diff options
Diffstat (limited to 'libc/sysdeps/sparc/sparc64/strcmp.S')
| -rw-r--r-- | libc/sysdeps/sparc/sparc64/strcmp.S | 416 |
1 files changed, 169 insertions, 247 deletions
diff --git a/libc/sysdeps/sparc/sparc64/strcmp.S b/libc/sysdeps/sparc/sparc64/strcmp.S index fade4c4cb..263bb40a2 100644 --- a/libc/sysdeps/sparc/sparc64/strcmp.S +++ b/libc/sysdeps/sparc/sparc64/strcmp.S @@ -1,9 +1,8 @@ /* Compare two strings for differences. For SPARC v9. - Copyright (C) 1997, 1999, 2003 Free Software Foundation, Inc. + Copyright (C) 2011 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 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 @@ -22,259 +21,182 @@ #include <sysdep.h> #include <asm/asi.h> + #ifndef XCC .register %g2, #scratch .register %g3, #scratch .register %g6, #scratch #endif - /* 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. +#define rSTR1 %o0 +#define rSTR2 %o1 +#define r0101 %o2 /* 0x0101010101010101 */ +#define r8080 %o3 /* 0x8080808080808080 */ +#define rSTRXOR %o4 +#define rWORD1 %o5 +#define rTMP1 %g1 +#define rTMP2 %g2 +#define rWORD2 %g3 +#define rSLL %g4 +#define rSRL %g5 +#define rBARREL %g6 + + /* There are two cases, either the two pointers are aligned + * identically or they are not. If they have the same + * alignment we can use the normal full speed loop. Otherwise + * we have to use the barrel-shifter version. */ .text - .align 32 + .align 32 ENTRY(strcmp) - sethi %hi(0x01010101), %g1 /* IEU0 Group */ - andcc %o0, 7, %g0 /* IEU1 */ - bne,pn %icc, 7f /* CTI */ - or %g1, %lo(0x01010101), %g1 /* IEU0 Group */ - - andcc %o1, 7, %g3 /* IEU1 */ - bne,pn %icc, 9f /* CTI */ - sllx %g1, 32, %g2 /* IEU0 Group */ - ldx [%o0], %o2 /* Load */ - - or %g1, %g2, %g1 /* IEU0 Group */ -1: ldx [%o1], %o3 /* Load */ - sub %o1, %o0, %o1 /* IEU1 */ - sllx %g1, 7, %g2 /* IEU0 Group */ - -2: add %o0, 8, %o0 /* IEU1 */ - sub %o2, %g1, %g3 /* IEU0 Group */ - subcc %o2, %o3, %g0 /* IEU1 */ - bne,pn %xcc, 13f /* CTI */ - -#ifdef EIGHTBIT_NOT_RARE - andn %g3, %o2, %g4 /* IEU0 Group */ - ldxa [%o0] ASI_PNF, %o2 /* Load */ - andcc %g4, %g2, %g0 /* IEU1 Group */ -#else - ldxa [%o0] ASI_PNF, %o2 /* Load Group */ - andcc %g3, %g2, %g0 /* IEU1 */ -#endif - be,a,pt %xcc, 2b /* CTI */ - ldxa [%o1 + %o0] ASI_PNF, %o3 /* Load Group */ - - addcc %g3, %g1, %o4 /* IEU1 */ - srlx %g3, 32, %g3 /* IEU0 */ - andcc %g3, %g2, %g0 /* IEU1 Group */ - be,pt %xcc, 3f /* CTI */ - - srlx %o4, 56, %o5 /* IEU0 */ - andcc %o5, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4f /* CTI */ - srlx %o4, 48, %o5 /* IEU0 */ - - andcc %o5, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4f /* CTI */ - srlx %o4, 40, %o5 /* IEU0 */ - andcc %o5, 0xff, %g0 /* IEU1 Group */ - - be,pn %icc, 4f /* CTI */ - srlx %o4, 32, %o5 /* IEU0 */ - andcc %o5, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4f /* CTI */ - -3: srlx %o4, 24, %o5 /* IEU0 */ - andcc %o5, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4f /* CTI */ - srlx %o4, 16, %o5 /* IEU0 */ - - andcc %o5, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4f /* CTI */ - srlx %o4, 8, %o5 /* IEU0 */ - andcc %o5, 0xff, %g0 /* IEU1 Group */ - - be,pn %icc, 4f /* CTI */ - andcc %o4, 0xff, %g0 /* IEU1 Group */ - bne,a,pn %icc, 2b /* CTI */ - ldxa [%o1 + %o0] ASI_PNF, %o3 /* Load */ - -4: retl /* CTI+IEU1 Group */ - clr %o0 /* IEU0 */ - - .align 32 -13: mov 0xff, %g6 /* IEU0 Group */ -#ifdef EIGHTBIT_NOT_RARE - andcc %g4, %g2, %g0 /* IEU1 */ -#else - andcc %g3, %g2, %g0 /* IEU1 */ -#endif - be,pt %xcc, 25f /* CTI */ - addcc %g3, %g1, %o4 /* IEU1 Group */ - - srlx %g3, 32, %g3 /* IEU0 */ - andcc %g3, %g2, %g0 /* IEU1 Group */ - be,pt %xcc, 23f /* CTI */ - sllx %g6, 56, %o5 /* IEU0 */ - - andcc %o4, %o5, %g0 /* IEU1 Group */ - be,pn %xcc, 24f /* CTI */ - sllx %g6, 48, %o5 /* IEU0 */ - andcc %o4, %o5, %g0 /* IEU1 Group */ - - be,pn %xcc, 24f /* CTI */ - sllx %g6, 40, %o5 /* IEU0 */ - andcc %o4, %o5, %g0 /* IEU1 Group */ - be,pn %xcc, 24f /* CTI */ - - sllx %g6, 32, %o5 /* IEU0 */ - andcc %o4, %o5, %g0 /* IEU1 Group */ - be,pn %xcc, 24f /* CTI */ -23: sllx %g6, 24, %o5 /* IEU0 */ - - andcc %o4, %o5, %g0 /* IEU1 Group */ - be,pn %icc, 24f /* CTI */ - sllx %g6, 16, %o5 /* IEU0 */ - andcc %o4, %o5, %g0 /* IEU1 Group */ - - be,pn %icc, 24f /* CTI */ - sllx %g6, 8, %o5 /* IEU0 */ - andcc %o4, %o5, %g0 /* IEU1 Group */ - be,pn %icc, 24f /* CTI */ - - mov %g6, %o5 /* IEU0 */ -25: cmp %o4, %o3 /* IEU1 Group */ -5: mov -1, %o0 /* IEU0 */ - retl /* CTI+IEU1 Group */ - - movgu %xcc, 1, %o0 /* Single Group */ - - .align 16 -24: sub %o5, 1, %g6 /* IEU0 Group */ - clr %o0 /* IEU1 */ - or %o5, %g6, %o5 /* IEU0 Group */ - andn %o4, %o5, %o4 /* IEU0 Group */ - - andn %o3, %o5, %o3 /* IEU1 */ - cmp %o4, %o3 /* IEU1 Group */ - movgu %xcc, 1, %o0 /* Single Group */ - retl /* CTI+IEU1 Group */ - - movlu %xcc, -1, %o0 /* Single Group */ -6: retl /* CTI+IEU1 Group */ - mov %o4, %o0 /* IEU0 */ - - .align 16 -7: ldub [%o0], %o2 /* Load */ - add %o0, 1, %o0 /* IEU1 */ - ldub [%o1], %o3 /* Load Group */ - sllx %g1, 32, %g2 /* IEU0 */ - -8: add %o1, 1, %o1 /* IEU1 */ - subcc %o2, %o3, %o4 /* IEU1 Group */ - bne,pn %xcc, 6b /* CTI */ - lduba [%o0] ASI_PNF, %o2 /* Load */ - - brz,pn %o3, 4b /* CTI+IEU1 Group */ - lduba [%o1] ASI_PNF, %o3 /* Load */ - andcc %o0, 7, %g0 /* IEU1 Group */ - bne,a,pn %icc, 8b /* CTI */ - - add %o0, 1, %o0 /* IEU0 */ - or %g1, %g2, %g1 /* IEU0 Group */ - andcc %o1, 7, %g3 /* IEU1 */ - be,a,pn %icc, 1b /* CTI */ - - ldxa [%o0] ASI_PNF, %o2 /* Load Group */ -9: sllx %g3, 3, %g5 /* IEU0 */ - mov 64, %o5 /* IEU1 */ - sub %o1, %g3, %o1 /* IEU0 Group */ - - sub %o5, %g5, %o5 /* IEU1 */ - ldxa [%o1] ASI_PNF, %g6 /* Load Group */ - or %g1, %g2, %g1 /* IEU0 */ - sub %o1, %o0, %o1 /* IEU1 */ - - sllx %g1, 7, %g2 /* IEU0 Group */ - add %o1, 8, %o1 /* IEU1 */ - /* %g1 = 0101010101010101 - * %g2 = 8080808080800880 - * %g5 = number of bits to shift left - * %o5 = number of bits to shift right */ -10: sllx %g6, %g5, %o3 /* IEU0 Group */ - ldxa [%o1 + %o0] ASI_PNF, %g6 /* Load */ - -11: srlx %g6, %o5, %o4 /* IEU0 Group */ - ldxa [%o0] ASI_PNF, %o2 /* Load */ - or %o3, %o4, %o3 /* IEU1 */ - add %o0, 8, %o0 /* IEU0 Group */ - - subcc %o2, %o3, %g0 /* IEU1 */ -#ifdef EIGHTBIT_NOT_RARE - sub %o2, %g1, %g3 /* IEU0 Group */ - bne,pn %xcc, 13b /* CTI */ - andn %g3, %o2, %g4 /* IEU0 Group */ - - andcc %g4, %g2, %g0 /* IEU1 Group */ - be,pt %xcc, 10b /* CTI */ - srlx %g4, 32, %g4 /* IEU0 */ - andcc %g4, %g2, %g0 /* IEU1 Group */ -#else - bne,pn %xcc, 13b /* CTI */ - sub %o2, %g1, %g3 /* IEU0 Group */ - andcc %g3, %g2, %g0 /* IEU1 Group */ - - be,pt %xcc, 10b /* CTI */ - srlx %g3, 32, %g3 /* IEU0 */ - andcc %g3, %g2, %g0 /* IEU1 Group */ -#endif - be,pt %xcc, 12f /* CTI */ - - srlx %o2, 56, %g3 /* IEU0 */ - andcc %g3, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4b /* CTI */ - srlx %o2, 48, %g3 /* IEU0 */ - - andcc %g3, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4b /* CTI */ - srlx %o2, 40, %g3 /* IEU0 */ - andcc %g3, 0xff, %g0 /* IEU1 Group */ - - be,pn %icc, 4b /* CTI */ - srlx %o2, 32, %g3 /* IEU0 */ - andcc %g3, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4b /* CTI */ - -12: srlx %o2, 24, %g3 /* IEU0 */ - andcc %g3, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4b /* CTI */ - srlx %o2, 16, %g3 /* IEU0 */ - - andcc %g3, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4b /* CTI */ - srlx %o2, 8, %g3 /* IEU0 */ - andcc %g3, 0xff, %g0 /* IEU1 Group */ - - be,pn %icc, 4b /* CTI */ - andcc %o2, 0xff, %g0 /* IEU1 Group */ - be,pn %icc, 4b /* CTI */ - sllx %g6, %g5, %o3 /* IEU0 */ - - ba,pt %xcc, 11b /* CTI Group */ - ldxa [%o1 + %o0] ASI_PNF, %g6 /* Load */ + or rSTR2, rSTR1, rTMP1 + sethi %hi(0x80808080), r8080 + + andcc rTMP1, 0x7, %g0 + bne,pn %icc, .Lmaybe_barrel_shift + or r8080, %lo(0x80808080), r8080 + ldx [rSTR1], rWORD1 + + sub rSTR2, rSTR1, rSTR2 + sllx r8080, 32, rTMP1 + + ldx [rSTR1 + rSTR2], rWORD2 + or r8080, rTMP1, r8080 + + ba,pt %xcc, .Laligned_loop_entry + srlx r8080, 7, r0101 + + .align 32 +.Laligned_loop_entry: +.Laligned_loop: + add rSTR1, 8, rSTR1 + + sub rWORD1, r0101, rTMP2 + xorcc rWORD1, rWORD2, rSTRXOR + bne,pn %xcc, .Lcommon_endstring + + andn r8080, rWORD1, rTMP1 + + ldxa [rSTR1] ASI_PNF, rWORD1 + andcc rTMP1, rTMP2, %g0 + be,a,pt %xcc, .Laligned_loop + + ldxa [rSTR1 + rSTR2] ASI_PNF, rWORD2 + +.Lcommon_equal: + retl + mov 0, %o0 + + /* All loops terminate here once they find an unequal word. + * If a zero byte appears in the word before the first unequal + * byte, we must report zero. Otherwise we report '1' or '-1' + * depending upon whether the first mis-matching byte is larger + * in the first string or the second, respectively. + * + * First we compute a 64-bit mask value that has "0x01" in + * each byte where a zero exists in rWORD1. rSTRXOR holds the + * value (rWORD1 ^ rWORD2). Therefore, if considered as an + * unsigned quantity, our "0x01" mask value is "greater than" + * rSTRXOR then a zero terminating byte comes first and + * therefore we report '0'. + * + * The formula for this mask is: + * + * mask_tmp1 = ~rWORD1 & 0x8080808080808080; + * mask_tmp2 = ((rWORD1 & 0x7f7f7f7f7f7f7f7f) + + * 0x7f7f7f7f7f7f7f7f); + * + * mask = ((mask_tmp1 & ~mask_tmp2) >> 7); + */ +.Lcommon_endstring: + andn rWORD1, r8080, rTMP2 + or r8080, 1, %o1 + + mov 1, %o0 + sub rTMP2, %o1, rTMP2 + + cmp rWORD1, rWORD2 + andn rTMP1, rTMP2, rTMP1 + + movleu %xcc, -1, %o0 + srlx rTMP1, 7, rTMP1 + + cmp rTMP1, rSTRXOR + retl + movgu %xcc, 0, %o0 + +.Lmaybe_barrel_shift: + sub rSTR2, rSTR1, rSTR2 + sllx r8080, 32, rTMP1 + + or r8080, rTMP1, r8080 + and rSTR1, 0x7, rTMP2 + + srlx r8080, 7, r0101 + andn rSTR1, 0x7, rSTR1 + + ldxa [rSTR1] ASI_PNF, rWORD1 + andcc rSTR2, 0x7, rSLL + sll rTMP2, 3, rSTRXOR + + bne,pn %icc, .Lneed_barrel_shift + mov -1, rTMP1 + ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL + + srlx rTMP1, rSTRXOR, rTMP2 + + orn rWORD1, rTMP2, rWORD1 + ba,pt %xcc, .Laligned_loop_entry + orn rBARREL, rTMP2, rWORD2 + +.Lneed_barrel_shift: + sllx rSLL, 3, rSLL + andn rSTR2, 0x7, rSTR2 + + ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL + mov 64, rTMP2 + sub rTMP2, rSLL, rSRL + + srlx rTMP1, rSTRXOR, rTMP1 + add rSTR2, 8, rSTR2 + + orn rWORD1, rTMP1, rWORD1 + sllx rBARREL, rSLL, rWORD2 + ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL + + add rSTR1, 8, rSTR1 + sub rWORD1, r0101, rTMP2 + + srlx rBARREL, rSRL, rSTRXOR + + or rWORD2, rSTRXOR, rWORD2 + + orn rWORD2, rTMP1, rWORD2 + ba,pt %xcc, .Lbarrel_shift_loop_entry + andn r8080, rWORD1, rTMP1 + +.Lbarrel_shift_loop: + sllx rBARREL, rSLL, rWORD2 + ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL + + add rSTR1, 8, rSTR1 + sub rWORD1, r0101, rTMP2 + + srlx rBARREL, rSRL, rSTRXOR + andn r8080, rWORD1, rTMP1 + + or rWORD2, rSTRXOR, rWORD2 + +.Lbarrel_shift_loop_entry: + xorcc rWORD1, rWORD2, rSTRXOR + bne,pn %xcc, .Lcommon_endstring + + andcc rTMP1, rTMP2, %g0 + be,a,pt %xcc, .Lbarrel_shift_loop + ldxa [rSTR1] ASI_PNF, rWORD1 + + retl + mov 0, %o0 END(strcmp) libc_hidden_builtin_def (strcmp) |