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/* string-fzc.h -- zero byte detection with indexes. HPPA version.
Copyright (C) 2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#ifndef _STRING_FZC_H
#define _STRING_FZC_H 1
#include <string-optype.h>
_Static_assert (sizeof (op_t) == 4, "64-bit not supported");
/* Given a word X that is known to contain a zero byte, return the
index of the first such within the long in memory order. */
static __always_inline unsigned int
index_first_zero (op_t x)
{
unsigned int ret;
/* Since we have no clz insn, direct tests of the bytes is faster
than loading up the constants to do the masking. */
asm ("extrw,u,<> %1,23,8,%%r0\n\t"
"ldi 2,%0\n\t"
"extrw,u,<> %1,15,8,%%r0\n\t"
"ldi 1,%0\n\t"
"extrw,u,<> %1,7,8,%%r0\n\t"
"ldi 0,%0"
: "=r"(ret) : "r"(x), "0"(3));
return ret;
}
/* Similarly, but perform the search for byte equality between X1 and X2. */
static __always_inline unsigned int
index_first_eq (op_t x1, op_t x2)
{
return index_first_zero (x1 ^ x2);
}
/* Similarly, but perform the search for zero within X1 or
equality between X1 and X2. */
static __always_inline unsigned int
index_first_zero_eq (op_t x1, op_t x2)
{
unsigned int ret;
/* Since we have no clz insn, direct tests of the bytes is faster
than loading up the constants to do the masking. */
asm ("extrw,u,= %1,23,8,%%r0\n\t"
"extrw,u,<> %2,23,8,%%r0\n\t"
"ldi 2,%0\n\t"
"extrw,u,= %1,15,8,%%r0\n\t"
"extrw,u,<> %2,15,8,%%r0\n\t"
"ldi 1,%0\n\t"
"extrw,u,= %1,7,8,%%r0\n\t"
"extrw,u,<> %2,7,8,%%r0\n\t"
"ldi 0,%0"
: "=r"(ret) : "r"(x1), "r"(x1 ^ x2), "0"(3));
return ret;
}
/* Similarly, but perform the search for zero within X1 or
inequality between X1 and X2. */
static __always_inline unsigned int
index_first_zero_ne (op_t x1, op_t x2)
{
unsigned int ret;
/* Since we have no clz insn, direct tests of the bytes is faster
than loading up the constants to do the masking. */
asm ("extrw,u,<> %2,23,8,%%r0\n\t"
"extrw,u,<> %1,23,8,%%r0\n\t"
"ldi 2,%0\n\t"
"extrw,u,<> %2,15,8,%%r0\n\t"
"extrw,u,<> %1,15,8,%%r0\n\t"
"ldi 1,%0\n\t"
"extrw,u,<> %2,7,8,%%r0\n\t"
"extrw,u,<> %1,7,8,%%r0\n\t"
"ldi 0,%0"
: "=r"(ret) : "r"(x1), "r"(x1 ^ x2), "0"(3));
return ret;
}
/* Similarly, but search for the last zero within X. */
static __always_inline unsigned int
index_last_zero (op_t x)
{
unsigned int ret;
/* Since we have no ctz insn, direct tests of the bytes is faster
than loading up the constants to do the masking. */
asm ("extrw,u,<> %1,15,8,%%r0\n\t"
"ldi 1,%0\n\t"
"extrw,u,<> %1,23,8,%%r0\n\t"
"ldi 2,%0\n\t"
"extrw,u,<> %1,31,8,%%r0\n\t"
"ldi 3,%0"
: "=r"(ret) : "r"(x), "0"(0));
return ret;
}
static __always_inline unsigned int
index_last_eq (op_t x1, op_t x2)
{
return index_last_zero (x1 ^ x2);
}
#endif /* _STRING_FZC_H */
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