From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1791) id 8D973385783F; Fri, 13 Jan 2023 20:03:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8D973385783F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1673640220; bh=MtN3IQX6B7gd4V2mwAnLlx0ftr5/DRnBBYsH4uIQDO0=; h=From:To:Subject:Date:From; b=DbaKciLI1loqzIKXSwoF/MkXbcfqaiMitCo7JeWVMv2SxssHCZUpe354XuErLtl7P iy169O+lFxT23PiqMwMuNsTKp+S17mGZopvsTyNCY3fb8KGFvpw9jXPW8DV4fn0Pd+ vfl5cSKnpeZVfi6yO6Jnrn7eXSkwhdaKrTw1YbJk= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Adhemerval Zanella To: glibc-cvs@sourceware.org Subject: [glibc/azanella/generic-strings] alpha: Add string-fzb.h and string-fzi.h X-Act-Checkin: glibc X-Git-Author: Richard Henderson X-Git-Refname: refs/heads/azanella/generic-strings X-Git-Oldrev: bd1edea1835fb2ae0d9925019818b8bc05517209 X-Git-Newrev: 27c71d8cfcfb331e9625cbd2047d8da1c8c3009b Message-Id: <20230113200340.8D973385783F@sourceware.org> Date: Fri, 13 Jan 2023 20:03:40 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=27c71d8cfcfb331e9625cbd2047d8da1c8c3009b commit 27c71d8cfcfb331e9625cbd2047d8da1c8c3009b Author: Richard Henderson Date: Tue Jan 10 18:01:03 2023 -0300 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 Diff: --- sysdeps/alpha/string-fza.h | 77 ++++++++++++++++++++++++++++++++++++++++++++ sysdeps/alpha/string-fzb.h | 52 ++++++++++++++++++++++++++++++ sysdeps/alpha/string-fzi.h | 62 +++++++++++++++++++++++++++++++++++ sysdeps/generic/string-fzi.h | 2 +- 4 files changed, 192 insertions(+), 1 deletion(-) 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 + . */ + +#ifndef _STRING_FZA_H +#define _STRING_FZA_H 1 + +#include +#include +#include + +/* 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 + . */ + +#ifndef _STRING_FZB_H +#define _STRING_FZB_H 1 + +#include +#include + +/* 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 + . */ + +#ifndef _STRING_FZI_H +#define _STRING_FZI_H + +#include +#include +#include + +/* 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)