linux-2.6.x/arch/nios2nommu/lib/memcpy.c | 237 +++++++++++++++++++++++-------
1 files changed, 182 insertions(+), 55 deletions(-)
diff --git a/linux-2.6.x/arch/nios2nommu/lib/memcpy.c
b/linux-2.6.x/arch/nios2nommu/lib/memcpy.c
index 6586b99..c59ab7a 100644
--- a/linux-2.6.x/arch/nios2nommu/lib/memcpy.c
+++ b/linux-2.6.x/arch/nios2nommu/lib/memcpy.c
@@ -1,62 +1,189 @@
-/*--------------------------------------------------------------------
- *
- * arch/nios2nommu/lib/memcpy.c
- *
- * Derived from various works, Alpha, ix86, M68K, Sparc, ...et al
- *
- * Copyright (C) 2004 Microtronix Datacom Ltd
- *
- * 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.
- *
- *
- * Jun/09/2004 dgt Split out separate source file from string.c
- *
- ---------------------------------------------------------------------*/
+/* Copy memory to memory until the specified number of bytes
+ has been copied. Overlap is NOT handled correctly.
+ Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Torbjorn Granlund ([EMAIL PROTECTED]).
+
+ stream-lined memory access
+*/
#include <linux/types.h>
#include <linux/autoconf.h>
-#include <asm/nios.h>
#include <asm/string.h>
#ifdef __HAVE_ARCH_MEMCPY
- void * memcpy(void * d, const void * s, size_t count)
- {
- unsigned long dst, src;
- dst = (unsigned long) d;
- src = (unsigned long) s;
-
- if ((count < 8) || ((dst ^ src) & 3))
- goto restup;
-
- if (dst & 1) {
- *(char*)dst++=*(char*)src++;
- count--;
- }
- if (dst & 2) {
- *(short*)dst=*(short*)src;
- src += 2;
- dst += 2;
- count -= 2;
- }
- while (count > 3) {
- *(long*)dst=*(long*)src;
- src += 4;
- dst += 4;
- count -= 4;
- }
-
- restup:
- while (count--)
- *(char*)dst++=*(char*)src++;
-
- return d;
- }
+
+/* Type to use for aligned memory operations.
+ This should normally be the biggest type supported by a single load
+ and store. */
+#define op_t unsigned long int
+#define OPSIZ (sizeof(op_t))
+
+/* Type to use for unaligned operations. */
+typedef unsigned char byte;
+
+/* Optimal type for storing bytes in registers. */
+#define reg_char char
+
+#define MERGE(w0, sh_1, w1, sh_2) (((w0) >> (sh_1)) | ((w1) << (sh_2)))
+
+/* Copy exactly NBYTES bytes from SRC_BP to DST_BP,
+ without any assumptions about alignment of the pointers. */
+#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes) \
+ do \
+ { \
+ size_t __nbytes = (nbytes); \
+ while (__nbytes > 0) \
+ { \
+ byte __x = ((byte *) src_bp)[0]; \
+ src_bp += 1; \
+ __nbytes -= 1; \
+ ((byte *) dst_bp)[0] = __x; \
+ dst_bp += 1; \
+ } \
+ } while (0)
+
+/* Copy *up to* NBYTES bytes from SRC_BP to DST_BP, with
+ the assumption that DST_BP is aligned on an OPSIZ multiple. If
+ not all bytes could be easily copied, store remaining number of bytes
+ in NBYTES_LEFT, otherwise store 0. */
+/* extern void _wordcopy_fwd_aligned __P ((long int, long int, size_t)); */
+/* extern void _wordcopy_fwd_dest_aligned __P ((long int, long int, size_t));
*/
+#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
+ do \
+ { \
+ if (src_bp % OPSIZ == 0) \
+ _wordcopy_fwd_aligned (dst_bp, src_bp, (nbytes) / OPSIZ); \
+ else \
+ _wordcopy_fwd_dest_aligned (dst_bp, src_bp, (nbytes) / OPSIZ); \
+ src_bp += (nbytes) & -OPSIZ; \
+ dst_bp += (nbytes) & -OPSIZ; \
+ (nbytes_left) = (nbytes) % OPSIZ;
\
+ } while (0)
+
+
+/* Threshold value for when to enter the unrolled loops. */
+#define OP_T_THRES 16
+
+/* _wordcopy_fwd_aligned -- Copy block beginning at SRCP to
+ block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
+ Both SRCP and DSTP should be aligned for memory operations on `op_t's. */
+/* stream-lined (read x8 + write x8) */
+static void _wordcopy_fwd_aligned (long int dstp, long int srcp, size_t len)
+{
+ while (len > 7) {
+ register op_t a0,a1,a2,a3,a4,a5,a6,a7;
+ a0 = ((op_t *) srcp)[0];
+ a1 = ((op_t *) srcp)[1];
+ a2 = ((op_t *) srcp)[2];
+ a3 = ((op_t *) srcp)[3];
+ a4 = ((op_t *) srcp)[4];
+ a5 = ((op_t *) srcp)[5];
+ a6 = ((op_t *) srcp)[6];
+ a7 = ((op_t *) srcp)[7];
+ ((op_t *) dstp)[0] = a0;
+ ((op_t *) dstp)[1] = a1;
+ ((op_t *) dstp)[2] = a2;
+ ((op_t *) dstp)[3] = a3;
+ ((op_t *) dstp)[4] = a4;
+ ((op_t *) dstp)[5] = a5;
+ ((op_t *) dstp)[6] = a6;
+ ((op_t *) dstp)[7] = a7;
+
+ srcp += 8 * OPSIZ;
+ dstp += 8 * OPSIZ;
+ len -= 8;
+ }
+ while (len > 0) {
+ *(op_t *)dstp=*(op_t *)srcp;
+
+ srcp += OPSIZ;
+ dstp += OPSIZ;
+ len -= 1;
+ }
+}
+
+/* _wordcopy_fwd_dest_aligned -- Copy block beginning at SRCP to
+ block beginning at DSTP with LEN `op_t' words (not LEN bytes!).
+ DSTP should be aligned for memory operations on `op_t's, but SRCP must
+ *not* be aligned. */
+/* stream-lined (read x4 + write x4) */
+static void _wordcopy_fwd_dest_aligned (long int dstp, long int srcp, size_t
len)
+{
+ op_t ap;
+ int sh_1, sh_2;
+
+ /* Calculate how to shift a word read at the memory operation
+ aligned srcp to make it aligned for copy. */
+
+ sh_1 = 8 * (srcp % OPSIZ);
+ sh_2 = 8 * OPSIZ - sh_1;
+
+ /* Make SRCP aligned by rounding it down to the beginning of the `op_t'
+ it points in the middle of. */
+ srcp &= -OPSIZ;
+ ap = ((op_t *) srcp)[0];
+ srcp += OPSIZ;
+
+ while (len > 3) {
+ op_t a0,a1,a2,a3;
+ a0 = ((op_t *) srcp)[0];
+ a1 = ((op_t *) srcp)[1];
+ a2 = ((op_t *) srcp)[2];
+ a3 = ((op_t *) srcp)[3];
+ ((op_t *) dstp)[0] = MERGE (ap, sh_1, a0, sh_2);
+ ((op_t *) dstp)[1] = MERGE (a0, sh_1, a1, sh_2);
+ ((op_t *) dstp)[2] = MERGE (a1, sh_1, a2, sh_2);
+ ((op_t *) dstp)[3] = MERGE (a2, sh_1, a3, sh_2);
+
+ ap = a3;
+ srcp += 4 * OPSIZ;
+ dstp += 4 * OPSIZ;
+ len -= 4;
+ }
+ while (len > 0) {
+ register op_t a0;
+ a0 = ((op_t *) srcp)[0];
+ ((op_t *) dstp)[0] = MERGE (ap, sh_1, a0, sh_2);
+
+ ap = a0;
+ srcp += OPSIZ;
+ dstp += OPSIZ;
+ len -= 1;
+ }
+}
+
+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 whole pages from SRCP to DSTP by virtual address manipulation,
+ as much as possible. */
+
+ /* PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len); */
+
+ /* 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;
+}
#endif
