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author | Richard Henderson <richard.henderson@linaro.org> | 2023-01-10 18:01:03 -0300 |
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committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-01-13 16:56:49 -0300 |
commit | 27c71d8cfcfb331e9625cbd2047d8da1c8c3009b (patch) | |
tree | e86bf83aeffb1d85dfdd615bfa70facb8003922f | |
parent | bd1edea1835fb2ae0d9925019818b8bc05517209 (diff) | |
download | glibc-27c71d8cfcfb331e9625cbd2047d8da1c8c3009b.tar.gz glibc-27c71d8cfcfb331e9625cbd2047d8da1c8c3009b.tar.xz glibc-27c71d8cfcfb331e9625cbd2047d8da1c8c3009b.zip |
alpha: Add string-fzb.h and string-fzi.h
While alpha has the more important string functions in assembly, there are still a few for find the generic routines are used. Use the CMPBGE insn, via the builtin, for testing of zeros. Use a simplified expansion of __builtin_ctz when the insn isn't available. Checked on alpha-linux-gnu. Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
-rw-r--r-- | sysdeps/alpha/string-fza.h | 77 | ||||
-rw-r--r-- | sysdeps/alpha/string-fzb.h | 52 | ||||
-rw-r--r-- | sysdeps/alpha/string-fzi.h | 62 | ||||
-rw-r--r-- | sysdeps/generic/string-fzi.h | 2 |
4 files changed, 192 insertions, 1 deletions
diff --git a/sysdeps/alpha/string-fza.h b/sysdeps/alpha/string-fza.h new file mode 100644 index 0000000000..97ee578fe3 --- /dev/null +++ b/sysdeps/alpha/string-fza.h @@ -0,0 +1,77 @@ +/* Basic zero byte detection. Generic C 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_FZA_H +#define _STRING_FZA_H 1 + +#include <limits.h> +#include <string-optype.h> +#include <string-maskoff.h> + +/* The CMPBGE instruction creates a bit mask rather than a byte mask. + However, if we narrow find_t to either 'int' or 'uint8_t', we get + unnecessary truncation instructions from the 'unsigned long' type + returned by __builtin_alpha_cmpbge. */ +typedef op_t find_t; + +/* Return the mask WORD shifted based on S_INT address value, to ignore + values not presented in the aligned word read. */ +static __always_inline find_t +shift_find (find_t word, uintptr_t s) +{ + return word >> (s % sizeof (op_t)); +} + +static __always_inline find_t +shift_find_last (find_t word, uintptr_t s) +{ + s = s % sizeof (op_t); + return word & ~((op_t)-1 << s); +} + +static __always_inline find_t +find_zero_all (op_t x) +{ + return __builtin_alpha_cmpbge (0, x); +} + +static __always_inline find_t +find_eq_all (op_t x1, op_t x2) +{ + return find_zero_all (x1 ^ x2); +} + +static __always_inline find_t +find_zero_eq_all (op_t x1, op_t x2) +{ + return find_zero_all (x1) | find_zero_all (x1 ^ x2); +} + +static __always_inline find_t +find_zero_ne_all (op_t x1, op_t x2) +{ + return find_zero_all (x1) | (find_zero_all (x1 ^ x2) ^ 0xff); +} + +/* Define the "inexact" versions in terms of the exact versions. */ +#define find_zero_low find_zero_all +#define find_eq_low find_eq_all +#define find_zero_eq_low find_zero_eq_all +#define find_zero_ne_low find_zero_ne_all + +#endif /* _STRING_FZA_H */ diff --git a/sysdeps/alpha/string-fzb.h b/sysdeps/alpha/string-fzb.h new file mode 100644 index 0000000000..e3934ba413 --- /dev/null +++ b/sysdeps/alpha/string-fzb.h @@ -0,0 +1,52 @@ +/* Zero byte detection; boolean. Alpha 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> + +/* Note that since CMPBGE creates a bit mask rather than a byte mask, + we cannot simply provide a target-specific string-fza.h. */ + +/* Determine if any byte within X is zero. This is a pure boolean test. */ + +static __always_inline _Bool +has_zero (op_t x) +{ + return __builtin_alpha_cmpbge (0, x) != 0; +} + +/* Likewise, but for byte equality between X1 and X2. */ + +static __always_inline _Bool +has_eq (op_t x1, op_t x2) +{ + return has_zero (x1 ^ x2); +} + +/* 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) +{ + return has_zero (x1) | has_eq (x1, x2); +} + +#endif /* _STRING_FZB_H */ diff --git a/sysdeps/alpha/string-fzi.h b/sysdeps/alpha/string-fzi.h new file mode 100644 index 0000000000..5129b892e7 --- /dev/null +++ b/sysdeps/alpha/string-fzi.h @@ -0,0 +1,62 @@ +/* string-fzi.h -- zero byte detection; indices. Alpha 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 + +#include <stdint.h> +#include <string-optype.h> +#include <string-fza.h> + +/* Note that since CMPBGE creates a bit mask rather than a byte mask, + we cannot simply provide a target-specific string-fza.h. */ + +/* A subroutine for the index_zero functions. Given a bitmask C, + return the index of the first bit set in memory order. */ +static __always_inline unsigned int +index_first (find_t c) +{ +#ifdef __alpha_cix__ + return __builtin_ctzl (c); +#else + c = c & -c; + return (c & 0xf0 ? 4 : 0) + (c & 0xcc ? 2 : 0) + (c & 0xaa ? 1 : 0); +#endif +} + +/* Similarly, but return the (memory order) index of the last bit + that is non-zero. Note that only the least 8 bits may be nonzero. */ + +static __always_inline unsigned int +index_last (find_t x) +{ +#ifdef __alpha_cix__ + return __builtin_clzl (x) ^ 63; +#else + unsigned r = 0; + if (x & 0xf0) + r += 4; + if (x & (0xc << r)) + r += 2; + if (x & (0x2 << r)) + r += 1; + return r; +#endif +} + +#endif /* _STRING_FZI_H */ diff --git a/sysdeps/generic/string-fzi.h b/sysdeps/generic/string-fzi.h index 71bb6103aa..2deecefc23 100644 --- a/sysdeps/generic/string-fzi.h +++ b/sysdeps/generic/string-fzi.h @@ -45,7 +45,7 @@ ctz (find_t c) the (memory order) index of the first byte (in memory order) that is non-zero. */ static __always_inline unsigned int -index_first (op_t c) +index_first (find_t c) { int r; if (__BYTE_ORDER == __LITTLE_ENDIAN) |