/* Optimized version of the standard memcpy() function.

   This file is part of the GNU C Library.

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

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

   Rewritten for McKinley by Sverre Jarp, HP Labs/CERN <Sverre.Jarp@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: dest

   Inputs:

        in0:    dest

        in1:    src

        in2:    byte count

   An assembly implementation of the algorithm used by the generic C

   version from glibc.  The case when source and sest are aligned is

   treated separately, for extra performance.

   In this form, memcpy assumes little endian mode.  For big endian mode,

   sh1 must be computed using an extra instruction: sub sh1 = 64, sh1

   and the order of r[MEMLAT] and r[MEMLAT+1] must be reverted in the

   shrp instruction.  */

#define USE_LFETCH

#define USE_FLP

#include <sysdep.h>

#undef ret

#define LFETCH_DIST     500

#define ALIGN_UNROLL_no   4 // no. of elements

#define ALIGN_UNROLL_sh	  2 // (shift amount)

#define MEMLAT	8

#define Nrot	((4*(MEMLAT+2) + 7) & ~7)

#define OP_T_THRES 	16

#define OPSIZ 		8

#define loopcnt		r14

#define elemcnt		r15

#define saved_pr	r16

#define saved_lc	r17

#define adest		r18

#define dest		r19

#define asrc		r20

#define src		r21

#define len		r22

#define tmp2		r23

#define tmp3		r24

#define	tmp4		r25

#define ptable		r26

#define ploop56		r27

#define	loopaddr	r28

#define	sh1		r29

#define ptr1		r30

#define ptr2		r31

#define movi0 		mov

#define p_scr		p6

#define p_xtr		p7

#define p_nxtr		p8

#define p_few		p9

#if defined(USE_FLP)

#define load		ldf8

#define store		stf8

#define tempreg		f6

#define the_r		fr

#define the_s		fs

#define the_t		ft

#define the_q		fq

#define the_w		fw

#define the_x		fx

#define the_y		fy

#define the_z		fz

#elif defined(USE_INT)

#define load		ld8

#define store		st8

#define tempreg		tmp2

#define the_r		r

#define the_s		s

#define the_t		t

#define the_q		q

#define the_w		w

#define the_x		x

#define the_y		y

#define the_z		z

#endif

#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

#if defined(USE_LFETCH)

#define LOOP(shift)						\

		ALIGN(32);					\

.loop##shift##:							\

{ .mmb								\

(p[0])	ld8.nt1	r[0] = [asrc], 8 ;				\

(p[0])	lfetch.nt1 [ptr1], 16 ;					\

	nop.b 0 ;						\

} { .mib							\

(p[MEMLAT+1]) st8 [dest] = tmp3, 8 ;				\

(p[MEMLAT]) shrp tmp3 = r[MEMLAT], s[MEMLAT+1], shift ;		\

	nop.b 0 ;;						\

 } { .mmb							\

(p[0])	ld8.nt1	s[0] = [asrc], 8 ;				\

(p[0])	lfetch.nt1	[ptr2], 16 ;				\

	nop.b 0 ;						\

} { .mib							\

(p[MEMLAT+1]) st8 [dest] = tmp4, 8 ;				\

(p[MEMLAT]) shrp tmp4 = s[MEMLAT], r[MEMLAT], shift ;		\

	br.ctop.sptk.many .loop##shift 				\

;; }								\

{ .mib								\

	br.cond.sptk.many .copy_bytes ; /* deal with the remaining bytes */  \

}

#else

#define LOOP(shift)						\

		ALIGN(32);					\

.loop##shift##:							\

{ .mmb								\

(p[0])	ld8.nt1	r[0] = [asrc], 8 ;				\

	nop.b 0 ;						\

} { .mib							\

(p[MEMLAT+1]) st8 [dest] = tmp3, 8 ;				\

(p[MEMLAT]) shrp tmp3 = r[MEMLAT], s[MEMLAT+1], shift ;		\

	nop.b 0 ;;						\

 } { .mmb							\

(p[0])	ld8.nt1	s[0] = [asrc], 8 ;				\

	nop.b 0 ;						\

} { .mib							\

(p[MEMLAT+1]) st8 [dest] = tmp4, 8 ;				\

(p[MEMLAT]) shrp tmp4 = s[MEMLAT], r[MEMLAT], shift ;		\

	br.ctop.sptk.many .loop##shift 				\

;; }								\

{ .mib								\

	br.cond.sptk.many .copy_bytes ; /* deal with the remaining bytes */  \

}

#endif

ENTRY(memcpy)

{ .mmi

	.prologue

	alloc 	r2 = ar.pfs, 3, Nrot - 3, 0, Nrot

	.rotr	r[MEMLAT+1], s[MEMLAT+2], q[MEMLAT+1], t[MEMLAT+1]

	.rotp	p[MEMLAT+2]

	.rotf	fr[MEMLAT+1], fq[MEMLAT+1], fs[MEMLAT+1], ft[MEMLAT+1]

	mov	ret0 = in0		// return tmp2 = dest

	.save   pr, saved_pr

	movi0	saved_pr = pr		// save the predicate registers

} { .mmi

	and	tmp4 = 7, in0 		// check if destination is aligned

	mov 	dest = in0		// dest

	mov 	src = in1		// src

;; }

{ .mii

	cmp.eq	p_scr, p0 = in2, r0	// if (len == 0)

	.save   ar.lc, saved_lc

        movi0 	saved_lc = ar.lc	// save the loop counter

	.body

	cmp.ge	p_few, p0 = OP_T_THRES, in2 // is len <= OP_T_THRESH

} { .mbb

	mov	len = in2		// len

(p_scr)	br.cond.dpnt.few .restore_and_exit // 	Branch no. 1: return dest

(p_few) br.cond.dpnt.many .copy_bytes	// Branch no. 2: copy byte by byte

;; }

{ .mmi

#if defined(USE_LFETCH)

	lfetch.nt1 [dest]		//

	lfetch.nt1 [src]		//

#endif

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

} { .mib

	cmp.eq	p_scr, p0 = tmp4, r0	// is destination aligned?

	sub	loopcnt = 7, tmp4	//

(p_scr) br.cond.dptk.many .dest_aligned

;; }

{ .mmi

	ld1	tmp2 = [src], 1		//

	sub	len = len, loopcnt, 1	// reduce len

	movi0	ar.lc = loopcnt		//

} { .mib

	cmp.ne  p_scr, p0 = 0, loopcnt	// avoid loading beyond end-point

;; }

.l0:	// ---------------------------- // L0: Align src on 8-byte boundary

{ .mmi

	st1	[dest] = tmp2, 1	//

(p_scr)	ld1	tmp2 = [src], 1		//

} { .mib

	cmp.lt	p_scr, p0 = 1, loopcnt	// avoid load beyond end-point

	add	loopcnt = -1, loopcnt

	br.cloop.dptk.few .l0		//

;; }

.dest_aligned:

{ .mmi

	and	tmp4 = 7, src		// ready for alignment check

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

;; }

{ .mib

	cmp.ne	p_scr, p0 = tmp4, r0	// is source also aligned

	tbit.nz p_xtr, p_nxtr = src, 3	// prepare a separate move if src

} { .mib				// is not 16B aligned

	add	ptr2 = LFETCH_DIST, dest	// prefetch address

	add	ptr1 = LFETCH_DIST, src

(p_scr) br.cond.dptk.many .src_not_aligned

;; }

// The optimal case, when dest, and src are aligned

.both_aligned:

{ .mmi

	.pred.rel "mutex",p_xtr,p_nxtr

(p_xtr)	cmp.gt  p_scr, p0 = ALIGN_UNROLL_no+1, elemcnt // Need N + 1 to qualify

(p_nxtr) cmp.gt p_scr, p0 = ALIGN_UNROLL_no, elemcnt  // Need only N to qualify

	movi0	pr.rot = 1 << 16	// set rotating predicates

} { .mib

(p_scr) br.cond.dpnt.many .copy_full_words

;; }

{ .mmi

(p_xtr)	load	tempreg = [src], 8

(p_xtr) add 	elemcnt = -1, elemcnt

	movi0	ar.ec = MEMLAT + 1	// set the epilog counter

;; }

{ .mmi

(p_xtr) add	len = -8, len		//

	add 	asrc = 16, src 		// one bank apart (for USE_INT)

	shr.u	loopcnt = elemcnt, ALIGN_UNROLL_sh  // cater for unrolling

;;}

{ .mmi

	add	loopcnt = -1, loopcnt

(p_xtr)	store	[dest] = tempreg, 8	// copy the "extra" word

	nop.i	0

;; }

{ .mib

	add	adest = 16, dest

	movi0	ar.lc = loopcnt 	// set the loop counter

;; }

#ifdef  GAS_ALIGN_BREAKS_UNWIND_INFO

	{ nop 0 }

#else

	.align	32

#endif

#if defined(USE_FLP)

.l1: // ------------------------------- // L1: Everything a multiple of 8

{ .mmi

#if defined(USE_LFETCH)

(p[0])	lfetch.nt1 [ptr2],32

#endif

(p[0])	ldfp8	the_r[0],the_q[0] = [src], 16

(p[0])	add	len = -32, len

} {.mmb

(p[MEMLAT]) store [dest] = the_r[MEMLAT], 8

(p[MEMLAT]) store [adest] = the_s[MEMLAT], 8

;; }

{ .mmi

#if defined(USE_LFETCH)

(p[0])	lfetch.nt1 [ptr1],32

#endif

(p[0])	ldfp8	the_s[0], the_t[0] = [src], 16

} {.mmb

(p[MEMLAT]) store [dest] = the_q[MEMLAT], 24

(p[MEMLAT]) store [adest] = the_t[MEMLAT], 24

	br.ctop.dptk.many .l1

;; }

#elif defined(USE_INT)

.l1: // ------------------------------- // L1: Everything a multiple of 8

{ .mmi

(p[0])	load	the_r[0] = [src], 8

(p[0])	load	the_q[0] = [asrc], 8

(p[0])	add	len = -32, len

} {.mmb

(p[MEMLAT]) store [dest] = the_r[MEMLAT], 8

(p[MEMLAT]) store [adest] = the_q[MEMLAT], 8

;; }

{ .mmi

(p[0])	load	the_s[0]  = [src], 24

(p[0])	load	the_t[0] = [asrc], 24

} {.mmb

(p[MEMLAT]) store [dest] = the_s[MEMLAT], 24

(p[MEMLAT]) store [adest] = the_t[MEMLAT], 24

#if defined(USE_LFETCH)

;; }

{ .mmb

(p[0])	lfetch.nt1 [ptr2],32

(p[0])	lfetch.nt1 [ptr1],32

#endif

	br.ctop.dptk.many .l1

;; }

#endif

.copy_full_words:

{ .mib

	cmp.gt	p_scr, p0 = 8, len	//

	shr.u	elemcnt = len, 3	//

(p_scr) br.cond.dpnt.many .copy_bytes

;; }

{ .mii

	load	tempreg = [src], 8

	add	loopcnt = -1, elemcnt	//

;; }

{ .mii

	cmp.ne	p_scr, p0 = 0, loopcnt	//

	mov	ar.lc = loopcnt		//

;; }

.l2: // ------------------------------- // L2: Max 4 words copied separately

{ .mmi

	store	[dest] = tempreg, 8

(p_scr)	load	tempreg = [src], 8	//

	add	len = -8, len

} { .mib

	cmp.lt	p_scr, p0 = 1, loopcnt	// avoid load beyond end-point

	add	loopcnt = -1, loopcnt

	br.cloop.dptk.few  .l2

;; }

.copy_bytes:

{ .mib

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

	add	loopcnt = -1, len	// len--;

(p_scr)	br.cond.spnt	.restore_and_exit

;; }

{ .mii

	ld1	tmp2 = [src], 1

	movi0	ar.lc = loopcnt

	cmp.ne	p_scr, p0 = 0, loopcnt	// avoid load beyond end-point

;; }

.l3: // ------------------------------- // L3: Final byte move

{ .mmi

	st1	[dest] = tmp2, 1

(p_scr)	ld1	tmp2 = [src], 1

} { .mib

	cmp.lt	p_scr, p0 = 1, loopcnt	// avoid load beyond end-point

	add	loopcnt = -1, loopcnt

	br.cloop.dptk.few  .l3

;; }

.restore_and_exit:

{ .mmi

	movi0	pr = saved_pr, -1	// restore the predicate registers

;; }

{ .mib

	movi0	ar.lc = saved_lc	// restore the loop counter

	br.ret.sptk.many b0

;; }

.src_not_aligned:

{ .mmi

	cmp.gt	p_scr, p0 = 16, len

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

	shr.u	loopcnt = len, 4	// element-cnt = len / 16

} { .mib

	add	tmp4 = @ltoff(.table), gp

	add 	tmp3 = @ltoff(.loop56), gp

(p_scr)	br.cond.dpnt.many .copy_bytes	// do byte by byte if too few

;; }

{ .mmi

	and	asrc = -8, src		// asrc = (-8) -- align src for loop

	add 	loopcnt = -1, loopcnt	// loopcnt--

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

} { .mmi

	ld8	ptable = [tmp4]		// ptable = &table

	ld8	ploop56 = [tmp3]	// ploop56 = &loop56

	and	tmp2 = -16, len		// tmp2 = len & -OPSIZ

;; }

{ .mmi

	add	tmp3 = ptable, sh1	// tmp3 = &table + sh1

	add	src = src, tmp2		// src += len & (-16)

	movi0	ar.lc = loopcnt		// set LC

;; }

{ .mmi

	ld8	tmp4 = [tmp3]		// tmp4 = loop offset

	sub	len = len, tmp2		// len -= len & (-16)

	movi0	ar.ec = MEMLAT + 2 	// one more pass needed

;; }

{ .mmi

	ld8	s[1] = [asrc], 8	// preload

	sub	loopaddr = ploop56,tmp4	// loopadd = &loop56 - loop offset

	movi0   pr.rot = 1 << 16	// set rotating predicates

;; }

{ .mib

	nop.m	0

	movi0	b6 = loopaddr

	br	b6			// jump to the appropriate loop

;; }

	LOOP(8)

	LOOP(16)

	LOOP(24)

	LOOP(32)

	LOOP(40)

	LOOP(48)

	LOOP(56)

END(memcpy)

libc_hidden_builtin_def (memcpy)

	.rodata

	.align 8

.table:

	data8	0			// dummy entry

	data8 	.loop56 - .loop8

	data8 	.loop56 - .loop16

	data8 	.loop56 - .loop24

	data8	.loop56 - .loop32

	data8	.loop56 - .loop40

	data8	.loop56 - .loop48

	data8	.loop56 - .loop56