| /* |
| * 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]; |
| } |