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-rw-r--r--sysdeps/aarch64/memcpy.S348
-rw-r--r--sysdeps/aarch64/memmove.S313
2 files changed, 209 insertions, 452 deletions
diff --git a/sysdeps/aarch64/memcpy.S b/sysdeps/aarch64/memcpy.S
index 442f390426..c256828af7 100644
--- a/sysdeps/aarch64/memcpy.S
+++ b/sysdeps/aarch64/memcpy.S
@@ -16,161 +16,229 @@
    License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <sysdep.h>
+
 /* Assumptions:
  *
- * ARMv8-a, AArch64
- * Unaligned accesses
+ * ARMv8-a, AArch64, unaligned accesses.
  *
  */
 
 #define dstin	x0
 #define src	x1
 #define count	x2
-#define tmp1	x3
-#define tmp1w	w3
-#define tmp2	x4
-#define tmp2w	w4
-#define tmp3	x5
-#define tmp3w	w5
-#define dst	x6
-
-#define A_l	x7
-#define A_h	x8
-#define B_l	x9
-#define B_h	x10
-#define C_l	x11
-#define C_h	x12
-#define D_l	x13
-#define D_h	x14
+#define dst	x3
+#define srcend	x4
+#define dstend	x5
+#define A_l	x6
+#define A_lw	w6
+#define A_h	x7
+#define A_hw	w7
+#define B_l	x8
+#define B_h	x9
+#define C_l	x10
+#define C_h	x11
+#define D_l	x12
+#define D_h	x13
+#define E_l	src
+#define E_h	count
+#define F_l	srcend
+#define F_h	dst
+#define G_l	count
+#define G_h	dst
+#define tmp1	x14
 
-#include <sysdep.h>
+/* Copies are split into 3 main cases: small copies of up to 16 bytes,
+   medium copies of 17..96 bytes which are fully unrolled. Large copies
+   of more than 96 bytes align the destination and use an unrolled loop
+   processing 64 bytes per iteration.
+   In order to share code with memmove, small and medium copies read all
+   data before writing, allowing any kind of overlap. So small, medium
+   and large backwards memmoves are handled by falling through into memcpy.
+   Overlapping large forward memmoves use a loop that copies backwards.
+*/
 
-ENTRY_ALIGN (memcpy, 6)
-
-	mov	dst, dstin
-	cmp	count, #64
-	b.ge	L(cpy_not_short)
-	cmp	count, #15
-	b.le	L(tail15tiny)
-
-	/* Deal with small copies quickly by dropping straight into the
-	 * exit block.  */
-L(tail63):
-	/* Copy up to 48 bytes of data.  At this point we only need the
-	 * bottom 6 bits of count to be accurate.  */
-	ands	tmp1, count, #0x30
-	b.eq	L(tail15)
-	add	dst, dst, tmp1
-	add	src, src, tmp1
-	cmp	tmp1w, #0x20
-	b.eq	1f
-	b.lt	2f
-	ldp	A_l, A_h, [src, #-48]
-	stp	A_l, A_h, [dst, #-48]
-1:
-	ldp	A_l, A_h, [src, #-32]
-	stp	A_l, A_h, [dst, #-32]
-2:
-	ldp	A_l, A_h, [src, #-16]
-	stp	A_l, A_h, [dst, #-16]
-
-L(tail15):
-	ands	count, count, #15
-	beq	1f
-	add	src, src, count
-	ldp	A_l, A_h, [src, #-16]
-	add	dst, dst, count
-	stp	A_l, A_h, [dst, #-16]
-1:
-	RET
-
-L(tail15tiny):
-	/* Copy up to 15 bytes of data.  Does not assume additional data
-	   being copied.  */
-	tbz	count, #3, 1f
-	ldr	tmp1, [src], #8
-	str	tmp1, [dst], #8
+ENTRY_ALIGN (memmove, 6)
+
+	sub	tmp1, dstin, src
+	cmp	count, 96
+	ccmp	tmp1, count, 2, hi
+	b.lo	L(move_long)
+
+	/* Common case falls through into memcpy.  */
+END (memmove)
+libc_hidden_builtin_def (memmove)
+ENTRY (memcpy)
+
+	add	srcend, src, count
+	add	dstend, dstin, count
+	cmp	count, 96
+	b.hi	L(copy_long)
+	cmp	count, 16
+	b.hs	L(copy_medium)
+
+	/* Small copies: 0..16 bytes.  */
+L(copy16):
+	tbz	count, 3, 1f
+	ldr	A_l, [src]
+	ldr	A_h, [srcend, -8]
+	str	A_l, [dstin]
+	str	A_h, [dstend, -8]
+	ret
 1:
-	tbz	count, #2, 1f
-	ldr	tmp1w, [src], #4
-	str	tmp1w, [dst], #4
+	tbz	count, 2, 1f
+	ldr	A_lw, [src]
+	ldr	A_hw, [srcend, -4]
+	str	A_lw, [dstin]
+	str	A_hw, [dstend, -4]
+	ret
+	.p2align 4
 1:
-	tbz	count, #1, 1f
-	ldrh	tmp1w, [src], #2
-	strh	tmp1w, [dst], #2
+	cbz	count, 2f
+	ldrb	A_lw, [src]
+	tbz	count, 1, 1f
+	ldrh	A_hw, [srcend, -2]
+	strh	A_hw, [dstend, -2]
+1:	strb	A_lw, [dstin]
+2:	ret
+
+	.p2align 4
+	/* Medium copies: 17..96 bytes.  */
+L(copy_medium):
+	ldp	A_l, A_h, [src]
+	tbnz	count, 6, L(copy96)
+	ldp	D_l, D_h, [srcend, -16]
+	tbz	count, 5, 1f
+	ldp	B_l, B_h, [src, 16]
+	ldp	C_l, C_h, [srcend, -32]
+	stp	B_l, B_h, [dstin, 16]
+	stp	C_l, C_h, [dstend, -32]
 1:
-	tbz	count, #0, 1f
-	ldrb	tmp1w, [src]
-	strb	tmp1w, [dst]
+	stp	A_l, A_h, [dstin]
+	stp	D_l, D_h, [dstend, -16]
+	ret
+
+	.p2align 4
+	/* Copy 64..96 bytes.  Copy 64 bytes from the start and
+	   32 bytes from the end.  */
+L(copy96):
+	ldp	B_l, B_h, [src, 16]
+	ldp	C_l, C_h, [src, 32]
+	ldp	D_l, D_h, [src, 48]
+	ldp	E_l, E_h, [srcend, -32]
+	ldp	F_l, F_h, [srcend, -16]
+	stp	A_l, A_h, [dstin]
+	stp	B_l, B_h, [dstin, 16]
+	stp	C_l, C_h, [dstin, 32]
+	stp	D_l, D_h, [dstin, 48]
+	stp	E_l, E_h, [dstend, -32]
+	stp	F_l, F_h, [dstend, -16]
+	ret
+
+	/* Align DST to 16 byte alignment so that we don't cross cache line
+	   boundaries on both loads and stores.  There are at least 96 bytes
+	   to copy, so copy 16 bytes unaligned and then align.  The loop
+	   copies 64 bytes per iteration and prefetches one iteration ahead.  */
+
+	.p2align 4
+L(copy_long):
+	and	tmp1, dstin, 15
+	bic	dst, dstin, 15
+	ldp	D_l, D_h, [src]
+	sub	src, src, tmp1
+	add	count, count, tmp1	/* Count is now 16 too large.  */
+	ldp	A_l, A_h, [src, 16]
+	stp	D_l, D_h, [dstin]
+	ldp	B_l, B_h, [src, 32]
+	ldp	C_l, C_h, [src, 48]
+	ldp	D_l, D_h, [src, 64]!
+	subs	count, count, 128 + 16	/* Test and readjust count.  */
+	b.ls	2f
 1:
-	RET
-
-L(cpy_not_short):
-	/* We don't much care about the alignment of DST, but we want SRC
-	 * to be 128-bit (16 byte) aligned so that we don't cross cache line
-	 * boundaries on both loads and stores.  */
-	neg	tmp2, src
-	ands	tmp2, tmp2, #15		/* Bytes to reach alignment.  */
-	b.eq	2f
-	sub	count, count, tmp2
-	/* Copy more data than needed; it's faster than jumping
-	 * around copying sub-Quadword quantities.  We know that
-	 * it can't overrun.  */
-	ldp	A_l, A_h, [src]
-	add	src, src, tmp2
-	stp	A_l, A_h, [dst]
-	add	dst, dst, tmp2
-	/* There may be less than 63 bytes to go now.  */
-	cmp	count, #63
-	b.le	L(tail63)
+	stp	A_l, A_h, [dst, 16]
+	ldp	A_l, A_h, [src, 16]
+	stp	B_l, B_h, [dst, 32]
+	ldp	B_l, B_h, [src, 32]
+	stp	C_l, C_h, [dst, 48]
+	ldp	C_l, C_h, [src, 48]
+	stp	D_l, D_h, [dst, 64]!
+	ldp	D_l, D_h, [src, 64]!
+	subs	count, count, 64
+	b.hi	1b
+
+	/* Write the last full set of 64 bytes.  The remainder is at most 64
+	   bytes, so it is safe to always copy 64 bytes from the end even if
+	   there is just 1 byte left.  */
 2:
-	subs	count, count, #128
-	b.ge	L(cpy_body_large)
-	/* Less than 128 bytes to copy, so handle 64 here and then jump
-	 * to the tail.  */
-	ldp	A_l, A_h, [src]
-	ldp	B_l, B_h, [src, #16]
-	ldp	C_l, C_h, [src, #32]
-	ldp	D_l, D_h, [src, #48]
-	stp	A_l, A_h, [dst]
-	stp	B_l, B_h, [dst, #16]
-	stp	C_l, C_h, [dst, #32]
-	stp	D_l, D_h, [dst, #48]
-	tst	count, #0x3f
-	add	src, src, #64
-	add	dst, dst, #64
-	b.ne	L(tail63)
-	RET
-
-	/* Critical loop.  Start at a new cache line boundary.  Assuming
-	 * 64 bytes per line this ensures the entire loop is in one line.  */
-	.p2align 6
-L(cpy_body_large):
-	/* There are at least 128 bytes to copy.  */
-	ldp	A_l, A_h, [src, #0]
-	sub	dst, dst, #16		/* Pre-bias.  */
-	ldp	B_l, B_h, [src, #16]
-	ldp	C_l, C_h, [src, #32]
-	ldp	D_l, D_h, [src, #48]!	/* src += 64 - Pre-bias.  */
+	ldp	E_l, E_h, [srcend, -64]
+	stp	A_l, A_h, [dst, 16]
+	ldp	A_l, A_h, [srcend, -48]
+	stp	B_l, B_h, [dst, 32]
+	ldp	B_l, B_h, [srcend, -32]
+	stp	C_l, C_h, [dst, 48]
+	ldp	C_l, C_h, [srcend, -16]
+	stp	D_l, D_h, [dst, 64]
+	stp	E_l, E_h, [dstend, -64]
+	stp	A_l, A_h, [dstend, -48]
+	stp	B_l, B_h, [dstend, -32]
+	stp	C_l, C_h, [dstend, -16]
+	ret
+
+	.p2align 4
+L(move_long):
+	cbz	tmp1, 3f
+
+	add	srcend, src, count
+	add	dstend, dstin, count
+
+	/* Align dstend to 16 byte alignment so that we don't cross cache line
+	   boundaries on both loads and stores.  There are at least 96 bytes
+	   to copy, so copy 16 bytes unaligned and then align.  The loop
+	   copies 64 bytes per iteration and prefetches one iteration ahead.  */
+
+	and	tmp1, dstend, 15
+	ldp	D_l, D_h, [srcend, -16]
+	sub	srcend, srcend, tmp1
+	sub	count, count, tmp1
+	ldp	A_l, A_h, [srcend, -16]
+	stp	D_l, D_h, [dstend, -16]
+	ldp	B_l, B_h, [srcend, -32]
+	ldp	C_l, C_h, [srcend, -48]
+	ldp	D_l, D_h, [srcend, -64]!
+	sub	dstend, dstend, tmp1
+	subs	count, count, 128
+	b.ls	2f
+
+	nop
 1:
-	stp	A_l, A_h, [dst, #16]
-	ldp	A_l, A_h, [src, #16]
-	stp	B_l, B_h, [dst, #32]
-	ldp	B_l, B_h, [src, #32]
-	stp	C_l, C_h, [dst, #48]
-	ldp	C_l, C_h, [src, #48]
-	stp	D_l, D_h, [dst, #64]!
-	ldp	D_l, D_h, [src, #64]!
-	subs	count, count, #64
-	b.ge	1b
-	stp	A_l, A_h, [dst, #16]
-	stp	B_l, B_h, [dst, #32]
-	stp	C_l, C_h, [dst, #48]
-	stp	D_l, D_h, [dst, #64]
-	add	src, src, #16
-	add	dst, dst, #64 + 16
-	tst	count, #0x3f
-	b.ne	L(tail63)
-	RET
+	stp	A_l, A_h, [dstend, -16]
+	ldp	A_l, A_h, [srcend, -16]
+	stp	B_l, B_h, [dstend, -32]
+	ldp	B_l, B_h, [srcend, -32]
+	stp	C_l, C_h, [dstend, -48]
+	ldp	C_l, C_h, [srcend, -48]
+	stp	D_l, D_h, [dstend, -64]!
+	ldp	D_l, D_h, [srcend, -64]!
+	subs	count, count, 64
+	b.hi	1b
+
+	/* Write the last full set of 64 bytes.  The remainder is at most 64
+	   bytes, so it is safe to always copy 64 bytes from the start even if
+	   there is just 1 byte left.  */
+2:
+	ldp	G_l, G_h, [src, 48]
+	stp	A_l, A_h, [dstend, -16]
+	ldp	A_l, A_h, [src, 32]
+	stp	B_l, B_h, [dstend, -32]
+	ldp	B_l, B_h, [src, 16]
+	stp	C_l, C_h, [dstend, -48]
+	ldp	C_l, C_h, [src]
+	stp	D_l, D_h, [dstend, -64]
+	stp	G_l, G_h, [dstin, 48]
+	stp	A_l, A_h, [dstin, 32]
+	stp	B_l, B_h, [dstin, 16]
+	stp	C_l, C_h, [dstin]
+3:	ret
+
 END (memcpy)
 libc_hidden_builtin_def (memcpy)
diff --git a/sysdeps/aarch64/memmove.S b/sysdeps/aarch64/memmove.S
index dd91db0ff6..0feeac8414 100644
--- a/sysdeps/aarch64/memmove.S
+++ b/sysdeps/aarch64/memmove.S
@@ -1,312 +1 @@
-/* Copyright (C) 2012-2016 Free Software Foundation, Inc.
-
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library 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
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-
-/* Assumptions:
- *
- * ARMv8-a, AArch64
- * Unaligned accesses
- */
-
-/* Parameters and result.  */
-#define dstin	x0
-#define src	x1
-#define count	x2
-#define tmp1	x3
-#define tmp1w	w3
-#define tmp2	x4
-#define tmp2w	w4
-#define tmp3	x5
-#define tmp3w	w5
-#define dst	x6
-
-#define A_l	x7
-#define A_h	x8
-#define B_l	x9
-#define B_h	x10
-#define C_l	x11
-#define C_h	x12
-#define D_l	x13
-#define D_h	x14
-
-ENTRY_ALIGN (memmove, 6)
-
-	cmp	dstin, src
-	b.lo	L(downwards)
-	add	tmp1, src, count
-	cmp	dstin, tmp1
-	b.hs	memcpy		/* No overlap.  */
-
-	/* Upwards move with potential overlap.
-	 * Need to move from the tail backwards.  SRC and DST point one
-	 * byte beyond the remaining data to move.  */
-	add	dst, dstin, count
-	add	src, src, count
-	cmp	count, #64
-	b.ge	L(mov_not_short_up)
-
-	/* Deal with small moves quickly by dropping straight into the
-	 * exit block.  */
-L(tail63up):
-	/* Move up to 48 bytes of data.  At this point we only need the
-	 * bottom 6 bits of count to be accurate.  */
-	ands	tmp1, count, #0x30
-	b.eq	L(tail15up)
-	sub	dst, dst, tmp1
-	sub	src, src, tmp1
-	cmp	tmp1w, #0x20
-	b.eq	1f
-	b.lt	2f
-	ldp	A_l, A_h, [src, #32]
-	stp	A_l, A_h, [dst, #32]
-1:
-	ldp	A_l, A_h, [src, #16]
-	stp	A_l, A_h, [dst, #16]
-2:
-	ldp	A_l, A_h, [src]
-	stp	A_l, A_h, [dst]
-L(tail15up):
-	/* Move up to 15 bytes of data.  Does not assume additional data
-	 * being moved.  */
-	tbz	count, #3, 1f
-	ldr	tmp1, [src, #-8]!
-	str	tmp1, [dst, #-8]!
-1:
-	tbz	count, #2, 1f
-	ldr	tmp1w, [src, #-4]!
-	str	tmp1w, [dst, #-4]!
-1:
-	tbz	count, #1, 1f
-	ldrh	tmp1w, [src, #-2]!
-	strh	tmp1w, [dst, #-2]!
-1:
-	tbz	count, #0, 1f
-	ldrb	tmp1w, [src, #-1]
-	strb	tmp1w, [dst, #-1]
-1:
-	RET
-
-L(mov_not_short_up):
-	/* We don't much care about the alignment of DST, but we want SRC
-	 * to be 128-bit (16 byte) aligned so that we don't cross cache line
-	 * boundaries on both loads and stores.  */
-	ands	tmp2, src, #15		/* Bytes to reach alignment.  */
-	b.eq	2f
-	sub	count, count, tmp2
-	/* Move enough data to reach alignment; unlike memcpy, we have to
-	 * be aware of the overlap, which means we can't move data twice.  */
-	tbz	tmp2, #3, 1f
-	ldr	tmp1, [src, #-8]!
-	str	tmp1, [dst, #-8]!
-1:
-	tbz	tmp2, #2, 1f
-	ldr	tmp1w, [src, #-4]!
-	str	tmp1w, [dst, #-4]!
-1:
-	tbz	tmp2, #1, 1f
-	ldrh	tmp1w, [src, #-2]!
-	strh	tmp1w, [dst, #-2]!
-1:
-	tbz	tmp2, #0, 1f
-	ldrb	tmp1w, [src, #-1]!
-	strb	tmp1w, [dst, #-1]!
-1:
-
-	/* There may be less than 63 bytes to go now.  */
-	cmp	count, #63
-	b.le	L(tail63up)
-2:
-	subs	count, count, #128
-	b.ge	L(mov_body_large_up)
-	/* Less than 128 bytes to move, so handle 64 here and then jump
-	 * to the tail.  */
-	ldp	A_l, A_h, [src, #-64]!
-	ldp	B_l, B_h, [src, #16]
-	ldp	C_l, C_h, [src, #32]
-	ldp	D_l, D_h, [src, #48]
-	stp	A_l, A_h, [dst, #-64]!
-	stp	B_l, B_h, [dst, #16]
-	stp	C_l, C_h, [dst, #32]
-	stp	D_l, D_h, [dst, #48]
-	tst	count, #0x3f
-	b.ne	L(tail63up)
-	RET
-
-	/* Critical loop.  Start at a new Icache line boundary.  Assuming
-	 * 64 bytes per line this ensures the entire loop is in one line.  */
-	.p2align 6
-L(mov_body_large_up):
-	/* There are at least 128 bytes to move.  */
-	ldp	A_l, A_h, [src, #-16]
-	ldp	B_l, B_h, [src, #-32]
-	ldp	C_l, C_h, [src, #-48]
-	ldp	D_l, D_h, [src, #-64]!
-1:
-	stp	A_l, A_h, [dst, #-16]
-	ldp	A_l, A_h, [src, #-16]
-	stp	B_l, B_h, [dst, #-32]
-	ldp	B_l, B_h, [src, #-32]
-	stp	C_l, C_h, [dst, #-48]
-	ldp	C_l, C_h, [src, #-48]
-	stp	D_l, D_h, [dst, #-64]!
-	ldp	D_l, D_h, [src, #-64]!
-	subs	count, count, #64
-	b.ge	1b
-	stp	A_l, A_h, [dst, #-16]
-	stp	B_l, B_h, [dst, #-32]
-	stp	C_l, C_h, [dst, #-48]
-	stp	D_l, D_h, [dst, #-64]!
-	tst	count, #0x3f
-	b.ne	L(tail63up)
-	RET
-
-L(downwards):
-	/* For a downwards move we can safely use memcpy provided that
-	 * DST is more than 16 bytes away from SRC.  */
-	sub	tmp1, src, #16
-	cmp	dstin, tmp1
-	b.ls	memcpy		/* May overlap, but not critically.  */
-
-	mov	dst, dstin	/* Preserve DSTIN for return value.  */
-	cmp	count, #64
-	b.ge	L(mov_not_short_down)
-
-	/* Deal with small moves quickly by dropping straight into the
-	 * exit block.  */
-L(tail63down):
-	/* Move up to 48 bytes of data.  At this point we only need the
-	 * bottom 6 bits of count to be accurate.  */
-	ands	tmp1, count, #0x30
-	b.eq	L(tail15down)
-	add	dst, dst, tmp1
-	add	src, src, tmp1
-	cmp	tmp1w, #0x20
-	b.eq	1f
-	b.lt	2f
-	ldp	A_l, A_h, [src, #-48]
-	stp	A_l, A_h, [dst, #-48]
-1:
-	ldp	A_l, A_h, [src, #-32]
-	stp	A_l, A_h, [dst, #-32]
-2:
-	ldp	A_l, A_h, [src, #-16]
-	stp	A_l, A_h, [dst, #-16]
-L(tail15down):
-	/* Move up to 15 bytes of data.  Does not assume additional data
-	   being moved.  */
-	tbz	count, #3, 1f
-	ldr	tmp1, [src], #8
-	str	tmp1, [dst], #8
-1:
-	tbz	count, #2, 1f
-	ldr	tmp1w, [src], #4
-	str	tmp1w, [dst], #4
-1:
-	tbz	count, #1, 1f
-	ldrh	tmp1w, [src], #2
-	strh	tmp1w, [dst], #2
-1:
-	tbz	count, #0, 1f
-	ldrb	tmp1w, [src]
-	strb	tmp1w, [dst]
-1:
-	RET
-
-L(mov_not_short_down):
-	/* We don't much care about the alignment of DST, but we want SRC
-	 * to be 128-bit (16 byte) aligned so that we don't cross cache line
-	 * boundaries on both loads and stores.  */
-	neg	tmp2, src
-	ands	tmp2, tmp2, #15		/* Bytes to reach alignment.  */
-	b.eq	2f
-	sub	count, count, tmp2
-	/* Move enough data to reach alignment; unlike memcpy, we have to
-	 * be aware of the overlap, which means we can't move data twice.  */
-	tbz	tmp2, #3, 1f
-	ldr	tmp1, [src], #8
-	str	tmp1, [dst], #8
-1:
-	tbz	tmp2, #2, 1f
-	ldr	tmp1w, [src], #4
-	str	tmp1w, [dst], #4
-1:
-	tbz	tmp2, #1, 1f
-	ldrh	tmp1w, [src], #2
-	strh	tmp1w, [dst], #2
-1:
-	tbz	tmp2, #0, 1f
-	ldrb	tmp1w, [src], #1
-	strb	tmp1w, [dst], #1
-1:
-
-	/* There may be less than 63 bytes to go now.  */
-	cmp	count, #63
-	b.le	L(tail63down)
-2:
-	subs	count, count, #128
-	b.ge	L(mov_body_large_down)
-	/* Less than 128 bytes to move, so handle 64 here and then jump
-	 * to the tail.  */
-	ldp	A_l, A_h, [src]
-	ldp	B_l, B_h, [src, #16]
-	ldp	C_l, C_h, [src, #32]
-	ldp	D_l, D_h, [src, #48]
-	stp	A_l, A_h, [dst]
-	stp	B_l, B_h, [dst, #16]
-	stp	C_l, C_h, [dst, #32]
-	stp	D_l, D_h, [dst, #48]
-	tst	count, #0x3f
-	add	src, src, #64
-	add	dst, dst, #64
-	b.ne	L(tail63down)
-	RET
-
-	/* Critical loop.  Start at a new cache line boundary.  Assuming
-	 * 64 bytes per line this ensures the entire loop is in one line.  */
-	.p2align 6
-L(mov_body_large_down):
-	/* There are at least 128 bytes to move.  */
-	ldp	A_l, A_h, [src, #0]
-	sub	dst, dst, #16		/* Pre-bias.  */
-	ldp	B_l, B_h, [src, #16]
-	ldp	C_l, C_h, [src, #32]
-	ldp	D_l, D_h, [src, #48]!	/* src += 64 - Pre-bias.  */
-1:
-	stp	A_l, A_h, [dst, #16]
-	ldp	A_l, A_h, [src, #16]
-	stp	B_l, B_h, [dst, #32]
-	ldp	B_l, B_h, [src, #32]
-	stp	C_l, C_h, [dst, #48]
-	ldp	C_l, C_h, [src, #48]
-	stp	D_l, D_h, [dst, #64]!
-	ldp	D_l, D_h, [src, #64]!
-	subs	count, count, #64
-	b.ge	1b
-	stp	A_l, A_h, [dst, #16]
-	stp	B_l, B_h, [dst, #32]
-	stp	C_l, C_h, [dst, #48]
-	stp	D_l, D_h, [dst, #64]
-	add	src, src, #16
-	add	dst, dst, #64 + 16
-	tst	count, #0x3f
-	b.ne	L(tail63down)
-	RET
-END (memmove)
-
-libc_hidden_builtin_def (memmove)
+/* memmove is part of memcpy.S.  */