1 // Translated from C to Rust. The original C code can be found at
2 // https://github.com/ulfjack/ryu and carries the following license:
3 //
4 // Copyright 2018 Ulf Adams
5 //
6 // The contents of this file may be used under the terms of the Apache License,
7 // Version 2.0.
8 //
9 // (See accompanying file LICENSE-Apache or copy at
10 // http://www.apache.org/licenses/LICENSE-2.0)
11 //
12 // Alternatively, the contents of this file may be used under the terms of
13 // the Boost Software License, Version 1.0.
14 // (See accompanying file LICENSE-Boost or copy at
15 // https://www.boost.org/LICENSE_1_0.txt)
16 //
17 // Unless required by applicable law or agreed to in writing, this software
18 // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
19 // KIND, either express or implied.
20
21 // Returns (lo, hi).
22 #[cfg(not(integer128))]
23 #[cfg_attr(feature = "no-panic", inline)]
umul128(a: u64, b: u64) -> (u64, u64)24 pub fn umul128(a: u64, b: u64) -> (u64, u64) {
25 let a_lo = a as u32;
26 let a_hi = (a >> 32) as u32;
27 let b_lo = b as u32;
28 let b_hi = (b >> 32) as u32;
29
30 let b00 = a_lo as u64 * b_lo as u64;
31 let b01 = a_lo as u64 * b_hi as u64;
32 let b10 = a_hi as u64 * b_lo as u64;
33 let b11 = a_hi as u64 * b_hi as u64;
34
35 let b00_lo = b00 as u32;
36 let b00_hi = (b00 >> 32) as u32;
37
38 let mid1 = b10 + b00_hi as u64;
39 let mid1_lo = mid1 as u32;
40 let mid1_hi = (mid1 >> 32) as u32;
41
42 let mid2 = b01 + mid1_lo as u64;
43 let mid2_lo = mid2 as u32;
44 let mid2_hi = (mid2 >> 32) as u32;
45
46 let p_hi = b11 + mid1_hi as u64 + mid2_hi as u64;
47 let p_lo = ((mid2_lo as u64) << 32) + b00_lo as u64;
48
49 (p_lo, p_hi)
50 }
51
52 #[cfg(not(integer128))]
53 #[cfg_attr(feature = "no-panic", inline)]
shiftright128(lo: u64, hi: u64, dist: u32) -> u6454 pub fn shiftright128(lo: u64, hi: u64, dist: u32) -> u64 {
55 // We don't need to handle the case dist >= 64 here (see above).
56 debug_assert!(dist > 0);
57 debug_assert!(dist < 64);
58 (hi << (64 - dist)) | (lo >> dist)
59 }
60
61 #[cfg_attr(feature = "no-panic", inline)]
div5(x: u64) -> u6462 pub fn div5(x: u64) -> u64 {
63 x / 5
64 }
65
66 #[cfg_attr(feature = "no-panic", inline)]
div10(x: u64) -> u6467 pub fn div10(x: u64) -> u64 {
68 x / 10
69 }
70
71 #[cfg_attr(feature = "no-panic", inline)]
div100(x: u64) -> u6472 pub fn div100(x: u64) -> u64 {
73 x / 100
74 }
75
76 #[cfg_attr(feature = "no-panic", inline)]
div100_000_000(x: u64) -> u6477 pub fn div100_000_000(x: u64) -> u64 {
78 x / 100_000_000
79 }
80