/* Vector optimized 32/64 bit S/390 version of wcsncat.

   Copyright (C) 2015-2018 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/>.  */

#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)

# include "sysdep.h"

# include "asm-syntax.h"

	.text

/* wchar_t * wcsncat (wchar_t *dest, const wchar_t *src, size_t n)

   Concatenate two strings - at most n characters of src.

   Register usage:

   -r0=saved dest pointer for return

   -r1=tmp

   -r2=dest

   -r3=src

   -r4=n

   -r5=current_len

   -r6=tmp

   -r7=tmp

   -v16=part of src

   -v17=index of zero

   -v18=part of src

   -v31=register save area for r6, r7

*/

ENTRY(__wcsncat_vx)

	.machine "z13"

	.machinemode "zarch_nohighgprs"

# if !defined __s390x__

	llgfr	%r4,%r4

# endif /* !defined __s390x__ */

	clgfi	%r4,0

	ber	%r14		/* Nothing to do, if n == 0.  */

	vlbb	%v16,0(%r2),6	/* Load s until next 4k-byte boundary.  */

	lcbb	%r1,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */

	/* If either src or dest is not 4byte aligned, use __wcsncat_c.  */

	tmll	%r2,3		/* Test if s is 4-byte aligned?   */

	jne	.Lfallback	/* And use common-code variant if not.  */

	tmll	%r3,3		/* Test if src is 4-byte aligned?   */

	jne	.Lfallback	/* And use common-code variant if not.  */

	lgr	%r0,%r2		/* Save destination pointer for return.  */

	vlvgp	%v31,%r6,%r7	/* Save registers.  */

	/* WCSLEN

	   %r1 = loaded bytes (tmp)

	   %r6 = zero byte index (tmp)

	   %r2 = dst

	*/

	vfenezf	%v16,%v16,%v16	/* Find element not equal with zero search.  */

	vlgvb	%r5,%v16,7	/* Load zero index or 16 if not found.  */

	clrjl	%r5,%r1,.Llen_end /* Found zero within loaded bytes, end.  */

	/* Align s to 16 byte.  */

	risbgn	%r1,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */

	lghi	%r5,16		/* current_len = 16.  */

	slr	%r5,%r1		/* Compute bytes to 16bytes boundary.  */

	/* Find zero in 16byte aligned loop.  */

.Llen_loop:

	vl	%v16,0(%r5,%r2)	/* Load s.  */

	vfenezfs %v16,%v16,%v16	/* Find element not equal with zero search.  */

	je	.Llen_found	/* Jump away if zero was found.  */

	vl	%v16,16(%r5,%r2)

	vfenezfs %v16,%v16,%v16

	je	.Llen_found16

	vl	%v16,32(%r5,%r2)

	vfenezfs %v16,%v16,%v16

	je	.Llen_found32

	vl	%v16,48(%r5,%r2)

	vfenezfs %v16,%v16,%v16

	je	.Llen_found48

	aghi	%r5,64

	j	.Llen_loop	/* No zero -> loop.  */

.Llen_found48:

	aghi	%r5,16

.Llen_found32:

	aghi	%r5,16

.Llen_found16:

	aghi	%r5,16

.Llen_found:

	vlgvb	%r1,%v16,7	/* Load byte index of zero.  */

	algr	%r5,%r1

.Llen_end:

	/* WCSNCPY

	   %r1 = zero byte index (tmp)

	   %r6 = loaded bytes (tmp)

	   %r3 = curr src pointer

	   %r2 = curr dst pointer

	   %r7 = border, tmp

	*/

	la	%r2,0(%r5,%r2)	/* strcpy at end of dst-string.  */

	vlbb	%v16,0(%r3),6	/* Load s until next 4k-byte boundary.  */

	lcbb	%r6,0(%r3),6	/* Get bytes to 4k-byte boundary or 16.  */

	llgfr	%r6,%r6		/* Convert 32bit to 64bit.  */

	lghi	%r5,0		/* current_len = 0.  */

	/* Check range of maxlen and convert to byte-count.  */

# ifdef __s390x__

	tmhh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */

	lghi	%r1,-4		/* Max byte-count is 18446744073709551612.  */

# else

	tmlh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */

	llilf	%r1,4294967292	/* Max byte-count is 4294967292.  */

# endif /* !__s390x__ */

	sllg	%r4,%r4,2	/* Convert character-count to byte-count.  */

	locgrne	%r4,%r1		/* Use max byte-count, if bit 0/1 was one.  */

	clgrjle	%r4,%r6,.Lcpy_remaining_v16 /* If n <= loaded-bytes

					       -> process remaining.  */

	/* n > loaded-byte-count.  */

	vfenezf	%v17,%v16,%v16	/* Find element not equal with zero search.  */

	vlgvb	%r1,%v17,7	/* Load zero index or 16 if not found.  */

	clrjl	%r1,%r6,.Lcpy_found_v16_store /* Found zero within loaded bytes,

					         copy and return.  */

	/* Align s to 16 byte.  */

	risbgn	%r1,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */

	lghi	%r5,15		/* current_len = 15.  */

	slr	%r5,%r1		/* Compute highest index to 16byte boundary.  *

	/* Zero not found and maxlen > loaded-byte-count.  */

	vstl	%v16,%r5,0(%r2)	/* Copy loaded characters - no zero.  */

	ahi	%r5,1		/* Start loop at next character.  */

	/*

	  Now we are 16byte aligned, so we can load a full vreg

	  without page fault.

	 */

	lgr	%r1,%r5		/* If %r5 + 64 < maxlen? -> loop64.  */

	aghi	%r1,64

	clgrjl	%r1,%r4,.Lcpy_loop64

	vl	%v16,0(%r5,%r3)	/* Load s.  */

	clgijl	%r4,17,.Lcpy_remaining_v16 /* If n <=16,

					       process remaining bytes.  */

.Lcpy_lt64:

	lgr	%r7,%r4

	slgfi	%r7,16		/* border_len = n - 16.  */

	clgrjhe	%r5,%r7,.Lcpy_remaining_v16

	vfenezfs %v17,%v16,%v16	/* Find element not equal with zero search.  */

	je	.Lcpy_found_v16 /* Jump away if zero was found.  */

	vl	%v18,16(%r5,%r3) /* Load next part of s.  */

	vst	%v16,0(%r5,%r2)	/* Save previous part without zero to dst.  */

	aghi	%r5,16

	clgrjhe	%r5,%r7,.Lcpy_remaining_v18

	vfenezfs %v17,%v18,%v18

	je	.Lcpy_found_v18

	vl	%v16,16(%r5,%r3)

	vst	%v18,0(%r5,%r2)

	aghi	%r5,16

	clgrjhe	%r5,%r7,.Lcpy_remaining_v16

	vfenezfs %v17,%v16,%v16

	je	.Lcpy_found_v16

	vl	%v18,16(%r5,%r3)

	vst	%v16,0(%r5,%r2)

	aghi	%r5,16

.Lcpy_remaining_v18:

	vlr	%v16,%v18

.Lcpy_remaining_v16:

	/* v16 contains the remaining bytes [1...16].

	   Store remaining bytes and append string-termination.  */

	vfenezf	%v17,%v16,%v16	/* Find element not equal with zero search.  */

	slgrk	%r7,%r4,%r5	/* Remaining bytes = maxlen - current_len.  */

	aghi	%r7,-1		/* vstl needs highest index.  */

	vlgvb	%r1,%v17,7	/* Load zero index or 16 if not found.  */

	la	%r2,0(%r5,%r2)	/* vstl has no index register.  */

	/* Zero-index within remaining-bytes, store up to zero and end.  */

	clgrjle	%r1,%r7,.Lcpy_found_v16_store

	vstl	%v16,%r7,0(%r2)	/* Store remaining bytes.  */

	lghi	%r1,0

	st	%r1,1(%r7,%r2)	/* Store string-null-termination beyond n.  */

.Lcpy_end:

	/* Restore saved registers.  */

	vlgvg	%r6,%v31,0

	vlgvg	%r7,%v31,1

	lgr	%r2,%r0		/* Load saved dest-ptr.  */

	br	%r14

.Lcpy_found_v16_32:

	aghi	%r5,32

	j	.Lcpy_found_v16

.Lcpy_found_v18_48:

	aghi	%r5,32

.Lcpy_found_v18_16:

	aghi	%r5,16

.Lcpy_found_v18:

	vlr	%v16,%v18

.Lcpy_found_v16:

	/* v16 contains a zero. Store remaining bytes to zero. current_len

	   has not reached border, thus checking for n is not needed!  */

	vlgvb	%r1,%v17,7	/* Load byte index of zero.  */

	la	%r2,0(%r5,%r2)

.Lcpy_found_v16_store:

	aghi	%r1,3		/* Also copy remaining bytes of zero.  */

	vstl	%v16,%r1,0(%r2)	/* Copy characters including zero.  */

	j	.Lcpy_end

	/* Find zero in 16byte aligned loop.  */

.Lcpy_loop2:

	vl	%v16,16(%r5,%r3)

	vst	%v18,0(%r5,%r2)

	aghi	%r5,16

.Lcpy_loop64:

	vl	%v16,0(%r5,%r3)

	vfenezfs %v17,%v16,%v16	/* Find element not equal with zero search.  */

	je	.Lcpy_found_v16 /* Jump away if zero was found.  */

	vl	%v18,16(%r5,%r3) /* Load next part of s.  */

	vst	%v16,0(%r5,%r2)	/* Save previous part without zero to dst.  */

	vfenezfs %v17,%v18,%v18

	je	.Lcpy_found_v18_16

	vl	%v16,32(%r5,%r3)

	vst	%v18,16(%r5,%r2)

	vfenezfs %v17,%v16,%v16

	je	.Lcpy_found_v16_32

	vl	%v18,48(%r5,%r3)

	vst	%v16,32(%r5,%r2)

	vfenezfs %v17,%v18,%v18

	je	.Lcpy_found_v18_48

	vst	%v18,48(%r5,%r2)

	aghi	%r5,64

	lgr	%r1,%r5		/* If %r5 + 64 < maxlen? -> loop64.  */

	aghi	%r1,64

	clgrjl	%r1,%r4,.Lcpy_loop64

	vl	%v16,0(%r5,%r3)	/* Load s.  */

	j	.Lcpy_lt64

.Lfallback:

	jg	__wcsncat_c

END(__wcsncat_vx)

#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */