/* Optimized version of the memccpy() function.

   This file is part of the GNU C Library.

   Copyright (C) 2000-2018 Free Software Foundation, Inc.

   Contributed by Dan Pop <Dan.Pop@cern.ch>.

   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/>.  */

/* Return: a pointer to the next byte after char in dest or NULL

   Inputs:

        in0:    dest

        in1:    src

        in2:    char

        in3:    byte count

   This implementation assumes little endian mode (UM.be = 0).

   This implementation assumes that it is safe to do read ahead

   in the src block, without getting beyond its limit.  */

#include <sysdep.h>

#undef ret

#define OP_T_THRES 	16

#define OPSIZ 		8

#define saved_pr	r17

#define saved_lc	r18

#define dest		r19

#define src		r20

#define len		r21

#define asrc		r22

#define tmp		r23

#define char		r24

#define charx8		r25

#define saved_ec	r26

#define sh2		r28

#define	sh1		r29

#define loopcnt		r30

#define	value		r31

#ifdef GAS_ALIGN_BREAKS_UNWIND_INFO

/* Manually force proper loop-alignment.  Note: be sure to

   double-check the code-layout after making any changes to

   this routine! */

# define ALIGN(n)	{ nop 0 }

#else

# define ALIGN(n)	.align n

#endif

ENTRY(memccpy)

	.prologue

	alloc 	r2 = ar.pfs, 4, 40 - 4, 0, 40

#include "softpipe.h"

	.rotr	r[MEMLAT + 7], tmp1[4], tmp2[4], val[4], tmp3[2], pos0[2]

	.rotp	p[MEMLAT + 6 + 1]

	mov	ret0 = r0		// return NULL if no match

	.save pr, saved_pr

	mov	saved_pr = pr		// save the predicate registers

	mov 	dest = in0		// dest

	.save ar.lc, saved_lc

        mov 	saved_lc = ar.lc	// save the loop counter

        mov 	saved_ec = ar.ec	// save the loop counter

	.body

	mov 	src = in1		// src

	extr.u	char = in2, 0, 8	// char

	mov	len = in3		// len

	sub	tmp = r0, in0		// tmp = -dest

	cmp.ne	p7, p0 = r0, r0		// clear p7

	;;

	and	loopcnt = 7, tmp	// loopcnt = -dest % 8

	cmp.ge	p6, p0 = OP_T_THRES, len	// is len <= OP_T_THRES

	mov	ar.ec = 0		// ec not guaranteed zero on entry

(p6)	br.cond.spnt	.cpyfew		// copy byte by byte

	;;

	cmp.eq	p6, p0 = loopcnt, r0

	mux1	charx8 = char, @brcst

(p6)	br.cond.sptk .dest_aligned

	sub	len = len, loopcnt	// len -= -dest % 8

	adds	loopcnt = -1, loopcnt	// --loopcnt

	;;

	mov	ar.lc = loopcnt

.l1:					// copy -dest % 8 bytes

	ld1	value = [src], 1	// value = *src++

	;;

	st1	[dest] = value, 1	// *dest++ = value

	cmp.eq	p6, p0 = value, char

(p6)	br.cond.spnt .foundit

	br.cloop.dptk .l1

.dest_aligned:

	and	sh1 = 7, src 		// sh1 = src % 8

	and	tmp = -8, len   	// tmp = len & -OPSIZ

	and	asrc = -8, src		// asrc = src & -OPSIZ  -- align src

	shr.u	loopcnt = len, 3	// loopcnt = len / 8

	and	len = 7, len ;;		// len = len % 8

	shl	sh1 = sh1, 3		// sh1 = 8 * (src % 8)

	adds	loopcnt = -1, loopcnt	// --loopcnt

	mov     pr.rot = 1 << 16 ;;	// set rotating predicates

	sub	sh2 = 64, sh1		// sh2 = 64 - sh1

	mov	ar.lc = loopcnt		// set LC

	cmp.eq  p6, p0 = sh1, r0 	// is the src aligned?

(p6)    br.cond.sptk .src_aligned ;;

	add	src = src, tmp		// src += len & -OPSIZ

	mov	ar.ec = MEMLAT + 6 + 1 	// six more passes needed

	ld8	r[1] = [asrc], 8 	// r[1] = w0

	cmp.ne	p6, p0 = r0, r0	;;	// clear p6

	ALIGN(32)

.l2:

(p[0])		ld8.s	r[0] = [asrc], 8		// r[0] = w1

(p[MEMLAT])	shr.u	tmp1[0] = r[1 + MEMLAT], sh1	// tmp1 = w0 >> sh1

(p[MEMLAT])	shl	tmp2[0] = r[0 + MEMLAT], sh2  	// tmp2 = w1 << sh2

(p[MEMLAT+4])	xor	tmp3[0] = val[1], charx8

(p[MEMLAT+5])	czx1.r	pos0[0] = tmp3[1]

(p[MEMLAT+6])	chk.s	r[6 + MEMLAT], .recovery1	// our data isn't

							// valid - rollback!

(p[MEMLAT+6])	cmp.ne	p6, p0 = 8, pos0[1]

(p6)		br.cond.spnt	.gotit

(p[MEMLAT+6])	st8	[dest] = val[3], 8		// store val to dest

(p[MEMLAT+3])	or	val[0] = tmp1[3], tmp2[3] 	// val = tmp1 | tmp2

		br.ctop.sptk    .l2

		br.cond.sptk .cpyfew

.src_aligned:

		cmp.ne  p6, p0 = r0, r0			// clear p6

		mov     ar.ec = MEMLAT + 2 + 1 ;;	// set EC

.l3:

(p[0])		ld8.s	r[0] = [src], 8

(p[MEMLAT])	xor	tmp3[0] = r[MEMLAT], charx8

(p[MEMLAT+1])	czx1.r	pos0[0] = tmp3[1]

(p[MEMLAT+2])	cmp.ne	p7, p0 = 8, pos0[1]

(p[MEMLAT+2])	chk.s	r[MEMLAT+2], .recovery2

(p7)		br.cond.spnt	.gotit

.back2:

(p[MEMLAT+2])	st8	[dest] = r[MEMLAT+2], 8

		br.ctop.dptk .l3

.cpyfew:

	cmp.eq	p6, p0 = len, r0	// is len == 0 ?

	adds	len = -1, len		// --len;

(p6)	br.cond.spnt	.restore_and_exit ;;

	mov	ar.lc = len

.l4:

	ld1	value = [src], 1

	;;

	st1	[dest] = value, 1

	cmp.eq	p6, p0 = value, char

(p6)	br.cond.spnt .foundit

	br.cloop.dptk	.l4 ;;

.foundit:

(p6)	mov	ret0 = dest

.restore_and_exit:

	mov     pr = saved_pr, -1    	// restore the predicate registers

	mov 	ar.lc = saved_lc	// restore the loop counter

	mov 	ar.ec = saved_ec ;;	// restore the epilog counter

	br.ret.sptk.many b0

.gotit:

	.pred.rel "mutex" p6, p7

(p6)	mov	value = val[3]		// if coming from l2

(p7)	mov	value = r[MEMLAT+2]	// if coming from l3

	mov	ar.lc = pos0[1] ;;

.l5:

	extr.u	tmp = value, 0, 8 ;;

	st1	[dest] = tmp, 1

	shr.u	value = value, 8

	br.cloop.sptk .l5 ;;

	mov 	ret0 = dest

	mov	pr = saved_pr, -1

	mov	ar.lc = saved_lc

	br.ret.sptk.many b0

.recovery1:

#if MEMLAT != 6

# error "MEMLAT must be 6!"

#endif

	adds	src = -8, asrc

	mov	loopcnt = ar.lc

	mov	tmp = ar.ec

	;;

(p[0])	adds	src = -8, src

	;;

(p[1])	adds	src = -8, src

	sub	sh1 = (MEMLAT + 6 + 1), tmp

	;;

(p[2])	adds	src = -8, src

	;;

(p[3])	adds	src = -8, src

	shl	loopcnt = loopcnt, 3

	;;

(p[4])	adds	src = -8, src

	;;

(p[5])	adds	src = -8, src

	shl	sh1 = sh1, 3

	;;

(p[6])	adds	src = -8, src

	;;

(p[7])	adds	src = -8, src

	shl	tmp = tmp, 3

	;;

(p[8])	adds	src = -8, src

	;;

(p[9])	adds	src = -8, src

	shr.u	sh2 = sh2, 3

	;;

(p[10])	adds	src = -8, src

	;;

(p[11])	adds	src = -8, src

	add	len = len, loopcnt

	;;

	sub	src = src, sh2

	;;

	add	len = tmp, len

	add	src = sh1, src

	br.cond.sptk .cpyfew

.recovery2:

#if MEMLAT != 6

# error "MEMLAT must be 6!"

#endif

	add	tmp = -8, src

(p7)	br.cond.spnt .gotit

	;;

(p[0])	add	tmp = -8, tmp ;;

(p[1])	add	tmp = -8, tmp ;;

(p[2])	add	tmp = -8, tmp ;;

(p[3])	add	tmp = -8, tmp ;;

(p[4])	add	tmp = -8, tmp ;;

(p[5])	add	tmp = -8, tmp ;;

(p[6])	add	tmp = -8, tmp ;;

(p[7])	add	tmp = -8, tmp ;;

	ld8	r[MEMLAT+2] = [tmp] ;;

	xor	pos0[1] = r[MEMLAT+2], charx8 ;;

	czx1.r	pos0[1] = pos0[1] ;;

	cmp.ne	p7, p6 = 8, pos0[1]

(p7)	br.cond.spnt .gotit

	br.cond.sptk .back2

END(memccpy)