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| author | Alexander Regueiro <alex@noldorin.com> | 2019-01-13 03:14:18 +0000 |
|---|---|---|
| committer | Mazdak Farrokhzad <twingoow@gmail.com> | 2019-01-13 04:58:18 +0100 |
| commit | b172e89c148d11afc85147294c47496bda48fce7 (patch) | |
| tree | d310753c22ca69e2d076366dab73616ce87b31f1 | |
| parent | 2b234f61c6e1c0dbed8d3fc7ff8cac8c08401c23 (diff) | |
| download | rust-b172e89c148d11afc85147294c47496bda48fce7.tar.gz rust-b172e89c148d11afc85147294c47496bda48fce7.zip | |
Minor cosmetic changes
| -rw-r--r-- | src/libcore/num/bignum.rs | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/src/libcore/num/bignum.rs b/src/libcore/num/bignum.rs index aaf944df668..5326ef1e7c1 100644 --- a/src/libcore/num/bignum.rs +++ b/src/libcore/num/bignum.rs @@ -48,8 +48,8 @@ macro_rules! impl_full_ops { impl FullOps for $ty { #[cfg(stage0)] fn full_add(self, other: $ty, carry: bool) -> (bool, $ty) { - // this cannot overflow, the output is between 0 and 2*2^nbits - 1 - // FIXME will LLVM optimize this into ADC or similar??? + // This cannot overflow; the output is between `0` and `2 * 2^nbits - 1`. + // FIXME: will LLVM optimize this into ADC or similar? let (v, carry1) = unsafe { intrinsics::add_with_overflow(self, other) }; let (v, carry2) = unsafe { intrinsics::add_with_overflow(v, if carry {1} else {0}) @@ -58,22 +58,25 @@ macro_rules! impl_full_ops { } #[cfg(not(stage0))] fn full_add(self, other: $ty, carry: bool) -> (bool, $ty) { - // this cannot overflow, the output is between 0 and 2*2^nbits - 1 - // FIXME will LLVM optimize this into ADC or similar??? + // This cannot overflow; the output is between `0` and `2 * 2^nbits - 1`. + // FIXME: will LLVM optimize this into ADC or similar? let (v, carry1) = intrinsics::add_with_overflow(self, other); let (v, carry2) = intrinsics::add_with_overflow(v, if carry {1} else {0}); (carry1 || carry2, v) } fn full_mul(self, other: $ty, carry: $ty) -> ($ty, $ty) { - // this cannot overflow, the output is between 0 and 2^nbits * (2^nbits - 1) + // This cannot overflow; + // the output is between `0` and `2^nbits * (2^nbits - 1)`. + // FIXME: will LLVM optimize this into ADC or similar? let nbits = mem::size_of::<$ty>() * 8; let v = (self as $bigty) * (other as $bigty) + (carry as $bigty); ((v >> nbits) as $ty, v as $ty) } fn full_mul_add(self, other: $ty, other2: $ty, carry: $ty) -> ($ty, $ty) { - // this cannot overflow, the output is between 0 and 2^(2*nbits) - 1 + // This cannot overflow; + // the output is between `0` and `2^nbits * (2^nbits - 1)`. let nbits = mem::size_of::<$ty>() * 8; let v = (self as $bigty) * (other as $bigty) + (other2 as $bigty) + (carry as $bigty); @@ -82,7 +85,7 @@ macro_rules! impl_full_ops { fn full_div_rem(self, other: $ty, borrow: $ty) -> ($ty, $ty) { debug_assert!(borrow < other); - // this cannot overflow, the dividend is between 0 and other * 2^nbits - 1 + // This cannot overflow; the output is between `0` and `other * (2^nbits - 1)`. let nbits = mem::size_of::<$ty>() * 8; let lhs = ((borrow as $bigty) << nbits) | (self as $bigty); let rhs = other as $bigty; @@ -97,7 +100,8 @@ impl_full_ops! { u8: add(intrinsics::u8_add_with_overflow), mul/div(u16); u16: add(intrinsics::u16_add_with_overflow), mul/div(u32); u32: add(intrinsics::u32_add_with_overflow), mul/div(u64); -// u64: add(intrinsics::u64_add_with_overflow), mul/div(u128); // see RFC #521 for enabling this. + // See RFC #521 for enabling this. + // u64: add(intrinsics::u64_add_with_overflow), mul/div(u128); } /// Table of powers of 5 representable in digits. Specifically, the largest {u8, u16, u32} value |
