69 lines
2.3 KiB
C
69 lines
2.3 KiB
C
/*
|
|
* 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];
|
|
}
|