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author | David S. Miller <davem@davemloft.net> | 2010-03-09 06:42:53 -0800 |
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committer | David S. Miller <davem@davemloft.net> | 2010-03-09 06:42:53 -0800 |
commit | 462a5227b0d3220ab68f65272bd5b9d6d4f49b1f (patch) | |
tree | c294d0568ec8d2d65520227423def46b215ab297 /sysdeps/sparc/sparc64/strlen.S | |
parent | 2fe000dfd673859eb3b1e1c9739de66445d9fe08 (diff) | |
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sparc: Optimize strlen using techniques from powerpc implementation.
Diffstat (limited to 'sysdeps/sparc/sparc64/strlen.S')
-rw-r--r-- | sysdeps/sparc/sparc64/strlen.S | 210 |
1 files changed, 61 insertions, 149 deletions
diff --git a/sysdeps/sparc/sparc64/strlen.S b/sysdeps/sparc/sparc64/strlen.S index cc15e4e3fb..64350fb05e 100644 --- a/sysdeps/sparc/sparc64/strlen.S +++ b/sysdeps/sparc/sparc64/strlen.S @@ -1,8 +1,9 @@ /* Determine the length of a string. For SPARC v9. - Copyright (C) 1998, 1999, 2003 Free Software Foundation, Inc. + Copyright (C) 1998, 1999, 2003, 2010 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>. + Contributed by Jan Vondrak <jvon4518@ss1000.ms.mff.cuni.cz>, + Jakub Jelinek <jj@ultra.linux.cz>, and + David S. Miller <davem@davemloft.net>. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public @@ -20,155 +21,66 @@ 02111-1307 USA. */ #include <sysdep.h> -#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. - */ + + .register %g2, #scratch + .register %g3, #scratch .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 */ + mov %o0, %o1 + andn %o0, 0x7, %o0 + + ldx [%o0], %o5 + and %o1, 0x7, %g1 + mov -1, %g5 + + sethi %hi(0x01010101), %o2 + sll %g1, 3, %g1 + + or %o2, %lo(0x01010101), %o2 + srlx %g5, %g1, %o3 + + sllx %o2, 32, %g1 + sethi %hi(0x0000ff00), %g5 + + orn %o5, %o3, %o5 + or %o2, %g1, %o2 + + sllx %o2, 7, %o3 +10: add %o0, 8, %o0 + + andn %o3, %o5, %g1 + sub %o5, %o2, %g2 + + andcc %g1, %g2, %g0 + be,a,pt %xcc, 10b + ldx [%o0], %o5 + srlx %o5, 32, %g1 + + andn %o3, %g1, %o4 + sub %g1, %o2, %g2 + + add %o0, 4, %g3 + andcc %o4, %g2, %g0 + movne %icc, %g1, %o5 + + move %icc, %g3, %o0 + or %g5, %lo(0x0000ff00), %g5 + mov 3 - 8, %g2 + + andcc %o5, %g5, %g0 + srlx %o5, 16, %g1 + move %icc, 2 - 8, %g2 + + andcc %g1, 0xff, %g0 + srl %o5, 24, %o5 + move %icc, 1 - 8, %g2 + + movrz %o5, 0 - 8, %g2 + sub %o0, %o1, %o0 + + retl + add %o0, %g2, %o0 END(strlen) libc_hidden_builtin_def (strlen) |