diff options
Diffstat (limited to 'contrib/llvm-project/compiler-rt/lib/builtins/muldi3.c')
-rw-r--r-- | contrib/llvm-project/compiler-rt/lib/builtins/muldi3.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/builtins/muldi3.c b/contrib/llvm-project/compiler-rt/lib/builtins/muldi3.c new file mode 100644 index 000000000000..013f669a1833 --- /dev/null +++ b/contrib/llvm-project/compiler-rt/lib/builtins/muldi3.c @@ -0,0 +1,51 @@ +//===-- muldi3.c - Implement __muldi3 -------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// 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 + +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; +} + +#if defined(__ARM_EABI__) +COMPILER_RT_ALIAS(__muldi3, __aeabi_lmul) +#endif |