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

   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-strcspn.h>

#if HAVE_STRCSPN_Z13

# include "sysdep.h"

# include "asm-syntax.h"

	.text

/* size_t strcspn (const char *s, const char * reject)

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

   of s which consists entirely of characters not in reject.

   This method checks the length of reject 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 reject-string

   r2:  pointer to start of search-string

   r0:  loaded byte count of vlbb search-string

   r4:  found byte index

   r1:  current return len

   v16: search-string

   v17: reject-string

   v18: temp-vreg

   ONLY FOR SLOW:

   v19: first reject-string

   v20: zero for preparing acc-vector

   v21: global mask; 1 indicates a match between

	search-string-vreg and any reject-character

   v22: current mask; 1 indicates a match between

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

   v24: one for result-checking of former string-part

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

   r5:  current len of reject-string

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

	or min(zero-index, loaded byte count)

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

			otherwise =0;

   r9:  loaded byte count of vlbb reject-string

*/

ENTRY(STRCSPN_Z13)

	.machine "z13"

	.machinemode "zarch_nohighgprs"

	/*

	  Check if reject-string fits in one vreg:

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

	*/

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

	lghi	%r1,0		/* Zero out current len.  */

	lcbb	%r0,0(%r3),6

	jo	.Lcheck_onbb	/* Special case if reject

				   lays on block-boundary.  */

.Lcheck_notonbb:

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

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

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

.Lcheck_onbb:

	/* Reject lays on block-boundary.  */

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

	vlgvb	%r4,%v18,7	/* Get index of zero or 16 if not found.  */

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

					    Reject fits in one vreg;

					    Fill with zeros and proceed

					    with FAST.  */

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

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

	/*

	  Search s for reject in one vreg

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

	*/

.Lfast:

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

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

	lcbb	%r0,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */

	vfaezbs	%v18,%v16,%v17,0 /* Find first element in v16

				    unequal to any in v17

				    or first zero element.  */

	vlgvb	%r4,%v18,7	/* Load byte index of found element.  */

	clrjl	%r4,%r0,.Lfast_loop_found2 /* If found index is within loaded

					       bytes, return with found element

					       index (=equal count).  */

	/* 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.  */

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

.Lfast_loop:

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

	vfaezbs	%v18,%v16,%v17,0 /* Find first element in v16 equal to any

				    in v17 or first zero element.  */

	jno	.Lfast_loop_found

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

	vfaezbs	%v18,%v16,%v17,0

	jno	.Lfast_loop_found16

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

	vfaezbs	%v18,%v16,%v17,0

	jno	.Lfast_loop_found32

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

	vfaezbs	%v18,%v16,%v17,0

	jno	.Lfast_loop_found48

	aghi	%r1,64

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

				   and not zero.  */

	/* Found equal 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	%r4,%v18,7	/* Load byte index of found element or zero.  */

.Lfast_loop_found2:

	algrk	%r2,%r1,%r4	/* Add found index to current len.  */

	br	%r14

	/*

	  Search s for reject in multiple vregs

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

	*/

.Lslow:

	/* Save registers.  */

	vlvgg	%v30,%r6,0

	vlvgp	%v31,%r8,%r9

	/* Reject in v17 without zero.  */

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

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

	vone	%v24		/* One for checking result of former

				   string-part.  */

	/* Align s to 16 byte.  */

	risbg	%r4,%r2,60,128+63,0 /* Test if s is aligned and

				       %r4 = bits 60-63 'and' 15.   */

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

	lghi	%r0,15

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

	vll	%v16,%r0,0(%r2) /* Load up to 16 byte boundary (vll needs

				   highest index, remaining bytes are 0).  */

	ahi	%r0,1		/* Work with loaded byte count.  */

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

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

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

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

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

	clije	%r6,0,.Lslow_end /* If first element is zero -> return 0.  */

	clr	%r0,%r6		/* cc==1 if loaded byte count < zero-index.  */

	locrl	%r6,%r0		/* Load on cc==1; zero-index = lbc.  */

	j	.Lslow_loop_acc

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

.Lslow_next_str:

	/* Check results of former processed str-part.  */

	vfeeb	%v18,%v21,%v24	/* Find first equal match in global mask

				   (ones in element).  */

	vlgvb	%r4,%v18,7	/* Get index of first one (=equal) or 16.  */

	/* Equal-index < min(zero-index, loaded byte count)

	   -> Return pointer to equal element.  */

	clrjl	%r4,%r6,.Lslow_index_found

	/* Zero-index < loaded byte count

	   -> Former str-part was last str-part

	   -> Return null */

	clrjl	%r6,%r0,.Lslow_end_not_found

	/* All elements are zero (=no match) -> Proceed with next str-part.  */

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

	algfr	%r1,%r0		/* Add loaded byte count to current len.  */

.Lslow_loop_str:

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

	lghi	%r0,16		/* Loaded byte count is 16.  */

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

	lghi	%r5,0		/* Set current len of reject to zero.  */

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

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

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

	clije	%r6,0,.Lslow_end /* If first element is zero (end of string)

				     -> Return current length.  */

.Lslow_loop_acc:

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

				    Character matches any rejected character in

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

	vlgvb	%r4,%v22,0	/* Get result of first element.  */

	/* First element is equal to any rejected characters?

	   (all other parts of reject cannot lead to a match before this one)

	   -> Return current len, which is pointing to this element.  */

	clijh	%r4,0,.Lslow_end

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

	/* Proceed with next acc until end of acc is reached.  */

.Lslow_next_acc:

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

					  -> Add found index to current len

					     and end.  */

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

	aghi	%r5,16		/* Increment current len of reject-string.  */

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

	jo	.Lslow_next_acc_onbb /* Jump away if reject-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 reject-part: fill zeros with first-reject-character.  */

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

	clije	%r8,0,.Lslow_next_str /* Process next str-part if first

					  character in this part of reject

					  is a zero.  */

	/* 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 /* Reject-string part is prepared.  */

.Lslow_next_acc_onbb:

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

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

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

						    -> Prepare vreg.  */

	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.  */

.Lslow_end_not_found:

	algfr	%r1,%r6		/* Add zero-index to current len.  */

	j	.Lslow_end

.Lslow_index_found:

	algfr	%r1,%r4		/* Add found index of char to current len.  */

.Lslow_end:

	lgr	%r2,%r1

	/* Restore registers.  */

	vlgvg	%r6,%v30,0

	vlgvg	%r8,%v31,0

	vlgvg	%r9,%v31,1

	br	%r14

END(STRCSPN_Z13)

# if ! HAVE_STRCSPN_IFUNC

strong_alias (STRCSPN_Z13, strcspn)

# endif

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

strong_alias (STRCSPN_Z13, __GI_strcspn)

# endif

#endif /* HAVE_STRCSPN_Z13  */