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Diffstat (limited to 'REORG.TODO/sysdeps/sparc/sparc64/strcmp.S')
| -rw-r--r-- | REORG.TODO/sysdeps/sparc/sparc64/strcmp.S | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/sparc/sparc64/strcmp.S b/REORG.TODO/sysdeps/sparc/sparc64/strcmp.S new file mode 100644 index 0000000000..d4b0a22f18 --- /dev/null +++ b/REORG.TODO/sysdeps/sparc/sparc64/strcmp.S @@ -0,0 +1,232 @@ +/* Compare two strings for differences. + For SPARC v9. + Copyright (C) 2011-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + 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 + 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/>. */ + +#include <sysdep.h> +#include <asm/asi.h> + +#ifndef XCC + .register %g2, #scratch + .register %g3, #scratch + .register %g6, #scratch +#endif + +#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 +ENTRY(strcmp) + 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 + + /* In order not to be influenced by bytes after the zero byte, we + * have to retain only the highest bit in the mask for the comparison + * with rSTRXOR to work properly. + */ + mov 0, rTMP2 + andcc rTMP1, 0x0100, %g0 + + movne %xcc, 8, rTMP2 + sllx rTMP1, 63 - 16, %o1 + + movrlz %o1, 16, rTMP2 + sllx rTMP1, 63 - 24, %o1 + + movrlz %o1, 24, rTMP2 + sllx rTMP1, 63 - 32, %o1 + + movrlz %o1, 32, rTMP2 + sllx rTMP1, 63 - 40, %o1 + + movrlz %o1, 40, rTMP2 + sllx rTMP1, 63 - 48, %o1 + + movrlz %o1, 48, rTMP2 + sllx rTMP1, 63 - 56, %o1 + + movrlz %o1, 56, rTMP2 + + srlx rTMP1, rTMP2, rTMP1 + + sllx rTMP1, rTMP2, 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) |