/* Copy memory to memory until the specified number of bytes

   has been copied.  Overlap is handled correctly.

   For SPARC V9.

   Copyright (C) 2017-2018 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>

#ifndef XCC

# define XCC    xcc

	.register	%g2, #scratch

#endif

ENTRY(memmove)

	mov	%o0, %g2	/* Save pointer to destination  */

	cmp	%o1, %o0	/* if from address is >= to use forward copy  */

	bgeu,a	%XCC, 2f	/* else use backward if ...  */

	 cmp	%o2, 17		/* delay slot, for small counts copy bytes  */

	sub	%o0, %o1, %o4	/* get difference of two addresses  */

	cmp	%o2, %o4	/* compare size and difference of addresses  */

	bgu	%XCC, .Lovbc	/* if size is bigger, have to do overlapped copy  */

	 cmp	%o2, 17		/* delay slot, for small counts copy bytes  */

/*

 * normal, copy forwards

 */

2:	ble	%XCC, .Ldbytecp

	 andcc	%o1, 3, %o5	/* is src word aligned  */

	bz,pn	%icc, .Laldst

	 cmp	%o5, 2		/* is src half-word aligned  */

	be,pn	%icc, .Ls2alg

	 cmp	%o5, 3		/* src is byte aligned  */

	ldub	[%o1], %o3	/* move 1 or 3 bytes to align it  */

	inc	1, %o1

	stb	%o3, [%o0]	/* move a byte to align src  */

	inc	1, %o0

	bne,pn	%icc, .Ls2alg

	 dec	%o2

	b	.Lald		/* now go align dest  */

	 andcc	%o0, 3, %o5

.Ls2alg:

	lduh	[%o1], %o3	/* know src is 2 byte aligned  */

	inc	2, %o1

	srl	%o3, 8, %o4

	stb	%o4, [%o0]	/* have to do bytes,  */

	stb	%o3, [%o0 + 1]	/* don't know dst alingment  */

	inc	2, %o0

	dec	2, %o2

.Laldst:

	andcc	%o0, 3, %o5	/* align the destination address  */

.Lald:	bz,pn	%icc, .Lw4cp

	 cmp	%o5, 2

	bz,pn	%icc, .Lw2cp

	 cmp	%o5, 3

.Lw3cp:

	lduw	[%o1], %o4

	inc	4, %o1

	srl	%o4, 24, %o5

	stb	%o5, [%o0]

	bne,pt	%icc, .Lw1cp

	 inc	%o0

	dec	1, %o2

	andn	%o2, 3, %o3	/* i3 is aligned word count  */

	dec	4, %o3		/* avoid reading beyond tail of src  */

	sub	%o1, %o0, %o1	/* i1 gets the difference  */

1:	sll	%o4, 8, %g1	/* save residual bytes  */

	lduw	[%o1+%o0], %o4

	deccc	4, %o3

	srl	%o4, 24, %o5	/* merge with residual  */

	or	%o5, %g1, %g1

	st	%g1, [%o0]

	bnz,pt	%XCC, 1b

	 inc	4, %o0

	sub	%o1, 3, %o1	/* used one byte of last word read  */

	and	%o2, 3, %o2

	b	7f

	 inc	4, %o2

.Lw1cp:

	srl	%o4, 8, %o5

	sth	%o5, [%o0]

	inc	2, %o0

	dec	3, %o2

	andn	%o2, 3, %o3

	dec	4, %o3		/* avoid reading beyond tail of src  */

	sub	%o1, %o0, %o1	/* i1 gets the difference  */

2:	sll	%o4, 24, %g1	/* save residual bytes  */

	lduw	[%o1+%o0], %o4

	deccc	4, %o3

	srl	%o4, 8, %o5	/* merge with residual  */

	or	%o5, %g1, %g1

	st	%g1, [%o0]

	bnz,pt	%XCC, 2b

	 inc	4, %o0

	sub	%o1, 1, %o1	/* used three bytes of last word read  */

	and	%o2, 3, %o2

	b	7f

	inc	4, %o2

.Lw2cp:

	lduw	[%o1], %o4

	inc	4, %o1

	srl	%o4, 16, %o5

	sth	%o5, [%o0]

	inc	2, %o0

	dec	2, %o2

	andn	%o2, 3, %o3	/* i3 is aligned word count  */

	dec	4, %o3		/* avoid reading beyond tail of src  */

	sub	%o1, %o0, %o1	/* i1 gets the difference  */

3:	sll	%o4, 16, %g1	/* save residual bytes  */

	lduw	[%o1+%o0], %o4

	deccc	4, %o3

	srl	%o4, 16, %o5	/* merge with residual  */

	or	%o5, %g1, %g1

	st	%g1, [%o0]

	bnz,pt	%XCC, 3b

	 inc	4, %o0

	sub	%o1, 2, %o1	/* used two bytes of last word read  */

	and	%o2, 3, %o2

	b	7f

	 inc	4, %o2

.Lw4cp:

	andn	%o2, 3, %o3	/* i3 is aligned word count  */

	sub	%o1, %o0, %o1	/* i1 gets the difference  */

1:	lduw	[%o1+%o0], %o4	/* read from address  */

	deccc	4, %o3		/* decrement count  */

	st	%o4, [%o0]	/* write at destination address  */

	bg,pt	%XCC, 1b

	 inc	4, %o0		/* increment to address  */

	b	7f

	 and	%o2, 3, %o2	/* number of leftover bytes, if any  */

/*

 * differenced byte copy, works with any alignment

 */

.Ldbytecp:

	b	7f

	 sub	%o1, %o0, %o1	/* i1 gets the difference  */

4:	stb	%o4, [%o0]	/* write to address  */

	inc	%o0		/* inc to address  */

7:	deccc	%o2		/* decrement count  */

	bge,a	%XCC, 4b	/* loop till done  */

	 ldub	[%o1+%o0], %o4	/* read from address  */

	retl

	 mov	%g2, %o0	/* return pointer to destination  */

/*

 * an overlapped copy that must be done "backwards"

 */

.Lovbc:

	add	%o1, %o2, %o1	/* get to end of source space  */

	add	%o0, %o2, %o0	/* get to end of destination space  */

	sub	%o1, %o0, %o1	/* i1 gets the difference  */

5:	dec	%o0		/* decrement to address  */

	ldub	[%o1+%o0], %o3	/* read a byte  */

	deccc	%o2		/* decrement count  */

	bg,pt	%XCC, 5b 	/* loop until done  */

	 stb	%o3, [%o0]	/* write byte  */

	retl

	 mov	%g2, %o0	/* return pointer to destination  */

END(memmove)

libc_hidden_builtin_def (memmove)