true>(src, dst, byte_count); |
| } else { |
| do_conjoint_swap<T,direction,swap,false,false>(src, dst, byte_count); |
| } |
| } |
| } |
| |
| |
| /** |
| * Copy and byte swap elements |
| * |
| * <D> - copy direction |
| * <swap> - true if elements should be byte swapped |
| * |
| * @param src address of source |
| * @param dst address of destination |
| * @param byte_count number of bytes to copy |
| * @param elem_size size of the elements to copy-swap |
| */ |
| template <CopyDirection D, bool swap> |
| static void do_conjoint_swap(const void* src, void* dst, size_t byte_count, size_t elem_size) { |
| switch (elem_size) { |
| case 2: do_conjoint_swap<uint16_t,D,swap>(src, dst, byte_count); break; |
| case 4: do_conjoint_swap<uint32_t,D,swap>(src, dst, byte_count); break; |
| case 8: do_conjoint_swap<uint64_t,D,swap>(src, dst, byte_count); break; |
| default: guarantee(false, "do_conjoint_swap: Invalid elem_size " SIZE_FORMAT "\n", elem_size); |
| } |
| } |
| }; |
| |
| void Copy::conjoint_copy(const void* src, void* dst, size_t byte_count, size_t elem_size) { |
| CopySwap::conjoint_swap_if_needed<false>(src, dst, byte_count, elem_size); |
| } |
| |
| void Copy::conjoint_swap(const void* src, void* dst, size_t byte_count, size_t elem_size) { |
| CopySwap::conjoint_swap_if_needed<true>(src, dst, byte_count, elem_size); |
| } |
| |
| // Fill bytes; larger units are filled atomically if everything is aligned. |
| void Copy::fill_to_memory_atomic(void* to, size_t size, jubyte value) { |
| address dst = (address) to; |
| uintptr_t bits = (uintptr_t) to | (uintptr_t) size; |
| if (bits % sizeof(jlong) == 0) { |
| jlong fill = (julong)( (jubyte)value ); // zero-extend |
| if (fill != 0) { |
| fill += fill << 8; |
| fill += fill << 16; |
| fill += fill << 32; |
| } |
| //Copy::fill_to_jlongs_atomic((jlong*) dst, size / sizeof(jlong)); |
| for (uintptr_t off = 0; off < size; off += sizeof(jlong)) { |
| *(jlong*)(dst + off) = fill; |
| } |
| } else if (bits % sizeof(jint) == 0) { |
| jint fill = (juint)( (jubyte)value ); // zero-extend |
| if (fill != 0) { |
| fill += fill << 8; |
| fill += fill << 16; |
| } |
| //Copy::fill_to_jints_atomic((jint*) dst, size / sizeof(jint)); |
| for (uintptr_t off = 0; off < size; off += sizeof(jint)) { |
| *(jint*)(dst + off) = fill; |
| } |
| } else if (bits % sizeof(jshort) == 0) { |
| jshort fill = (jushort)( (jubyte)value ); // zero-extend |
| fill += fill << 8; |
| //Copy::fill_to_jshorts_atomic((jshort*) dst, size / sizeof(jshort)); |
| for (uintptr_t off = 0; off < size; off += sizeof(jshort)) { |
| *(jshort*)(dst + off) = fill; |
| } |
| } else { |
| // Not aligned, so no need to be atomic. |
| Copy::fill_to_bytes(dst, size, value); |
| } |
| } |