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Diffstat (limited to 'sysdeps/s390/multiarch/strncpy-vx.S')
| -rw-r--r-- | sysdeps/s390/multiarch/strncpy-vx.S | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/sysdeps/s390/multiarch/strncpy-vx.S b/sysdeps/s390/multiarch/strncpy-vx.S new file mode 100644 index 0000000000..08a0b29e8b --- /dev/null +++ b/sysdeps/s390/multiarch/strncpy-vx.S @@ -0,0 +1,207 @@ +/* Vector optimized 32/64 bit S/390 version of strncpy. + Copyright (C) 2015-2016 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 + +/* char * strncpy (const char *dest, const char *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(__strncpy_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. */ + lgr %r0,%r2 /* Save destination pointer for return. */ + vlvgp %v31,%r6,%r7 /* Save registers. */ + + vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */ + 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. */ + + clgrjle %r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes + -> process remaining. */ + + /* n > loaded-byte-count. */ + vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */ + vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */ + 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 = n - 16. */ + + clgrjhe %r5,%r7,.Lremaining_v16 /* If current_len >= border + then process remaining bytes. */ + vfenezbs %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 + vfenezbs %v17,%v18,%v18 + je .Lfound_v18 + vl %v16,16(%r5,%r3) + vst %v18,0(%r5,%r2) + aghi %r5,16 + + clgrjhe %r5,%r7,.Lremaining_v16 + vfenezbs %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. */ + vfenezb %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. */ + /* 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. */ +.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 /* = n - (current_len + 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) + +.Lloop64: + vl %v16,0(%r5,%r3) /* Load s. */ + vfenezbs %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. */ + vfenezbs %v17,%v18,%v18 + je .Lfound_v18_16 + vl %v16,32(%r5,%r3) + vst %v18,16(%r5,%r2) + vfenezbs %v17,%v16,%v16 + je .Lfound_v16_32 + vl %v18,48(%r5,%r3) + vst %v16,32(%r5,%r2) + vfenezbs %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 +END(__strncpy_vx) + +# define strncpy __strncpy_c +# undef libc_hidden_builtin_def +# define libc_hidden_builtin_def(name) strong_alias(__strncpy_c, __GI_strncpy) +#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */ + +/* Include strncpy-implementation in s390-32/s390-64 subdirectory. */ +#include <strncpy.S> |