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| 1 | +use Int; |
| 2 | + |
| 3 | +macro_rules! div { |
| 4 | + ($intrinsic:ident: $ty:ty, $uty:ty) => { |
| 5 | + /// Returns `a / b` |
| 6 | + #[cfg_attr(not(test), no_mangle)] |
| 7 | + pub extern "C" fn $intrinsic(a: $ty, b: $ty) -> $ty { |
| 8 | + let s_a = a >> (<$ty>::bits() - 1); |
| 9 | + let s_b = b >> (<$ty>::bits() - 1); |
| 10 | + let a = (a ^ s_a) - s_a; |
| 11 | + let b = (b ^ s_b) - s_b; |
| 12 | + let s = s_a ^ s_b; |
| 13 | + let r = (a as $uty) / (b as $uty); |
| 14 | + (r as $ty ^ s) - s |
| 15 | + } |
| 16 | + } |
| 17 | +} |
| 18 | + |
| 19 | +macro_rules! mod_ { |
| 20 | + ($intrinsic:ident: $ty:ty, $uty:ty) => { |
| 21 | + /// Returns `a % b` |
| 22 | + #[cfg_attr(not(test), no_mangle)] |
| 23 | + pub extern "C" fn $intrinsic(a: $ty, b: $ty) -> $ty { |
| 24 | + let s = b >> (<$ty>::bits() - 1); |
| 25 | + let b = (b ^ s) - s; |
| 26 | + let s = a >> (<$ty>::bits() - 1); |
| 27 | + let a = (a ^ s) - s; |
| 28 | + let r = (a as $uty) % (b as $uty); |
| 29 | + (r as $ty ^ s) - s |
| 30 | + } |
| 31 | + } |
| 32 | +} |
| 33 | + |
| 34 | +macro_rules! divmod { |
| 35 | + ($intrinsic:ident, $div:ident: $ty:ty, $uty:ty) => { |
| 36 | + /// Returns `a / b` and sets `*rem = n % d` |
| 37 | + #[cfg_attr(not(test), no_mangle)] |
| 38 | + pub extern "C" fn $intrinsic(a: $ty, b: $ty, rem: &mut $ty) -> $ty { |
| 39 | + let r = $div(a, b); |
| 40 | + *rem = a - (r * b); |
| 41 | + r |
| 42 | + } |
| 43 | + } |
| 44 | +} |
| 45 | + |
| 46 | +div!(__divsi3: i32, u32); |
| 47 | +div!(__divdi3: i64, u64); |
| 48 | +mod_!(__modsi3: i32, u32); |
| 49 | +mod_!(__moddi3: i64, u64); |
| 50 | +divmod!(__divmodsi4, __divsi3: i32, u32); |
| 51 | +divmod!(__divmoddi4, __divdi3: i64, u64); |
| 52 | + |
| 53 | +#[cfg(test)] |
| 54 | +mod tests { |
| 55 | + use quickcheck::TestResult; |
| 56 | + use qc::{U32, U64}; |
| 57 | + |
| 58 | + quickcheck!{ |
| 59 | + fn divdi3(n: U64, d: U64) -> TestResult { |
| 60 | + let (n, d) = (n.0 as i64, d.0 as i64); |
| 61 | + if d == 0 { |
| 62 | + TestResult::discard() |
| 63 | + } else { |
| 64 | + let q = super::__divdi3(n, d); |
| 65 | + TestResult::from_bool(q == n / d) |
| 66 | + } |
| 67 | + } |
| 68 | + |
| 69 | + fn moddi3(n: U64, d: U64) -> TestResult { |
| 70 | + let (n, d) = (n.0 as i64, d.0 as i64); |
| 71 | + if d == 0 { |
| 72 | + TestResult::discard() |
| 73 | + } else { |
| 74 | + let r = super::__moddi3(n, d); |
| 75 | + TestResult::from_bool(r == n % d) |
| 76 | + } |
| 77 | + } |
| 78 | + |
| 79 | + fn divmoddi4(n: U64, d: U64) -> TestResult { |
| 80 | + let (n, d) = (n.0 as i64, d.0 as i64); |
| 81 | + if d == 0 { |
| 82 | + TestResult::discard() |
| 83 | + } else { |
| 84 | + let mut r = 0; |
| 85 | + let q = super::__divmoddi4(n, d, &mut r); |
| 86 | + TestResult::from_bool(q == n / d && r == n % d) |
| 87 | + } |
| 88 | + } |
| 89 | + |
| 90 | + fn divsi3(n: U32, d: U32) -> TestResult { |
| 91 | + let (n, d) = (n.0 as i32, d.0 as i32); |
| 92 | + if d == 0 { |
| 93 | + TestResult::discard() |
| 94 | + } else { |
| 95 | + let q = super::__divsi3(n, d); |
| 96 | + TestResult::from_bool(q == n / d) |
| 97 | + } |
| 98 | + } |
| 99 | + |
| 100 | + fn modsi3(n: U32, d: U32) -> TestResult { |
| 101 | + let (n, d) = (n.0 as i32, d.0 as i32); |
| 102 | + if d == 0 { |
| 103 | + TestResult::discard() |
| 104 | + } else { |
| 105 | + let r = super::__modsi3(n, d); |
| 106 | + TestResult::from_bool(r == n % d) |
| 107 | + } |
| 108 | + } |
| 109 | + |
| 110 | + fn divmodsi4(n: U32, d: U32) -> TestResult { |
| 111 | + let (n, d) = (n.0 as i32, d.0 as i32); |
| 112 | + if d == 0 { |
| 113 | + TestResult::discard() |
| 114 | + } else { |
| 115 | + let mut r = 0; |
| 116 | + let q = super::__divmodsi4(n, d, &mut r); |
| 117 | + TestResult::from_bool(q == n / d && r == n % d) |
| 118 | + } |
| 119 | + } |
| 120 | + } |
| 121 | +} |
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