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![Ley Foon Tan](/assets/img/avatar_default.png)
Add optimised library functions for nios2. Signed-off-by: Ley Foon Tan <lftan@altera.com>
202 lines
5.9 KiB
C
202 lines
5.9 KiB
C
/* Extracted from GLIBC memcpy.c and memcopy.h, which is:
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Copyright (C) 1991, 1992, 1993, 1997, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Torbjorn Granlund (tege@sics.se).
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <linux/types.h>
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/* Type to use for aligned memory operations.
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This should normally be the biggest type supported by a single load
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and store. */
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#define op_t unsigned long int
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#define OPSIZ (sizeof(op_t))
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/* Optimal type for storing bytes in registers. */
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#define reg_char char
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#define MERGE(w0, sh_1, w1, sh_2) (((w0) >> (sh_1)) | ((w1) << (sh_2)))
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/* Copy exactly NBYTES bytes from SRC_BP to DST_BP,
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without any assumptions about alignment of the pointers. */
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#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes) \
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do { \
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size_t __nbytes = (nbytes); \
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while (__nbytes > 0) { \
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unsigned char __x = ((unsigned char *) src_bp)[0]; \
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src_bp += 1; \
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__nbytes -= 1; \
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((unsigned char *) dst_bp)[0] = __x; \
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dst_bp += 1; \
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} \
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} while (0)
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/* Copy *up to* NBYTES bytes from SRC_BP to DST_BP, with
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the assumption that DST_BP is aligned on an OPSIZ multiple. If
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not all bytes could be easily copied, store remaining number of bytes
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in NBYTES_LEFT, otherwise store 0. */
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/* extern void _wordcopy_fwd_aligned __P ((long int, long int, size_t)); */
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/* extern void _wordcopy_fwd_dest_aligned __P ((long int, long int, size_t)); */
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#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
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do { \
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if (src_bp % OPSIZ == 0) \
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_wordcopy_fwd_aligned(dst_bp, src_bp, (nbytes) / OPSIZ);\
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else \
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_wordcopy_fwd_dest_aligned(dst_bp, src_bp, (nbytes) / OPSIZ);\
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src_bp += (nbytes) & -OPSIZ; \
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dst_bp += (nbytes) & -OPSIZ; \
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(nbytes_left) = (nbytes) % OPSIZ; \
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} while (0)
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/* Threshold value for when to enter the unrolled loops. */
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#define OP_T_THRES 16
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/* _wordcopy_fwd_aligned -- Copy block beginning at SRCP to
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block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
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Both SRCP and DSTP should be aligned for memory operations on `op_t's. */
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/* stream-lined (read x8 + write x8) */
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static void _wordcopy_fwd_aligned(long int dstp, long int srcp, size_t len)
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{
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while (len > 7) {
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register op_t a0, a1, a2, a3, a4, a5, a6, a7;
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a0 = ((op_t *) srcp)[0];
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a1 = ((op_t *) srcp)[1];
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a2 = ((op_t *) srcp)[2];
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a3 = ((op_t *) srcp)[3];
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a4 = ((op_t *) srcp)[4];
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a5 = ((op_t *) srcp)[5];
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a6 = ((op_t *) srcp)[6];
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a7 = ((op_t *) srcp)[7];
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((op_t *) dstp)[0] = a0;
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((op_t *) dstp)[1] = a1;
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((op_t *) dstp)[2] = a2;
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((op_t *) dstp)[3] = a3;
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((op_t *) dstp)[4] = a4;
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((op_t *) dstp)[5] = a5;
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((op_t *) dstp)[6] = a6;
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((op_t *) dstp)[7] = a7;
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srcp += 8 * OPSIZ;
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dstp += 8 * OPSIZ;
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len -= 8;
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}
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while (len > 0) {
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*(op_t *)dstp = *(op_t *)srcp;
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srcp += OPSIZ;
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dstp += OPSIZ;
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len -= 1;
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}
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}
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/* _wordcopy_fwd_dest_aligned -- Copy block beginning at SRCP to
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block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
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DSTP should be aligned for memory operations on `op_t's, but SRCP must
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*not* be aligned. */
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/* stream-lined (read x4 + write x4) */
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static void _wordcopy_fwd_dest_aligned(long int dstp, long int srcp,
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size_t len)
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{
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op_t ap;
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int sh_1, sh_2;
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/* Calculate how to shift a word read at the memory operation
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aligned srcp to make it aligned for copy. */
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sh_1 = 8 * (srcp % OPSIZ);
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sh_2 = 8 * OPSIZ - sh_1;
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/* Make SRCP aligned by rounding it down to the beginning of the `op_t'
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it points in the middle of. */
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srcp &= -OPSIZ;
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ap = ((op_t *) srcp)[0];
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srcp += OPSIZ;
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while (len > 3) {
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op_t a0, a1, a2, a3;
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a0 = ((op_t *) srcp)[0];
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a1 = ((op_t *) srcp)[1];
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a2 = ((op_t *) srcp)[2];
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a3 = ((op_t *) srcp)[3];
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((op_t *) dstp)[0] = MERGE(ap, sh_1, a0, sh_2);
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((op_t *) dstp)[1] = MERGE(a0, sh_1, a1, sh_2);
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((op_t *) dstp)[2] = MERGE(a1, sh_1, a2, sh_2);
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((op_t *) dstp)[3] = MERGE(a2, sh_1, a3, sh_2);
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ap = a3;
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srcp += 4 * OPSIZ;
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dstp += 4 * OPSIZ;
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len -= 4;
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}
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while (len > 0) {
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register op_t a0;
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a0 = ((op_t *) srcp)[0];
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((op_t *) dstp)[0] = MERGE(ap, sh_1, a0, sh_2);
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ap = a0;
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srcp += OPSIZ;
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dstp += OPSIZ;
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len -= 1;
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}
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}
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void *memcpy(void *dstpp, const void *srcpp, size_t len)
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{
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unsigned long int dstp = (long int) dstpp;
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unsigned long int srcp = (long int) srcpp;
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/* Copy from the beginning to the end. */
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/* If there not too few bytes to copy, use word copy. */
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if (len >= OP_T_THRES) {
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/* Copy just a few bytes to make DSTP aligned. */
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len -= (-dstp) % OPSIZ;
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BYTE_COPY_FWD(dstp, srcp, (-dstp) % OPSIZ);
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/* Copy whole pages from SRCP to DSTP by virtual address
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manipulation, as much as possible. */
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/* PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); */
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/* Copy from SRCP to DSTP taking advantage of the known
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alignment of DSTP. Number of bytes remaining is put in the
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third argument, i.e. in LEN. This number may vary from
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machine to machine. */
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WORD_COPY_FWD(dstp, srcp, len, len);
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/* Fall out and copy the tail. */
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}
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/* There are just a few bytes to copy. Use byte memory operations. */
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BYTE_COPY_FWD(dstp, srcp, len);
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return dstpp;
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}
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void *memcpyb(void *dstpp, const void *srcpp, unsigned len)
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{
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unsigned long int dstp = (long int) dstpp;
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unsigned long int srcp = (long int) srcpp;
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BYTE_COPY_FWD(dstp, srcp, len);
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return dstpp;
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}
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