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125 lines
3.6 KiB
C
125 lines
3.6 KiB
C
/* string-fzc.h -- zero byte detection with indexes. HPPA version.
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Copyright (C) 2023-2024 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _STRING_FZC_H
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#define _STRING_FZC_H 1
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#include <string-optype.h>
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_Static_assert (sizeof (op_t) == 4, "64-bit not supported");
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/* Given a word X that is known to contain a zero byte, return the
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index of the first such within the long in memory order. */
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static __always_inline unsigned int
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index_first_zero (op_t x)
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{
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unsigned int ret;
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/* Since we have no clz insn, direct tests of the bytes is faster
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than loading up the constants to do the masking. */
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asm ("extrw,u,<> %1,23,8,%%r0\n\t"
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"ldi 2,%0\n\t"
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"extrw,u,<> %1,15,8,%%r0\n\t"
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"ldi 1,%0\n\t"
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"extrw,u,<> %1,7,8,%%r0\n\t"
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"ldi 0,%0"
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: "=r"(ret) : "r"(x), "0"(3));
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return ret;
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}
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/* Similarly, but perform the search for byte equality between X1 and X2. */
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static __always_inline unsigned int
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index_first_eq (op_t x1, op_t x2)
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{
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return index_first_zero (x1 ^ x2);
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}
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/* Similarly, but perform the search for zero within X1 or
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equality between X1 and X2. */
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static __always_inline unsigned int
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index_first_zero_eq (op_t x1, op_t x2)
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{
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unsigned int ret;
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/* Since we have no clz insn, direct tests of the bytes is faster
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than loading up the constants to do the masking. */
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asm ("extrw,u,= %1,23,8,%%r0\n\t"
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"extrw,u,<> %2,23,8,%%r0\n\t"
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"ldi 2,%0\n\t"
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"extrw,u,= %1,15,8,%%r0\n\t"
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"extrw,u,<> %2,15,8,%%r0\n\t"
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"ldi 1,%0\n\t"
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"extrw,u,= %1,7,8,%%r0\n\t"
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"extrw,u,<> %2,7,8,%%r0\n\t"
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"ldi 0,%0"
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: "=r"(ret) : "r"(x1), "r"(x1 ^ x2), "0"(3));
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return ret;
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}
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/* Similarly, but perform the search for zero within X1 or
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inequality between X1 and X2. */
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static __always_inline unsigned int
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index_first_zero_ne (op_t x1, op_t x2)
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{
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unsigned int ret;
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/* Since we have no clz insn, direct tests of the bytes is faster
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than loading up the constants to do the masking. */
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asm ("extrw,u,<> %2,23,8,%%r0\n\t"
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"extrw,u,<> %1,23,8,%%r0\n\t"
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"ldi 2,%0\n\t"
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"extrw,u,<> %2,15,8,%%r0\n\t"
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"extrw,u,<> %1,15,8,%%r0\n\t"
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"ldi 1,%0\n\t"
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"extrw,u,<> %2,7,8,%%r0\n\t"
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"extrw,u,<> %1,7,8,%%r0\n\t"
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"ldi 0,%0"
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: "=r"(ret) : "r"(x1), "r"(x1 ^ x2), "0"(3));
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return ret;
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}
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/* Similarly, but search for the last zero within X. */
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static __always_inline unsigned int
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index_last_zero (op_t x)
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{
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unsigned int ret;
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/* Since we have no ctz insn, direct tests of the bytes is faster
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than loading up the constants to do the masking. */
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asm ("extrw,u,<> %1,15,8,%%r0\n\t"
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"ldi 1,%0\n\t"
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"extrw,u,<> %1,23,8,%%r0\n\t"
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"ldi 2,%0\n\t"
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"extrw,u,<> %1,31,8,%%r0\n\t"
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"ldi 3,%0"
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: "=r"(ret) : "r"(x), "0"(0));
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return ret;
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}
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static __always_inline unsigned int
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index_last_eq (op_t x1, op_t x2)
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{
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return index_last_zero (x1 ^ x2);
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}
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#endif /* _STRING_FZC_H */
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