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From: Adhemerval Zanella <azanella@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/azanella/generic-strings] hppa: Add string-fzb.h and string-fzi.h Date: Fri, 13 Jan 2023 20:03:35 +0000 (GMT) [thread overview] Message-ID: <20230113200335.7BBF138493CA@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=bd1edea1835fb2ae0d9925019818b8bc05517209 commit bd1edea1835fb2ae0d9925019818b8bc05517209 Author: Richard Henderson <richard.henderson@linaro.org> Date: Tue Jan 10 18:01:02 2023 -0300 hppa: Add string-fzb.h and string-fzi.h Use UXOR,SBZ to test for a zero byte within a word. While we can get semi-decent code out of asm-goto, we would do slightly better with a compiler builtin. For index_zero et al, sequential testing of bytes is less expensive than any tricks that involve a count-leading-zeros insn that we don't have. Checked on hppa-linux-gnu. Diff: --- sysdeps/hppa/string-fzb.h | 70 ++++++++++++++++++++++++++ sysdeps/hppa/string-fzc.h | 124 ++++++++++++++++++++++++++++++++++++++++++++++ sysdeps/hppa/string-fzi.h | 63 +++++++++++++++++++++++ 3 files changed, 257 insertions(+) diff --git a/sysdeps/hppa/string-fzb.h b/sysdeps/hppa/string-fzb.h new file mode 100644 index 0000000000..865e548492 --- /dev/null +++ b/sysdeps/hppa/string-fzb.h @@ -0,0 +1,70 @@ +/* Zero byte detection, boolean. 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_FZB_H +#define _STRING_FZB_H 1 + +#include <sys/cdefs.h> +#include <string-optype.h> + +/* Determine if any byte within X is zero. This is a pure boolean test. */ + +static __always_inline _Bool +has_zero (op_t x) +{ + _Static_assert (sizeof (op_t) == 4, "64-bit not supported"); + + /* It's more useful to expose a control transfer to the compiler + than to expose a proper boolean result. */ + asm goto ("uxor,sbz %%r0,%0,%%r0\n\t" + "b,n %l1" : : "r"(x) : : nbz); + return 1; + nbz: + return 0; +} + +/* Likewise, but for byte equality between X1 and X2. */ + +static __always_inline _Bool +has_eq (op_t x1, op_t x2) +{ + _Static_assert (sizeof (op_t) == 4, "64-bit not supported"); + + asm goto ("uxor,sbz %0,%1,%%r0\n\t" + "b,n %l2" : : "r"(x1), "r"(x2) : : nbz); + return 1; + nbz: + return 0; +} + +/* Likewise, but for zeros in X1 and equal bytes between X1 and X2. */ + +static __always_inline _Bool +has_zero_eq (op_t x1, op_t x2) +{ + _Static_assert (sizeof (op_t) == 4, "64-bit not supported"); + + asm goto ("uxor,sbz %%r0,%0,%%r0\n\t" + "uxor,nbz %0,%1,%%r0\n\t" + "b,n %l2" : : "r"(x1), "r"(x2) : : sbz); + return 0; + sbz: + return 1; +} + +#endif /* _STRING_FZB_H */ diff --git a/sysdeps/hppa/string-fzc.h b/sysdeps/hppa/string-fzc.h new file mode 100644 index 0000000000..8ff3416b41 --- /dev/null +++ b/sysdeps/hppa/string-fzc.h @@ -0,0 +1,124 @@ +/* string-fzc.h -- zero byte detection with indexes. HPPA version. + Copyright (C) 2022 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 */ diff --git a/sysdeps/hppa/string-fzi.h b/sysdeps/hppa/string-fzi.h new file mode 100644 index 0000000000..b560fa1a89 --- /dev/null +++ b/sysdeps/hppa/string-fzi.h @@ -0,0 +1,63 @@ +/* string-fzi.h -- zero byte indexes. HPPA version. + Copyright (C) 2022 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_FZI_H +#define _STRING_FZI_H 1 + +#include <string-optype.h> +#include <string-fza.h> + +_Static_assert (sizeof (op_t) == 4, "64-bit not supported"); + +static __always_inline unsigned int +index_first (find_t c) +{ + 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"(c), "0"(3)); + + return ret; +} + +static __always_inline unsigned int +index_last (find_t c) +{ + 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"(c), "0"(0)); + + return ret; +} + +#endif /* _STRING_FZI_H */
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