sysdeps/s390/wcsncmp-vx.S

   1 /* Vector optimized 32/64 bit S/390 version of wcsncmp.
   2    Copyright (C) 2015-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <ifunc-wcsncmp.h>
  20 #if HAVE_WCSNCMP_Z13
  21
  22 # include "sysdep.h"
  23 # include "asm-syntax.h"
  24
  25         .text
  26
  27 /* int wcsncmp (const wchar_t *s1, const wchar_t *s2, size_t n)
  28    Compare at most n characters of two strings.
  29
  30    Register usage:
  31    -r0=tmp
  32    -r1=tmp
  33    -r2=s1
  34    -r3=s2
  35    -r4=n
  36    -r5=current_len
  37    -v16=part of s1
  38    -v17=part of s2
  39    -v18=index of unequal
  40 */
  41 ENTRY(WCSNCMP_Z13)
  42         .machine "z13"
  43         .machinemode "zarch_nohighgprs"
  44
  45 # if !defined __s390x__
  46         llgfr   %r4,%r4
  47 # endif /* !defined __s390x__ */
  48
  49         clgije  %r4,0,.Lend_equal /* Nothing to do if n == 0.  */
  50
  51         /* Check range of n and convert to byte-count.  */
  52 # ifdef __s390x__
  53         tmhh    %r4,49152       /* Test bit 0 or 1 of maxlen.  */
  54         lghi    %r1,-4          /* Max byte-count is 18446744073709551612.  */
  55 # else
  56         tmlh    %r4,49152       /* Test bit 0 or 1 of maxlen.  */
  57         llilf   %r1,4294967292  /* Max byte-count is 4294967292.  */
  58 # endif /* !__s390x__ */
  59         sllg    %r4,%r4,2       /* Convert character-count to byte-count.  */
  60         locgrne %r4,%r1         /* Use max byte-count, if bit 0/1 was one.  */
  61
  62         /* Check first character without vector load.  */
  63         lghi    %r5,4           /* current_len = 4 bytes.  */
  64         /* Check s1/2[0].  */
  65         lt      %r0,0(%r2)
  66         l       %r1,0(%r3)
  67         je      .Lend_cmp_one_char
  68         crjne   %r0,%r1,.Lend_cmp_one_char
  69
  70 .Lloop:
  71         vlbb    %v17,0(%r5,%r3),6 /* Load s2 to block boundary.  */
  72         vlbb    %v16,0(%r5,%r2),6 /* Load s1 to block boundary.  */
  73         lcbb    %r0,0(%r5,%r2),6 /* Get loaded byte count of s1.  */
  74         jo      .Llt16_1        /* Jump away if vector not fully loaded.  */
  75         lcbb    %r1,0(%r5,%r3),6 /* Get loaded byte count of s2.  */
  76         jo      .Llt16_2        /* Jump away if vector not fully loaded.  */
  77         aghi    %r5,16          /* Both vectors are fully loaded.  */
  78         vfenezfs %v18,%v16,%v17 /* Compare not equal with zero search.  */
  79         clgrjhe %r5,%r4,.Llastcmp /* If current_len >= n ->last compare.  */
  80         jno     .Lfound
  81
  82         vlbb    %v17,0(%r5,%r3),6
  83         vlbb    %v16,0(%r5,%r2),6
  84         lcbb    %r0,0(%r5,%r2),6
  85         jo      .Llt16_1
  86         lcbb    %r1,0(%r5,%r3),6
  87         jo      .Llt16_2
  88         aghi    %r5,16
  89         vfenezfs %v18,%v16,%v17
  90         clgrjhe %r5,%r4,.Llastcmp
  91         jno     .Lfound
  92
  93         vlbb    %v17,0(%r5,%r3),6
  94         vlbb    %v16,0(%r5,%r2),6
  95         lcbb    %r0,0(%r5,%r2),6
  96         jo      .Llt16_1
  97         lcbb    %r1,0(%r5,%r3),6
  98         jo      .Llt16_2
  99         aghi    %r5,16
 100         vfenezfs %v18,%v16,%v17
 101         clgrjhe %r5,%r4,.Llastcmp
 102         jno     .Lfound
 103
 104         vlbb    %v17,0(%r5,%r3),6
 105         vlbb    %v16,0(%r5,%r2),6
 106         lcbb    %r0,0(%r5,%r2),6
 107         jo      .Llt16_1
 108         lcbb    %r1,0(%r5,%r3),6
 109         jo      .Llt16_2
 110         aghi    %r5,16
 111         vfenezfs %v18,%v16,%v17
 112         clgrjhe %r5,%r4,.Llastcmp
 113         jno     .Lfound
 114
 115         j       .Lloop
 116
 117 .Llt16_1:
 118         lcbb    %r1,0(%r5,%r3),6 /* Get loaded byte count of s2.  */
 119 .Llt16_2:
 120         clr     %r0,%r1         /* Compare logical.  */
 121         locrh   %r0,%r1         /* Compute minimum of bytes loaded.  */
 122         nill    %r0,65532       /* Align bytes loaded to full characters.  */
 123         jz      .Lcmp_one_char  /* Jump away if no full char is available.  */
 124 .Llt_cmp:
 125         algfr   %r5,%r0         /* Add smallest loaded bytes to current_len.  */
 126         vfenezfs %v18,%v16,%v17 /* Compare not equal with zero search.  */
 127         clgrj   %r5,%r4,10,.Llastcmp /* If current_len >= n -> last compare  */
 128         vlgvb   %r1,%v18,7      /* Get not equal index or 16 if all equal.  */
 129         clrjl   %r1,%r0,.Lfound /* Jump away if miscompare is within
 130                                    loaded bytes; (index < loaded-bytes) */
 131         j       .Lloop
 132
 133 .Lcmp_one_char:
 134         /* At least one of both strings is not 4-byte aligned
 135            and there is no full character before next block-boundary.
 136            Compare one character to get over the boundary and
 137            proceed with normal loop!  */
 138         vlef    %v16,0(%r5,%r2),0 /* Load one character.  */
 139         lghi    %r0,4           /* Loaded byte count is 4.  */
 140         vlef    %v17,0(%r5,%r3),0
 141         j       .Llt_cmp        /* Proceed with comparision.  */
 142
 143 .Llastcmp:
 144         /* Use comparision result only if located within first n characters.
 145            %r0: loaded byte count in vreg;
 146            %r5: current_len;
 147            %r4: n;
 148            (current_len - n): [0...16[
 149            First ignored match index: loaded bytes - (current_len-n): ]0...16]
 150         */
 151         slgr    %r5,%r4         /* %r5 = current_len - n.  */
 152         slr     %r0,%r5         /* %r0 = first ignored match index.  */
 153         vlgvb   %r4,%v18,7      /* Get not equal index or 16 if all equal.  */
 154         clrjl   %r4,%r0,.Lfound2 /* Jump away if miscompare is within
 155                                      loaded bytes and below n bytes.  */
 156 .Lend_equal:
 157         lghi    %r2,0
 158         br      %r14
 159
 160 .Lfound:
 161         /* Difference or end of string.  */
 162         /* vfenezf found an unequal element or zero.
 163            This instruction compares unsigned words, but wchar_t is signed.
 164            Thus we have to compare the found element again.  */
 165         vlgvb   %r4,%v18,7      /* Extract not equal byte-index.  */
 166 .Lfound2:
 167         srl     %r4,2           /* And convert it to character-index.  */
 168         vlgvf   %r0,%v16,0(%r4) /* Load character-values.  */
 169         vlgvf   %r1,%v17,0(%r4)
 170 .Lend_cmp_one_char:
 171         cr      %r0,%r1
 172         je      .Lend_equal
 173         lghi    %r2,1
 174         lghi    %r1,-1
 175         locgrl  %r2,%r1
 176         br      %r14
 177 END(WCSNCMP_Z13)
 178
 179 # if ! HAVE_WCSNCMP_IFUNC
 180 strong_alias (WCSNCMP_Z13, wcsncmp)
 181 # endif
 182 #endif