1 /*- 2 * Copyright (c) 2018 Conrad Meyer <cem@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include "zstd_kfreebsd.h" 30 #include <sys/endian.h> 31 32 /* 33 * The kernel as a standalone target does not link against libgcc or 34 * libcompiler-rt. On platforms (e.g., MIPS and RISCV) that do not have a 35 * direct assembly implementation of the relevant builtin functions that zstd 36 * references, the compiler converts them into calls to the runtime library 37 * intrinsics. Since the kernel does not link against the runtime libraries, 38 * this results in a failure to link the kernel. 39 * 40 * The goal of the following definitions is to use supported kernel constructs 41 * to implement the same functionality, without adding diff to the Zstd contrib 42 * code. 43 * 44 * A subsequent enhancement might create a mini compiler-rt library for kernel 45 * use and move these over there instead. 46 */ 47 48 /* Swap endianness */ 49 int 50 __bswapsi2(int x) 51 { 52 return (bswap32(x)); 53 } 54 55 long long 56 __bswapdi2(long long x) 57 { 58 return (bswap64(x)); 59 } 60 61 /* Count trailing zeros */ 62 int 63 __ctzsi2(int x) 64 { 65 if (x == 0) 66 return (sizeof(x) * NBBY); 67 return (ffs(x) - 1); 68 } 69 70 long long 71 __ctzdi2(long long x) 72 { 73 if (x == 0) 74 return (sizeof(x) * NBBY); 75 return (ffsll(x) - 1); 76 } 77 78 /* Count leading zeros */ 79 int 80 __clzsi2(int x) 81 { 82 return (sizeof(x) * NBBY - fls(x)); 83 } 84 85 long long 86 __clzdi2(long long x) 87 { 88 return (sizeof(x) * NBBY - flsll(x)); 89 } 90