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

   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/>.  */

#include <ifunc-strspn.h>

#if HAVE_STRSPN_Z13

# include "sysdep.h"

# include "asm-syntax.h"

	.text

/* size_t strspn (const char *s, const char * accept)

   The strspn() function calculates the length of the initial segment

   of s which consists entirely of characters in accept.

   This method checks the length of accept string. If it fits entirely

   in one vector register, a fast algorithm is used, which does not need

   to check multiple parts of accept-string. Otherwise a slower full

   check of accept-string is used.

   register overview:

   r3:  pointer to start of accept-string

   r2:  pointer to start of search-string

   r4:  loaded byte count of vl search-string

   r0:  found byte index

   r1:  current return len of s

   v16: search-string

   v17: accept-string

   v18: temp-vreg

   ONLY FOR SLOW:

   v19: first accept-string

   v20: zero for preparing acc-vector

   v21: global mask; 1 indicates a match between

	search-string-vreg and any accept-character

   v22: current mask; 1 indicates a match between

	search-string-vreg and any accept-character in current acc-vreg

   v30, v31: for re-/storing registers r6, r8, r9

   r5:  current len of accept-string

   r6:	zero-index in search-string or 16 if no zero

	or min(zero-index, loaded byte count)

   r8:	>0, if former accept-string-part contains a zero,

	otherwise =0;

   r9: loaded byte count of vlbb accept-string

*/

ENTRY(STRSPN_Z13)

	.machine "z13"

	.machinemode "zarch_nohighgprs"

	/*

	  Check if accept-string fits in one vreg:

	  ----------------------------------------

	*/

	vlbb	%v17,0(%r3),6	/* Load accept.  */

	lcbb	%r4,0(%r3),6

	jo	.Lcheck_onbb	/* Special case if accept lays

				   on block-boundary.  */

.Lcheck_notonbb:

	vistrbs	%v17,%v17	/* Fill with zeros after first zero.  */

	je	.Lfast		/* Zero found -> accept fits in one vreg.  */

	j	.Lslow		/* No zero -> accept exceeds one vreg.  */

.Lcheck_onbb:

	/* Accept lays on block-boundary.  */

	vfenezb	%v18,%v17,%v17	/* Search zero in loaded accept bytes.  */

	vlgvb	%r0,%v18,7	/* Get index of zero or 16 if not found.  */

	clrjl	%r0,%r4,.Lcheck_notonbb /* Zero index < loaded bytes count ->

					   Accept fits in one vreg;

					   Fill with zeros and proceed

					   with FAST.  */

	vl	%v17,0(%r3)	/* Load accept, which exceeds loaded bytes.  */

	j	.Lcheck_notonbb /* Check if accept fits in one vreg.  */

	/*

	  Search s for accept in one vreg

	  -------------------------------

	*/

.Lfast:

	/* Complete accept-string is in v17 and remaining bytes are zero.  */

	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.  */

	vfaezbs	%v16,%v16,%v17,8 /* Find first element in v16

				    unequal to any in v17

				    or first zero element.  */

	vlgvb	%r0,%v16,7	/* Load byte index of found element.  */

	/* If found index is within loaded bytes (%r0 < %r1),

	   return with found element index (=equal count).  */

	clr	%r0,%r1

	locgrl	%r2,%r0

	blr	%r14

	/* Align s to 16 byte.  */

	risbgn	%r4,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */

	lghi	%r1,16		/* current_len = 16.  */

	slr	%r1,%r4		/* Compute bytes to 16bytes boundary.  */

.Lfast_loop:

	vl	%v16,0(%r1,%r2)	/* Load search-string.  */

	vfaezbs	%v16,%v16,%v17,8 /* Find first element in v16

				    unequal to any in v17

				    or first zero element.  */

	jno	.Lfast_loop_found

	vl	%v16,16(%r1,%r2)

	vfaezbs	%v16,%v16,%v17,8

	jno	.Lfast_loop_found16

	vl	%v16,32(%r1,%r2)

	vfaezbs	%v16,%v16,%v17,8

	jno	.Lfast_loop_found32

	vl	%v16,48(%r1,%r2)

	vfaezbs	%v16,%v16,%v17,8

	jno	.Lfast_loop_found48

	aghi	%r1,64

	j	.Lfast_loop	/* Loop if no element was unequal to accept

				   and not zero.  */

	/* Found unequal or zero element.  */

.Lfast_loop_found48:

	aghi	%r1,16

.Lfast_loop_found32:

	aghi	%r1,16

.Lfast_loop_found16:

	aghi	%r1,16

.Lfast_loop_found:

	vlgvb	%r0,%v16,7	/* Load byte index of found element.  */

	algrk	%r2,%r1,%r0	/* And add it to current len.  */

	br	%r14

	/*

	  Search s for accept in multiple vregs

	  -------------------------------------

	*/

.Lslow:

	/* Save registers.  */

	vlvgg	%v30,%r6,0

	vlvgp	%v31,%r8,%r9

	lghi	%r1,0		/* current_len = 0.  */

	/* Accept in v17 without zero.  */

	vlr	%v19,%v17	/* Save first acc-part for a fast reload.  */

	vzero	%v20		/* Zero for preparing acc-vector.  */

	/* Align s to 16 byte.  */

	risbg	%r0,%r2,60,128+63,0 /* Test if s is aligned and

				     %r0 = bits 60-63 'and' 15  */

	je	.Lslow_loop_str /* If s is aligned, loop aligned */

	lghi	%r4,15

	slr	%r4,%r0		/* Compute highest index to load (15-x).  */

	vll	%v16,%r4,0(%r2) /* Load up to 16byte boundary (vll needs

				   highest index, left bytes are 0).  */

	ahi	%r4,1		/* Work with loaded byte count.  */

	vzero	%v21		/* Zero out global mask.  */

	lghi	%r5,0		/* Set current len of accept-string to zero.  */

	vfenezb	%v18,%v16,%v16	/* Find zero in current string-part.  */

	lghi	%r8,0		/* There is no zero in first accept-part.  */

	vlgvb	%r6,%v18,7	/* Load byte index of zero or 16

				   if there is no zero.  */

	clr	%r4,%r6		/* cc==1 if loaded byte count < zero-index.  */

	locrl	%r6,%r4		/* Load on cc==1.  */

	j	.Lslow_loop_acc

	/* Process s in 16byte aligned loop.  */

.Lslow_next_str:

	vlr	%v17,%v19	/* Load first part of accept (no zero).  */

	algfr	%r1,%r4		/* Add loaded byte count to current len.  */

.Lslow_loop_str:

	vl	%v16,0(%r1,%r2)	/* Load search-string.  */

	lghi	%r4,16		/* Loaded byte count is 16.  */

	vzero	%v21		/* Zero out global mask.  */

	lghi	%r5,0		/* Set current len of accept-string to zero.  */

	vfenezb	%v18,%v16,%v16	/* Find zero in current string-part.  */

	lghi	%r8,0		/* There is no zero in first accept-part.  */

	vlgvb	%r6,%v18,7	/* Load byte index of zero or 16 if no zero.  */

.Lslow_loop_acc:

	vfaeb	%v22,%v16,%v17,4 /* Create matching-mask (1 in mask ->

				    character matches any accepted character in

				    this accept-string-part) IN=0, RT=1.  */

	vo	%v21,%v21,%v22	/* global-mask = global- | matching-mask.  */

	vfenezb	%v18,%v21,%v21	/* Find first zero in global-mask.  */

	vlgvb	%r0,%v18,7	/* Get first found zero-index

				   (= first mismatch).  */

	clrjl	%r0,%r6,.Lslow_next_acc /* Mismatch-index < min(lbc,zero-index)

					    -> Process this string-part

					       with next acc-part.  */

	clrjhe	%r0,%r4,.Lslow_next_str /* Found-index >= loaded byte count

					   -> All loaded bytes are matching

					      any accept-character

					      and are not zero.  */

	/* All bytes are matching any characters in accept-string

	   and search-string is fully processed (found-index == zero-index)  */

.Lslow_add_lbc_end:

	algrk	%r2,%r1,%r0	/* Add matching characters to current_len.  */

	/* Restore registers.  */

	vlgvg	%r6,%v30,0

	vlgvg	%r8,%v31,0

	vlgvg	%r9,%v31,1

	br	%r14

.Lslow_next_acc:

	clijh	%r8,0,.Lslow_add_lbc_end /* There was a zero in last acc-part

					     -> Add found index to current len

						and end.  */

	vlbb	%v17,16(%r5,%r3),6 /* Load next accept part.  */

	aghi	%r5,16		/* Add current_len of accept-string.  */

	lcbb	%r9,0(%r5,%r3),6 /* Get loaded byte count of accept-string.  */

	jo	.Lslow_next_acc_onbb /* Jump away if accept-string is

					 on block-boundary.  */

.Lslow_next_acc_notonbb:

	vistrbs	%v17,%v17	/* Fill with zeros after first zero.  */

	jo	.Lslow_loop_acc /* No zero found -> no preparation needed.  */

.Lslow_next_acc_prepare_zero:

	/* Zero in accept-part: fill zeros with first-accept-character.  */

	vlgvb	%r8,%v17,0	/* Load first element of acc-part.  */

	clije	%r8,0,.Lslow_add_lbc_end /* End if zero is first character

					     in this part of accept-string.  */

	/* r8>0 -> zero found in this acc-part.  */

	vrepb	%v18,%v17,0	/* Replicate first char accross all chars.  */

	vceqb	%v22,%v20,%v17	/* Create a mask (v22) of null chars

				   by comparing with 0 (v20).  */

	vsel	%v17,%v18,%v17,%v22 /* Replace null chars with first char.  */

	j	.Lslow_loop_acc /* Accept part is prepared -> process.  */

.Lslow_next_acc_onbb:

	vfenezb	%v18,%v17,%v17	/* Find zero in loaded bytes of accept part.  */

	vlgvb	%r8,%v18,7	/* Load byte index of zero.  */

	clrjl	%r8,%r9,.Lslow_next_acc_notonbb /* Found a zero in loaded bytes

						    -> Prepare vr.  */

	vl	%v17,0(%r5,%r3)	/* Load over boundary ...  */

	lghi	%r8,0		/* r8=0 -> no zero in this part of acc,

				   Check for zero is in jump-target.  */

	j	.Lslow_next_acc_notonbb /* ... and search for zero in

					    fully loaded vreg again.  */

END(STRSPN_Z13)

# if ! HAVE_STRSPN_IFUNC

strong_alias (STRSPN_Z13, strspn)

# endif

# if ! HAVE_STRSPN_C && defined SHARED && IS_IN (libc)

strong_alias (STRSPN_Z13, __GI_strspn)

# endif

#endif /* HAVE_STRSPN_Z13  */