opnsense-src/contrib/llvm-project/compiler-rt/lib/builtins/multi3.c
Dimitry Andric 0b57cec536 Move all sources from the llvm project into contrib/llvm-project.
This uses the new layout of the upstream repository, which was recently
migrated to GitHub, and converted into a "monorepo".  That is, most of
the earlier separate sub-projects with their own branches and tags were
consolidated into one top-level directory, and are now branched and
tagged together.

Updating the vendor area to match this layout is next.
2019-12-20 19:53:05 +00:00

51 lines
1.5 KiB
C

//===-- multi3.c - Implement __multi3 -------------------------------------===//
//
// 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 __multi3 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "int_lib.h"
#ifdef CRT_HAS_128BIT
// Returns: a * b
static ti_int __mulddi3(du_int a, du_int b) {
twords r;
const int bits_in_dword_2 = (int)(sizeof(di_int) * CHAR_BIT) / 2;
const du_int lower_mask = (du_int)~0 >> bits_in_dword_2;
r.s.low = (a & lower_mask) * (b & lower_mask);
du_int t = r.s.low >> bits_in_dword_2;
r.s.low &= lower_mask;
t += (a >> bits_in_dword_2) * (b & lower_mask);
r.s.low += (t & lower_mask) << bits_in_dword_2;
r.s.high = t >> bits_in_dword_2;
t = r.s.low >> bits_in_dword_2;
r.s.low &= lower_mask;
t += (b >> bits_in_dword_2) * (a & lower_mask);
r.s.low += (t & lower_mask) << bits_in_dword_2;
r.s.high += t >> bits_in_dword_2;
r.s.high += (a >> bits_in_dword_2) * (b >> bits_in_dword_2);
return r.all;
}
// Returns: a * b
COMPILER_RT_ABI ti_int __multi3(ti_int a, ti_int b) {
twords x;
x.all = a;
twords y;
y.all = b;
twords r;
r.all = __mulddi3(x.s.low, y.s.low);
r.s.high += x.s.high * y.s.low + x.s.low * y.s.high;
return r.all;
}
#endif // CRT_HAS_128BIT