/rust/registry/src/index.crates.io-1949cf8c6b5b557f/v_frame-0.3.9/src/math.rs

Source
// Copyright (c) 2017-2020, The rav1e contributors. All rights reserved
//
// This source code is subject to the terms of the BSD 2 Clause License and
// the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
// was not distributed with this source code in the LICENSE file, you can
// obtain it at www.aomedia.org/license/software. If the Alliance for Open
// Media Patent License 1.0 was not distributed with this source code in the
// PATENTS file, you can obtain it at www.aomedia.org/license/patent.

use num_traits::PrimInt;
use std::mem::size_of;

pub trait Fixed {
    fn floor_log2(&self, n: usize) -> usize;
    fn ceil_log2(&self, n: usize) -> usize;
    fn align_power_of_two(&self, n: usize) -> usize;
    fn align_power_of_two_and_shift(&self, n: usize) -> usize;
}

impl Fixed for usize {
    #[inline]
    fn floor_log2(&self, n: usize) -> usize {
        self & !((1 << n) - 1)
    }
    #[inline]
    fn ceil_log2(&self, n: usize) -> usize {
        (self + (1 << n) - 1).floor_log2(n)
    }
    #[inline]
    fn align_power_of_two(&self, n: usize) -> usize {
        self.ceil_log2(n)
    }
    #[inline]
    fn align_power_of_two_and_shift(&self, n: usize) -> usize {
        (self + (1 << n) - 1) >> n
    }
}

pub fn clamp<T: PartialOrd>(input: T, min: T, max: T) -> T {
    if input < min {
        min
    } else if input > max {
        max
    } else {
        input
    }
}

pub trait ILog: PrimInt {
    // Integer binary logarithm of an integer value.
    // Returns floor(log2(self)) + 1, or 0 if self == 0.
    // This is the number of bits that would be required to represent self in two's
    //  complement notation with all of the leading zeros stripped.
    // TODO: Mark const once trait functions can be constant
    fn ilog(self) -> usize {
        size_of::<Self>() * 8 - self.leading_zeros() as usize
    }
}

impl<T> ILog for T where T: PrimInt {}

#[inline(always)]
pub fn msb(x: i32) -> i32 {
    debug_assert!(x > 0);
    31 ^ (x.leading_zeros() as i32)
}

#[inline(always)]
pub const fn round_shift(value: i32, bit: usize) -> i32 {
    (value + (1 << bit >> 1)) >> bit
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_floor_log2() {
        assert_eq!(123usize.floor_log2(4), 112);
        assert_eq!(16usize.floor_log2(4), 16);
        assert_eq!(0usize.floor_log2(4), 0);
    }

    #[test]
    fn test_ceil_log2() {
        assert_eq!(123usize.ceil_log2(4), 128);
        assert_eq!(16usize.ceil_log2(4), 16);
        assert_eq!(0usize.ceil_log2(4), 0);
    }

    #[test]
    fn test_align_power_of_two() {
        assert_eq!(123usize.align_power_of_two(4), 128);
        assert_eq!(16usize.align_power_of_two(4), 16);
        assert_eq!(0usize.align_power_of_two(4), 0);
    }

    #[test]
    fn test_align_power_of_two_and_shift() {
        assert_eq!(123usize.align_power_of_two_and_shift(4), 8);
        assert_eq!(16usize.align_power_of_two_and_shift(4), 1);
        assert_eq!(0usize.align_power_of_two_and_shift(4), 0);
    }

    #[test]
    fn test_clamp() {
        assert_eq!(clamp(5, 0, 10), 5);
        assert_eq!(clamp(-1, 0, 10), 0);
        assert_eq!(clamp(11, 0, 10), 10);
    }

    #[test]
    fn test_ilog() {
        assert_eq!(ILog::ilog(0i32), 0);
        assert_eq!(ILog::ilog(1i32), 1);
        assert_eq!(ILog::ilog(2i32), 2);
        assert_eq!(ILog::ilog(3i32), 2);
        assert_eq!(ILog::ilog(4i32), 3);
    }

    #[test]
    fn test_msb() {
        assert_eq!(msb(1), 0);
        assert_eq!(msb(2), 1);
        assert_eq!(msb(3), 1);
        assert_eq!(msb(4), 2);
    }

    #[test]
    fn test_round_shift() {
        assert_eq!(round_shift(7, 2), 2);
        assert_eq!(round_shift(8, 2), 2);
        assert_eq!(round_shift(9, 2), 2);
        assert_eq!(round_shift(10, 2), 3);
    }
}

Coverage Report

Created: 2026-04-12 07:31

Line	Count	Source
1		// Copyright (c) 2017-2020, The rav1e contributors. All rights reserved
2		//
3		// This source code is subject to the terms of the BSD 2 Clause License and
4		// the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
5		// was not distributed with this source code in the LICENSE file, you can
6		// obtain it at www.aomedia.org/license/software. If the Alliance for Open
7		// Media Patent License 1.0 was not distributed with this source code in the
8		// PATENTS file, you can obtain it at www.aomedia.org/license/patent.
9
10		use num_traits::PrimInt;
11		use std::mem::size_of;
12
13		pub trait Fixed {
14		fn floor_log2(&self, n: usize) -> usize;
15		fn ceil_log2(&self, n: usize) -> usize;
16		fn align_power_of_two(&self, n: usize) -> usize;
17		fn align_power_of_two_and_shift(&self, n: usize) -> usize;
18		}
19
20		impl Fixed for usize {
21		#[inline]
22	0	fn floor_log2(&self, n: usize) -> usize {
23	0	self & !((1 << n) - 1)
24	0	} Unexecuted instantiation: <usize as v_frame::math::Fixed>::floor_log2 Unexecuted instantiation: <usize as v_frame::math::Fixed>::floor_log2 Unexecuted instantiation: <usize as v_frame::math::Fixed>::floor_log2 Unexecuted instantiation: <usize as v_frame::math::Fixed>::floor_log2
25		#[inline]
26	0	fn ceil_log2(&self, n: usize) -> usize {
27	0	(self + (1 << n) - 1).floor_log2(n)
28	0	} Unexecuted instantiation: <usize as v_frame::math::Fixed>::ceil_log2 Unexecuted instantiation: <usize as v_frame::math::Fixed>::ceil_log2 Unexecuted instantiation: <usize as v_frame::math::Fixed>::ceil_log2 Unexecuted instantiation: <usize as v_frame::math::Fixed>::ceil_log2
29		#[inline]
30	0	fn align_power_of_two(&self, n: usize) -> usize {
31	0	self.ceil_log2(n)
32	0	} Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two
33		#[inline]
34	0	fn align_power_of_two_and_shift(&self, n: usize) -> usize {
35	0	(self + (1 << n) - 1) >> n
36	0	} Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two_and_shift Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two_and_shift Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two_and_shift Unexecuted instantiation: <usize as v_frame::math::Fixed>::align_power_of_two_and_shift
37		}
38
39	0	pub fn clamp<T: PartialOrd>(input: T, min: T, max: T) -> T {
40	0	if input < min {
41	0	min
42	0	} else if input > max {
43	0	max
44		} else {
45	0	input
46		}
47	0	} Unexecuted instantiation: v_frame::math::clamp::<i8> Unexecuted instantiation: v_frame::math::clamp::<i16> Unexecuted instantiation: v_frame::math::clamp::<i64> Unexecuted instantiation: v_frame::math::clamp::<isize> Unexecuted instantiation: v_frame::math::clamp::<f64> Unexecuted instantiation: v_frame::math::clamp::<u8> Unexecuted instantiation: v_frame::math::clamp::<usize> Unexecuted instantiation: v_frame::math::clamp::<i32> Unexecuted instantiation: v_frame::math::clamp::<_>
48
49		pub trait ILog: PrimInt {
50		// Integer binary logarithm of an integer value.
51		// Returns floor(log2(self)) + 1, or 0 if self == 0.
52		// This is the number of bits that would be required to represent self in two's
53		// complement notation with all of the leading zeros stripped.
54		// TODO: Mark const once trait functions can be constant
55	0	fn ilog(self) -> usize {
56	0	size_of::<Self>() * 8 - self.leading_zeros() as usize
57	0	} Unexecuted instantiation: <usize as v_frame::math::ILog>::ilog Unexecuted instantiation: <i16 as v_frame::math::ILog>::ilog Unexecuted instantiation: <_ as v_frame::math::ILog>::ilog
58		}
59
60		impl<T> ILog for T where T: PrimInt {}
61
62		#[inline(always)]
63	0	pub fn msb(x: i32) -> i32 {
64	0	debug_assert!(x > 0);
65	0	31 ^ (x.leading_zeros() as i32)
66	0	}
67
68		#[inline(always)]
69	0	pub const fn round_shift(value: i32, bit: usize) -> i32 {
70	0	(value + (1 << bit >> 1)) >> bit
71	0	}
72
73		#[cfg(test)]
74		mod tests {
75		use super::*;
76
77		#[test]
78		fn test_floor_log2() {
79		assert_eq!(123usize.floor_log2(4), 112);
80		assert_eq!(16usize.floor_log2(4), 16);
81		assert_eq!(0usize.floor_log2(4), 0);
82		}
83
84		#[test]
85		fn test_ceil_log2() {
86		assert_eq!(123usize.ceil_log2(4), 128);
87		assert_eq!(16usize.ceil_log2(4), 16);
88		assert_eq!(0usize.ceil_log2(4), 0);
89		}
90
91		#[test]
92		fn test_align_power_of_two() {
93		assert_eq!(123usize.align_power_of_two(4), 128);
94		assert_eq!(16usize.align_power_of_two(4), 16);
95		assert_eq!(0usize.align_power_of_two(4), 0);
96		}
97
98		#[test]
99		fn test_align_power_of_two_and_shift() {
100		assert_eq!(123usize.align_power_of_two_and_shift(4), 8);
101		assert_eq!(16usize.align_power_of_two_and_shift(4), 1);
102		assert_eq!(0usize.align_power_of_two_and_shift(4), 0);
103		}
104
105		#[test]
106		fn test_clamp() {
107		assert_eq!(clamp(5, 0, 10), 5);
108		assert_eq!(clamp(-1, 0, 10), 0);
109		assert_eq!(clamp(11, 0, 10), 10);
110		}
111
112		#[test]
113		fn test_ilog() {
114		assert_eq!(ILog::ilog(0i32), 0);
115		assert_eq!(ILog::ilog(1i32), 1);
116		assert_eq!(ILog::ilog(2i32), 2);
117		assert_eq!(ILog::ilog(3i32), 2);
118		assert_eq!(ILog::ilog(4i32), 3);
119		}
120
121		#[test]
122		fn test_msb() {
123		assert_eq!(msb(1), 0);
124		assert_eq!(msb(2), 1);
125		assert_eq!(msb(3), 1);
126		assert_eq!(msb(4), 2);
127		}
128
129		#[test]
130		fn test_round_shift() {
131		assert_eq!(round_shift(7, 2), 2);
132		assert_eq!(round_shift(8, 2), 2);
133		assert_eq!(round_shift(9, 2), 2);
134		assert_eq!(round_shift(10, 2), 3);
135		}
136		}