Merge pull request rust-lang#67 from rust-lang/limit-lanes

Limit all types to 64 lanes

crates/core_simd/src/fmt.rs

@@ -33,7 +33,10 @@ macro_rules! impl_fmt_trait {
     { $($type:ident => $(($trait:ident, $format:ident)),*;)* } => {
         $( // repeat type
             $( // repeat trait
-                impl<const LANES: usize> core::fmt::$trait for crate::$type<LANES> {
+                impl<const LANES: usize> core::fmt::$trait for crate::$type<LANES>
+                where
+                    Self: crate::LanesAtMost64,
+                {
                     fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
                         $format(self.as_ref(), f)
                     }

crates/core_simd/src/lanes_at_most_64.rs

@@ -0,0 +1,35 @@
+/// Implemented for bitmask sizes that are supported by the implementation.
+pub trait LanesAtMost64 {}
+
+macro_rules! impl_for {
+    { $name:ident } => {
+        impl LanesAtMost64 for $name<1> {}
+        impl LanesAtMost64 for $name<2> {}
+        impl LanesAtMost64 for $name<4> {}
+        impl LanesAtMost64 for $name<8> {}
+        impl LanesAtMost64 for $name<16> {}
+        impl LanesAtMost64 for $name<32> {}
+        impl LanesAtMost64 for $name<64> {}
+    }
+}
+
+use crate::*;
+
+impl_for! { SimdU8 }
+impl_for! { SimdU16 }
+impl_for! { SimdU32 }
+impl_for! { SimdU64 }
+impl_for! { SimdU128 }
+impl_for! { SimdUsize }
+
+impl_for! { SimdI8 }
+impl_for! { SimdI16 }
+impl_for! { SimdI32 }
+impl_for! { SimdI64 }
+impl_for! { SimdI128 }
+impl_for! { SimdIsize }
+
+impl_for! { SimdF32 }
+impl_for! { SimdF64 }
+
+impl_for! { BitMask }

crates/core_simd/src/lib.rs

@@ -14,6 +14,9 @@ mod intrinsics;
 mod ops;
 mod round;
 
+mod lanes_at_most_64;
+pub use lanes_at_most_64::LanesAtMost64;
+
 mod masks;
 pub use masks::*;
 

crates/core_simd/src/macros.rs

@@ -29,7 +29,7 @@ macro_rules! from_transmute_x86 {
 /// Implements common traits on the specified vector `$name`, holding multiple `$lanes` of `$type`.
 macro_rules! impl_vector {
     { $name:ident, $type:ty } => {
-        impl<const LANES: usize> $name<LANES> {
+        impl<const LANES: usize> $name<LANES> where Self: crate::LanesAtMost64 {
             /// Construct a SIMD vector by setting all lanes to the given value.
             pub const fn splat(value: $type) -> Self {
                 Self([value; LANES])
@@ -72,31 +72,31 @@ macro_rules! impl_vector {
             }
         }
 
-        impl<const LANES: usize> Copy for $name<LANES> {}
+        impl<const LANES: usize> Copy for $name<LANES> where Self: crate::LanesAtMost64 {}
 
-        impl<const LANES: usize> Clone for $name<LANES> {
+        impl<const LANES: usize> Clone for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn clone(&self) -> Self {
                 *self
             }
         }
 
-        impl<const LANES: usize> Default for $name<LANES> {
+        impl<const LANES: usize> Default for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn default() -> Self {
                 Self::splat(<$type>::default())
             }
         }
 
-        impl<const LANES: usize> PartialEq for $name<LANES> {
+        impl<const LANES: usize> PartialEq for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn eq(&self, other: &Self) -> bool {
                 // TODO use SIMD equality
                 self.to_array() == other.to_array()
             }
         }
 
-        impl<const LANES: usize> PartialOrd for $name<LANES> {
+        impl<const LANES: usize> PartialOrd for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
                 // TODO use SIMD equalitya
@@ -105,44 +105,44 @@ macro_rules! impl_vector {
         }
 
         // array references
-        impl<const LANES: usize> AsRef<[$type; LANES]> for $name<LANES> {
+        impl<const LANES: usize> AsRef<[$type; LANES]> for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn as_ref(&self) -> &[$type; LANES] {
                 &self.0
             }
         }
 
-        impl<const LANES: usize> AsMut<[$type; LANES]> for $name<LANES> {
+        impl<const LANES: usize> AsMut<[$type; LANES]> for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn as_mut(&mut self) -> &mut [$type; LANES] {
                 &mut self.0
             }
         }
 
         // slice references
-        impl<const LANES: usize> AsRef<[$type]> for $name<LANES> {
+        impl<const LANES: usize> AsRef<[$type]> for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn as_ref(&self) -> &[$type] {
                 &self.0
             }
         }
 
-        impl<const LANES: usize> AsMut<[$type]> for $name<LANES> {
+        impl<const LANES: usize> AsMut<[$type]> for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn as_mut(&mut self) -> &mut [$type] {
                 &mut self.0
             }
         }
 
         // vector/array conversion
-        impl<const LANES: usize> From<[$type; LANES]> for $name<LANES> {
+        impl<const LANES: usize> From<[$type; LANES]> for $name<LANES> where Self: crate::LanesAtMost64 {
             fn from(array: [$type; LANES]) -> Self {
                 Self(array)
             }
         }
 
         // splat
-        impl<const LANES: usize> From<$type> for $name<LANES> {
+        impl<const LANES: usize> From<$type> for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn from(value: $type) -> Self {
                 Self::splat(value)
@@ -158,17 +158,17 @@ macro_rules! impl_integer_vector {
     { $name:ident, $type:ty } => {
         impl_vector! { $name, $type }
 
-        impl<const LANES: usize> Eq for $name<LANES> {}
+        impl<const LANES: usize> Eq for $name<LANES> where Self: crate::LanesAtMost64 {}
 
-        impl<const LANES: usize> Ord for $name<LANES> {
+        impl<const LANES: usize> Ord for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn cmp(&self, other: &Self) -> core::cmp::Ordering {
                 // TODO use SIMD cmp
                 self.to_array().cmp(other.as_ref())
             }
         }
 
-        impl<const LANES: usize> core::hash::Hash for $name<LANES> {
+        impl<const LANES: usize> core::hash::Hash for $name<LANES> where Self: crate::LanesAtMost64 {
             #[inline]
             fn hash<H>(&self, state: &mut H)
             where
@@ -187,7 +187,11 @@ macro_rules! impl_float_vector {
     { $name:ident, $type:ty, $bits_ty:ident } => {
         impl_vector! { $name, $type }
 
-        impl<const LANES: usize> $name<LANES> {
+        impl<const LANES: usize> $name<LANES>
+        where
+            Self: crate::LanesAtMost64,
+            crate::$bits_ty<LANES>: crate::LanesAtMost64,
+        {
             /// Raw transmutation to an unsigned integer vector type with the
             /// same size and number of lanes.
             #[inline]

crates/core_simd/src/masks/bitmask.rs

@@ -1,12 +1,4 @@
-/// Implemented for bitmask sizes that are supported by the implementation.
-pub trait LanesAtMost64 {}
-impl LanesAtMost64 for BitMask<1> {}
-impl LanesAtMost64 for BitMask<2> {}
-impl LanesAtMost64 for BitMask<4> {}
-impl LanesAtMost64 for BitMask<8> {}
-impl LanesAtMost64 for BitMask<16> {}
-impl LanesAtMost64 for BitMask<32> {}
-impl LanesAtMost64 for BitMask<64> {}
+use crate::LanesAtMost64;
 
 /// A mask where each lane is represented by a single bit.
 #[derive(Copy, Clone, Debug)]