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Diffstat (limited to 'arch/m68k/lib/ashrdi3.c')
| -rw-r--r-- | arch/m68k/lib/ashrdi3.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/m68k/lib/ashrdi3.c b/arch/m68k/lib/ashrdi3.c new file mode 100644 index 0000000000..e144378b7f --- /dev/null +++ b/arch/m68k/lib/ashrdi3.c @@ -0,0 +1,48 @@ +// 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; +} + |