u-boot/arch/m68k/lib/ashrdi3.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* ashrdi3.c extracted from gcc-2.7.2/libgcc2.c which is:
* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
*/
#define BITS_PER_UNIT 8
typedef int SItype __attribute__((mode(SI)));
typedef unsigned int USItype __attribute__((mode(SI)));
typedef int DItype __attribute__((mode(DI)));
typedef int word_type __attribute__((mode(__word__)));
struct DIstruct {
SItype high, low;
};
typedef union {
struct DIstruct s;
DItype ll;
} di_union;
DItype __ashrdi3(DItype u, word_type b)
{
di_union w;
word_type bm;
di_union uu;
if (b == 0)
return u;
uu.ll = u;
bm = (sizeof(SItype) * BITS_PER_UNIT) - b;
if (bm <= 0) {
/* w.s.high = 1..1 or 0..0 */
w.s.high = uu.s.high >> (sizeof(SItype) * BITS_PER_UNIT - 1);
w.s.low = uu.s.high >> -bm;
} else {
USItype carries = (USItype)uu.s.high << bm;
w.s.high = uu.s.high >> b;
w.s.low = ((USItype)uu.s.low >> b) | carries;
}
return w.ll;
}