diff options
Diffstat (limited to 'sysdeps/s390/multiarch/strlen-vx.S')
| -rw-r--r-- | sysdeps/s390/multiarch/strlen-vx.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/sysdeps/s390/multiarch/strlen-vx.S b/sysdeps/s390/multiarch/strlen-vx.S new file mode 100644 index 0000000000..83f360f505 --- /dev/null +++ b/sysdeps/s390/multiarch/strlen-vx.S @@ -0,0 +1,84 @@ +/* Vector optimized 32/64 bit S/390 version of strlen. + Copyright (C) 2015 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 + +/* size_t strlen (const char *s) + Returns length of string s. + + Register usage: + -r1=bytes to 4k-byte boundary + -r2=s + -r3=tmp + -r4=tmp + -r5=current_len and return_value + -v16=part of s +*/ +ENTRY(__strlen_vx) + .machine "z13" + .machinemode "zarch_nohighgprs" + + vlbb %v16,0(%r2),6 /* Load s until next 4k-byte boundary. */ + lcbb %r1,0(%r2),6 /* Get bytes to 4k-byte boundary or 16. */ + + vfenezb %v16,%v16,%v16 /* Find element not equal with zero search. */ + vlgvb %r4,%v16,7 /* Load zero index or 16 if not found. */ + clr %r4,%r1 /* If found zero within loaded bytes? */ + locgrl %r2,%r4 /* Then copy return value. */ + blr %r14 /* And return. */ + + /* Align s to 16 byte. */ + risbgn %r3,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */ + lghi %r5,16 /* current_len = 16. */ + slr %r5,%r3 /* Compute bytes to 16bytes boundary. */ + + /* Find zero in 16 byte aligned loop. */ +.Lloop: + vl %v16,0(%r5,%r2) /* Load s. */ + vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search. */ + je .Lfound /* Jump away if zero was found. */ + vl %v16,16(%r5,%r2) + vfenezbs %v16,%v16,%v16 + je .Lfound16 + vl %v16,32(%r5,%r2) + vfenezbs %v16,%v16,%v16 + je .Lfound32 + vl %v16,48(%r5,%r2) + vfenezbs %v16,%v16,%v16 + je .Lfound48 + + aghi %r5,64 + j .Lloop /* No zero found -> loop. */ + +.Lfound48: + aghi %r5,16 +.Lfound32: + aghi %r5,16 +.Lfound16: + aghi %r5,16 +.Lfound: + vlgvb %r2,%v16,7 /* Load byte index of zero. */ + algr %r2,%r5 + br %r14 +END(__strlen_vx) +#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */ |