Revived C implementations of memcpy() and memset() for platforms without asm optimized versions (gmini), replacing the intermediate strings.c. Moved the asm optimized versions 'out of the way' for the implicit 'make' rules by renaming them to *_a.S (for assembler/alternative).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5628 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 196 insertions, 0 deletions

diff --git a/firmware/common/memcpy_a.S b/firmware/common/memcpy_a.S
new file mode 100644
index 0000000000..e129b99442
--- /dev/null
+++ b/firmware/common/memcpy_a.S
@@ -0,0 +1,196 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2004 by Jens Arnold
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "config.h"
+
+    .section    .icode,"ax",@progbits
+
+#if CONFIG_CPU == SH7034
+    .align      2
+    .global     _memcpy
+    .type       _memcpy,@function
+
+/* Copies <length> bytes of data in memory from <source> to <dest>
+ * This version is optimized for speed
+ *
+ * arguments:
+ *  r4 - destination address
+ *  r5 - source address
+ *  r6 - length
+ *
+ * return value:
+ *  r0 - destination address (like ANSI version)
+ *
+ * register usage:
+ *  r0 - data / temporary
+ *  r1 - bit mask for rounding to long bounds / 2nd data
+ *  r2 - first long bound (only if >= 12 bytes)
+ *  r3 - last long bound (-4) (only if >= 12 bytes)
+ *  r4 - current dest address
+ *  r5 - current source address
+ *  r6 - source end address
+ *  r7 - stored dest start address
+ *
+ * The instruction order below is devised in a way to utilize the pipelining
+ * of the SH1 to the max. The routine also tries to utilize fast page mode.
+ */
+
+_memcpy:
+    add     r5,r6       /* r6 = source_end */
+    mov     r4,r7       /* store for returning */
+    add     #-8,r4      /* adjust for early increments (max. 2 longs) */
+
+    mov     r6,r0
+    add     #-12,r0     /* r0 = r6 - 12; don't go below 12 here! */
+    cmp/hs  r5,r0       /* >= 12 bytes to copy? */
+    bf      .start_b2   /* no, jump into byte loop */
+
+    mov     #-4,r1      /* r1 = 0xFFFFFFFC */
+
+    mov     r5,r2
+    add     #3,r2
+    and     r1,r2       /* r2 = first source long bound */
+    mov     r6,r3
+    add     #-4,r3      /* end offset for copying 2 longs per pass */
+    bra     .start_b1   /* jump into leading byte loop */
+    and     r1,r3       /* r3 = last source long bound - 4 */
+
+    /* leading byte loop: copies 0..3 bytes */
+    .align  2
+.loop_b1:
+    mov.b   @r5+,r0     /* load byte & increment source addr */
+    add     #1,r4       /* increment dest addr */
+    mov.b   r0,@(7,r4)  /* store byte */
+.start_b1:
+    cmp/hi  r5,r2       /* runs r5 up to first long bound */
+    bt      .loop_b1
+    /* now r5 is always at a long boundary */
+    /* -> memory reading is done in longs for all dest alignments */
+
+    /* selector for main copy loop */
+    mov     r4,r0
+    tst     #3,r0       /* dest now also at long bound? */
+    bt      .loop2_l    /* yes, do long copy */
+    tst     #1,r0       /* dest now at least at word bound? */
+    bt      .start4_w   /* yes, do word copy */
+
+    /* main loop for byte aligned destination (fast) */
+    /* copies 1 long per pass */
+    add     #4,r3       /* reset end offset */
+    add     #-1,r4      /* adjust to word alignment for word write+ */
+
+.loop4_b:
+    mov.l   @r5+,r0     /* load a long & increment source addr */
+    add     #4,r4       /* increment dest addr */
+    mov.b   r0,@(8,r4)  /* store low byte */
+    shlr8   r0          /* get middle 2 bytes */
+    mov.w   r0,@(6,r4)  /* store as word+ */
+    shlr16  r0          /* get upper byte */
+    mov.b   r0,@(5,r4)  /* and store */
+    cmp/hi  r5,r3       /* runs r5 up to last long bound */
+    bt      .loop4_b
+
+    bra     .start_b2   /* jump to trailing byte loop */
+    add     #1,r4       /* readjust */
+
+    /* main loop for word aligned destination (faster) */
+    /* copies 2 longs per pass, utilizing fast page mode */
+.start4_w:
+    add     #-2,r4      /* adjust to long alignment for long write+ */
+
+.loop4_w:
+    mov.l   @r5+,r1     /* load first long & increment source addr */
+    add     #8,r4       /* increment dest addr */
+    mov.l   @r5+,r0     /* load second long & increment source addr */
+    cmp/hi  r5,r3       /* runs r5 up to last or second last long bound */
+    mov.w   r0,@(8,r4)  /* store low word of second long */
+    xtrct   r1,r0       /* extract low word of first long & high word of second long */
+    mov.l   r0,@(4,r4)  /* and store as long+ */
+    swap.w  r1,r0       /* get high word of first long */
+    mov.w   r0,@(2,r4)  /* and store it */
+    bt      .loop4_w
+
+    add     #2,r4       /* readjust destination */
+    add     #4,r3       /* reset end offset */
+    cmp/hi  r5,r3       /* one long left? */
+    bf      .start_b2   /* no, jump to trailing byte loop */
+
+    mov.l   @r5+,r0     /* load last long & increment source addr */
+    add     #4,r4       /* increment dest addr */
+    mov.w   r0,@(6,r4)  /* store low word */
+    shlr16  r0          /* get high word */
+    bra     .start_b2   /* jump to trailing byte loop */
+    mov.w   r0,@(4,r4)  /* and store it */
+
+    /* main loop for long aligned destination (fastest) */
+    /* copies 2 longs per pass, utilizing fast page mode */
+.loop2_l:
+    mov.l   @r5+,r1     /* load first long & increment source addr */
+    add     #8,r4       /* increment dest addr */
+    mov.l   @r5+,r0     /* load second long & increment source addr */
+    cmp/hi  r5,r3       /* runs r5 up to last or second last long bound */
+    mov.l   r1,@r4      /* store first long */
+    mov.l   r0,@(4,r4)  /* store second long; NOT ALIGNED - no speed loss here! */
+    bt      .loop2_l
+
+    add     #4,r3       /* reset end offset */
+    cmp/hi  r5,r3       /* one long left? */
+    bf      .start_b2   /* no, jump to trailing byte loop */
+
+    mov.l   @r5+,r0     /* load last long & increment source addr */
+    add     #4,r4       /* increment dest addr */
+    bra     .start_b2   /* jump to trailing byte loop */
+    mov.l   r0,@(4,r4)  /* store last long */
+
+    /* trailing byte loop: copies 0..3 bytes (or all for < 12 in total) */
+.loop_b2:
+    mov.b   @r5+,r0     /* load byte & increment source addr */
+    add     #1,r4       /* increment dest addr */
+    mov.b   r0,@(7,r4)  /* store byte */
+.start_b2:
+    cmp/hi  r5,r6       /* runs r5 up to end address */
+    bt      .loop_b2
+
+    rts
+    mov     r7,r0       /* return dest start address */
+.end:
+    .size   _memcpy,.end-_memcpy
+#elif CONFIG_CPU == MCF5249
+    .align      2
+    .global     memcpy
+    .type       memcpy,@function
+
+/* Copies <length> bytes of data in memory from <source> to <dest>
+ * This version is not optimized at all
+ */
+memcpy:
+        move.l  (4,%sp),%a1    /* Destination */
+        move.l  (8,%sp),%a0     /* Source */
+        move.l  (12,%sp),%d1    /* Length */
+
+        cmp.l   #0,%d1
+        bra.b   .byteloopend
+
+.byteloop:
+        move.b  (%a0)+,(%a1)+
+        subq.l  #1,%d1
+.byteloopend:
+        bne.b   .byteloop
+
+        rts
+#endif