From 25788431c0f5264c4830415de0cdd4d9926cbad9 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 1 Feb 2023 12:44:17 -0300 Subject: riscv: Add string-fza.h and string-fzi.h It uses the bitmanip extension to optimize index_fist and index_last with clz/ctz (using generic implementation that routes to compiler builtin) and orc.b to check null bytes. Checked the string test on riscv64 user mode. Reviewed-by: Richard Henderson --- sysdeps/riscv/string-fza.h | 69 +++++++++++++++++++++++++++++++++++++++++ sysdeps/riscv/string-fzi.h | 77 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 146 insertions(+) create mode 100644 sysdeps/riscv/string-fza.h create mode 100644 sysdeps/riscv/string-fzi.h (limited to 'sysdeps/riscv') diff --git a/sysdeps/riscv/string-fza.h b/sysdeps/riscv/string-fza.h new file mode 100644 index 0000000000..4429653a00 --- /dev/null +++ b/sysdeps/riscv/string-fza.h @@ -0,0 +1,69 @@ +/* Zero byte detection; basics. RISCV 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 _RISCV_STRING_FZA_H +#define _RISCV_STRING_FZA_H 1 + +#ifdef __riscv_zbb +/* With bitmap extension we can use orc.b to find all zero bytes. */ +# include +# include + +/* The functions return a byte mask. */ +typedef op_t find_t; + +/* This function returns 0xff for each byte that is zero in X. */ +static __always_inline find_t +find_zero_all (op_t x) +{ + find_t r; + asm ("orc.b %0, %1" : "=r" (r) : "r" (x)); + return ~r; +} + +/* This function returns 0xff for each byte that is equal between X1 and + X2. */ +static __always_inline find_t +find_eq_all (op_t x1, op_t x2) +{ + return find_zero_all (x1 ^ x2); +} + +/* Identify zero bytes in X1 or equality between X1 and X2. */ +static __always_inline find_t +find_zero_eq_all (op_t x1, op_t x2) +{ + return find_zero_all (x1) | find_eq_all (x1, x2); +} + +/* Identify zero bytes in X1 or inequality between X1 and X2. */ +static __always_inline find_t +find_zero_ne_all (op_t x1, op_t x2) +{ + return find_zero_all (x1) | ~find_eq_all (x1, x2); +} + +/* 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 +#else +#include +#endif + +#endif /* _RISCV_STRING_FZA_H */ diff --git a/sysdeps/riscv/string-fzi.h b/sysdeps/riscv/string-fzi.h new file mode 100644 index 0000000000..8f56c378ff --- /dev/null +++ b/sysdeps/riscv/string-fzi.h @@ -0,0 +1,77 @@ +/* Zero byte detection; indexes. RISCV 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_RISCV_FZI_H +#define _STRING_RISCV_FZI_H 1 + +#ifdef __riscv_zbb +# include +#else +/* Without bitmap clz/ctz extensions, it is faster to direct test the bits + instead of calling compiler auxiliary functions. */ +# include + +static __always_inline unsigned int +index_first (find_t c) +{ + if (c & 0x80U) + return 0; + if (c & 0x8000U) + return 1; + if (c & 0x800000U) + return 2; + + if (sizeof (op_t) == 4) + return 3; + + if (c & 0x80000000U) + return 3; + if (c & 0x8000000000UL) + return 4; + if (c & 0x800000000000UL) + return 5; + if (c & 0x80000000000000UL) + return 6; + return 7; +} + +static __always_inline unsigned int +index_last (find_t c) +{ + if (sizeof (op_t) == 8) + { + if (c & 0x8000000000000000UL) + return 7; + if (c & 0x80000000000000UL) + return 6; + if (c & 0x800000000000UL) + return 5; + if (c & 0x8000000000UL) + return 4; + } + if (c & 0x80000000U) + return 3; + if (c & 0x800000U) + return 2; + if (c & 0x8000U) + return 1; + return 0; +} +#endif + +#endif /* STRING_FZI_H */ -- cgit 1.4.1