root/arch/s390/lib/tishift.c
// SPDX-License-Identifier: GPL-2.0

#include <linux/export.h>
#include <linux/types.h>
#include "tishift.h"

union ti {
        __int128_t val;
        struct {
                u64 high;
                u64 low;
        };
};

noinstr __int128_t __ashlti3(__int128_t a, int shift)
{
        union ti ti = { .val = a };

        if (!shift)
                return ti.val;
        if (shift < 64) {
                ti.high = (ti.high << shift) | (ti.low >> (64 - shift));
                ti.low = ti.low << shift;
        } else {
                ti.high = ti.low << (shift - 64);
                ti.low = 0;
        }
        return ti.val;
}
EXPORT_SYMBOL(__ashlti3);

noinstr __int128_t __ashrti3(__int128_t a, int shift)
{
        union ti ti = { .val = a };

        if (!shift)
                return ti.val;
        if (shift < 64) {
                ti.low = (ti.low >> shift) | (ti.high << (64 - shift));
                ti.high = (int64_t)ti.high >> shift;
        } else {
                ti.low = (int64_t)ti.high >> (shift - 64);
                ti.high = (int64_t)ti.high >> 63;
        }
        return ti.val;
}
EXPORT_SYMBOL(__ashrti3);

noinstr __int128_t __lshrti3(__int128_t a, int shift)
{
        union ti ti = { .val = a };

        if (!shift)
                return ti.val;
        if (shift < 64) {
                ti.low = (ti.low >> shift) | (ti.high << (64 - shift));
                ti.high = ti.high >> shift;
        } else {
                ti.low = ti.high >> (shift - 64);
                ti.high = 0;
        }
        return ti.val;
}
EXPORT_SYMBOL(__lshrti3);