Use snake case for magic numbers computation;

This commit is contained in:
Benjamin Bouvier
2018-11-15 12:44:14 +01:00
committed by Dan Gohman
parent e9cb50313d
commit 7e42966c68
2 changed files with 230 additions and 232 deletions

View File

@@ -8,39 +8,37 @@
//! so as to emphasise the similarity of the U32 and U64 cases and the S32
//! and S64 cases.
#![allow(non_snake_case)]
// Structures to hold the "magic numbers" computed.
#[derive(PartialEq, Debug)]
pub struct MU32 {
pub mulBy: u32,
pub doAdd: bool,
pub shiftBy: i32,
pub mul_by: u32,
pub do_add: bool,
pub shift_by: i32,
}
#[derive(PartialEq, Debug)]
pub struct MU64 {
pub mulBy: u64,
pub doAdd: bool,
pub shiftBy: i32,
pub mul_by: u64,
pub do_add: bool,
pub shift_by: i32,
}
#[derive(PartialEq, Debug)]
pub struct MS32 {
pub mulBy: i32,
pub shiftBy: i32,
pub mul_by: i32,
pub shift_by: i32,
}
#[derive(PartialEq, Debug)]
pub struct MS64 {
pub mulBy: i64,
pub shiftBy: i32,
pub mul_by: i64,
pub shift_by: i32,
}
// The actual "magic number" generators follow.
pub fn magicU32(d: u32) -> MU32 {
pub fn magic_u32(d: u32) -> MU32 {
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1); // d==1 generates out of range shifts.
@@ -80,13 +78,13 @@ pub fn magicU32(d: u32) -> MU32 {
}
MU32 {
mulBy: q2 + 1,
doAdd: do_add,
shiftBy: p - 32,
mul_by: q2 + 1,
do_add: do_add,
shift_by: p - 32,
}
}
pub fn magicU64(d: u64) -> MU64 {
pub fn magic_u64(d: u64) -> MU64 {
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1); // d==1 generates out of range shifts.
@@ -126,13 +124,13 @@ pub fn magicU64(d: u64) -> MU64 {
}
MU64 {
mulBy: q2 + 1,
doAdd: do_add,
shiftBy: p - 64,
mul_by: q2 + 1,
do_add: do_add,
shift_by: p - 64,
}
}
pub fn magicS32(d: i32) -> MS32 {
pub fn magic_s32(d: i32) -> MS32 {
debug_assert_ne!(d, -1);
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1);
@@ -166,16 +164,16 @@ pub fn magicS32(d: i32) -> MS32 {
}
MS32 {
mulBy: (if d < 0 {
mul_by: (if d < 0 {
u32::wrapping_neg(q2 + 1)
} else {
q2 + 1
}) as i32,
shiftBy: p - 32,
shift_by: p - 32,
}
}
pub fn magicS64(d: i64) -> MS64 {
pub fn magic_s64(d: i64) -> MS64 {
debug_assert_ne!(d, -1);
debug_assert_ne!(d, 0);
debug_assert_ne!(d, 1);
@@ -209,266 +207,266 @@ pub fn magicS64(d: i64) -> MS64 {
}
MS64 {
mulBy: (if d < 0 {
mul_by: (if d < 0 {
u64::wrapping_neg(q2 + 1)
} else {
q2 + 1
}) as i64,
shiftBy: p - 64,
shift_by: p - 64,
}
}
#[cfg(test)]
mod tests {
use super::{magicS32, magicS64, magicU32, magicU64};
use super::{magic_s32, magic_s64, magic_u32, magic_u64};
use super::{MS32, MS64, MU32, MU64};
fn mkMU32(mulBy: u32, doAdd: bool, shiftBy: i32) -> MU32 {
fn mkMU32(mul_by: u32, do_add: bool, shift_by: i32) -> MU32 {
MU32 {
mulBy,
doAdd,
shiftBy,
mul_by,
do_add,
shift_by,
}
}
fn mkMU64(mulBy: u64, doAdd: bool, shiftBy: i32) -> MU64 {
fn mkMU64(mul_by: u64, do_add: bool, shift_by: i32) -> MU64 {
MU64 {
mulBy,
doAdd,
shiftBy,
mul_by,
do_add,
shift_by,
}
}
fn mkMS32(mulBy: i32, shiftBy: i32) -> MS32 {
MS32 { mulBy, shiftBy }
fn mkMS32(mul_by: i32, shift_by: i32) -> MS32 {
MS32 { mul_by, shift_by }
}
fn mkMS64(mulBy: i64, shiftBy: i32) -> MS64 {
MS64 { mulBy, shiftBy }
fn mkMS64(mul_by: i64, shift_by: i32) -> MS64 {
MS64 { mul_by, shift_by }
}
#[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));
assert_eq!(magic_u32(2u32), mkMU32(0x80000000u32, false, 0));
assert_eq!(magic_u32(3u32), mkMU32(0xaaaaaaabu32, false, 1));
assert_eq!(magic_u32(4u32), mkMU32(0x40000000u32, false, 0));
assert_eq!(magic_u32(5u32), mkMU32(0xcccccccdu32, false, 2));
assert_eq!(magic_u32(6u32), mkMU32(0xaaaaaaabu32, false, 2));
assert_eq!(magic_u32(7u32), mkMU32(0x24924925u32, true, 3));
assert_eq!(magic_u32(9u32), mkMU32(0x38e38e39u32, false, 1));
assert_eq!(magic_u32(10u32), mkMU32(0xcccccccdu32, false, 3));
assert_eq!(magic_u32(11u32), mkMU32(0xba2e8ba3u32, false, 3));
assert_eq!(magic_u32(12u32), mkMU32(0xaaaaaaabu32, false, 3));
assert_eq!(magic_u32(25u32), mkMU32(0x51eb851fu32, false, 3));
assert_eq!(magic_u32(125u32), mkMU32(0x10624dd3u32, false, 3));
assert_eq!(magic_u32(625u32), mkMU32(0xd1b71759u32, false, 9));
assert_eq!(magic_u32(1337u32), mkMU32(0x88233b2bu32, true, 11));
assert_eq!(magic_u32(65535u32), mkMU32(0x80008001u32, false, 15));
assert_eq!(magic_u32(65536u32), mkMU32(0x00010000u32, false, 0));
assert_eq!(magic_u32(65537u32), mkMU32(0xffff0001u32, false, 16));
assert_eq!(magic_u32(31415927u32), mkMU32(0x445b4553u32, false, 23));
assert_eq!(magic_u32(0xdeadbeefu32), mkMU32(0x93275ab3u32, false, 31));
assert_eq!(magic_u32(0xfffffffdu32), mkMU32(0x40000001u32, false, 30));
assert_eq!(magic_u32(0xfffffffeu32), mkMU32(0x00000003u32, true, 32));
assert_eq!(magic_u32(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!(magic_u64(2u64), mkMU64(0x8000000000000000u64, false, 0));
assert_eq!(magic_u64(3u64), mkMU64(0xaaaaaaaaaaaaaaabu64, false, 1));
assert_eq!(magic_u64(4u64), mkMU64(0x4000000000000000u64, false, 0));
assert_eq!(magic_u64(5u64), mkMU64(0xcccccccccccccccdu64, false, 2));
assert_eq!(magic_u64(6u64), mkMU64(0xaaaaaaaaaaaaaaabu64, false, 2));
assert_eq!(magic_u64(7u64), mkMU64(0x2492492492492493u64, true, 3));
assert_eq!(magic_u64(9u64), mkMU64(0xe38e38e38e38e38fu64, false, 3));
assert_eq!(magic_u64(10u64), mkMU64(0xcccccccccccccccdu64, false, 3));
assert_eq!(magic_u64(11u64), mkMU64(0x2e8ba2e8ba2e8ba3u64, false, 1));
assert_eq!(magic_u64(12u64), mkMU64(0xaaaaaaaaaaaaaaabu64, false, 3));
assert_eq!(magic_u64(25u64), mkMU64(0x47ae147ae147ae15u64, true, 5));
assert_eq!(magic_u64(125u64), mkMU64(0x0624dd2f1a9fbe77u64, true, 7));
assert_eq!(magic_u64(625u64), mkMU64(0x346dc5d63886594bu64, false, 7));
assert_eq!(magic_u64(1337u64), mkMU64(0xc4119d952866a139u64, false, 10));
assert_eq!(
magicU64(31415927u64),
magic_u64(31415927u64),
mkMU64(0x116d154b9c3d2f85u64, true, 25)
);
assert_eq!(
magicU64(0x00000000deadbeefu64),
magic_u64(0x00000000deadbeefu64),
mkMU64(0x93275ab2dfc9094bu64, false, 31)
);
assert_eq!(
magicU64(0x00000000fffffffdu64),
magic_u64(0x00000000fffffffdu64),
mkMU64(0x8000000180000005u64, false, 31)
);
assert_eq!(
magicU64(0x00000000fffffffeu64),
magic_u64(0x00000000fffffffeu64),
mkMU64(0x0000000200000005u64, true, 32)
);
assert_eq!(
magicU64(0x00000000ffffffffu64),
magic_u64(0x00000000ffffffffu64),
mkMU64(0x8000000080000001u64, false, 31)
);
assert_eq!(
magicU64(0x0000000100000000u64),
magic_u64(0x0000000100000000u64),
mkMU64(0x0000000100000000u64, false, 0)
);
assert_eq!(
magicU64(0x0000000100000001u64),
magic_u64(0x0000000100000001u64),
mkMU64(0xffffffff00000001u64, false, 32)
);
assert_eq!(
magicU64(0x0ddc0ffeebadf00du64),
magic_u64(0x0ddc0ffeebadf00du64),
mkMU64(0x2788e9d394b77da1u64, true, 60)
);
assert_eq!(
magicU64(0xfffffffffffffffdu64),
magic_u64(0xfffffffffffffffdu64),
mkMU64(0x4000000000000001u64, false, 62)
);
assert_eq!(
magicU64(0xfffffffffffffffeu64),
magic_u64(0xfffffffffffffffeu64),
mkMU64(0x0000000000000003u64, true, 64)
);
assert_eq!(
magicU64(0xffffffffffffffffu64),
magic_u64(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));
assert_eq!(magic_s32(-0x80000000i32), mkMS32(0x7fffffffu32 as i32, 30));
assert_eq!(magic_s32(-0x7FFFFFFFi32), mkMS32(0xbfffffffu32 as i32, 29));
assert_eq!(magic_s32(-0x7FFFFFFEi32), mkMS32(0x7ffffffdu32 as i32, 30));
assert_eq!(magic_s32(-31415927i32), mkMS32(0xbba4baadu32 as i32, 23));
assert_eq!(magic_s32(-1337i32), mkMS32(0x9df73135u32 as i32, 9));
assert_eq!(magic_s32(-256i32), mkMS32(0x7fffffffu32 as i32, 7));
assert_eq!(magic_s32(-5i32), mkMS32(0x99999999u32 as i32, 1));
assert_eq!(magic_s32(-3i32), mkMS32(0x55555555u32 as i32, 1));
assert_eq!(magic_s32(-2i32), mkMS32(0x7fffffffu32 as i32, 0));
assert_eq!(magic_s32(2i32), mkMS32(0x80000001u32 as i32, 0));
assert_eq!(magic_s32(3i32), mkMS32(0x55555556u32 as i32, 0));
assert_eq!(magic_s32(4i32), mkMS32(0x80000001u32 as i32, 1));
assert_eq!(magic_s32(5i32), mkMS32(0x66666667u32 as i32, 1));
assert_eq!(magic_s32(6i32), mkMS32(0x2aaaaaabu32 as i32, 0));
assert_eq!(magic_s32(7i32), mkMS32(0x92492493u32 as i32, 2));
assert_eq!(magic_s32(9i32), mkMS32(0x38e38e39u32 as i32, 1));
assert_eq!(magic_s32(10i32), mkMS32(0x66666667u32 as i32, 2));
assert_eq!(magic_s32(11i32), mkMS32(0x2e8ba2e9u32 as i32, 1));
assert_eq!(magic_s32(12i32), mkMS32(0x2aaaaaabu32 as i32, 1));
assert_eq!(magic_s32(25i32), mkMS32(0x51eb851fu32 as i32, 3));
assert_eq!(magic_s32(125i32), mkMS32(0x10624dd3u32 as i32, 3));
assert_eq!(magic_s32(625i32), mkMS32(0x68db8badu32 as i32, 8));
assert_eq!(magic_s32(1337i32), mkMS32(0x6208cecbu32 as i32, 9));
assert_eq!(magic_s32(31415927i32), mkMS32(0x445b4553u32 as i32, 23));
assert_eq!(magic_s32(0x7ffffffei32), mkMS32(0x80000003u32 as i32, 30));
assert_eq!(magic_s32(0x7fffffffi32), mkMS32(0x40000001u32 as i32, 29));
}
#[test]
fn test_magicS64() {
assert_eq!(
magicS64(-0x8000000000000000i64),
magic_s64(-0x8000000000000000i64),
mkMS64(0x7fffffffffffffffu64 as i64, 62)
);
assert_eq!(
magicS64(-0x7FFFFFFFFFFFFFFFi64),
magic_s64(-0x7FFFFFFFFFFFFFFFi64),
mkMS64(0xbfffffffffffffffu64 as i64, 61)
);
assert_eq!(
magicS64(-0x7FFFFFFFFFFFFFFEi64),
magic_s64(-0x7FFFFFFFFFFFFFFEi64),
mkMS64(0x7ffffffffffffffdu64 as i64, 62)
);
assert_eq!(
magicS64(-0x0ddC0ffeeBadF00di64),
magic_s64(-0x0ddC0ffeeBadF00di64),
mkMS64(0x6c3b8b1635a4412fu64 as i64, 59)
);
assert_eq!(
magicS64(-0x100000001i64),
magic_s64(-0x100000001i64),
mkMS64(0x800000007fffffffu64 as i64, 31)
);
assert_eq!(
magicS64(-0x100000000i64),
magic_s64(-0x100000000i64),
mkMS64(0x7fffffffffffffffu64 as i64, 31)
);
assert_eq!(
magicS64(-0xFFFFFFFFi64),
magic_s64(-0xFFFFFFFFi64),
mkMS64(0x7fffffff7fffffffu64 as i64, 31)
);
assert_eq!(
magicS64(-0xFFFFFFFEi64),
magic_s64(-0xFFFFFFFEi64),
mkMS64(0x7ffffffefffffffdu64 as i64, 31)
);
assert_eq!(
magicS64(-0xFFFFFFFDi64),
magic_s64(-0xFFFFFFFDi64),
mkMS64(0x7ffffffe7ffffffbu64 as i64, 31)
);
assert_eq!(
magicS64(-0xDeadBeefi64),
magic_s64(-0xDeadBeefi64),
mkMS64(0x6cd8a54d2036f6b5u64 as i64, 31)
);
assert_eq!(
magicS64(-31415927i64),
magic_s64(-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!(magic_s64(-1337i64), mkMS64(0x9df731356bccaf63u64 as i64, 9));
assert_eq!(magic_s64(-256i64), mkMS64(0x7fffffffffffffffu64 as i64, 7));
assert_eq!(magic_s64(-5i64), mkMS64(0x9999999999999999u64 as i64, 1));
assert_eq!(magic_s64(-3i64), mkMS64(0x5555555555555555u64 as i64, 1));
assert_eq!(magic_s64(-2i64), mkMS64(0x7fffffffffffffffu64 as i64, 0));
assert_eq!(magic_s64(2i64), mkMS64(0x8000000000000001u64 as i64, 0));
assert_eq!(magic_s64(3i64), mkMS64(0x5555555555555556u64 as i64, 0));
assert_eq!(magic_s64(4i64), mkMS64(0x8000000000000001u64 as i64, 1));
assert_eq!(magic_s64(5i64), mkMS64(0x6666666666666667u64 as i64, 1));
assert_eq!(magic_s64(6i64), mkMS64(0x2aaaaaaaaaaaaaabu64 as i64, 0));
assert_eq!(magic_s64(7i64), mkMS64(0x4924924924924925u64 as i64, 1));
assert_eq!(magic_s64(9i64), mkMS64(0x1c71c71c71c71c72u64 as i64, 0));
assert_eq!(magic_s64(10i64), mkMS64(0x6666666666666667u64 as i64, 2));
assert_eq!(magic_s64(11i64), mkMS64(0x2e8ba2e8ba2e8ba3u64 as i64, 1));
assert_eq!(magic_s64(12i64), mkMS64(0x2aaaaaaaaaaaaaabu64 as i64, 1));
assert_eq!(magic_s64(25i64), mkMS64(0xa3d70a3d70a3d70bu64 as i64, 4));
assert_eq!(magic_s64(125i64), mkMS64(0x20c49ba5e353f7cfu64 as i64, 4));
assert_eq!(magic_s64(625i64), mkMS64(0x346dc5d63886594bu64 as i64, 7));
assert_eq!(magic_s64(1337i64), mkMS64(0x6208ceca9433509du64 as i64, 9));
assert_eq!(
magicS64(31415927i64),
magic_s64(31415927i64),
mkMS64(0x88b68aa5ce1e97c3u64 as i64, 24)
);
assert_eq!(
magicS64(0x00000000deadbeefi64),
magic_s64(0x00000000deadbeefi64),
mkMS64(0x93275ab2dfc9094bu64 as i64, 31)
);
assert_eq!(
magicS64(0x00000000fffffffdi64),
magic_s64(0x00000000fffffffdi64),
mkMS64(0x8000000180000005u64 as i64, 31)
);
assert_eq!(
magicS64(0x00000000fffffffei64),
magic_s64(0x00000000fffffffei64),
mkMS64(0x8000000100000003u64 as i64, 31)
);
assert_eq!(
magicS64(0x00000000ffffffffi64),
magic_s64(0x00000000ffffffffi64),
mkMS64(0x8000000080000001u64 as i64, 31)
);
assert_eq!(
magicS64(0x0000000100000000i64),
magic_s64(0x0000000100000000i64),
mkMS64(0x8000000000000001u64 as i64, 31)
);
assert_eq!(
magicS64(0x0000000100000001i64),
magic_s64(0x0000000100000001i64),
mkMS64(0x7fffffff80000001u64 as i64, 31)
);
assert_eq!(
magicS64(0x0ddc0ffeebadf00di64),
magic_s64(0x0ddc0ffeebadf00di64),
mkMS64(0x93c474e9ca5bbed1u64 as i64, 59)
);
assert_eq!(
magicS64(0x7ffffffffffffffdi64),
magic_s64(0x7ffffffffffffffdi64),
mkMS64(0x2000000000000001u64 as i64, 60)
);
assert_eq!(
magicS64(0x7ffffffffffffffei64),
magic_s64(0x7ffffffffffffffei64),
mkMS64(0x8000000000000003u64 as i64, 62)
);
assert_eq!(
magicS64(0x7fffffffffffffffi64),
magic_s64(0x7fffffffffffffffi64),
mkMS64(0x4000000000000001u64 as i64, 61)
);
}
@@ -478,67 +476,67 @@ mod tests {
// don't panic with integer wraparounds, especially at boundary
// cases for their arguments. The actual results are thrown away.
let mut total: u64 = 0;
// Testing UP magicU32
// Testing UP magic_u32
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 });
let m = magic_u32(x);
total = total ^ (m.mul_by as u64);
total = total + (m.shift_by as u64);
total = total - (if m.do_add { 123 } else { 456 });
}
assert_eq!(total, 1747815691);
// Testing DOWN magicU32
// Testing DOWN magic_u32
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 });
let m = magic_u32(0xFFFF_FFFFu32 - x);
total = total ^ (m.mul_by as u64);
total = total + (m.shift_by as u64);
total = total - (if m.do_add { 123 } else { 456 });
}
assert_eq!(total, 2210292772);
// Testing UP magicU64
// Testing UP magic_u64
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 });
let m = magic_u64(x);
total = total ^ m.mul_by;
total = total + (m.shift_by as u64);
total = total - (if m.do_add { 123 } else { 456 });
}
assert_eq!(total, 7430004084791260605);
// Testing DOWN magicU64
// Testing DOWN magic_u64
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 });
let m = magic_u64(0xFFFF_FFFF_FFFF_FFFFu64 - x);
total = total ^ m.mul_by;
total = total + (m.shift_by as u64);
total = total - (if m.do_add { 123 } else { 456 });
}
assert_eq!(total, 7547519887519825919);
// Testing UP magicS32
// Testing UP magic_s32
for x in 0..(200 * 1000i32) {
let m = magicS32(-0x8000_0000i32 + x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
let m = magic_s32(-0x8000_0000i32 + x);
total = total ^ (m.mul_by as u64);
total = total + (m.shift_by as u64);
}
assert_eq!(total, 10899224186731671235);
// Testing DOWN magicS32
// Testing DOWN magic_s32
for x in 0..(200 * 1000i32) {
let m = magicS32(0x7FFF_FFFFi32 - x);
total = total ^ (m.mulBy as u64);
total = total + (m.shiftBy as u64);
let m = magic_s32(0x7FFF_FFFFi32 - x);
total = total ^ (m.mul_by as u64);
total = total + (m.shift_by as u64);
}
assert_eq!(total, 7547519887517897369);
// Testing UP magicS64
// Testing UP magic_s64
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);
let m = magic_s64(-0x8000_0000_0000_0000i64 + x);
total = total ^ (m.mul_by as u64);
total = total + (m.shift_by as u64);
}
assert_eq!(total, 8029756891368555163);
// Testing DOWN magicS64
// Testing DOWN magic_s64
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);
let m = magic_s64(0x7FFF_FFFF_FFFF_FFFFi64 - x);
total = total ^ (m.mul_by as u64);
total = total + (m.shift_by as u64);
}
// Force `total` -- and hence, the entire computation -- to
// be used, so that rustc can't optimise it out.

View File

@@ -3,7 +3,7 @@
#![allow(non_snake_case)]
use crate::cursor::{Cursor, FuncCursor};
use crate::divconst_magic_numbers::{magicS32, magicS64, magicU32, magicU64};
use crate::divconst_magic_numbers::{magic_s32, magic_s64, magic_u32, magic_u64};
use crate::divconst_magic_numbers::{MS32, MS64, MU32, MU64};
use crate::ir::dfg::ValueDef;
use crate::ir::instructions::Opcode;
@@ -183,27 +183,27 @@ fn do_divrem_transformation(divrem_info: &DivRemByConstInfo, pos: &mut FuncCurso
DivRemByConstInfo::DivU32(n1, d) | DivRemByConstInfo::RemU32(n1, d) => {
debug_assert!(d >= 3);
let MU32 {
mulBy,
doAdd,
shiftBy,
} = magicU32(d);
mul_by,
do_add,
shift_by,
} = magic_u32(d);
let qf; // final quotient
let q0 = pos.ins().iconst(I32, mulBy as i64);
let q0 = pos.ins().iconst(I32, mul_by as i64);
let q1 = pos.ins().umulhi(n1, q0);
if doAdd {
debug_assert!(shiftBy >= 1 && shiftBy <= 32);
if do_add {
debug_assert!(shift_by >= 1 && shift_by <= 32);
let t1 = pos.ins().isub(n1, q1);
let t2 = pos.ins().ushr_imm(t1, 1);
let t3 = pos.ins().iadd(t2, q1);
// I never found any case where shiftBy == 1 here.
// I never found any case where shift_by == 1 here.
// So there's no attempt to fold out a zero shift.
debug_assert_ne!(shiftBy, 1);
qf = pos.ins().ushr_imm(t3, (shiftBy - 1) as i64);
debug_assert_ne!(shift_by, 1);
qf = pos.ins().ushr_imm(t3, (shift_by - 1) as i64);
} else {
debug_assert!(shiftBy >= 0 && shiftBy <= 31);
// Whereas there are known cases here for shiftBy == 0.
if shiftBy > 0 {
qf = pos.ins().ushr_imm(q1, shiftBy as i64);
debug_assert!(shift_by >= 0 && shift_by <= 31);
// Whereas there are known cases here for shift_by == 0.
if shift_by > 0 {
qf = pos.ins().ushr_imm(q1, shift_by as i64);
} else {
qf = q1;
}
@@ -253,27 +253,27 @@ fn do_divrem_transformation(divrem_info: &DivRemByConstInfo, pos: &mut FuncCurso
DivRemByConstInfo::DivU64(n1, d) | DivRemByConstInfo::RemU64(n1, d) => {
debug_assert!(d >= 3);
let MU64 {
mulBy,
doAdd,
shiftBy,
} = magicU64(d);
mul_by,
do_add,
shift_by,
} = magic_u64(d);
let qf; // final quotient
let q0 = pos.ins().iconst(I64, mulBy as i64);
let q0 = pos.ins().iconst(I64, mul_by as i64);
let q1 = pos.ins().umulhi(n1, q0);
if doAdd {
debug_assert!(shiftBy >= 1 && shiftBy <= 64);
if do_add {
debug_assert!(shift_by >= 1 && shift_by <= 64);
let t1 = pos.ins().isub(n1, q1);
let t2 = pos.ins().ushr_imm(t1, 1);
let t3 = pos.ins().iadd(t2, q1);
// I never found any case where shiftBy == 1 here.
// I never found any case where shift_by == 1 here.
// So there's no attempt to fold out a zero shift.
debug_assert_ne!(shiftBy, 1);
qf = pos.ins().ushr_imm(t3, (shiftBy - 1) as i64);
debug_assert_ne!(shift_by, 1);
qf = pos.ins().ushr_imm(t3, (shift_by - 1) as i64);
} else {
debug_assert!(shiftBy >= 0 && shiftBy <= 63);
// Whereas there are known cases here for shiftBy == 0.
if shiftBy > 0 {
qf = pos.ins().ushr_imm(q1, shiftBy as i64);
debug_assert!(shift_by >= 0 && shift_by <= 63);
// Whereas there are known cases here for shift_by == 0.
if shift_by > 0 {
qf = pos.ins().ushr_imm(q1, shift_by as i64);
} else {
qf = q1;
}
@@ -334,21 +334,21 @@ fn do_divrem_transformation(divrem_info: &DivRemByConstInfo, pos: &mut FuncCurso
} else {
// S32 div, rem by a non-power-of-2
debug_assert!(d < -2 || d > 2);
let MS32 { mulBy, shiftBy } = magicS32(d);
let q0 = pos.ins().iconst(I32, mulBy as i64);
let MS32 { mul_by, shift_by } = magic_s32(d);
let q0 = pos.ins().iconst(I32, mul_by as i64);
let q1 = pos.ins().smulhi(n1, q0);
let q2 = if d > 0 && mulBy < 0 {
let q2 = if d > 0 && mul_by < 0 {
pos.ins().iadd(q1, n1)
} else if d < 0 && mulBy > 0 {
} else if d < 0 && mul_by > 0 {
pos.ins().isub(q1, n1)
} else {
q1
};
debug_assert!(shiftBy >= 0 && shiftBy <= 31);
let q3 = if shiftBy == 0 {
debug_assert!(shift_by >= 0 && shift_by <= 31);
let q3 = if shift_by == 0 {
q2
} else {
pos.ins().sshr_imm(q2, shiftBy as i64)
pos.ins().sshr_imm(q2, shift_by as i64)
};
let t1 = pos.ins().ushr_imm(q3, 31);
let qf = pos.ins().iadd(q3, t1);
@@ -409,21 +409,21 @@ fn do_divrem_transformation(divrem_info: &DivRemByConstInfo, pos: &mut FuncCurso
} else {
// S64 div, rem by a non-power-of-2
debug_assert!(d < -2 || d > 2);
let MS64 { mulBy, shiftBy } = magicS64(d);
let q0 = pos.ins().iconst(I64, mulBy);
let MS64 { mul_by, shift_by } = magic_s64(d);
let q0 = pos.ins().iconst(I64, mul_by);
let q1 = pos.ins().smulhi(n1, q0);
let q2 = if d > 0 && mulBy < 0 {
let q2 = if d > 0 && mul_by < 0 {
pos.ins().iadd(q1, n1)
} else if d < 0 && mulBy > 0 {
} else if d < 0 && mul_by > 0 {
pos.ins().isub(q1, n1)
} else {
q1
};
debug_assert!(shiftBy >= 0 && shiftBy <= 63);
let q3 = if shiftBy == 0 {
debug_assert!(shift_by >= 0 && shift_by <= 63);
let q3 = if shift_by == 0 {
q2
} else {
pos.ins().sshr_imm(q2, shiftBy as i64)
pos.ins().sshr_imm(q2, shift_by as i64)
};
let t1 = pos.ins().ushr_imm(q3, 63);
let qf = pos.ins().iadd(q3, t1);