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/* Vector optimized 32/64 bit S/390 version of strspn.
Copyright (C) 2015-2023 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
<https://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 across 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 */
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