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Diffstat (limited to 'sysdeps/s390/strstr-arch13.S')
| -rw-r--r-- | sysdeps/s390/strstr-arch13.S | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/sysdeps/s390/strstr-arch13.S b/sysdeps/s390/strstr-arch13.S new file mode 100644 index 0000000000..929b026adf --- /dev/null +++ b/sysdeps/s390/strstr-arch13.S @@ -0,0 +1,179 @@ +/* Vector optimized 32/64 bit S/390 version of strstr. + Copyright (C) 2019 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/>. */ + +#include <ifunc-strstr.h> +#if HAVE_STRSTR_ARCH13 +# include "sysdep.h" +# include "asm-syntax.h" + .text + +/* char *strstr (const char *haystack=r2, const char *needle=r3) + Locate a substring. */ +ENTRY(STRSTR_ARCH13) + .machine "arch13" + .machinemode "zarch_nohighgprs" + lcbb %r1,0(%r3),6 + jo .Lneedle_on_bb /* Needle on block-boundary? */ + vl %v18,0(%r3),6 /* Load needle. */ + vfenezb %v19,%v18,%v18 /* v19[7] contains the length of needle. */ +.Lneedle_loaded: + vlgvb %r4,%v19,7 /* Get index of zero or 16 if not found. */ + lghi %r5,17 /* See below: min-skip-partial-match-index. */ + cgibe %r4,0,0(%r14) /* Test if needle is zero and return. */ + + /* The vstrs instruction is able to handle needles up to a length of 16, + but then we may have to load the next part of haystack with a + small offset. This will be slow - see examples: + haystack =mmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmm...mmmmmmmmmmmmmmmmmmma + needle = mmmmmmmmmmmmmma0 + => needle_len=15; vstrs reports a partial match; haystack+=2 + haystack =mmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmm...mmmmmmmmmmmmmmmmmmma + needle = mmmmmmmma0000000 + => needle_len=9; vstrs reports a partial match; haystack+=8 */ +# if ! HAVE_STRSTR_Z13 +# error The arch13 variant of strstr needs the z13 variant of strstr! +# endif + clgfi %r4,9 + jh STRSTR_Z13 + + /* In case of a partial match, the vstrs instruction returns the index + of the partial match in a vector-register. Then we have to + reload the string at the "current-position plus this index" and run + vstrs again in order to determine if it was a full match or no match. + Transferring this index from vr to gr, compute the haystack-address + and loading with vl is quite slow as all instructions have data + dependencies. Thus we assume, that a partial match is always at the + first possible index and just load the next part of haystack from + there instead of waiting until the correct index is computed: + min-skip-partial-match-index = (16 - n_len) + 1 */ + sgr %r5,%r4 + +.Lloop: + lcbb %r1,0(%r2),6 + jo .Lloop_haystack_on_bb /* Haystack on block-boundary? */ + vl %v16,0(%r2) /* Load next part of haystack. */ +.Lloop_haystack_loaded: + /* Vector string search with zero search (cc=0 => no match). */ + vstrs %v20,%v16,%v18,%v19,0,2 + jne .Lloop_vstrs_nonzero_cc + lcbb %r1,16(%r2),6 /* Next part of haystack. */ + jo .Lloop_haystack_on_bb16 + vl %v16,16(%r2) + vstrs %v20,%v16,%v18,%v19,0,2 + jne .Lloop_vstrs_nonzero_cc16 + lcbb %r1,32(%r2),6 /* Next part of haystack. */ + jo .Lloop_haystack_on_bb32 + vl %v16,32(%r2) + vstrs %v20,%v16,%v18,%v19,0,2 + jne .Lloop_vstrs_nonzero_cc32 + lcbb %r1,48(%r2),6 /* Next part of haystack. */ + jo .Lloop_haystack_on_bb48 + vl %v16,48(%r2) + vstrs %v20,%v16,%v18,%v19,0,2 + jne .Lloop_vstrs_nonzero_cc48 + la %r2,64(%r2) + j .Lloop + +.Lloop_vstrs_nonzero_cc48: + la %r2,16(%r2) +.Lloop_vstrs_nonzero_cc32: + la %r2,16(%r2) +.Lloop_vstrs_nonzero_cc16: + la %r2,16(%r2) +.Lloop_vstrs_nonzero_cc: + jh .Lend_match_found /* cc == 2 (full match) */ + jl .Lend_no_match /* cc == 1 (no match, end of string) */ + /* cc == 3 (partial match) See above: min-skip-partial-match-index! */ + lcbb %r1,0(%r5,%r2),6 + la %r2,0(%r5,%r2) + jo .Lloop_haystack_on_bb + vl %v16,0(%r2) + vstrs %v20,%v16,%v18,%v19,0,2 +.Lloop_vstrs_nonzero_cc_loop: + jh .Lend_match_found + jl .Lend_no_match + la %r2,0(%r5,%r2) + je .Lloop + lcbb %r1,0(%r2),6 /* Next part of haystack. */ + jo .Lloop_haystack_on_bb + vl %v16,0(%r2) + vstrs %v20,%v16,%v18,%v19,0,2 + jh .Lend_match_found + jl .Lend_no_match + la %r2,0(%r5,%r2) + je .Lloop + lcbb %r1,0(%r2),6 /* Next part of haystack. */ + jo .Lloop_haystack_on_bb + vl %v16,0(%r2) + vstrs %v20,%v16,%v18,%v19,0,2 + jh .Lend_match_found + jl .Lend_no_match + la %r2,0(%r5,%r2) + je .Lloop + lcbb %r1,0(%r2),6 /* Next part of haystack. */ + jo .Lloop_haystack_on_bb + vl %v16,0(%r2) + vstrs %v20,%v16,%v18,%v19,0,2 + j .Lloop_vstrs_nonzero_cc_loop + +.Lend_no_match: + lghi %r2,0 + br %r14 +.Lend_match_found: + vlgvb %r4,%v20,7 + la %r2,0(%r4,%r2) + br %r14 + +.Lloop_haystack_on_bb48: + la %r2,16(%r2) +.Lloop_haystack_on_bb32: + la %r2,16(%r2) +.Lloop_haystack_on_bb16: + la %r2,16(%r2) +.Lloop_haystack_on_bb: + /* Haystack located on page-boundary. */ + ahi %r1,-1 /* vll needs highest index instead of count. */ + vll %v16,%r1,0(%r2) + vlvgb %v21,%r1,7 + vfenezb %v17,%v16,%v16 /* Search zero in loaded haystack bytes. */ + veclb %v17,%v21 /* Zero index <= loaded byte index? */ + jle .Lloop_haystack_loaded /* -> v16 contains full haystack. */ + vl %v16,0(%r2) /* Load haystack beyond page boundary. */ + j .Lloop_haystack_loaded + +.Lneedle_on_bb: + /* Needle located on page-boundary. */ + ahi %r1,-1 /* vll needs highest index instead of count. */ + vll %v18,%r1,0(%r3) + vlvgb %v21,%r1,7 + vfenezb %v19,%v18,%v18 /* Search zero in loaded needle bytes. */ + veclb %v19,%v21 /* Zero index <= max loaded byte index? */ + jle .Lneedle_loaded /* -> v18 contains full needle. */ + vl %v16,0(%r3) /* Load needle beyond page boundary. */ + vfenezb %v19,%v18,%v18 + j .Lneedle_loaded +END(STRSTR_ARCH13) + +# if ! HAVE_STRSTR_IFUNC +strong_alias (STRSTR_ARCH13, strstr) +# endif + +# if STRSTR_Z13_ONLY_USED_AS_FALLBACK && defined SHARED && IS_IN (libc) +strong_alias (STRSTR_ARCH13, __GI_strstr) +# endif +#endif |