mirror of
https://github.com/vlang/v.git
synced 2023-08-10 21:13:21 +03:00
48 lines
1.5 KiB
Go
48 lines
1.5 KiB
Go
// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
|
|
// Use of this source code is governed by an MIT license
|
|
// that can be found in the LICENSE file.
|
|
|
|
module bits
|
|
|
|
// --- RotateLeft ---
|
|
|
|
// rotate_left_8 returns the value of x rotated left by (k mod 8) bits.
|
|
// To rotate x right by k bits, call rotate_left_8(x, -k).
|
|
//
|
|
// This function's execution time does not depend on the inputs.
|
|
pub fn rotate_left_8(x u8, k int) u8 {
|
|
n := u8(8)
|
|
s := u8(k) & u8(n - u8(1))
|
|
return u8((x<<s) | (x>>(n-s)))
|
|
}
|
|
|
|
// rotate_left_16 returns the value of x rotated left by (k mod 16) bits.
|
|
// To rotate x right by k bits, call rotate_left_16(x, -k).
|
|
//
|
|
// This function's execution time does not depend on the inputs.
|
|
pub fn rotate_left_16(x u16, k int) u16 {
|
|
n := u16(16)
|
|
s := u16(k) & (n - u16(1))
|
|
return u16((x<<s) | (x>>(n-s)))
|
|
}
|
|
|
|
// rotate_left_32 returns the value of x rotated left by (k mod 32) bits.
|
|
// To rotate x right by k bits, call rotate_left_32(x, -k).
|
|
//
|
|
// This function's execution time does not depend on the inputs.
|
|
pub fn rotate_left_32(x u32, k int) u32 {
|
|
n := u32(32)
|
|
s := u32(k) & (n - u32(1))
|
|
return u32(u32(x<<s) | u32(x>>(n-s)))
|
|
}
|
|
|
|
// rotate_left_64 returns the value of x rotated left by (k mod 64) bits.
|
|
// To rotate x right by k bits, call rotate_left_64(x, -k).
|
|
//
|
|
// This function's execution time does not depend on the inputs.
|
|
pub fn rotate_left_64(x u64, k int) u64 {
|
|
n := u64(64)
|
|
s := u64(k) & (n - u64(1))
|
|
return u64(u64(x<<s) | u64(x>>(n-s)))
|
|
}
|