#![allow(non_snake_case)]
#[derive(PartialEq, Debug)]
pub struct MU32 {
pub mulBy: u32,
pub doAdd: bool,
pub shiftBy: i32,
}
#[derive(PartialEq, Debug)]
pub struct MU64 {
pub mulBy: u64,
pub doAdd: bool,
pub shiftBy: i32,
}
#[derive(PartialEq, Debug)]
pub struct MS32 {
pub mulBy: i32,
pub shiftBy: i32,
}
#[derive(PartialEq, Debug)]
pub struct MS64 {
pub mulBy: i64,
pub shiftBy: i32,
}
pub fn magicU32(d: u32) -> MU32 {
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1);
let mut do_add: bool = false;
let mut p: i32 = 31;
let nc: u32 = 0xFFFFFFFFu32 - u32::wrapping_neg(d) % d;
let mut q1: u32 = 0x80000000u32 / nc;
let mut r1: u32 = 0x80000000u32 - q1 * nc;
let mut q2: u32 = 0x7FFFFFFFu32 / d;
let mut r2: u32 = 0x7FFFFFFFu32 - q2 * d;
loop {
p = p + 1;
if r1 >= nc - r1 {
q1 = u32::wrapping_add(u32::wrapping_mul(2, q1), 1);
r1 = u32::wrapping_sub(u32::wrapping_mul(2, r1), nc);
} else {
q1 = 2 * q1;
r1 = 2 * r1;
}
if r2 + 1 >= d - r2 {
if q2 >= 0x7FFFFFFFu32 {
do_add = true;
}
q2 = 2 * q2 + 1;
r2 = u32::wrapping_sub(u32::wrapping_add(u32::wrapping_mul(2, r2), 1), d);
} else {
if q2 >= 0x80000000u32 {
do_add = true;
}
q2 = u32::wrapping_mul(2, q2);
r2 = 2 * r2 + 1;
}
let delta: u32 = d - 1 - r2;
if !(p < 64 && (q1 < delta || (q1 == delta && r1 == 0))) {
break;
}
}
MU32 {
mulBy: q2 + 1,
doAdd: do_add,
shiftBy: p - 32,
}
}
pub fn magicU64(d: u64) -> MU64 {
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1);
let mut do_add: bool = false;
let mut p: i32 = 63;
let nc: u64 = 0xFFFFFFFFFFFFFFFFu64 - u64::wrapping_neg(d) % d;
let mut q1: u64 = 0x8000000000000000u64 / nc;
let mut r1: u64 = 0x8000000000000000u64 - q1 * nc;
let mut q2: u64 = 0x7FFFFFFFFFFFFFFFu64 / d;
let mut r2: u64 = 0x7FFFFFFFFFFFFFFFu64 - q2 * d;
loop {
p = p + 1;
if r1 >= nc - r1 {
q1 = u64::wrapping_add(u64::wrapping_mul(2, q1), 1);
r1 = u64::wrapping_sub(u64::wrapping_mul(2, r1), nc);
} else {
q1 = 2 * q1;
r1 = 2 * r1;
}
if r2 + 1 >= d - r2 {
if q2 >= 0x7FFFFFFFFFFFFFFFu64 {
do_add = true;
}
q2 = 2 * q2 + 1;
r2 = u64::wrapping_sub(u64::wrapping_add(u64::wrapping_mul(2, r2), 1), d);
} else {
if q2 >= 0x8000000000000000u64 {
do_add = true;
}
q2 = u64::wrapping_mul(2, q2);
r2 = 2 * r2 + 1;
}
let delta: u64 = d - 1 - r2;
if !(p < 128 && (q1 < delta || (q1 == delta && r1 == 0))) {
break;
}
}
MU64 {
mulBy: q2 + 1,
doAdd: do_add,
shiftBy: p - 64,
}
}
pub fn magicS32(d: i32) -> MS32 {
debug_assert_ne!(d, -1);
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1);
let two31: u32 = 0x80000000u32;
let mut p: i32 = 31;
let ad: u32 = i32::wrapping_abs(d) as u32;
let t: u32 = two31 + ((d as u32) >> 31);
let anc: u32 = u32::wrapping_sub(t - 1, t % ad);
let mut q1: u32 = two31 / anc;
let mut r1: u32 = two31 - q1 * anc;
let mut q2: u32 = two31 / ad;
let mut r2: u32 = two31 - q2 * ad;
loop {
p = p + 1;
q1 = 2 * q1;
r1 = 2 * r1;
if r1 >= anc {
q1 = q1 + 1;
r1 = r1 - anc;
}
q2 = 2 * q2;
r2 = 2 * r2;
if r2 >= ad {
q2 = q2 + 1;
r2 = r2 - ad;
}
let delta: u32 = ad - r2;
if !(q1 < delta || (q1 == delta && r1 == 0)) {
break;
}
}
MS32 {
mulBy: (if d < 0 {
u32::wrapping_neg(q2 + 1)
} else {
q2 + 1
}) as i32,
shiftBy: p - 32,
}
}
pub fn magicS64(d: i64) -> MS64 {
debug_assert_ne!(d, -1);
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1);
let two63: u64 = 0x8000000000000000u64;
let mut p: i32 = 63;
let ad: u64 = i64::wrapping_abs(d) as u64;
let t: u64 = two63 + ((d as u64) >> 63);
let anc: u64 = u64::wrapping_sub(t - 1, t % ad);
let mut q1: u64 = two63 / anc;
let mut r1: u64 = two63 - q1 * anc;
let mut q2: u64 = two63 / ad;
let mut r2: u64 = two63 - q2 * ad;
loop {
p = p + 1;
q1 = 2 * q1;
r1 = 2 * r1;
if r1 >= anc {
q1 = q1 + 1;
r1 = r1 - anc;
}
q2 = 2 * q2;
r2 = 2 * r2;
if r2 >= ad {
q2 = q2 + 1;
r2 = r2 - ad;
}
let delta: u64 = ad - r2;
if !(q1 < delta || (q1 == delta && r1 == 0)) {
break;
}
}
MS64 {
mulBy: (if d < 0 {
u64::wrapping_neg(q2 + 1)
} else {
q2 + 1
}) as i64,
shiftBy: p - 64,
}
}
#[cfg(test)]
mod tests {
use super::{magicS32, magicS64, magicU32, magicU64};
use super::{MS32, MS64, MU32, MU64};
fn mkMU32(mulBy: u32, doAdd: bool, shiftBy: i32) -> MU32 {
MU32 {
mulBy,
doAdd,
shiftBy,
}
}
fn mkMU64(mulBy: u64, doAdd: bool, shiftBy: i32) -> MU64 {
MU64 {
mulBy,
doAdd,
shiftBy,
}
}
fn mkMS32(mulBy: i32, shiftBy: i32) -> MS32 {
MS32 { mulBy, shiftBy }
}
fn mkMS64(mulBy: i64, shiftBy: i32) -> MS64 {
MS64 { mulBy, shiftBy }
}
#[test]
fn test_magicU32() {
assert_eq!(magicU32(2u32), mkMU32(0x80000000u32, false, 0));
assert_eq!(magicU32(3u32), mkMU32(0xaaaaaaabu32, false, 1));
assert_eq!(magicU32(4u32), mkMU32(0x40000000u32, false, 0));
assert_eq!(magicU32(5u32), mkMU32(0xcccccccdu32, false, 2));
assert_eq!(magicU32(6u32), mkMU32(0xaaaaaaabu32, false, 2));
assert_eq!(magicU32(7u32), mkMU32(0x24924925u32, true, 3));
assert_eq!(magicU32(9u32), mkMU32(0x38e38e39u32, false, 1));
assert_eq!(magicU32(10u32), mkMU32(0xcccccccdu32, false, 3));
assert_eq!(magicU32(11u32), mkMU32(0xba2e8ba3u32, false, 3));
assert_eq!(magicU32(12u32), mkMU32(0xaaaaaaabu32, false, 3));
assert_eq!(magicU32(25u32), mkMU32(0x51eb851fu32, false, 3));
assert_eq!(magicU32(125u32), mkMU32(0x10624dd3u32, false, 3));
assert_eq!(magicU32(625u32), mkMU32(0xd1b71759u32, false, 9));
assert_eq!(magicU32(1337u32), mkMU32(0x88233b2bu32, true, 11));
assert_eq!(magicU32(65535u32), mkMU32(0x80008001u32, false, 15));
assert_eq!(magicU32(65536u32), mkMU32(0x00010000u32, false, 0));
assert_eq!(magicU32(65537u32), mkMU32(0xffff0001u32, false, 16));
assert_eq!(magicU32(31415927u32), mkMU32(0x445b4553u32, false, 23));
assert_eq!(magicU32(0xdeadbeefu32), mkMU32(0x93275ab3u32, false, 31));
assert_eq!(magicU32(0xfffffffdu32), mkMU32(0x40000001u32, false, 30));
assert_eq!(magicU32(0xfffffffeu32), mkMU32(0x00000003u32, true, 32));
assert_eq!(magicU32(0xffffffffu32), mkMU32(0x80000001u32, false, 31));
}
#[test]
fn test_magicU64() {
assert_eq!(magicU64(2u64), mkMU64(0x8000000000000000u64, false, 0));
assert_eq!(magicU64(3u64), mkMU64(0xaaaaaaaaaaaaaaabu64, false, 1));
assert_eq!(magicU64(4u64), mkMU64(0x4000000000000000u64, false, 0));
assert_eq!(magicU64(5u64), mkMU64(0xcccccccccccccccdu64, false, 2));
assert_eq!(magicU64(6u64), mkMU64(0xaaaaaaaaaaaaaaabu64, false, 2));
assert_eq!(magicU64(7u64), mkMU64(0x2492492492492493u64, true, 3));
assert_eq!(magicU64(9u64), mkMU64(0xe38e38e38e38e38fu64, false, 3));
assert_eq!(magicU64(10u64), mkMU64(0xcccccccccccccccdu64, false, 3));
assert_eq!(magicU64(11u64), mkMU64(0x2e8ba2e8ba2e8ba3u64, false, 1));
assert_eq!(magicU64(12u64), mkMU64(0xaaaaaaaaaaaaaaabu64, false, 3));
assert_eq!(magicU64(25u64), mkMU64(0x47ae147ae147ae15u64, true, 5));
assert_eq!(magicU64(125u64), mkMU64(0x0624dd2f1a9fbe77u64, true, 7));
assert_eq!(magicU64(625u64), mkMU64(0x346dc5d63886594bu64, false, 7));
assert_eq!(magicU64(1337u64), mkMU64(0xc4119d952866a139u64, false, 10));
assert_eq!(
magicU64(31415927u64),
mkMU64(0x116d154b9c3d2f85u64, true, 25)
);
assert_eq!(
magicU64(0x00000000deadbeefu64),
mkMU64(0x93275ab2dfc9094bu64, false, 31)
);
assert_eq!(
magicU64(0x00000000fffffffdu64),
mkMU64(0x8000000180000005u64, false, 31)
);
assert_eq!(
magicU64(0x00000000fffffffeu64),
mkMU64(0x0000000200000005u64, true, 32)
);
assert_eq!(
magicU64(0x00000000ffffffffu64),
mkMU64(0x8000000080000001u64, false, 31)
);
assert_eq!(
magicU64(0x0000000100000000u64),
mkMU64(0x0000000100000000u64, false, 0)
);
assert_eq!(
magicU64(0x0000000100000001u64),
mkMU64(0xffffffff00000001u64, false, 32)
);
assert_eq!(
magicU64(0x0ddc0ffeebadf00du64),
mkMU64(0x2788e9d394b77da1u64, true, 60)
);
assert_eq!(
magicU64(0xfffffffffffffffdu64),
mkMU64(0x4000000000000001u64, false, 62)
);
assert_eq!(
magicU64(0xfffffffffffffffeu64),
mkMU64(0x0000000000000003u64, true, 64)
);
assert_eq!(
magicU64(0xffffffffffffffffu64),
mkMU64(0x8000000000000001u64, false, 63)
);
}
#[test]
fn test_magicS32() {
assert_eq!(magicS32(-0x80000000i32), mkMS32(0x7fffffffu32 as i32, 30));
assert_eq!(magicS32(-0x7FFFFFFFi32), mkMS32(0xbfffffffu32 as i32, 29));
assert_eq!(magicS32(-0x7FFFFFFEi32), mkMS32(0x7ffffffdu32 as i32, 30));
assert_eq!(magicS32(-31415927i32), mkMS32(0xbba4baadu32 as i32, 23));
assert_eq!(magicS32(-1337i32), mkMS32(0x9df73135u32 as i32, 9));
assert_eq!(magicS32(-256i32), mkMS32(0x7fffffffu32 as i32, 7));
assert_eq!(magicS32(-5i32), mkMS32(0x99999999u32 as i32, 1));
assert_eq!(magicS32(-3i32), mkMS32(0x55555555u32 as i32, 1));
assert_eq!(magicS32(-2i32), mkMS32(0x7fffffffu32 as i32, 0));
assert_eq!(magicS32(2i32), mkMS32(0x80000001u32 as i32, 0));
assert_eq!(magicS32(3i32), mkMS32(0x55555556u32 as i32, 0));
assert_eq!(magicS32(4i32), mkMS32(0x80000001u32 as i32, 1));
assert_eq!(magicS32(5i32), mkMS32(0x66666667u32 as i32, 1));
assert_eq!(magicS32(6i32), mkMS32(0x2aaaaaabu32 as i32, 0));
assert_eq!(magicS32(7i32), mkMS32(0x92492493u32 as i32, 2));
assert_eq!(magicS32(9i32), mkMS32(0x38e38e39u32 as i32, 1));
assert_eq!(magicS32(10i32), mkMS32(0x66666667u32 as i32, 2));
assert_eq!(magicS32(11i32), mkMS32(0x2e8ba2e9u32 as i32, 1));
assert_eq!(magicS32(12i32), mkMS32(0x2aaaaaabu32 as i32, 1));
assert_eq!(magicS32(25i32), mkMS32(0x51eb851fu32 as i32, 3));
assert_eq!(magicS32(125i32), mkMS32(0x10624dd3u32 as i32, 3));
assert_eq!(magicS32(625i32), mkMS32(0x68db8badu32 as i32, 8));
assert_eq!(magicS32(1337i32), mkMS32(0x6208cecbu32 as i32, 9));
assert_eq!(magicS32(31415927i32), mkMS32(0x445b4553u32 as i32, 23));
assert_eq!(magicS32(0x7ffffffei32), mkMS32(0x80000003u32 as i32, 30));
assert_eq!(magicS32(0x7fffffffi32), mkMS32(0x40000001u32 as i32, 29));
}
#[test]
fn test_magicS64() {
assert_eq!(
magicS64(-0x8000000000000000i64),
mkMS64(0x7fffffffffffffffu64 as i64, 62)
);
assert_eq!(
magicS64(-0x7FFFFFFFFFFFFFFFi64),
mkMS64(0xbfffffffffffffffu64 as i64, 61)
);
assert_eq!(
magicS64(-0x7FFFFFFFFFFFFFFEi64),
mkMS64(0x7ffffffffffffffdu64 as i64, 62)
);
assert_eq!(
magicS64(-0x0ddC0ffeeBadF00di64),
mkMS64(0x6c3b8b1635a4412fu64 as i64, 59)
);
assert_eq!(
magicS64(-0x100000001i64),
mkMS64(0x800000007fffffffu64 as i64, 31)
);
assert_eq!(
magicS64(-0x100000000i64),
mkMS64(0x7fffffffffffffffu64 as i64, 31)
);
assert_eq!(
magicS64(-0xFFFFFFFFi64),
mkMS64(0x7fffffff7fffffffu64 as i64, 31)
);
assert_eq!(
magicS64(-0xFFFFFFFEi64),
mkMS64(0x7ffffffefffffffdu64 as i64, 31)
);
assert_eq!(
magicS64(-0xFFFFFFFDi64),
mkMS64(0x7ffffffe7ffffffbu64 as i64, 31)
);
assert_eq!(
magicS64(-0xDeadBeefi64),
mkMS64(0x6cd8a54d2036f6b5u64 as i64, 31)
);
assert_eq!(
magicS64(-31415927i64),
mkMS64(0x7749755a31e1683du64 as i64, 24)
);
assert_eq!(magicS64(-1337i64), mkMS64(0x9df731356bccaf63u64 as i64, 9));
assert_eq!(magicS64(-256i64), mkMS64(0x7fffffffffffffffu64 as i64, 7));
assert_eq!(magicS64(-5i64), mkMS64(0x9999999999999999u64 as i64, 1));
assert_eq!(magicS64(-3i64), mkMS64(0x5555555555555555u64 as i64, 1));
assert_eq!(magicS64(-2i64), mkMS64(0x7fffffffffffffffu64 as i64, 0));
assert_eq!(magicS64(2i64), mkMS64(0x8000000000000001u64 as i64, 0));
assert_eq!(magicS64(3i64), mkMS64(0x5555555555555556u64 as i64, 0));
assert_eq!(magicS64(4i64), mkMS64(0x8000000000000001u64 as i64, 1));
assert_eq!(magicS64(5i64), mkMS64(0x6666666666666667u64 as i64, 1));
assert_eq!(magicS64(6i64), mkMS64(0x2aaaaaaaaaaaaaabu64 as i64, 0));
assert_eq!(magicS64(7i64), mkMS64(0x4924924924924925u64 as i64, 1));
assert_eq!(magicS64(9i64), mkMS64(0x1c71c71c71c71c72u64 as i64, 0));
assert_eq!(magicS64(10i64), mkMS64(0x6666666666666667u64 as i64, 2));
assert_eq!(magicS64(11i64), mkMS64(0x2e8ba2e8ba2e8ba3u64 as i64, 1));
assert_eq!(magicS64(12i64), mkMS64(0x2aaaaaaaaaaaaaabu64 as i64, 1));
assert_eq!(magicS64(25i64), mkMS64(0xa3d70a3d70a3d70bu64 as i64, 4));
assert_eq!(magicS64(125i64), mkMS64(0x20c49ba5e353f7cfu64 as i64, 4));
assert_eq!(magicS64(625i64), mkMS64(0x346dc5d63886594bu64 as i64, 7));
assert_eq!(magicS64(1337i64), mkMS64(0x6208ceca9433509du64 as i64, 9));
assert_eq!(
magicS64(31415927i64),
mkMS64(0x88b68aa5ce1e97c3u64 as i64, 24)
);
assert_eq!(
magicS64(0x00000000deadbeefi64),
mkMS64(0x93275ab2dfc9094bu64 as i64, 31)
);
assert_eq!(
magicS64(0x00000000fffffffdi64),
mkMS64(0x8000000180000005u64 as i64, 31)
);
assert_eq!(
magicS64(0x00000000fffffffei64),
mkMS64(0x8000000100000003u64 as i64, 31)
);
assert_eq!(
magicS64(0x00000000ffffffffi64),
mkMS64(0x8000000080000001u64 as i64, 31)
);
assert_eq!(
magicS64(0x0000000100000000i64),
mkMS64(0x8000000000000001u64 as i64, 31)
);
assert_eq!(
magicS64(0x0000000100000001i64),
mkMS64(0x7fffffff80000001u64 as i64, 31)
);
assert_eq!(
magicS64(0x0ddc0ffeebadf00di64),
mkMS64(0x93c474e9ca5bbed1u64 as i64, 59)
);
assert_eq!(
magicS64(0x7ffffffffffffffdi64),
mkMS64(0x2000000000000001u64 as i64, 60)
);
assert_eq!(
magicS64(0x7ffffffffffffffei64),
mkMS64(0x8000000000000003u64 as i64, 62)
);
assert_eq!(
magicS64(0x7fffffffffffffffi64),
mkMS64(0x4000000000000001u64 as i64, 61)
);
}
#[test]
fn test_magic_generators_dont_panic() {
let mut total: u64 = 0;
for x in 2..(200 * 1000u32) {
let m = magicU32(x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
total = total - (if m.doAdd { 123 } else { 456 });
}
assert_eq!(total, 1747815691);
for x in 0..(200 * 1000u32) {
let m = magicU32(0xFFFF_FFFFu32 - x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
total = total - (if m.doAdd { 123 } else { 456 });
}
assert_eq!(total, 2210292772);
for x in 2..(200 * 1000u64) {
let m = magicU64(x);
total = total ^ m.mulBy;
total = total + (m.shiftBy as u64);
total = total - (if m.doAdd { 123 } else { 456 });
}
assert_eq!(total, 7430004084791260605);
for x in 0..(200 * 1000u64) {
let m = magicU64(0xFFFF_FFFF_FFFF_FFFFu64 - x);
total = total ^ m.mulBy;
total = total + (m.shiftBy as u64);
total = total - (if m.doAdd { 123 } else { 456 });
}
assert_eq!(total, 7547519887519825919);
for x in 0..(200 * 1000i32) {
let m = magicS32(-0x8000_0000i32 + x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
}
assert_eq!(total, 10899224186731671235);
for x in 0..(200 * 1000i32) {
let m = magicS32(0x7FFF_FFFFi32 - x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
}
assert_eq!(total, 7547519887517897369);
for x in 0..(200 * 1000i64) {
let m = magicS64(-0x8000_0000_0000_0000i64 + x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
}
assert_eq!(total, 8029756891368555163);
for x in 0..(200 * 1000i64) {
let m = magicS64(0x7FFF_FFFF_FFFF_FFFFi64 - x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
}
assert_eq!(total, 7547519887532559585u64);
}
}