/* * This file is part of the libpayload project. * * Copyright 2015 Google Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <libpayload.h> /* * Provide platform-independent backend implementation for __builtin_clz() in * <libpayload.h> in case GCC does not have an assembly version for this arch. */ int __clzsi2(u32 a); int __clzsi2(u32 a) { static const u8 four_bit_table[] = { [0x0] = 4, [0x1] = 3, [0x2] = 2, [0x3] = 2, [0x4] = 1, [0x5] = 1, [0x6] = 1, [0x7] = 1, [0x8] = 0, [0x9] = 0, [0xa] = 0, [0xb] = 0, [0xc] = 0, [0xd] = 0, [0xe] = 0, [0xf] = 0, }; int r = 0; if (!(a & (0xffff << 16))) { r += 16; a <<= 16; } if (!(a & (0xff << 24))) { r += 8; a <<= 8; } if (!(a & (0xf << 28))) { r += 4; a <<= 4; } return r + four_bit_table[a >> 28]; }