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148 lines
3.9 KiB
ArmAsm
148 lines
3.9 KiB
ArmAsm
/* Vector optimized 32/64 bit S/390 version of strnlen.
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Copyright (C) 2015-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <ifunc-strnlen.h>
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#if HAVE_STRNLEN_Z13
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# include "sysdep.h"
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# include "asm-syntax.h"
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.text
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/* size_t strnlen (const char *s, size_t maxlen)
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Returns the number of characters in s or at most maxlen.
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Register usage:
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-r1=tmp
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-r2=address of string
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-r3=maxlen (number of characters to be read)
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-r4=tmp
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-r5=current_len and return_value
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-v16=part of s
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*/
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ENTRY(STRNLEN_Z13)
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.machine "z13"
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.machinemode "zarch_nohighgprs"
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# if !defined __s390x__
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llgfr %r3,%r3
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# endif /* !defined __s390x__ */
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clgfi %r3,0 /* if maxlen == 0, return 0. */
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locgre %r2,%r3
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ber %r14
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vlbb %v16,0(%r2),6 /* Load s until next 4k-byte boundary. */
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lcbb %r1,0(%r2),6 /* Get bytes to 4k-byte boundary or 16. */
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llgfr %r1,%r1 /* Convert 32bit to 64bit. */
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vfenezb %v16,%v16,%v16 /* Find element not equal with zero search. */
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clgr %r1,%r3
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locgrh %r1,%r3 /* loaded_byte_count
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= min (loaded_byte_count, maxlen) */
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vlgvb %r5,%v16,7 /* Load zero index or 16 if not found. */
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clr %r5,%r1 /* If found zero within loaded bytes? */
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locgrl %r2,%r5 /* Then copy return value. */
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blr %r14 /* And return. */
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clgr %r1,%r3 /* If loaded_byte_count == maxlen? */
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locgre %r2,%r3 /* Then copy return value. */
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ber %r14 /* And return. */
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/* Align s to 16 byte. */
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risbgn %r4,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */
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lghi %r5,16 /* current_len = 16. */
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slr %r5,%r4 /* Compute bytes to 16bytes boundary. */
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lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
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aghi %r1,64
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clgrjl %r1,%r3,.Lloop64
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/* Find zero in max 64byte with aligned s. */
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.Llt64:
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vl %v16,0(%r5,%r2) /* Load s. */
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vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search. */
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je .Lfound /* Jump away if zero was found. */
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aghi %r5,16
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clgrjhe %r5,%r3,.Lfound /* current_len >= maxlen -> end. */
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vl %v16,0(%r5,%r2)
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vfenezbs %v16,%v16,%v16
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je .Lfound
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aghi %r5,16
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clgrjhe %r5,%r3,.Lfound
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vl %v16,0(%r5,%r2)
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vfenezbs %v16,%v16,%v16
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je .Lfound
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aghi %r5,16
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clgrjhe %r5,%r3,.Lfound
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vl %v16,0(%r5,%r2)
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vfenezbs %v16,%v16,%v16
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j .Lfound
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.Lfound48:
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aghi %r5,16
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.Lfound32:
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aghi %r5,16
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.Lfound16:
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aghi %r5,16
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.Lfound:
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vlgvb %r4,%v16,7 /* Load byte index of zero or 16 if no zero. */
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algr %r5,%r4
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clgr %r5,%r3
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locgrh %r5,%r3 /* Return min (current_len, maxlen). */
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lgr %r2,%r5
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br %r14
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/* Find zero in 16 byte aligned loop. */
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.Lloop64:
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vl %v16,0(%r5,%r2) /* Load s. */
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vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search. */
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je .Lfound /* Jump away if zero was found. */
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vl %v16,16(%r5,%r2)
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vfenezbs %v16,%v16,%v16
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je .Lfound16
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vl %v16,32(%r5,%r2)
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vfenezbs %v16,%v16,%v16
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je .Lfound32
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vl %v16,48(%r5,%r2)
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vfenezbs %v16,%v16,%v16
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je .Lfound48
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aghi %r5,64
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lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
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aghi %r1,64
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clgrjl %r1,%r3,.Lloop64
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j .Llt64
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END(STRNLEN_Z13)
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# if ! HAVE_STRNLEN_IFUNC
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strong_alias (STRNLEN_Z13, __strnlen)
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weak_alias (__strnlen, strnlen)
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# endif
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# if ! HAVE_STRNLEN_C && defined SHARED && IS_IN (libc)
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strong_alias (STRNLEN_Z13, __GI_strnlen)
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strong_alias (STRNLEN_Z13, __GI___strnlen)
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# endif
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#endif /* HAVE_STRNLEN_Z13 */
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