| /* Vector optimized 32/64 bit S/390 version of wcsncpy. |
| 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 |
| |
| /* wchar_t *wcsncpy (const wchar_t *dest, const wchar_t *src, size_t n) |
| Copy at most n characters of string src to dest. |
| |
| Register usage: |
| -r0=dest pointer for return |
| -r1=tmp, zero byte index |
| -r2=dest |
| -r3=src |
| -r4=n |
| -r5=current_len |
| -r6=tmp, loaded bytes |
| -r7=tmp, border |
| -v16=part of src |
| -v17=index of zero |
| -v18=part of src |
| -v31=register save area for r6, r7 |
| */ |
| ENTRY(__wcsncpy_vx) |
| .machine "z13" |
| .machinemode "zarch_nohighgprs" |
| |
| # if !defined __s390x__ |
| llgfr %r4,%r4 |
| # endif /* !defined __s390x__ */ |
| |
| clgfi %r4,0 |
| ber %r14 /* Nothing to do, if n == 0. */ |
| |
| vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */ |
| |
| tmll %r3,3 /* Test if s is 4-byte aligned? */ |
| jne .Lfallback /* And use common-code variant if not. */ |
| |
| vlvgp %v31,%r6,%r7 /* Save registers. */ |
| lgr %r0,%r2 /* Save destination pointer for return. */ |
| |
| lcbb %r6,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */ |
| llgfr %r6,%r6 /* Convert 32bit to 64bit. */ |
| |
| lghi %r5,0 /* current_len = 0. */ |
| |
| /* Check range of maxlen and convert to byte-count. */ |
| # ifdef __s390x__ |
| tmhh %r4,49152 /* Test bit 0 or 1 of n. */ |
| lghi %r1,-4 /* Max byte-count is 18446744073709551612. */ |
| # else |
| tmlh %r4,49152 /* Test bit 0 or 1 of n. */ |
| llilf %r1,4294967292 /* Max byte-count is 4294967292. */ |
| # endif /* !__s390x__ */ |
| sllg %r4,%r4,2 /* Convert character-count to byte-count. */ |
| locgrne %r4,%r1 /* Use max byte-count, if bit 0/1 was one. */ |
| |
| clgrjle %r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes |
| -> process remaining. */ |
| |
| /* n > loaded-byte-count. */ |
| vfenezf %v17,%v16,%v16 /* Find element not equal with zero search. */ |
| vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */ |
| aghi %r1,3 /* Also copy remaining bytes of zero. */ |
| clrjl %r1,%r6,.Lfound_v16_store /* Found zero within loaded bytes, |
| copy and return. */ |
| |
| /* Align s to 16 byte. */ |
| risbgn %r7,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */ |
| lghi %r5,15 /* current_len = 15. */ |
| slr %r5,%r7 /* Compute highest index to 16byte boundary. */ |
| |
| /* Zero not found and n > loaded-byte-count. */ |
| vstl %v16,%r5,0(%r2) /* Copy loaded characters - no zero. */ |
| ahi %r5,1 /* Start loop at next character. */ |
| |
| /* Now we are 16byte aligned, so we can load |
| a full vreg without page fault. */ |
| lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ |
| aghi %r1,64 |
| clgrjl %r1,%r4,.Lloop64 |
| |
| vl %v16,0(%r5,%r3) /* Load s. */ |
| clgijl %r4,17,.Lremaining_v16 /* If n <=16, process remaining |
| bytes. */ |
| .Llt64: |
| lgr %r7,%r4 |
| slgfi %r7,16 /* border_len = maxlen - 16. */ |
| |
| clgrjhe %r5,%r7,.Lremaining_v16 /* If current_len >= border |
| then process remaining bytes. */ |
| vfenezfs %v17,%v16,%v16 /* Find element not equal with zero search. */ |
| je .Lfound_v16 /* Jump away if zero was found. */ |
| vl %v18,16(%r5,%r3) /* Load next part of s. */ |
| vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */ |
| aghi %r5,16 |
| |
| clgrjhe %r5,%r7,.Lremaining_v18 |
| vfenezfs %v17,%v18,%v18 |
| je .Lfound_v18 |
| vl %v16,16(%r5,%r3) |
| vst %v18,0(%r5,%r2) |
| aghi %r5,16 |
| |
| clgrjhe %r5,%r7,.Lremaining_v16 |
| vfenezfs %v17,%v16,%v16 |
| je .Lfound_v16 |
| vl %v18,16(%r5,%r3) |
| vst %v16,0(%r5,%r2) |
| aghi %r5,16 |
| |
| .Lremaining_v18: |
| vlr %v16,%v18 |
| .Lremaining_v16: |
| /* v16 contains the remaining bytes [1...16]. |
| Store remaining bytes and append string-termination. */ |
| vfenezf %v17,%v16,%v16 /* Find element not equal with zero search. */ |
| slgrk %r7,%r4,%r5 /* Remaining bytes = maxlen - current_len. */ |
| aghi %r7,-1 /* vstl needs highest index. */ |
| la %r2,0(%r5,%r2) /* vstl has no index register. */ |
| vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */ |
| aghi %r1,3 /* Also copy remaining bytes of zero. */ |
| /* Zero in remaining bytes? -> jump away (zero-index < max-index) |
| Do not jump away if zero-index == max-index, |
| but simply copy zero with vstl below. */ |
| clrjl %r1,%r7,.Lfound_v16_store |
| vstl %v16,%r7,0(%r2) /* Store remaining bytes without null |
| termination!. */ |
| .Lend: |
| /* Restore saved registers. */ |
| vlgvg %r6,%v31,0 |
| vlgvg %r7,%v31,1 |
| lgr %r2,%r0 /* Load saved dest-ptr. */ |
| br %r14 |
| |
| .Lfound_v16_32: |
| aghi %r5,32 |
| j .Lfound_v16 |
| .Lfound_v18_48: |
| aghi %r5,32 |
| .Lfound_v18_16: |
| aghi %r5,16 |
| .Lfound_v18: |
| vlr %v16,%v18 |
| .Lfound_v16: |
| /* v16 contains a zero. Store remaining bytes to zero. current_len |
| has not reached border, thus checking for n is not needed! */ |
| vlgvb %r1,%v17,7 /* Load byte index of zero. */ |
| la %r2,0(%r5,%r2) /* vstl has no support for index-register. */ |
| aghi %r1,3 /* Also copy remaining bytes of zero. */ |
| .Lfound_v16_store: |
| vstl %v16,%r1,0(%r2) /* Copy characters including zero. */ |
| /* Fill remaining bytes with zero - remaining count always > 0. */ |
| algr %r5,%r1 /* Remaining bytes (=%r4) = ... */ |
| slgr %r4,%r5 /* = maxlen - (currlen + zero_index + 1). */ |
| la %r2,0(%r1,%r2) /* Pointer to zero. start filling beyond. */ |
| aghi %r4,-2 /* mvc with exrl needs count - 1. |
| (additional -1, see remaining bytes above) */ |
| srlg %r6,%r4,8 /* Split into 256 byte blocks. */ |
| ltgr %r6,%r6 |
| je .Lzero_lt256 |
| .Lzero_loop256: |
| mvc 1(256,%r2),0(%r2) /* Fill 256 zeros at once. */ |
| la %r2,256(%r2) |
| brctg %r6,.Lzero_loop256 /* Loop until all blocks are processed. */ |
| .Lzero_lt256: |
| exrl %r4,.Lmvc_lt256 |
| j .Lend |
| .Lmvc_lt256: |
| mvc 1(1,%r2),0(%r2) |
| |
| /* Find zero in 16byte aligned loop. */ |
| .Lloop64: |
| vl %v16,0(%r5,%r3) /* Load s. */ |
| vfenezfs %v17,%v16,%v16 /* Find element not equal with zero search. */ |
| je .Lfound_v16 /* Jump away if zero was found. */ |
| vl %v18,16(%r5,%r3) /* Load next part of s. */ |
| vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */ |
| vfenezfs %v17,%v18,%v18 |
| je .Lfound_v18_16 |
| vl %v16,32(%r5,%r3) |
| vst %v18,16(%r5,%r2) |
| vfenezfs %v17,%v16,%v16 |
| je .Lfound_v16_32 |
| vl %v18,48(%r5,%r3) |
| vst %v16,32(%r5,%r2) |
| vfenezfs %v17,%v18,%v18 |
| je .Lfound_v18_48 |
| vst %v18,48(%r5,%r2) |
| |
| aghi %r5,64 |
| lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ |
| aghi %r1,64 |
| clgrjl %r1,%r4,.Lloop64 |
| |
| vl %v16,0(%r5,%r3) /* Load s. */ |
| j .Llt64 |
| |
| .Lfallback: |
| jg __wcsncpy_c |
| END(__wcsncpy_vx) |
| |
| #endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */ |
