diff options
Diffstat (limited to 'libc/string/sparc/sparc32/strcmp.S')
| -rw-r--r-- | libc/string/sparc/sparc32/strcmp.S | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/libc/string/sparc/sparc32/strcmp.S b/libc/string/sparc/sparc32/strcmp.S new file mode 100644 index 000000000..d6cf9e7d3 --- /dev/null +++ b/libc/string/sparc/sparc32/strcmp.S @@ -0,0 +1,255 @@ +/* Compare two strings for differences. + For SPARC v7. + Copyright (C) 1996, 97, 99, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by 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. */ + + /* Normally, this uses ((xword - 0x01010101) & 0x80808080) 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 - 0x01010101) & (~xword) & 0x80808080), + 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 4 +10: ldub [%o0], %o4 + add %o0, 1, %o0 + ldub [%o1], %o5 + cmp %o4, 0 + add %o1, 1, %o1 + be 2f + subcc %o4, %o5, %o4 + bne 2f + andcc %o0, 3, %g0 + be 4f + or %g1, %lo(0x80808080), %o3 + ldub [%o0], %o4 + add %o0, 1, %o0 + ldub [%o1], %o5 + cmp %o4, 0 + add %o1, 1, %o1 + be 2f + subcc %o4, %o5, %o4 + bne 2f + andcc %o0, 3, %g0 + be 5f + sethi %hi(0x01010101), %g1 + ldub [%o0], %o4 + add %o0, 1, %o0 + ldub [%o1], %o5 + cmp %o4, 0 + add %o1, 1, %o1 + be 2f + subcc %o4, %o5, %o4 + bne 2f + andcc %o1, 3, %g2 + bne 12f + or %g1, %lo(0x01010101), %o2 + b 1f + ld [%o0], %o4 +2: retl + mov %o4, %o0 + +ENTRY(strcmp) + andcc %o0, 3, %g0 + bne 10b + sethi %hi(0x80808080), %g1 + or %g1, %lo(0x80808080), %o3 +4: sethi %hi(0x01010101), %g1 +5: andcc %o1, 3, %g2 + bne 12f + or %g1, %lo(0x01010101), %o2 + +0: ld [%o0], %o4 +1: ld [%o1], %o5 + sub %o4, %o2, %g1 + add %o0, 4, %o0 + cmp %o4, %o5 +#ifdef EIGHTBIT_NOT_RARE + andn %g1, %o4, %g1 +#endif + bne 11f + andcc %g1, %o3, %g0 + be 0b + add %o1, 4, %o1 + + srl %o4, 24, %g4 + andcc %g4, 0xff, %g0 + be 2f + srl %o4, 16, %g4 + andcc %g4, 0xff, %g0 + be 2f + srl %o4, 8, %g4 + andcc %g4, 0xff, %g0 + be 2f + andcc %o4, 0xff, %g0 + bne,a 1b + ld [%o0], %o4 +2: retl + clr %o0 + +11: srl %o4, 24, %g4 + srl %o5, 24, %g5 + andcc %g4, 0xff, %g0 + be 3f + subcc %g4, %g5, %g4 + bne 3f + srl %o5, 16, %g5 + srl %o4, 16, %g4 + andcc %g4, 0xff, %g0 + be 3f + subcc %g4, %g5, %g4 + bne 3f + srl %o5, 8, %g5 + srl %o4, 8, %g4 + andcc %g4, 0xff, %g0 + be 3f + subcc %g4, %g5, %g4 + bne 3f + subcc %o4, %o5, %o4 + retl + mov %o4, %o0 +3: retl + mov %g4, %o0 + +12: save %sp, -64, %sp + ld [%i0], %i4 + sll %g2, 3, %g3 + andn %i1, 3, %i1 + mov 32, %l1 + ld [%i1], %l2 + mov -1, %g6 + add %i1, 4, %i1 + sub %l1, %g3, %l1 + sll %g6, %g3, %g6 + +1: sll %l2, %g3, %g5 + and %i4, %g6, %l3 + sub %i4, %i2, %g1 +#ifdef EIGHTBIT_NOT_RARE + andn %g1, %i4, %g1 +#endif + andcc %g1, %i3, %g1 + bne 3f + cmp %g5, %l3 + bne 2f + add %i0, 4, %i0 + ld [%i1], %l2 + add %i1, 4, %i1 + srl %l2, %l1, %l4 + or %l4, %g5, %l4 + cmp %l4, %i4 + be,a 1b + ld [%i0], %i4 + restore %l4, %g0, %o3 + retl + sub %o4, %o3, %o0 + +2: sll %l2, %g3, %i2 + srl %i4, %g3, %i3 + srl %i2, %g3, %i2 + restore + retl + sub %o3, %o2, %o0 + +3: srl %i4, 24, %g4 + srl %g5, 24, %l6 + andcc %g4, 0xff, %g0 + be 4f + subcc %g4, %l6, %g4 + bne 4f + cmp %g2, 3 + be 6f + srl %i4, 16, %g4 + srl %g5, 16, %l6 + andcc %g4, 0xff, %g0 + be 4f + subcc %g4, %l6, %g4 + bne 4f + cmp %g2, 2 + be 5f + srl %i4, 8, %g4 + srl %g5, 8, %l6 + andcc %g4, 0xff, %g0 + be 4f + subcc %g4, %l6, %g4 + bne 4f + add %i0, 4, %i0 + ld [%i1], %l2 + add %i1, 4, %i1 + srl %l2, 24, %g5 + andcc %i4, 0xff, %g4 + be 4f + subcc %g4, %g5, %g4 + be,a 1b + ld [%i0], %i4 +4: jmpl %i7 + 8, %g0 + restore %g4, %g0, %o0 + +5: ld [%i1], %l2 + add %i1, 4, %i1 + add %i0, 4, %i0 + srl %l2, 24, %l6 + andcc %g4, 0xff, %g4 + be 4b + subcc %g4, %l6, %g4 + bne 4b + srl %l2, 16, %l6 + andcc %i4, 0xff, %g4 + and %l6, 0xff, %l6 + be 4b + subcc %g4, %l6, %g4 + be,a 1b + ld [%i0], %i4 + jmpl %i7 + 8, %g0 + restore %g4, %g0, %o0 + +6: ld [%i1], %l2 + add %i1, 4, %i1 + add %i0, 4, %i0 + srl %l2, 24, %l6 + andcc %g4, 0xff, %g4 + be 4b + subcc %g4, %l6, %g4 + bne 4b + srl %l2, 16, %l6 + srl %i4, 8, %g4 + and %l6, 0xff, %l6 + andcc %g4, 0xff, %g4 + be 4b + subcc %g4, %l6, %g4 + bne 4b + srl %l2, 8, %l6 + andcc %i4, 0xff, %g4 + and %l6, 0xff, %l6 + be 4b + subcc %g4, %l6, %g4 + be,a 1b + ld [%i0], %i4 + jmpl %i7 + 8, %g0 + restore %g4, %g0, %o0 +END(strcmp) |