blob: aedcd353436f991542e0ca89cd03bbc7ad3a9526 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
//===-- Utilities for integers. ---------------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIBC_SRC_SUPPORT_INTEGER_UTILS_H
#define LLVM_LIBC_SRC_SUPPORT_INTEGER_UTILS_H
#include "src/__support/CPP/type_traits.h"
#include "src/__support/common.h"
#include "builtin_wrappers.h"
#include "number_pair.h"
#include <stdint.h>
namespace __llvm_libc {
template <typename T> NumberPair<T> full_mul(T a, T b);
template <>
LIBC_INLINE NumberPair<uint32_t> full_mul<uint32_t>(uint32_t a, uint32_t b) {
uint64_t prod = uint64_t(a) * uint64_t(b);
NumberPair<uint32_t> result;
result.lo = uint32_t(prod);
result.hi = uint32_t(prod >> 32);
return result;
}
template <>
LIBC_INLINE NumberPair<uint64_t> full_mul<uint64_t>(uint64_t a, uint64_t b) {
#ifdef __SIZEOF_INT128__
__uint128_t prod = __uint128_t(a) * __uint128_t(b);
NumberPair<uint64_t> result;
result.lo = uint64_t(prod);
result.hi = uint64_t(prod >> 64);
return result;
#else
NumberPair<uint64_t> pa = split(a);
NumberPair<uint64_t> pb = split(b);
NumberPair<uint64_t> prod;
prod.lo = pa.lo * pb.lo; // exact
prod.hi = pa.hi * pb.hi; // exact
NumberPair<uint64_t> lo_hi = split(pa.lo * pb.hi); // exact
NumberPair<uint64_t> hi_lo = split(pa.hi * pb.lo); // exact
auto r1 = add_with_carry(prod.lo, lo_hi.lo << 32, uint64_t(0));
prod.lo = r1.sum;
prod.hi = add_with_carry(prod.hi, lo_hi.hi, r1.carry).sum;
auto r2 = add_with_carry(prod.lo, hi_lo.lo << 32, uint64_t(0));
prod.lo = r2.sum;
prod.hi = add_with_carry(prod.hi, hi_lo.hi, r2.carry).sum;
return prod;
#endif // __SIZEOF_INT128__
}
} // namespace __llvm_libc
#endif // LLVM_LIBC_SRC_SUPPORT_INTEGER_UTILS_H
|
