| /* Vector optimized 32/64 bit S/390 version of strnlen. |
| 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 |
| |
| /* size_t strnlen (const char *s, size_t maxlen) |
| Returns the number of characters in s or at most maxlen. |
| |
| Register usage: |
| -r1=tmp |
| -r2=address of string |
| -r3=maxlen (number of characters to be read) |
| -r4=tmp |
| -r5=current_len and return_value |
| -v16=part of s |
| */ |
| ENTRY(__strnlen_vx) |
| .machine "z13" |
| .machinemode "zarch_nohighgprs" |
| |
| # if !defined __s390x__ |
| llgfr %r3,%r3 |
| # endif /* !defined __s390x__ */ |
| |
| clgfi %r3,0 /* if maxlen == 0, return 0. */ |
| locgre %r2,%r3 |
| ber %r14 |
| |
| 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. */ |
| llgfr %r1,%r1 /* Convert 32bit to 64bit. */ |
| |
| vfenezb %v16,%v16,%v16 /* Find element not equal with zero search. */ |
| clgr %r1,%r3 |
| locgrh %r1,%r3 /* loaded_byte_count |
| = min (loaded_byte_count, maxlen) */ |
| |
| vlgvb %r5,%v16,7 /* Load zero index or 16 if not found. */ |
| clr %r5,%r1 /* If found zero within loaded bytes? */ |
| locgrl %r2,%r5 /* Then copy return value. */ |
| blr %r14 /* And return. */ |
| |
| clgr %r1,%r3 /* If loaded_byte_count == maxlen? */ |
| locgre %r2,%r3 /* Then copy return value. */ |
| ber %r14 /* And return. */ |
| |
| /* Align s to 16 byte. */ |
| risbgn %r4,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */ |
| lghi %r5,16 /* current_len = 16. */ |
| slr %r5,%r4 /* Compute bytes to 16bytes boundary. */ |
| |
| lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ |
| aghi %r1,64 |
| clgrjl %r1,%r3,.Lloop64 |
| |
| /* Find zero in max 64byte with aligned s. */ |
| .Llt64: |
| vl %v16,0(%r5,%r2) /* Load s. */ |
| vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search. */ |
| je .Lfound /* Jump away if zero was found. */ |
| aghi %r5,16 |
| clgrjhe %r5,%r3,.Lfound /* current_len >= maxlen -> end. */ |
| vl %v16,0(%r5,%r2) |
| vfenezbs %v16,%v16,%v16 |
| je .Lfound |
| aghi %r5,16 |
| clgrjhe %r5,%r3,.Lfound |
| vl %v16,0(%r5,%r2) |
| vfenezbs %v16,%v16,%v16 |
| je .Lfound |
| aghi %r5,16 |
| clgrjhe %r5,%r3,.Lfound |
| vl %v16,0(%r5,%r2) |
| vfenezbs %v16,%v16,%v16 |
| j .Lfound |
| |
| .Lfound48: |
| aghi %r5,16 |
| .Lfound32: |
| aghi %r5,16 |
| .Lfound16: |
| aghi %r5,16 |
| .Lfound: |
| vlgvb %r4,%v16,7 /* Load byte index of zero or 16 if no zero. */ |
| algr %r5,%r4 |
| |
| clgr %r5,%r3 |
| locgrh %r5,%r3 /* Return min (current_len, maxlen). */ |
| lgr %r2,%r5 |
| br %r14 |
| |
| /* Find zero in 16 byte aligned loop. */ |
| .Lloop64: |
| vl %v16,0(%r5,%r2) /* Load s. */ |
| vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search. */ |
| je .Lfound /* Jump away if zero was found. */ |
| vl %v16,16(%r5,%r2) |
| vfenezbs %v16,%v16,%v16 |
| je .Lfound16 |
| vl %v16,32(%r5,%r2) |
| vfenezbs %v16,%v16,%v16 |
| je .Lfound32 |
| vl %v16,48(%r5,%r2) |
| vfenezbs %v16,%v16,%v16 |
| je .Lfound48 |
| |
| aghi %r5,64 |
| lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ |
| aghi %r1,64 |
| clgrjl %r1,%r3,.Lloop64 |
| |
| j .Llt64 |
| END(__strnlen_vx) |
| #endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */ |