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Diffstat (limited to 'contrib/compiler-rt/lib/builtins/muldi3.c')
-rw-r--r-- | contrib/compiler-rt/lib/builtins/muldi3.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/builtins/muldi3.c b/contrib/compiler-rt/lib/builtins/muldi3.c new file mode 100644 index 0000000..2dae44c --- /dev/null +++ b/contrib/compiler-rt/lib/builtins/muldi3.c @@ -0,0 +1,56 @@ +/* ===-- muldi3.c - Implement __muldi3 -------------------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is dual licensed under the MIT and the University of Illinois Open + * Source Licenses. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __muldi3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +/* Returns: a * b */ + +static +di_int +__muldsi3(su_int a, su_int b) +{ + dwords r; + const int bits_in_word_2 = (int)(sizeof(si_int) * CHAR_BIT) / 2; + const su_int lower_mask = (su_int)~0 >> bits_in_word_2; + r.s.low = (a & lower_mask) * (b & lower_mask); + su_int t = r.s.low >> bits_in_word_2; + r.s.low &= lower_mask; + t += (a >> bits_in_word_2) * (b & lower_mask); + r.s.low += (t & lower_mask) << bits_in_word_2; + r.s.high = t >> bits_in_word_2; + t = r.s.low >> bits_in_word_2; + r.s.low &= lower_mask; + t += (b >> bits_in_word_2) * (a & lower_mask); + r.s.low += (t & lower_mask) << bits_in_word_2; + r.s.high += t >> bits_in_word_2; + r.s.high += (a >> bits_in_word_2) * (b >> bits_in_word_2); + return r.all; +} + +/* Returns: a * b */ + +ARM_EABI_FNALIAS(lmul, muldi3) + +COMPILER_RT_ABI di_int +__muldi3(di_int a, di_int b) +{ + dwords x; + x.all = a; + dwords y; + y.all = b; + dwords r; + r.all = __muldsi3(x.s.low, y.s.low); + r.s.high += x.s.high * y.s.low + x.s.low * y.s.high; + return r.all; +} |