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Merge pull request #661 from rust-lang/revert-656-public-test-deps

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Revert "Eliminate the use of `public_test_dep!`"
This commit is contained in:
Trevor Gross 2024-08-06 21:18:16 -05:00 • committed by GitHub
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190
library/compiler-builtins/src/float/mod.rs
View file

@ -1,3 +1,7 @@
use core::ops;
use crate::int::{DInt, Int, MinInt};
pub mod add;
pub mod cmp;
pub mod conv;
@ -6,11 +10,187 @@ pub mod extend;
pub mod mul;
pub mod pow;
pub mod sub;
pub(crate) mod traits;
pub mod trunc;
#[cfg(not(feature = "public-test-deps"))]
pub(crate) use traits::{Float, HalfRep};
/// Wrapper to extract the integer type half of the float's size
pub(crate) type HalfRep<F> = <<F as Float>::Int as DInt>::H;
#[cfg(feature = "public-test-deps")]
pub use traits::{Float, HalfRep};
public_test_dep! {
/// Trait for some basic operations on floats
#[allow(dead_code)]
pub(crate) trait Float:
Copy
+ core::fmt::Debug
+ PartialEq
+ PartialOrd
+ ops::AddAssign
+ ops::MulAssign
+ ops::Add<Output = Self>
+ ops::Sub<Output = Self>
+ ops::Div<Output = Self>
+ ops::Rem<Output = Self>
{
/// A uint of the same width as the float
type Int: Int;
/// A int of the same width as the float
type SignedInt: Int;
/// An int capable of containing the exponent bits plus a sign bit. This is signed.
type ExpInt: Int;
const ZERO: Self;
const ONE: Self;
/// The bitwidth of the float type
const BITS: u32;
/// The bitwidth of the significand
const SIGNIFICAND_BITS: u32;
/// The bitwidth of the exponent
const EXPONENT_BITS: u32 = Self::BITS - Self::SIGNIFICAND_BITS - 1;
/// The maximum value of the exponent
const EXPONENT_MAX: u32 = (1 << Self::EXPONENT_BITS) - 1;
/// The exponent bias value
const EXPONENT_BIAS: u32 = Self::EXPONENT_MAX >> 1;
/// A mask for the sign bit
const SIGN_MASK: Self::Int;
/// A mask for the significand
const SIGNIFICAND_MASK: Self::Int;
/// The implicit bit of the float format
const IMPLICIT_BIT: Self::Int;
/// A mask for the exponent
const EXPONENT_MASK: Self::Int;
/// Returns `self` transmuted to `Self::Int`
fn repr(self) -> Self::Int;
/// Returns `self` transmuted to `Self::SignedInt`
fn signed_repr(self) -> Self::SignedInt;
/// Checks if two floats have the same bit representation. *Except* for NaNs! NaN can be
/// represented in multiple different ways. This method returns `true` if two NaNs are
/// compared.
fn eq_repr(self, rhs: Self) -> bool;
/// Returns true if the sign is negative
fn is_sign_negative(self) -> bool;
/// Returns the exponent with bias
fn exp(self) -> Self::ExpInt;
/// Returns the significand with no implicit bit (or the "fractional" part)
fn frac(self) -> Self::Int;
/// Returns the significand with implicit bit
fn imp_frac(self) -> Self::Int;
/// Returns a `Self::Int` transmuted back to `Self`
fn from_repr(a: Self::Int) -> Self;
/// Constructs a `Self` from its parts. Inputs are treated as bits and shifted into position.
fn from_parts(sign: bool, exponent: Self::Int, significand: Self::Int) -> Self;
/// Returns (normalized exponent, normalized significand)
fn normalize(significand: Self::Int) -> (i32, Self::Int);
/// Returns if `self` is subnormal
fn is_subnormal(self) -> bool;
}
}
macro_rules! float_impl {
($ty:ident, $ity:ident, $sity:ident, $expty:ident, $bits:expr, $significand_bits:expr) => {
impl Float for $ty {
type Int = $ity;
type SignedInt = $sity;
type ExpInt = $expty;
const ZERO: Self = 0.0;
const ONE: Self = 1.0;
const BITS: u32 = $bits;
const SIGNIFICAND_BITS: u32 = $significand_bits;
const SIGN_MASK: Self::Int = 1 << (Self::BITS - 1);
const SIGNIFICAND_MASK: Self::Int = (1 << Self::SIGNIFICAND_BITS) - 1;
const IMPLICIT_BIT: Self::Int = 1 << Self::SIGNIFICAND_BITS;
const EXPONENT_MASK: Self::Int = !(Self::SIGN_MASK | Self::SIGNIFICAND_MASK);
fn repr(self) -> Self::Int {
self.to_bits()
}
fn signed_repr(self) -> Self::SignedInt {
self.to_bits() as Self::SignedInt
}
fn eq_repr(self, rhs: Self) -> bool {
#[cfg(feature = "mangled-names")]
fn is_nan(x: $ty) -> bool {
// When using mangled-names, the "real" compiler-builtins might not have the
// necessary builtin (__unordtf2) to test whether `f128` is NaN.
// FIXME(f16_f128): Remove once the nightly toolchain has the __unordtf2 builtin
// x is NaN if all the bits of the exponent are set and the significand is non-0
x.repr() & $ty::EXPONENT_MASK == $ty::EXPONENT_MASK
&& x.repr() & $ty::SIGNIFICAND_MASK != 0
}
#[cfg(not(feature = "mangled-names"))]
fn is_nan(x: $ty) -> bool {
x.is_nan()
}
if is_nan(self) && is_nan(rhs) {
true
} else {
self.repr() == rhs.repr()
}
}
fn is_sign_negative(self) -> bool {
self.is_sign_negative()
}
fn exp(self) -> Self::ExpInt {
((self.to_bits() & Self::EXPONENT_MASK) >> Self::SIGNIFICAND_BITS) as Self::ExpInt
}
fn frac(self) -> Self::Int {
self.to_bits() & Self::SIGNIFICAND_MASK
}
fn imp_frac(self) -> Self::Int {
self.frac() | Self::IMPLICIT_BIT
}
fn from_repr(a: Self::Int) -> Self {
Self::from_bits(a)
}
fn from_parts(sign: bool, exponent: Self::Int, significand: Self::Int) -> Self {
Self::from_repr(
((sign as Self::Int) << (Self::BITS - 1))
| ((exponent << Self::SIGNIFICAND_BITS) & Self::EXPONENT_MASK)
| (significand & Self::SIGNIFICAND_MASK),
)
}
fn normalize(significand: Self::Int) -> (i32, Self::Int) {
let shift = significand
.leading_zeros()
.wrapping_sub((Self::Int::ONE << Self::SIGNIFICAND_BITS).leading_zeros());
(
1i32.wrapping_sub(shift as i32),
significand << shift as Self::Int,
)
}
fn is_subnormal(self) -> bool {
(self.repr() & Self::EXPONENT_MASK) == Self::Int::ZERO
}
}
};
}
#[cfg(f16_enabled)]
float_impl!(f16, u16, i16, i8, 16, 10);
float_impl!(f32, u32, i32, i16, 32, 23);
float_impl!(f64, u64, i64, i16, 64, 52);
#[cfg(f128_enabled)]
float_impl!(f128, u128, i128, i16, 128, 112);

184
library/compiler-builtins/src/float/traits.rs
View file

@ -1,184 +0,0 @@
use core::ops;
use crate::int::{DInt, Int, MinInt};
/// Wrapper to extract the integer type half of the float's size
pub type HalfRep<F> = <<F as Float>::Int as DInt>::H;
/// Trait for some basic operations on floats
#[allow(dead_code)]
pub trait Float:
Copy
+ core::fmt::Debug
+ PartialEq
+ PartialOrd
+ ops::AddAssign
+ ops::MulAssign
+ ops::Add<Output = Self>
+ ops::Sub<Output = Self>
+ ops::Div<Output = Self>
+ ops::Rem<Output = Self>
{
/// A uint of the same width as the float
type Int: Int;
/// A int of the same width as the float
type SignedInt: Int;
/// An int capable of containing the exponent bits plus a sign bit. This is signed.
type ExpInt: Int;
const ZERO: Self;
const ONE: Self;
/// The bitwidth of the float type
const BITS: u32;
/// The bitwidth of the significand
const SIGNIFICAND_BITS: u32;
/// The bitwidth of the exponent
const EXPONENT_BITS: u32 = Self::BITS - Self::SIGNIFICAND_BITS - 1;
/// The maximum value of the exponent
const EXPONENT_MAX: u32 = (1 << Self::EXPONENT_BITS) - 1;
/// The exponent bias value
const EXPONENT_BIAS: u32 = Self::EXPONENT_MAX >> 1;
/// A mask for the sign bit
const SIGN_MASK: Self::Int;
/// A mask for the significand
const SIGNIFICAND_MASK: Self::Int;
/// The implicit bit of the float format
const IMPLICIT_BIT: Self::Int;
/// A mask for the exponent
const EXPONENT_MASK: Self::Int;
/// Returns `self` transmuted to `Self::Int`
fn repr(self) -> Self::Int;
/// Returns `self` transmuted to `Self::SignedInt`
fn signed_repr(self) -> Self::SignedInt;
/// Checks if two floats have the same bit representation. *Except* for NaNs! NaN can be
/// represented in multiple different ways. This method returns `true` if two NaNs are
/// compared.
fn eq_repr(self, rhs: Self) -> bool;
/// Returns true if the sign is negative
fn is_sign_negative(self) -> bool;
/// Returns the exponent with bias
fn exp(self) -> Self::ExpInt;
/// Returns the significand with no implicit bit (or the "fractional" part)
fn frac(self) -> Self::Int;
/// Returns the significand with implicit bit
fn imp_frac(self) -> Self::Int;
/// Returns a `Self::Int` transmuted back to `Self`
fn from_repr(a: Self::Int) -> Self;
/// Constructs a `Self` from its parts. Inputs are treated as bits and shifted into position.
fn from_parts(sign: bool, exponent: Self::Int, significand: Self::Int) -> Self;
/// Returns (normalized exponent, normalized significand)
fn normalize(significand: Self::Int) -> (i32, Self::Int);
/// Returns if `self` is subnormal
fn is_subnormal(self) -> bool;
}
macro_rules! float_impl {
($ty:ident, $ity:ident, $sity:ident, $expty:ident, $bits:expr, $significand_bits:expr) => {
impl Float for $ty {
type Int = $ity;
type SignedInt = $sity;
type ExpInt = $expty;
const ZERO: Self = 0.0;
const ONE: Self = 1.0;
const BITS: u32 = $bits;
const SIGNIFICAND_BITS: u32 = $significand_bits;
const SIGN_MASK: Self::Int = 1 << (Self::BITS - 1);
const SIGNIFICAND_MASK: Self::Int = (1 << Self::SIGNIFICAND_BITS) - 1;
const IMPLICIT_BIT: Self::Int = 1 << Self::SIGNIFICAND_BITS;
const EXPONENT_MASK: Self::Int = !(Self::SIGN_MASK | Self::SIGNIFICAND_MASK);
fn repr(self) -> Self::Int {
self.to_bits()
}
fn signed_repr(self) -> Self::SignedInt {
self.to_bits() as Self::SignedInt
}
fn eq_repr(self, rhs: Self) -> bool {
#[cfg(feature = "mangled-names")]
fn is_nan(x: $ty) -> bool {
// When using mangled-names, the "real" compiler-builtins might not have the
// necessary builtin (__unordtf2) to test whether `f128` is NaN.
// FIXME(f16_f128): Remove once the nightly toolchain has the __unordtf2 builtin
// x is NaN if all the bits of the exponent are set and the significand is non-0
x.repr() & $ty::EXPONENT_MASK == $ty::EXPONENT_MASK
&& x.repr() & $ty::SIGNIFICAND_MASK != 0
}
#[cfg(not(feature = "mangled-names"))]
fn is_nan(x: $ty) -> bool {
x.is_nan()
}
if is_nan(self) && is_nan(rhs) {
true
} else {
self.repr() == rhs.repr()
}
}
fn is_sign_negative(self) -> bool {
self.is_sign_negative()
}
fn exp(self) -> Self::ExpInt {
((self.to_bits() & Self::EXPONENT_MASK) >> Self::SIGNIFICAND_BITS) as Self::ExpInt
}
fn frac(self) -> Self::Int {
self.to_bits() & Self::SIGNIFICAND_MASK
}
fn imp_frac(self) -> Self::Int {
self.frac() | Self::IMPLICIT_BIT
}
fn from_repr(a: Self::Int) -> Self {
Self::from_bits(a)
}
fn from_parts(sign: bool, exponent: Self::Int, significand: Self::Int) -> Self {
Self::from_repr(
((sign as Self::Int) << (Self::BITS - 1))
| ((exponent << Self::SIGNIFICAND_BITS) & Self::EXPONENT_MASK)
| (significand & Self::SIGNIFICAND_MASK),
)
}
fn normalize(significand: Self::Int) -> (i32, Self::Int) {
let shift = significand
.leading_zeros()
.wrapping_sub((Self::Int::ONE << Self::SIGNIFICAND_BITS).leading_zeros());
(
1i32.wrapping_sub(shift as i32),
significand << shift as Self::Int,
)
}
fn is_subnormal(self) -> bool {
(self.repr() & Self::EXPONENT_MASK) == Self::Int::ZERO
}
}
};
}
#[cfg(not(feature = "no-f16-f128"))]
float_impl!(f16, u16, i16, i8, 16, 10);
float_impl!(f32, u32, i32, i16, 32, 23);
float_impl!(f64, u64, i64, i16, 64, 52);
#[cfg(not(feature = "no-f16-f128"))]
float_impl!(f128, u128, i128, i16, 128, 112);

238
library/compiler-builtins/src/int/leading_zeros.rs
View file

@ -3,140 +3,136 @@
// adding a zero check at the beginning, but `__clzsi2` has a precondition that `x != 0`.
// Compilers will insert the check for zero in cases where it is needed.
mod implementation {
use crate::int::{CastInto, Int};
use crate::int::{CastInto, Int};
/// Returns the number of leading binary zeros in `x`.
#[allow(dead_code)]
pub fn leading_zeros_default<T: Int + CastInto<usize>>(x: T) -> usize {
// The basic idea is to test if the higher bits of `x` are zero and bisect the number
// of leading zeros. It is possible for all branches of the bisection to use the same
// code path by conditionally shifting the higher parts down to let the next bisection
// step work on the higher or lower parts of `x`. Instead of starting with `z == 0`
// and adding to the number of zeros, it is slightly faster to start with
// `z == usize::MAX.count_ones()` and subtract from the potential number of zeros,
// because it simplifies the final bisection step.
let mut x = x;
// the number of potential leading zeros
let mut z = T::BITS as usize;
// a temporary
let mut t: T;
public_test_dep! {
/// Returns the number of leading binary zeros in `x`.
#[allow(dead_code)]
pub(crate) fn leading_zeros_default<T: Int + CastInto<usize>>(x: T) -> usize {
// The basic idea is to test if the higher bits of `x` are zero and bisect the number
// of leading zeros. It is possible for all branches of the bisection to use the same
// code path by conditionally shifting the higher parts down to let the next bisection
// step work on the higher or lower parts of `x`. Instead of starting with `z == 0`
// and adding to the number of zeros, it is slightly faster to start with
// `z == usize::MAX.count_ones()` and subtract from the potential number of zeros,
// because it simplifies the final bisection step.
let mut x = x;
// the number of potential leading zeros
let mut z = T::BITS as usize;
// a temporary
let mut t: T;
const { assert!(T::BITS <= 64) };
if T::BITS >= 64 {
t = x >> 32;
if t != T::ZERO {
z -= 32;
x = t;
}
}
if T::BITS >= 32 {
t = x >> 16;
if t != T::ZERO {
z -= 16;
x = t;
}
}
const { assert!(T::BITS >= 16) };
t = x >> 8;
const { assert!(T::BITS <= 64) };
if T::BITS >= 64 {
t = x >> 32;
if t != T::ZERO {
z -= 8;
z -= 32;
x = t;
}
t = x >> 4;
}
if T::BITS >= 32 {
t = x >> 16;
if t != T::ZERO {
z -= 4;
z -= 16;
x = t;
}
t = x >> 2;
if t != T::ZERO {
z -= 2;
x = t;
}
// the last two bisections are combined into one conditional
t = x >> 1;
if t != T::ZERO {
z - 2
} else {
z - x.cast()
}
// We could potentially save a few cycles by using the LUT trick from
// "https://embeddedgurus.com/state-space/2014/09/
// fast-deterministic-and-portable-counting-leading-zeros/".
// However, 256 bytes for a LUT is too large for embedded use cases. We could remove
// the last 3 bisections and use this 16 byte LUT for the rest of the work:
//const LUT: [u8; 16] = [0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4];
//z -= LUT[x] as usize;
//z
// However, it ends up generating about the same number of instructions. When benchmarked
// on x86_64, it is slightly faster to use the LUT, but this is probably because of OOO
// execution effects. Changing to using a LUT and branching is risky for smaller cores.
}
const { assert!(T::BITS >= 16) };
t = x >> 8;
if t != T::ZERO {
z -= 8;
x = t;
}
t = x >> 4;
if t != T::ZERO {
z -= 4;
x = t;
}
t = x >> 2;
if t != T::ZERO {
z -= 2;
x = t;
}
// the last two bisections are combined into one conditional
t = x >> 1;
if t != T::ZERO {
z - 2
} else {
z - x.cast()
}
// The above method does not compile well on RISC-V (because of the lack of predicated
// instructions), producing code with many branches or using an excessively long
// branchless solution. This method takes advantage of the set-if-less-than instruction on
// RISC-V that allows `(x >= power-of-two) as usize` to be branchless.
/// Returns the number of leading binary zeros in `x`.
#[allow(dead_code)]
pub fn leading_zeros_riscv<T: Int + CastInto<usize>>(x: T) -> usize {
let mut x = x;
// the number of potential leading zeros
let mut z = T::BITS;
// a temporary
let mut t: u32;
// RISC-V does not have a set-if-greater-than-or-equal instruction and
// `(x >= power-of-two) as usize` will get compiled into two instructions, but this is
// still the most optimal method. A conditional set can only be turned into a single
// immediate instruction if `x` is compared with an immediate `imm` (that can fit into
// 12 bits) like `x < imm` but not `imm < x` (because the immediate is always on the
// right). If we try to save an instruction by using `x < imm` for each bisection, we
// have to shift `x` left and compare with powers of two approaching `usize::MAX + 1`,
// but the immediate will never fit into 12 bits and never save an instruction.
const { assert!(T::BITS <= 64) };
if T::BITS >= 64 {
// If the upper 32 bits of `x` are not all 0, `t` is set to `1 << 5`, otherwise
// `t` is set to 0.
t = ((x >= (T::ONE << 32)) as u32) << 5;
// If `t` was set to `1 << 5`, then the upper 32 bits are shifted down for the
// next step to process.
x >>= t;
// If `t` was set to `1 << 5`, then we subtract 32 from the number of potential
// leading zeros
z -= t;
}
if T::BITS >= 32 {
t = ((x >= (T::ONE << 16)) as u32) << 4;
x >>= t;
z -= t;
}
const { assert!(T::BITS >= 16) };
t = ((x >= (T::ONE << 8)) as u32) << 3;
x >>= t;
z -= t;
t = ((x >= (T::ONE << 4)) as u32) << 2;
x >>= t;
z -= t;
t = ((x >= (T::ONE << 2)) as u32) << 1;
x >>= t;
z -= t;
t = (x >= (T::ONE << 1)) as u32;
x >>= t;
z -= t;
// All bits except the LSB are guaranteed to be zero for this final bisection step.
// If `x != 0` then `x == 1` and subtracts one potential zero from `z`.
z as usize - x.cast()
}
// We could potentially save a few cycles by using the LUT trick from
// "https://embeddedgurus.com/state-space/2014/09/
// fast-deterministic-and-portable-counting-leading-zeros/".
// However, 256 bytes for a LUT is too large for embedded use cases. We could remove
// the last 3 bisections and use this 16 byte LUT for the rest of the work:
//const LUT: [u8; 16] = [0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4];
//z -= LUT[x] as usize;
//z
// However, it ends up generating about the same number of instructions. When benchmarked
// on x86_64, it is slightly faster to use the LUT, but this is probably because of OOO
// execution effects. Changing to using a LUT and branching is risky for smaller cores.
}
}
#[cfg(not(feature = "public-test-deps"))]
pub(crate) use implementation::*;
// The above method does not compile well on RISC-V (because of the lack of predicated
// instructions), producing code with many branches or using an excessively long
// branchless solution. This method takes advantage of the set-if-less-than instruction on
// RISC-V that allows `(x >= power-of-two) as usize` to be branchless.
#[cfg(feature = "public-test-deps")]
pub use implementation::*;
public_test_dep! {
/// Returns the number of leading binary zeros in `x`.
#[allow(dead_code)]
pub(crate) fn leading_zeros_riscv<T: Int + CastInto<usize>>(x: T) -> usize {
let mut x = x;
// the number of potential leading zeros
let mut z = T::BITS;
// a temporary
let mut t: u32;
// RISC-V does not have a set-if-greater-than-or-equal instruction and
// `(x >= power-of-two) as usize` will get compiled into two instructions, but this is
// still the most optimal method. A conditional set can only be turned into a single
// immediate instruction if `x` is compared with an immediate `imm` (that can fit into
// 12 bits) like `x < imm` but not `imm < x` (because the immediate is always on the
// right). If we try to save an instruction by using `x < imm` for each bisection, we
// have to shift `x` left and compare with powers of two approaching `usize::MAX + 1`,
// but the immediate will never fit into 12 bits and never save an instruction.
const { assert!(T::BITS <= 64) };
if T::BITS >= 64 {
// If the upper 32 bits of `x` are not all 0, `t` is set to `1 << 5`, otherwise
// `t` is set to 0.
t = ((x >= (T::ONE << 32)) as u32) << 5;
// If `t` was set to `1 << 5`, then the upper 32 bits are shifted down for the
// next step to process.
x >>= t;
// If `t` was set to `1 << 5`, then we subtract 32 from the number of potential
// leading zeros
z -= t;
}
if T::BITS >= 32 {
t = ((x >= (T::ONE << 16)) as u32) << 4;
x >>= t;
z -= t;
}
const { assert!(T::BITS >= 16) };
t = ((x >= (T::ONE << 8)) as u32) << 3;
x >>= t;
z -= t;
t = ((x >= (T::ONE << 4)) as u32) << 2;
x >>= t;
z -= t;
t = ((x >= (T::ONE << 2)) as u32) << 1;
x >>= t;
z -= t;
t = (x >= (T::ONE << 1)) as u32;
x >>= t;
z -= t;
// All bits except the LSB are guaranteed to be zero for this final bisection step.
// If `x != 0` then `x == 1` and subtracts one potential zero from `z`.
z as usize - x.cast()
}
}
intrinsics! {
/// Returns the number of leading binary zeros in `x`

417
library/compiler-builtins/src/int/mod.rs
View file

@ -1,4 +1,6 @@
pub(crate) mod specialized_div_rem;
use core::ops;
mod specialized_div_rem;
pub mod addsub;
mod big;
@ -8,13 +10,416 @@ pub mod mul;
pub mod sdiv;
pub mod shift;
pub mod trailing_zeros;
mod traits;
pub mod udiv;
pub use big::{i256, u256};
#[cfg(not(feature = "public-test-deps"))]
pub(crate) use traits::{CastFrom, CastInto, DInt, HInt, Int, MinInt};
public_test_dep! {
/// Minimal integer implementations needed on all integer types, including wide integers.
#[allow(dead_code)]
pub(crate) trait MinInt: Copy
+ core::fmt::Debug
+ ops::BitOr<Output = Self>
+ ops::Not<Output = Self>
+ ops::Shl<u32, Output = Self>
{
#[cfg(feature = "public-test-deps")]
pub use traits::{CastFrom, CastInto, DInt, HInt, Int, MinInt};
/// Type with the same width but other signedness
type OtherSign: MinInt;
/// Unsigned version of Self
type UnsignedInt: MinInt;
/// If `Self` is a signed integer
const SIGNED: bool;
/// The bitwidth of the int type
const BITS: u32;
const ZERO: Self;
const ONE: Self;
const MIN: Self;
const MAX: Self;
}
}
public_test_dep! {
/// Trait for some basic operations on integers
#[allow(dead_code)]
pub(crate) trait Int: MinInt
+ PartialEq
+ PartialOrd
+ ops::AddAssign
+ ops::SubAssign
+ ops::BitAndAssign
+ ops::BitOrAssign
+ ops::BitXorAssign
+ ops::ShlAssign<i32>
+ ops::ShrAssign<u32>
+ ops::Add<Output = Self>
+ ops::Sub<Output = Self>
+ ops::Mul<Output = Self>
+ ops::Div<Output = Self>
+ ops::Shr<u32, Output = Self>
+ ops::BitXor<Output = Self>
+ ops::BitAnd<Output = Self>
{
/// LUT used for maximizing the space covered and minimizing the computational cost of fuzzing
/// in `testcrate`. For example, Self = u128 produces [0,1,2,7,8,15,16,31,32,63,64,95,96,111,
/// 112,119,120,125,126,127].
const FUZZ_LENGTHS: [u8; 20] = make_fuzz_lengths(<Self as MinInt>::BITS);
/// The number of entries of `FUZZ_LENGTHS` actually used. The maximum is 20 for u128.
const FUZZ_NUM: usize = {
let log2 = (<Self as MinInt>::BITS - 1).count_ones() as usize;
if log2 == 3 {
// case for u8
6
} else {
// 3 entries on each extreme, 2 in the middle, and 4 for each scale of intermediate
// boundaries.
8 + (4 * (log2 - 4))
}
};
fn unsigned(self) -> Self::UnsignedInt;
fn from_unsigned(unsigned: Self::UnsignedInt) -> Self;
fn from_bool(b: bool) -> Self;
/// Prevents the need for excessive conversions between signed and unsigned
fn logical_shr(self, other: u32) -> Self;
/// Absolute difference between two integers.
fn abs_diff(self, other: Self) -> Self::UnsignedInt;
// copied from primitive integers, but put in a trait
fn is_zero(self) -> bool;
fn wrapping_neg(self) -> Self;
fn wrapping_add(self, other: Self) -> Self;
fn wrapping_mul(self, other: Self) -> Self;
fn wrapping_sub(self, other: Self) -> Self;
fn wrapping_shl(self, other: u32) -> Self;
fn wrapping_shr(self, other: u32) -> Self;
fn rotate_left(self, other: u32) -> Self;
fn overflowing_add(self, other: Self) -> (Self, bool);
fn leading_zeros(self) -> u32;
fn ilog2(self) -> u32;
}
}
pub(crate) const fn make_fuzz_lengths(bits: u32) -> [u8; 20] {
let mut v = [0u8; 20];
v[0] = 0;
v[1] = 1;
v[2] = 2; // important for parity and the iX::MIN case when reversed
let mut i = 3;
// No need for any more until the byte boundary, because there should be no algorithms
// that are sensitive to anything not next to byte boundaries after 2. We also scale
// in powers of two, which is important to prevent u128 corner tests from getting too
// big.
let mut l = 8;
loop {
if l >= ((bits / 2) as u8) {
break;
}
// get both sides of the byte boundary
v[i] = l - 1;
i += 1;
v[i] = l;
i += 1;
l *= 2;
}
if bits != 8 {
// add the lower side of the middle boundary
v[i] = ((bits / 2) - 1) as u8;
i += 1;
}
// We do not want to jump directly from the Self::BITS/2 boundary to the Self::BITS
// boundary because of algorithms that split the high part up. We reverse the scaling
// as we go to Self::BITS.
let mid = i;
let mut j = 1;
loop {
v[i] = (bits as u8) - (v[mid - j]) - 1;
if j == mid {
break;
}
i += 1;
j += 1;
}
v
}
macro_rules! int_impl_common {
($ty:ty) => {
fn from_bool(b: bool) -> Self {
b as $ty
}
fn logical_shr(self, other: u32) -> Self {
Self::from_unsigned(self.unsigned().wrapping_shr(other))
}
fn is_zero(self) -> bool {
self == Self::ZERO
}
fn wrapping_neg(self) -> Self {
<Self>::wrapping_neg(self)
}
fn wrapping_add(self, other: Self) -> Self {
<Self>::wrapping_add(self, other)
}
fn wrapping_mul(self, other: Self) -> Self {
<Self>::wrapping_mul(self, other)
}
fn wrapping_sub(self, other: Self) -> Self {
<Self>::wrapping_sub(self, other)
}
fn wrapping_shl(self, other: u32) -> Self {
<Self>::wrapping_shl(self, other)
}
fn wrapping_shr(self, other: u32) -> Self {
<Self>::wrapping_shr(self, other)
}
fn rotate_left(self, other: u32) -> Self {
<Self>::rotate_left(self, other)
}
fn overflowing_add(self, other: Self) -> (Self, bool) {
<Self>::overflowing_add(self, other)
}
fn leading_zeros(self) -> u32 {
<Self>::leading_zeros(self)
}
fn ilog2(self) -> u32 {
<Self>::ilog2(self)
}
};
}
macro_rules! int_impl {
($ity:ty, $uty:ty) => {
impl MinInt for $uty {
type OtherSign = $ity;
type UnsignedInt = $uty;
const BITS: u32 = <Self as MinInt>::ZERO.count_zeros();
const SIGNED: bool = Self::MIN != Self::ZERO;
const ZERO: Self = 0;
const ONE: Self = 1;
const MIN: Self = <Self>::MIN;
const MAX: Self = <Self>::MAX;
}
impl Int for $uty {
fn unsigned(self) -> $uty {
self
}
// It makes writing macros easier if this is implemented for both signed and unsigned
#[allow(clippy::wrong_self_convention)]
fn from_unsigned(me: $uty) -> Self {
me
}
fn abs_diff(self, other: Self) -> Self {
if self < other {
other.wrapping_sub(self)
} else {
self.wrapping_sub(other)
}
}
int_impl_common!($uty);
}
impl MinInt for $ity {
type OtherSign = $uty;
type UnsignedInt = $uty;
const BITS: u32 = <Self as MinInt>::ZERO.count_zeros();
const SIGNED: bool = Self::MIN != Self::ZERO;
const ZERO: Self = 0;
const ONE: Self = 1;
const MIN: Self = <Self>::MIN;
const MAX: Self = <Self>::MAX;
}
impl Int for $ity {
fn unsigned(self) -> $uty {
self as $uty
}
fn from_unsigned(me: $uty) -> Self {
me as $ity
}
fn abs_diff(self, other: Self) -> $uty {
self.wrapping_sub(other).wrapping_abs() as $uty
}
int_impl_common!($ity);
}
};
}
int_impl!(isize, usize);
int_impl!(i8, u8);
int_impl!(i16, u16);
int_impl!(i32, u32);
int_impl!(i64, u64);
int_impl!(i128, u128);
public_test_dep! {
/// Trait for integers twice the bit width of another integer. This is implemented for all
/// primitives except for `u8`, because there is not a smaller primitive.
pub(crate) trait DInt: MinInt {
/// Integer that is half the bit width of the integer this trait is implemented for
type H: HInt<D = Self>;
/// Returns the low half of `self`
fn lo(self) -> Self::H;
/// Returns the high half of `self`
fn hi(self) -> Self::H;
/// Returns the low and high halves of `self` as a tuple
fn lo_hi(self) -> (Self::H, Self::H) {
(self.lo(), self.hi())
}
/// Constructs an integer using lower and higher half parts
fn from_lo_hi(lo: Self::H, hi: Self::H) -> Self {
lo.zero_widen() | hi.widen_hi()
}
}
}
public_test_dep! {
/// Trait for integers half the bit width of another integer. This is implemented for all
/// primitives except for `u128`, because it there is not a larger primitive.
pub(crate) trait HInt: Int {
/// Integer that is double the bit width of the integer this trait is implemented for
type D: DInt<H = Self> + MinInt;
/// Widens (using default extension) the integer to have double bit width
fn widen(self) -> Self::D;
/// Widens (zero extension only) the integer to have double bit width. This is needed to get
/// around problems with associated type bounds (such as `Int<Othersign: DInt>`) being unstable
fn zero_widen(self) -> Self::D;
/// Widens the integer to have double bit width and shifts the integer into the higher bits
fn widen_hi(self) -> Self::D {
self.widen() << <Self as MinInt>::BITS
}
/// Widening multiplication with zero widening. This cannot overflow.
fn zero_widen_mul(self, rhs: Self) -> Self::D;
/// Widening multiplication. This cannot overflow.
fn widen_mul(self, rhs: Self) -> Self::D;
}
}
macro_rules! impl_d_int {
($($X:ident $D:ident),*) => {
$(
impl DInt for $D {
type H = $X;
fn lo(self) -> Self::H {
self as $X
}
fn hi(self) -> Self::H {
(self >> <$X as MinInt>::BITS) as $X
}
}
)*
};
}
macro_rules! impl_h_int {
($($H:ident $uH:ident $X:ident),*) => {
$(
impl HInt for $H {
type D = $X;
fn widen(self) -> Self::D {
self as $X
}
fn zero_widen(self) -> Self::D {
(self as $uH) as $X
}
fn zero_widen_mul(self, rhs: Self) -> Self::D {
self.zero_widen().wrapping_mul(rhs.zero_widen())
}
fn widen_mul(self, rhs: Self) -> Self::D {
self.widen().wrapping_mul(rhs.widen())
}
}
)*
};
}
impl_d_int!(u8 u16, u16 u32, u32 u64, u64 u128, i8 i16, i16 i32, i32 i64, i64 i128);
impl_h_int!(
u8 u8 u16,
u16 u16 u32,
u32 u32 u64,
u64 u64 u128,
i8 u8 i16,
i16 u16 i32,
i32 u32 i64,
i64 u64 i128
);
public_test_dep! {
/// Trait to express (possibly lossy) casting of integers
pub(crate) trait CastInto<T: Copy>: Copy {
fn cast(self) -> T;
}
pub(crate) trait CastFrom<T: Copy>:Copy {
fn cast_from(value: T) -> Self;
}
}
impl<T: Copy, U: CastInto<T> + Copy> CastFrom<U> for T {
fn cast_from(value: U) -> Self {
value.cast()
}
}
macro_rules! cast_into {
($ty:ty) => {
cast_into!($ty; usize, isize, u8, i8, u16, i16, u32, i32, u64, i64, u128, i128);
};
($ty:ty; $($into:ty),*) => {$(
impl CastInto<$into> for $ty {
fn cast(self) -> $into {
self as $into
}
}
)*};
}
cast_into!(usize);
cast_into!(isize);
cast_into!(u8);
cast_into!(i8);
cast_into!(u16);
cast_into!(i16);
cast_into!(u32);
cast_into!(i32);
cast_into!(u64);
cast_into!(i64);
cast_into!(u128);
cast_into!(i128);

4
library/compiler-builtins/src/int/specialized_div_rem/delegate.rs
View file

@ -185,6 +185,7 @@ macro_rules! impl_delegate {
};
}
public_test_dep! {
/// Returns `n / d` and sets `*rem = n % d`.
///
/// This specialization exists because:
@ -194,7 +195,7 @@ macro_rules! impl_delegate {
/// delegate algorithm strategy the only reasonably fast way to perform `u128` division.
// used on SPARC
#[allow(dead_code)]
pub fn u128_divide_sparc(duo: u128, div: u128, rem: &mut u128) -> u128 {
pub(crate) fn u128_divide_sparc(duo: u128, div: u128, rem: &mut u128) -> u128 {
use super::*;
let duo_lo = duo as u64;
let duo_hi = (duo >> 64) as u64;
@ -315,3 +316,4 @@ pub fn u128_divide_sparc(duo: u128, div: u128, rem: &mut u128) -> u128 {
}
}
}
}

82
library/compiler-builtins/src/int/trailing_zeros.rs
View file

@ -1,51 +1,45 @@
mod implementation {
use crate::int::{CastInto, Int};
use crate::int::{CastInto, Int};
/// Returns number of trailing binary zeros in `x`.
#[allow(dead_code)]
pub fn trailing_zeros<T: Int + CastInto<u32> + CastInto<u16> + CastInto<u8>>(x: T) -> usize {
let mut x = x;
let mut r: u32 = 0;
let mut t: u32;
public_test_dep! {
/// Returns number of trailing binary zeros in `x`.
#[allow(dead_code)]
pub(crate) fn trailing_zeros<T: Int + CastInto<u32> + CastInto<u16> + CastInto<u8>>(x: T) -> usize {
let mut x = x;
let mut r: u32 = 0;
let mut t: u32;
const { assert!(T::BITS <= 64) };
if T::BITS >= 64 {
r += ((CastInto::<u32>::cast(x) == 0) as u32) << 5; // if (x has no 32 small bits) t = 32 else 0
x >>= r; // remove 32 zero bits
}
if T::BITS >= 32 {
t = ((CastInto::<u16>::cast(x) == 0) as u32) << 4; // if (x has no 16 small bits) t = 16 else 0
r += t;
x >>= t; // x = [0 - 0xFFFF] + higher garbage bits
}
const { assert!(T::BITS >= 16) };
t = ((CastInto::<u8>::cast(x) == 0) as u32) << 3;
x >>= t; // x = [0 - 0xFF] + higher garbage bits
r += t;
let mut x: u8 = x.cast();
t = (((x & 0x0F) == 0) as u32) << 2;
x >>= t; // x = [0 - 0xF] + higher garbage bits
r += t;
t = (((x & 0x3) == 0) as u32) << 1;
x >>= t; // x = [0 - 0x3] + higher garbage bits
r += t;
x &= 3;
r as usize + ((2 - (x >> 1) as usize) & (((x & 1) == 0) as usize).wrapping_neg())
const { assert!(T::BITS <= 64) };
if T::BITS >= 64 {
r += ((CastInto::<u32>::cast(x) == 0) as u32) << 5; // if (x has no 32 small bits) t = 32 else 0
x >>= r; // remove 32 zero bits
}
if T::BITS >= 32 {
t = ((CastInto::<u16>::cast(x) == 0) as u32) << 4; // if (x has no 16 small bits) t = 16 else 0
r += t;
x >>= t; // x = [0 - 0xFFFF] + higher garbage bits
}
const { assert!(T::BITS >= 16) };
t = ((CastInto::<u8>::cast(x) == 0) as u32) << 3;
x >>= t; // x = [0 - 0xFF] + higher garbage bits
r += t;
let mut x: u8 = x.cast();
t = (((x & 0x0F) == 0) as u32) << 2;
x >>= t; // x = [0 - 0xF] + higher garbage bits
r += t;
t = (((x & 0x3) == 0) as u32) << 1;
x >>= t; // x = [0 - 0x3] + higher garbage bits
r += t;
x &= 3;
r as usize + ((2 - (x >> 1) as usize) & (((x & 1) == 0) as usize).wrapping_neg())
}
}
#[cfg(not(feature = "public-test-deps"))]
pub(crate) use implementation::*;
#[cfg(feature = "public-test-deps")]
pub use implementation::*;
intrinsics! {
/// Returns the number of trailing binary zeros in `x` (32 bit version).

402
library/compiler-builtins/src/int/traits.rs
View file

@ -1,402 +0,0 @@
use core::ops;
/// Minimal integer implementations needed on all integer types, including wide integers.
#[allow(dead_code)]
pub trait MinInt:
Copy
+ core::fmt::Debug
+ ops::BitOr<Output = Self>
+ ops::Not<Output = Self>
+ ops::Shl<u32, Output = Self>
{
/// Type with the same width but other signedness
type OtherSign: MinInt;
/// Unsigned version of Self
type UnsignedInt: MinInt;
/// If `Self` is a signed integer
const SIGNED: bool;
/// The bitwidth of the int type
const BITS: u32;
const ZERO: Self;
const ONE: Self;
const MIN: Self;
const MAX: Self;
}
/// Trait for some basic operations on integers
#[allow(dead_code)]
pub trait Int:
MinInt
+ PartialEq
+ PartialOrd
+ ops::AddAssign
+ ops::SubAssign
+ ops::BitAndAssign
+ ops::BitOrAssign
+ ops::BitXorAssign
+ ops::ShlAssign<i32>
+ ops::ShrAssign<u32>
+ ops::Add<Output = Self>
+ ops::Sub<Output = Self>
+ ops::Mul<Output = Self>
+ ops::Div<Output = Self>
+ ops::Shr<u32, Output = Self>
+ ops::BitXor<Output = Self>
+ ops::BitAnd<Output = Self>
{
/// LUT used for maximizing the space covered and minimizing the computational cost of fuzzing
/// in `testcrate`. For example, Self = u128 produces [0,1,2,7,8,15,16,31,32,63,64,95,96,111,
/// 112,119,120,125,126,127].
const FUZZ_LENGTHS: [u8; 20] = make_fuzz_lengths(<Self as MinInt>::BITS);
/// The number of entries of `FUZZ_LENGTHS` actually used. The maximum is 20 for u128.
const FUZZ_NUM: usize = {
let log2 = (<Self as MinInt>::BITS - 1).count_ones() as usize;
if log2 == 3 {
// case for u8
6
} else {
// 3 entries on each extreme, 2 in the middle, and 4 for each scale of intermediate
// boundaries.
8 + (4 * (log2 - 4))
}
};
fn unsigned(self) -> Self::UnsignedInt;
fn from_unsigned(unsigned: Self::UnsignedInt) -> Self;
fn from_bool(b: bool) -> Self;
/// Prevents the need for excessive conversions between signed and unsigned
fn logical_shr(self, other: u32) -> Self;
/// Absolute difference between two integers.
fn abs_diff(self, other: Self) -> Self::UnsignedInt;
// copied from primitive integers, but put in a trait
fn is_zero(self) -> bool;
fn wrapping_neg(self) -> Self;
fn wrapping_add(self, other: Self) -> Self;
fn wrapping_mul(self, other: Self) -> Self;
fn wrapping_sub(self, other: Self) -> Self;
fn wrapping_shl(self, other: u32) -> Self;
fn wrapping_shr(self, other: u32) -> Self;
fn rotate_left(self, other: u32) -> Self;
fn overflowing_add(self, other: Self) -> (Self, bool);
fn leading_zeros(self) -> u32;
fn ilog2(self) -> u32;
}
const fn make_fuzz_lengths(bits: u32) -> [u8; 20] {
let mut v = [0u8; 20];
v[0] = 0;
v[1] = 1;
v[2] = 2; // important for parity and the iX::MIN case when reversed
let mut i = 3;
// No need for any more until the byte boundary, because there should be no algorithms
// that are sensitive to anything not next to byte boundaries after 2. We also scale
// in powers of two, which is important to prevent u128 corner tests from getting too
// big.
let mut l = 8;
loop {
if l >= ((bits / 2) as u8) {
break;
}
// get both sides of the byte boundary
v[i] = l - 1;
i += 1;
v[i] = l;
i += 1;
l *= 2;
}
if bits != 8 {
// add the lower side of the middle boundary
v[i] = ((bits / 2) - 1) as u8;
i += 1;
}
// We do not want to jump directly from the Self::BITS/2 boundary to the Self::BITS
// boundary because of algorithms that split the high part up. We reverse the scaling
// as we go to Self::BITS.
let mid = i;
let mut j = 1;
loop {
v[i] = (bits as u8) - (v[mid - j]) - 1;
if j == mid {
break;
}
i += 1;
j += 1;
}
v
}
macro_rules! int_impl_common {
($ty:ty) => {
fn from_bool(b: bool) -> Self {
b as $ty
}
fn logical_shr(self, other: u32) -> Self {
Self::from_unsigned(self.unsigned().wrapping_shr(other))
}
fn is_zero(self) -> bool {
self == Self::ZERO
}
fn wrapping_neg(self) -> Self {
<Self>::wrapping_neg(self)
}
fn wrapping_add(self, other: Self) -> Self {
<Self>::wrapping_add(self, other)
}
fn wrapping_mul(self, other: Self) -> Self {
<Self>::wrapping_mul(self, other)
}
fn wrapping_sub(self, other: Self) -> Self {
<Self>::wrapping_sub(self, other)
}
fn wrapping_shl(self, other: u32) -> Self {
<Self>::wrapping_shl(self, other)
}
fn wrapping_shr(self, other: u32) -> Self {
<Self>::wrapping_shr(self, other)
}
fn rotate_left(self, other: u32) -> Self {
<Self>::rotate_left(self, other)
}
fn overflowing_add(self, other: Self) -> (Self, bool) {
<Self>::overflowing_add(self, other)
}
fn leading_zeros(self) -> u32 {
<Self>::leading_zeros(self)
}
fn ilog2(self) -> u32 {
<Self>::ilog2(self)
}
};
}
macro_rules! int_impl {
($ity:ty, $uty:ty) => {
impl MinInt for $uty {
type OtherSign = $ity;
type UnsignedInt = $uty;
const BITS: u32 = <Self as MinInt>::ZERO.count_zeros();
const SIGNED: bool = Self::MIN != Self::ZERO;
const ZERO: Self = 0;
const ONE: Self = 1;
const MIN: Self = <Self>::MIN;
const MAX: Self = <Self>::MAX;
}
impl Int for $uty {
fn unsigned(self) -> $uty {
self
}
// It makes writing macros easier if this is implemented for both signed and unsigned
#[allow(clippy::wrong_self_convention)]
fn from_unsigned(me: $uty) -> Self {
me
}
fn abs_diff(self, other: Self) -> Self {
if self < other {
other.wrapping_sub(self)
} else {
self.wrapping_sub(other)
}
}
int_impl_common!($uty);
}
impl MinInt for $ity {
type OtherSign = $uty;
type UnsignedInt = $uty;
const BITS: u32 = <Self as MinInt>::ZERO.count_zeros();
const SIGNED: bool = Self::MIN != Self::ZERO;
const ZERO: Self = 0;
const ONE: Self = 1;
const MIN: Self = <Self>::MIN;
const MAX: Self = <Self>::MAX;
}
impl Int for $ity {
fn unsigned(self) -> $uty {
self as $uty
}
fn from_unsigned(me: $uty) -> Self {
me as $ity
}
fn abs_diff(self, other: Self) -> $uty {
self.wrapping_sub(other).wrapping_abs() as $uty
}
int_impl_common!($ity);
}
};
}
int_impl!(isize, usize);
int_impl!(i8, u8);
int_impl!(i16, u16);
int_impl!(i32, u32);
int_impl!(i64, u64);
int_impl!(i128, u128);
/// Trait for integers twice the bit width of another integer. This is implemented for all
/// primitives except for `u8`, because there is not a smaller primitive.
pub trait DInt: MinInt {
/// Integer that is half the bit width of the integer this trait is implemented for
type H: HInt<D = Self>;
/// Returns the low half of `self`
fn lo(self) -> Self::H;
/// Returns the high half of `self`
fn hi(self) -> Self::H;
/// Returns the low and high halves of `self` as a tuple
fn lo_hi(self) -> (Self::H, Self::H) {
(self.lo(), self.hi())
}
/// Constructs an integer using lower and higher half parts
fn from_lo_hi(lo: Self::H, hi: Self::H) -> Self {
lo.zero_widen() | hi.widen_hi()
}
}
/// Trait for integers half the bit width of another integer. This is implemented for all
/// primitives except for `u128`, because it there is not a larger primitive.
pub trait HInt: Int {
/// Integer that is double the bit width of the integer this trait is implemented for
type D: DInt<H = Self> + MinInt;
/// Widens (using default extension) the integer to have double bit width
fn widen(self) -> Self::D;
/// Widens (zero extension only) the integer to have double bit width. This is needed to get
/// around problems with associated type bounds (such as `Int<Othersign: DInt>`) being unstable
fn zero_widen(self) -> Self::D;
/// Widens the integer to have double bit width and shifts the integer into the higher bits
fn widen_hi(self) -> Self::D {
self.widen() << <Self as MinInt>::BITS
}
/// Widening multiplication with zero widening. This cannot overflow.
fn zero_widen_mul(self, rhs: Self) -> Self::D;
/// Widening multiplication. This cannot overflow.
fn widen_mul(self, rhs: Self) -> Self::D;
}
macro_rules! impl_d_int {
($($X:ident $D:ident),*) => {
$(
impl DInt for $D {
type H = $X;
fn lo(self) -> Self::H {
self as $X
}
fn hi(self) -> Self::H {
(self >> <$X as MinInt>::BITS) as $X
}
}
)*
};
}
macro_rules! impl_h_int {
($($H:ident $uH:ident $X:ident),*) => {
$(
impl HInt for $H {
type D = $X;
fn widen(self) -> Self::D {
self as $X
}
fn zero_widen(self) -> Self::D {
(self as $uH) as $X
}
fn zero_widen_mul(self, rhs: Self) -> Self::D {
self.zero_widen().wrapping_mul(rhs.zero_widen())
}
fn widen_mul(self, rhs: Self) -> Self::D {
self.widen().wrapping_mul(rhs.widen())
}
}
)*
};
}
impl_d_int!(u8 u16, u16 u32, u32 u64, u64 u128, i8 i16, i16 i32, i32 i64, i64 i128);
impl_h_int!(
u8 u8 u16,
u16 u16 u32,
u32 u32 u64,
u64 u64 u128,
i8 u8 i16,
i16 u16 i32,
i32 u32 i64,
i64 u64 i128
);
/// Trait to express (possibly lossy) casting of integers
pub trait CastInto<T: Copy>: Copy {
fn cast(self) -> T;
}
pub trait CastFrom<T: Copy>: Copy {
fn cast_from(value: T) -> Self;
}
impl<T: Copy, U: CastInto<T> + Copy> CastFrom<U> for T {
fn cast_from(value: U) -> Self {
value.cast()
}
}
macro_rules! cast_into {
($ty:ty) => {
cast_into!($ty; usize, isize, u8, i8, u16, i16, u32, i32, u64, i64, u128, i128);
};
($ty:ty; $($into:ty),*) => {$(
impl CastInto<$into> for $ty {
fn cast(self) -> $into {
self as $into
}
}
)*};
}
cast_into!(usize);
cast_into!(isize);
cast_into!(u8);
cast_into!(i8);
cast_into!(u16);
cast_into!(i16);
cast_into!(u32);
cast_into!(i32);
cast_into!(u64);
cast_into!(i64);
cast_into!(u128);
cast_into!(i128);

16
library/compiler-builtins/src/macros.rs
View file

@ -1,5 +1,21 @@
//! Macros shared throughout the compiler-builtins implementation
/// Changes the visibility to `pub` if feature "public-test-deps" is set
#[cfg(not(feature = "public-test-deps"))]
macro_rules! public_test_dep {
($(#[$($meta:meta)*])* pub(crate) $ident:ident $($tokens:tt)*) => {
$(#[$($meta)*])* pub(crate) $ident $($tokens)*
};
}
/// Changes the visibility to `pub` if feature "public-test-deps" is set
#[cfg(feature = "public-test-deps")]
macro_rules! public_test_dep {
{$(#[$($meta:meta)*])* pub(crate) $ident:ident $($tokens:tt)*} => {
$(#[$($meta)*])* pub $ident $($tokens)*
};
}
/// The "main macro" used for defining intrinsics.
///
/// The compiler-builtins library is super platform-specific with tons of crazy