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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* libgcc replacement - count leading bits
*
* Copyright 2025, Heinrich Schuchardt <[email protected]>
*/
#include <linux/types.h>
/**
* __clzti2() - count number of leading zero bits
*
* @x: number to check
* Return: number of leading zero bits
*/
int __clzti2(long long x)
{
int ret = 64;
if (!x)
return 64;
if (x & 0xFFFFFFFF00000000LL) {
ret -= 32;
x >>= 32;
}
if (x & 0xFFFF0000LL) {
ret -= 16;
x >>= 16;
}
if (x & 0xFF00LL) {
ret -= 8;
x >>= 8;
}
if (x & 0xF0LL) {
ret -= 4;
x >>= 4;
}
if (x & 0xCLL) {
ret -= 2;
x >>= 2;
}
if (x & 0x2LL) {
ret -= 1;
x >>= 1;
}
if (x)
ret -= 1;
return ret;
}
/**
* __clzsi2() - count number of leading zero bits
*
* @x: number to check
* Return: number of leading zero bits
*/
int __clzsi2(int x)
{
int ret = 32;
if (!x)
return 32;
if (x & 0xFFFF0000) {
ret -= 16;
x >>= 16;
}
if (x & 0xFF00) {
ret -= 8;
x >>= 8;
}
if (x & 0xF0) {
ret -= 4;
x >>= 4;
}
if (x & 0xC) {
ret -= 2;
x >>= 2;
}
if (x & 0x2) {
ret -= 1;
x >>= 1;
}
if (x)
ret -= 1;
return ret;
}
/**
* __clzdi2() - count number of leading zero bits
*
* @x: number to check
* Return: number of leading zero bits
*/
int __clzdi2(long x)
{
#if BITS_PER_LONG == 64
return __clzti2(x);
#else
return __clzsi2(x);
#endif
}
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