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Diffstat (limited to 'sysdeps/s390/multiarch/memrchr-vx.S')
| -rw-r--r-- | sysdeps/s390/multiarch/memrchr-vx.S | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/sysdeps/s390/multiarch/memrchr-vx.S b/sysdeps/s390/multiarch/memrchr-vx.S new file mode 100644 index 0000000000..fdb8c30ebe --- /dev/null +++ b/sysdeps/s390/multiarch/memrchr-vx.S @@ -0,0 +1,160 @@ +/* Vector optimized 32/64 bit S/390 version of memrchr. + 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 + +/* void *memrchr (const void *s, int c, size_t n) + Scans memory for character c backwards + and returns pointer to first c. + + Register usage: + -r0=tmp + -r1=tmp + -r2=s + -r3=c + -r4=n + -r5=s in loop + + -v16=part of s + -v17=index of found c + -v18=c replicated + -v20=permute pattern +*/ +ENTRY(__memrchr_vx) + .machine "z13" + .machinemode "zarch_nohighgprs" + +# if !defined __s390x__ + llgfr %r4,%r4 +# endif /* !defined __s390x__ */ + clgije %r4,0,.Lnot_found + + vlvgb %v18,%r3,0 /* Generate vector which elements are all c. + If c > 255, c will be truncated. */ + vrepb %v18,%v18,0 + + llcr %r3,%r3 /* char c_char = (char) c. */ + + /* check byte n - 1. */ + llc %r0,-1(%r4,%r2) + slgfi %r4,1 + clrje %r0,%r3,.Lfound_end + jh .Lnot_found /* Return NULL if n is now 0. */ + + larl %r1,.Lpermute_mask /* Load permute mask. */ + vl %v20,0(%r1) + + /* check byte n - 2. */ + llc %r0,-1(%r4,%r2) + slgfi %r4,1 + clrje %r0,%r3,.Lfound_end + jh .Lnot_found /* Return NULL if n is now 0. */ + + clgijhe %r4,64,.Lloop64 /* If n >= 64 -> loop64. */ + +.Llt64: + /* Process n < 64 bytes. */ + clgijl %r4,16,.Llt16 /* Jump away if n < 16. */ + aghi %r4,-16 + vl %v16,0(%r4,%r2) + vfeebs %v17,%v16,%v18 + jno .Lfound0 + clgijl %r4,16,.Llt16 + aghi %r4,-16 + vl %v16,0(%r4,%r2) + vfeebs %v17,%v16,%v18 + jno .Lfound0 + clgijl %r4,16,.Llt16 + aghi %r4,-16 + vl %v16,0(%r4,%r2) + vfeebs %v17,%v16,%v18 + jno .Lfound0 +.Llt16: + clgfi %r4,0 /* if remaining bytes == 0, return NULL. */ + locghie %r2,0 + ber %r14 + + aghi %r4,-1 /* vll needs highest index. */ + vll %v16,%r4,0(%r2) /* Load remaining bytes. */ + + /* Right-shift of v16 to mask bytes after highest index. */ + 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 %v16,%v16,%v17 /* Vector shift right by byte by number of bytes + specified in bits 1-4 of byte 7 in v17. */ + j .Lfound_permute + +.Lfound48: + aghi %r4,16 +.Lfound32: + aghi %r4,16 +.Lfound16: + aghi %r4,16 +.Lfound0: + la %r2,0(%r4,%r2) /* Set pointer to start of v16. */ + lghi %r4,15 /* Set highest index in v16 to last index. */ +.Lfound_permute: + /* Search for a c in v16 in reversed byte order. v16 contains %r4 + 1 + bytes. If v16 was not fully loaded, the bytes are already + right shifted, so that the bytes in v16 can simply be reversed. */ + vperm %v16,%v16,%v16,%v20 /* Permute v16 to reversed order. */ + vfeeb %v16,%v16,%v18 /* Find c in reversed v16. */ + vlgvb %r1,%v16,7 /* Index of c or 16 if not found. */ + + /* Return NULL if there is no c in loaded bytes. */ + clrjh %r1,%r4,.Lnot_found + + slgr %r4,%r1 +.Lfound_end: + la %r2,0(%r4,%r2) /* Return pointer to c. */ + br %r14 + +.Lnot_found: + lghi %r2,0 + br %r14 + +.Lpermute_mask: + .byte 0x0F,0x0E,0x0D,0x0C,0x0B,0x0A,0x09,0x08 + .byte 0x07,0x06,0x05,0x04,0x03,0x02,0x01,0x00 + +.Lloop64: + aghi %r4,-64 + vl %v16,48(%r4,%r2) /* Load 16bytes of memory area. */ + vfeebs %v17,%v16,%v18 /* Find c. */ + jno .Lfound48 /* Jump away if c was found. */ + vl %v16,32(%r4,%r2) + vfeebs %v17,%v16,%v18 + jno .Lfound32 + vl %v16,16(%r4,%r2) + vfeebs %v17,%v16,%v18 + jno .Lfound16 + vl %v16,0(%r4,%r2) + vfeebs %v17,%v16,%v18 + jno .Lfound0 + + clgijhe %r4,64,.Lloop64 /* If n >= 64 -> loop64. */ + j .Llt64 +END(__memrchr_vx) +#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */ |