diff options
Diffstat (limited to 'libc/string/sparc/sparc64/strlen.S')
| -rw-r--r-- | libc/string/sparc/sparc64/strlen.S | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/libc/string/sparc/sparc64/strlen.S b/libc/string/sparc/sparc64/strlen.S new file mode 100644 index 000000000..5167ad5ba --- /dev/null +++ b/libc/string/sparc/sparc64/strlen.S @@ -0,0 +1,172 @@ +/* Determine the length of a string. For SPARC v9. + Copyright (C) 1998, 1999, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jan Vondrak <jvon4518@ss1000.ms.mff.cuni.cz> and + Jakub Jelinek <jj@ultra.linux.cz>. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <asm/asi.h> + + /* Normally, this uses + ((xword - 0x0101010101010101) & 0x8080808080808080) test + to find out if any byte in xword could be zero. This is fast, but + also gives false alarm for any byte in range 0x81-0xff. It does + not matter for correctness, as if this test tells us there could + be some zero byte, we check it byte by byte, but if bytes with + high bits set are common in the strings, then this will give poor + performance. You can #define EIGHTBIT_NOT_RARE and the algorithm + will use one tick slower, but more precise test + ((xword - 0x0101010101010101) & (~xword) & 0x8080808080808080), + which does not give any false alarms (but if some bits are set, + one cannot assume from it which bytes are zero and which are not). + It is yet to be measured, what is the correct default for glibc + in these days for an average user. + */ + + .text + .align 32 +ENTRY(strlen) + sethi %hi(0x01010101), %g1 /* IEU0 Group */ + ldub [%o0], %o3 /* Load */ + or %g1, %lo(0x01010101), %g1 /* IEU0 Group */ + mov %o0, %o1 /* IEU1 */ + + sllx %g1, 32, %g4 /* IEU0 Group */ + andcc %o0, 7, %g0 /* IEU1 */ + or %g1, %g4, %g1 /* IEU0 Group */ + brz,pn %o3, 13f /* CTI+IEU1 */ + + sllx %g1, 7, %g4 /* IEU0 Group */ + bne,a,pn %icc, 15f /* CTI */ + add %o0, 1, %o0 /* IEU1 */ + /* %g1 = 0x0101010101010101 * + * %g4 = 0x8080808080808080 * + * %o0 = string pointer * + * %o1 = start of string */ +1: ldx [%o0], %o3 /* Load Group */ + + add %o0, 8, %o0 /* IEU1 */ +2: sub %o3, %g1, %o2 /* IEU0 Group */ +#ifdef EIGHTBIT_NOT_RARE + andn %o2, %o3, %o5 /* IEU0 Group */ + ldxa [%o0] ASI_PNF, %o3 /* Load */ + andcc %o5, %g4, %g0 /* IEU1 Group */ +#else + ldxa [%o0] ASI_PNF, %o3 /* Load */ + andcc %o2, %g4, %g0 /* IEU1 Group */ +#endif + + be,pt %xcc, 2b /* CTI */ + add %o0, 8, %o0 /* IEU0 */ + addcc %o2, %g1, %g5 /* IEU1 Group */ +#ifdef EIGHTBIT_NOT_RARE + srlx %o5, 32, %o5 /* IEU0 */ + +3: andcc %o5, %g4, %g0 /* IEU1 Group */ +#else + srlx %o2, 32, %o2 /* IEU0 */ + +3: andcc %o2, %g4, %g0 /* IEU1 Group */ +#endif + be,pn %xcc, 4f /* CTI */ + srlx %g5, 56, %o2 /* IEU0 */ + andcc %o2, 0xff, %g0 /* IEU1 Group */ + + be,pn %icc, 12f /* CTI */ + srlx %g5, 48, %o2 /* IEU0 */ + andcc %o2, 0xff, %g0 /* IEU1 Group */ + be,pn %icc, 11f /* CTI */ + + srlx %g5, 40, %o2 /* IEU0 */ + andcc %o2, 0xff, %g0 /* IEU1 Group */ + be,pn %icc, 10f /* CTI */ + srlx %g5, 32, %o2 /* IEU0 */ + + andcc %o2, 0xff, %g0 /* IEU1 Group */ + be,pn %icc, 9f /* CTI */ +4: srlx %g5, 24, %o2 /* IEU0 */ + andcc %o2, 0xff, %g0 /* IEU1 Group */ + + be,pn %icc, 8f /* CTI */ + srlx %g5, 16, %o2 /* IEU0 */ + andcc %o2, 0xff, %g0 /* IEU1 Group */ + be,pn %icc, 7f /* CTI */ + + srlx %g5, 8, %o2 /* IEU0 */ + andcc %o2, 0xff, %g0 /* IEU1 Group */ + be,pn %icc, 6f /* CTI */ + sub %o3, %g1, %o2 /* IEU0 */ + + andcc %g5, 0xff, %g0 /* IEU1 Group */ + be,pn %icc, 5f /* CTI */ + ldxa [%o0] ASI_PNF, %o3 /* Load */ + andcc %o2, %g4, %g0 /* IEU1 Group */ + + be,pt %xcc, 2b /* CTI */ + add %o0, 8, %o0 /* IEU0 */ + addcc %o2, %g1, %g5 /* IEU1 Group */ + ba,pt %xcc, 3b /* CTI */ + + srlx %o2, 32, %o2 /* IEU0 */ +5: add %o0, -9, %o0 /* IEU0 Group */ + retl /* CTI+IEU1 Group */ + sub %o0, %o1, %o0 /* IEU0 */ + +6: add %o0, -10, %o0 /* IEU0 Group */ + retl /* CTI+IEU1 Group */ + sub %o0, %o1, %o0 /* IEU0 */ +7: add %o0, -11, %o0 /* IEU0 Group */ + + retl /* CTI+IEU1 Group */ + sub %o0, %o1, %o0 /* IEU0 */ +8: add %o0, -12, %o0 /* IEU0 Group */ + retl /* CTI+IEU1 Group */ + + sub %o0, %o1, %o0 /* IEU0 */ +9: add %o0, -13, %o0 /* IEU0 Group */ + retl /* CTI+IEU1 Group */ + sub %o0, %o1, %o0 /* IEU0 */ + +10: add %o0, -14, %o0 /* IEU0 Group */ + retl /* CTI+IEU1 Group */ + sub %o0, %o1, %o0 /* IEU0 */ +11: add %o0, -15, %o0 /* IEU0 Group */ + + retl /* CTI+IEU1 Group */ + sub %o0, %o1, %o0 /* IEU0 */ +12: add %o0, -16, %o0 /* IEU0 Group */ + retl /* CTI+IEU1 Group */ + + sub %o0, %o1, %o0 /* IEU0 */ +13: retl /* CTI+IEU1 Group */ + mov 0, %o0 /* IEU0 */ + nop + +15: ldub [%o0], %o3 /* Load Group */ +16: andcc %o0, 7, %g0 /* IEU1 */ + be,pn %icc, 1b /* CTI */ + nop /* IEU0 Group */ + + add %o0, 1, %o0 /* IEU1 */ + andcc %o3, 0xff, %g0 /* IEU1 Group */ + bne,a,pt %icc, 16b /* CTI */ + lduba [%o0] ASI_PNF, %o3 /* Load */ + + add %o0, -1, %o0 /* IEU0 Group */ + retl /* CTI+IEU1 Group */ + sub %o0, %o1, %o0 /* IEU0 */ +END(strlen) |