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Diffstat (limited to 'sysdeps/s390/multiarch/strrchr-vx.S')
| -rw-r--r-- | sysdeps/s390/multiarch/strrchr-vx.S | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/sysdeps/s390/multiarch/strrchr-vx.S b/sysdeps/s390/multiarch/strrchr-vx.S new file mode 100644 index 0000000000..175d2cba3c --- /dev/null +++ b/sysdeps/s390/multiarch/strrchr-vx.S @@ -0,0 +1,180 @@ +/* Vector optimized 32/64 bit S/390 version of strrchr. + 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 *strrchr (const char *s, int c) + Locate the last character c in string. + + Register usage: + -r0=loaded bytes in first part of s. + -r1=pointer to last occurence of c or NULL if not found. + -r2=s + -r3=c + -r4=tmp + -r5=current_len + -v16=part of s + -v17=index of found element + -v18=replicated c + -v19=part of s with last occurence of c. + -v20=permute pattern +*/ +ENTRY(__strrchr_vx) + .machine "z13" + .machinemode "zarch_nohighgprs" + + vlbb %v16,0(%r2),6 /* Load s until next 4k-byte boundary. */ + lcbb %r0,0(%r2),6 /* Get bytes to 4k-byte boundary or 16. */ + + vlvgb %v18,%r3,0 /* Generate vector which elements are all c. + if c > 255, c will be truncated. */ + vrepb %v18,%v18,0 + + lghi %r1,-1 /* Currently no c found. */ + lghi %r5,0 /* current_len = 0. */ + + vfeezbs %v17,%v16,%v18 /* Find element equal or zero. */ + vlgvb %r4,%v17,7 /* Load byte index of c/zero or 16. */ + clrjl %r4,%r0,.Lfound_first_part /* Found c/zero in loaded bytes. */ +.Lalign: + /* 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. */ + +.Lloop: + vl %v16,0(%r5,%r2) /* Load s. */ + vfeezbs %v17,%v16,%v18 /* Find element equal with zero search. */ + jno .Lfound /* Found c/zero (cc=0|1|2). */ + vl %v16,16(%r5,%r2) + vfeezbs %v17,%v16,%v18 + jno .Lfound16 + vl %v16,32(%r5,%r2) + vfeezbs %v17,%v16,%v18 + jno .Lfound32 + vl %v16,48(%r5,%r2) + vfeezbs %v17,%v16,%v18 + jno .Lfound48 + + aghi %r5,64 + j .Lloop /* No character and no zero -> loop. */ + +.Lfound48: + la %r5,16(%r5) /* Use la since aghi would clobber cc. */ +.Lfound32: + la %r5,16(%r5) +.Lfound16: + la %r5,16(%r5) +.Lfound: + je .Lzero /* Found zero, but no c before that zero. */ + /* Save this part of s to check for further matches after reaching + the end of the complete string. */ + vlr %v19,%v16 + lgr %r1,%r5 + + jh .Lzero /* Found a zero after the found c. */ + aghi %r5,16 /* Start search of next part of s. */ + j .Lloop + +.Lfound_first_part: + /* This code is only executed if the found c/zero is whithin loaded + bytes. If no c/zero was found (cc==3) the found index = 16, thus + this code is not called. + Resulting condition code of vector find element equal: + cc==0: no c, found zero + cc==1: c found, no zero + cc==2: c found, found zero after c + cc==3: no c, no zero (this case can be ignored). */ + je .Lzero /* Found zero, but no c before that zero. */ + + locgrne %r1,%r5 /* Mark c as found in first part of s. */ + vlr %v19,%v16 + + jl .Lalign /* No zero (e.g. if vr was fully loaded) + -> Align and loop afterwards. */ + + /* Found a zero in vr. If vr was not fully loaded due to block + boundary, the remaining bytes are filled with zero and we can't + rely on zero indication of condition code here! */ + + vfenezb %v17,%v16,%v16 /* Find zero. */ + vlgvb %r4,%v17,7 /* Load byte index of zero or 16. */ + clrjl %r4,%r0,.Lzero /* Zero within loaded bytes -> end. */ + j .Lalign /* Align and loop afterwards. */ + +.Lend_searched_zero: + vlgvb %r4,%v17,7 /* Load byte index of zero. */ + algr %r5,%r4 + la %r2,0(%r5,%r2) /* Return pointer to zero. */ + br %r14 + +.Lzero: + /* Reached end of string. Check if one c was found before. */ + clije %r3,0,.Lend_searched_zero /* Found zero and c is zero. */ + + cgfi %r1,-1 /* No c found -> return NULL. */ + locghie %r2,0 + ber %r14 + + larl %r3,.Lpermute_mask /* Load permute mask. */ + vl %v20,0(%r3) + + /* c was found and is part of v19. */ + vfenezb %v17,%v19,%v19 /* Find zero. */ + vlgvb %r4,%v17,7 /* Load byte index of zero or 16. */ + + clgfi %r5,0 /* Loaded byte count in v19 is 16, ... */ + lochine %r0,16 /* ... if v19 is not the first part of s. */ + ahi %r0,-1 /* Convert byte count to highest index. */ + + clr %r0,%r4 + locrl %r4,%r0 /* r4 = min (zero-index, highest-index). */ + + /* Right-shift of v19 to mask bytes after zero. */ + clije %r4,15,.Lzero_permute /* No shift is needed if highest index + in vr is 15. */ + lhi %r0,15 + slr %r0,%r4 /* Compute byte count for vector shift right. */ + sll %r0,3 /* Convert to bit count. */ + vlvgb %v17,%r0,7 + vsrlb %v19,%v19,%v17 /* Vector shift right by byte by number of bytes + specified in bits 1-4 of byte 7 in v17. */ + + /* Reverse bytes in v19. */ +.Lzero_permute: + vperm %v19,%v19,%v19,%v20 /* Permute v19 to reversed order. */ + + /* Find c in reversed v19. */ + vfeeb %v19,%v19,%v18 /* Find c. */ + la %r2,0(%r1,%r2) + vlgvb %r3,%v19,7 /* Load byte index of c. */ + + /* Compute index in real s and return. */ + slgr %r4,%r3 + la %r2,0(%r4,%r2) /* Return pointer to zero. */ + br %r14 +.Lpermute_mask: + .byte 0x0F,0x0E,0x0D,0x0C,0x0B,0x0A,0x09,0x08 + .byte 0x07,0x06,0x05,0x04,0x03,0x02,0x01,0x00 +END(__strrchr_vx) +#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */ |