* This file is part of the GNU C Library.
* Copyright (c) 2011 The Chromium OS Authors.
*
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program 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 for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * SPDX-License-Identifier: GPL-2.0+
*/
/* From glibc-2.14, sysdeps/i386/memset.c */
return dstpp;
}
+
+#define OP_T_THRES 8
+#define OPSIZ (sizeof(op_t))
+
+#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes) \
+do { \
+ int __d0; \
+ asm volatile( \
+ /* Clear the direction flag, so copying goes forward. */ \
+ "cld\n" \
+ /* Copy bytes. */ \
+ "rep\n" \
+ "movsb" : \
+ "=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
+ "0" (dst_bp), "1" (src_bp), "2" (nbytes) : \
+ "memory"); \
+} while (0)
+
+#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
+do { \
+ int __d0; \
+ asm volatile( \
+ /* Clear the direction flag, so copying goes forward. */ \
+ "cld\n" \
+ /* Copy longwords. */ \
+ "rep\n" \
+ "movsl" : \
+ "=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
+ "0" (dst_bp), "1" (src_bp), "2" ((nbytes) / 4) : \
+ "memory"); \
+ (nbytes_left) = (nbytes) % 4; \
+} while (0)
+
+void *memcpy(void *dstpp, const void *srcpp, size_t len)
+{
+ unsigned long int dstp = (long int)dstpp;
+ unsigned long int srcp = (long int)srcpp;
+
+ /* Copy from the beginning to the end. */
+
+ /* If there not too few bytes to copy, use word copy. */
+ if (len >= OP_T_THRES) {
+ /* Copy just a few bytes to make DSTP aligned. */
+ len -= (-dstp) % OPSIZ;
+ BYTE_COPY_FWD(dstp, srcp, (-dstp) % OPSIZ);
+
+ /* Copy from SRCP to DSTP taking advantage of the known
+ * alignment of DSTP. Number of bytes remaining is put
+ * in the third argument, i.e. in LEN. This number may
+ * vary from machine to machine.
+ */
+ WORD_COPY_FWD(dstp, srcp, len, len);
+
+ /* Fall out and copy the tail. */
+ }
+
+ /* There are just a few bytes to copy. Use byte memory operations. */
+ BYTE_COPY_FWD(dstp, srcp, len);
+
+ return dstpp;
+}