Module wasmtime_environ::__core::simd
source · portable_simd
)Expand description
Portable SIMD module.
This module offers a portable abstraction for SIMD operations that is not bound to any particular hardware architecture.
§What is “portable”?
This module provides a SIMD implementation that is fast and predictable on any target.
§Portable SIMD works on every target
Unlike target-specific SIMD in std::arch
, portable SIMD compiles for every target.
In this regard, it is just like “regular” Rust.
§Portable SIMD is consistent between targets
A program using portable SIMD can expect identical behavior on any target.
In most regards, Simd<T, N>
can be thought of as a parallelized [T; N]
and operates like a sequence of T
.
This has one notable exception: a handful of older architectures (e.g. armv7
and powerpc
) flush subnormal f32
values to zero.
On these architectures, subnormal f32
input values are replaced with zeros, and any operation producing subnormal f32
values produces zeros instead.
This doesn’t affect most architectures or programs.
§Operations use the best instructions available
Operations provided by this module compile to the best available SIMD instructions.
Portable SIMD is not a low-level vendor library, and operations in portable SIMD do not necessarily map to a single instruction. Instead, they map to a reasonable implementation of the operation for the target.
Consistency between targets is not compromised to use faster or fewer instructions.
In some cases, std::arch
will provide a faster function that has slightly different behavior than the std::simd
equivalent.
For example, _mm_min_ps
1 can be slightly faster than SimdFloat::simd_min
, but does not conform to the IEEE standard also used by f32::min
.
When necessary, Simd<T, N>
can be converted to the types provided by std::arch
to make use of target-specific functions.
Many targets simply don’t have SIMD, or don’t support SIMD for a particular element type. In those cases, regular scalar operations are generated instead.
_mm_min_ps(x, y)
is equivalent tox.simd_lt(y).select(x, y)
↩
Modules§
- cmpExperimentalTraits for comparing and ordering vectors.
- numExperimentalTraits for vectors with numeric elements.
- preludeExperimentalThe portable SIMD prelude.
- ptrExperimentalTraits for vectors of pointers.
Macros§
- simd_swizzleExperimentalConstructs a new SIMD vector by copying elements from selected elements in other vectors.
Structs§
- LaneCountExperimentalSpecifies the number of lanes in a SIMD vector as a type.
- MaskExperimentalA SIMD vector mask for
N
elements of width specified byElement
. - SimdExperimentalA SIMD vector with the shape of
[T; N]
but the operations ofT
.
Traits§
- MaskElementExperimentalMarker trait for types that may be used as SIMD mask elements.
- SimdCastExperimentalSupporting trait for
Simd::cast
. Typically doesn’t need to be used directly. - SimdElementExperimentalMarker trait for types that may be used as SIMD vector elements.
- SupportedLaneCountExperimentalStatically guarantees that a lane count is marked as supported.
- SwizzleExperimentalCreate a vector from the elements of another vector.
- ToBytesExperimentalConvert SIMD vectors to vectors of bytes
Type Aliases§
- f32x1ExperimentalA SIMD vector with one element of type
f32
. - f32x2ExperimentalA SIMD vector with two elements of type
f32
. - f32x4ExperimentalA SIMD vector with four elements of type
f32
. - f32x8ExperimentalA SIMD vector with eight elements of type
f32
. - f32x16ExperimentalA SIMD vector with 16 elements of type
f32
. - f32x32ExperimentalA SIMD vector with 32 elements of type
f32
. - f32x64ExperimentalA SIMD vector with 64 elements of type
f32
. - f64x1ExperimentalA SIMD vector with one element of type
f64
. - f64x2ExperimentalA SIMD vector with two elements of type
f64
. - f64x4ExperimentalA SIMD vector with four elements of type
f64
. - f64x8ExperimentalA SIMD vector with eight elements of type
f64
. - f64x16ExperimentalA SIMD vector with 16 elements of type
f64
. - f64x32ExperimentalA SIMD vector with 32 elements of type
f64
. - f64x64ExperimentalA SIMD vector with 64 elements of type
f64
. - i8x1ExperimentalA SIMD vector with one element of type
i8
. - i8x2ExperimentalA SIMD vector with two elements of type
i8
. - i8x4ExperimentalA SIMD vector with four elements of type
i8
. - i8x8ExperimentalA SIMD vector with eight elements of type
i8
. - i8x16ExperimentalA SIMD vector with 16 elements of type
i8
. - i8x32ExperimentalA SIMD vector with 32 elements of type
i8
. - i8x64ExperimentalA SIMD vector with 64 elements of type
i8
. - i16x1ExperimentalA SIMD vector with one element of type
i16
. - i16x2ExperimentalA SIMD vector with two elements of type
i16
. - i16x4ExperimentalA SIMD vector with four elements of type
i16
. - i16x8ExperimentalA SIMD vector with eight elements of type
i16
. - i16x16ExperimentalA SIMD vector with 16 elements of type
i16
. - i16x32ExperimentalA SIMD vector with 32 elements of type
i16
. - i16x64ExperimentalA SIMD vector with 64 elements of type
i16
. - i32x1ExperimentalA SIMD vector with one element of type
i32
. - i32x2ExperimentalA SIMD vector with two elements of type
i32
. - i32x4ExperimentalA SIMD vector with four elements of type
i32
. - i32x8ExperimentalA SIMD vector with eight elements of type
i32
. - i32x16ExperimentalA SIMD vector with 16 elements of type
i32
. - i32x32ExperimentalA SIMD vector with 32 elements of type
i32
. - i32x64ExperimentalA SIMD vector with 64 elements of type
i32
. - i64x1ExperimentalA SIMD vector with one element of type
i64
. - i64x2ExperimentalA SIMD vector with two elements of type
i64
. - i64x4ExperimentalA SIMD vector with four elements of type
i64
. - i64x8ExperimentalA SIMD vector with eight elements of type
i64
. - i64x16ExperimentalA SIMD vector with 16 elements of type
i64
. - i64x32ExperimentalA SIMD vector with 32 elements of type
i64
. - i64x64ExperimentalA SIMD vector with 64 elements of type
i64
. - isizex1ExperimentalA SIMD vector with one element of type
isize
. - isizex2ExperimentalA SIMD vector with two elements of type
isize
. - isizex4ExperimentalA SIMD vector with four elements of type
isize
. - isizex8ExperimentalA SIMD vector with eight elements of type
isize
. - isizex16ExperimentalA SIMD vector with 16 elements of type
isize
. - isizex32ExperimentalA SIMD vector with 32 elements of type
isize
. - isizex64ExperimentalA SIMD vector with 64 elements of type
isize
. - mask8x1ExperimentalA SIMD mask with one element for vectors with 8-bit element types.
- mask8x2ExperimentalA SIMD mask with two elements for vectors with 8-bit element types.
- mask8x4ExperimentalA SIMD mask with four elements for vectors with 8-bit element types.
- mask8x8ExperimentalA SIMD mask with eight elements for vectors with 8-bit element types.
- mask8x16ExperimentalA SIMD mask with 16 elements for vectors with 8-bit element types.
- mask8x32ExperimentalA SIMD mask with 32 elements for vectors with 8-bit element types.
- mask8x64ExperimentalA SIMD mask with 64 elements for vectors with 8-bit element types.
- mask16x1ExperimentalA SIMD mask with one element for vectors with 16-bit element types.
- mask16x2ExperimentalA SIMD mask with two elements for vectors with 16-bit element types.
- mask16x4ExperimentalA SIMD mask with four elements for vectors with 16-bit element types.
- mask16x8ExperimentalA SIMD mask with eight elements for vectors with 16-bit element types.
- mask16x16ExperimentalA SIMD mask with 16 elements for vectors with 16-bit element types.
- mask16x32ExperimentalA SIMD mask with 32 elements for vectors with 16-bit element types.
- mask16x64ExperimentalA SIMD mask with 64 elements for vectors with 16-bit element types.
- mask32x1ExperimentalA SIMD mask with one element for vectors with 32-bit element types.
- mask32x2ExperimentalA SIMD mask with two elements for vectors with 32-bit element types.
- mask32x4ExperimentalA SIMD mask with four elements for vectors with 32-bit element types.
- mask32x8ExperimentalA SIMD mask with eight elements for vectors with 32-bit element types.
- mask32x16ExperimentalA SIMD mask with 16 elements for vectors with 32-bit element types.
- mask32x32ExperimentalA SIMD mask with 32 elements for vectors with 32-bit element types.
- mask32x64ExperimentalA SIMD mask with 64 elements for vectors with 32-bit element types.
- mask64x1ExperimentalA SIMD mask with one element for vectors with 64-bit element types.
- mask64x2ExperimentalA SIMD mask with two elements for vectors with 64-bit element types.
- mask64x4ExperimentalA SIMD mask with four elements for vectors with 64-bit element types.
- mask64x8ExperimentalA SIMD mask with eight elements for vectors with 64-bit element types.
- mask64x16ExperimentalA SIMD mask with 16 elements for vectors with 64-bit element types.
- mask64x32ExperimentalA SIMD mask with 32 elements for vectors with 64-bit element types.
- mask64x64ExperimentalA SIMD mask with 64 elements for vectors with 64-bit element types.
- masksizex1ExperimentalA SIMD mask with one element for vectors with pointer-sized element types.
- masksizex2ExperimentalA SIMD mask with two elements for vectors with pointer-sized element types.
- masksizex4ExperimentalA SIMD mask with four elements for vectors with pointer-sized element types.
- masksizex8ExperimentalA SIMD mask with eight elements for vectors with pointer-sized element types.
- masksizex16ExperimentalA SIMD mask with 16 elements for vectors with pointer-sized element types.
- masksizex32ExperimentalA SIMD mask with 32 elements for vectors with pointer-sized element types.
- masksizex64ExperimentalA SIMD mask with 64 elements for vectors with pointer-sized element types.
- u8x1ExperimentalA SIMD vector with one element of type
u8
. - u8x2ExperimentalA SIMD vector with two elements of type
u8
. - u8x4ExperimentalA SIMD vector with four elements of type
u8
. - u8x8ExperimentalA SIMD vector with eight elements of type
u8
. - u8x16ExperimentalA SIMD vector with 16 elements of type
u8
. - u8x32ExperimentalA SIMD vector with 32 elements of type
u8
. - u8x64ExperimentalA SIMD vector with 64 elements of type
u8
. - u16x1ExperimentalA SIMD vector with one element of type
u16
. - u16x2ExperimentalA SIMD vector with two elements of type
u16
. - u16x4ExperimentalA SIMD vector with four elements of type
u16
. - u16x8ExperimentalA SIMD vector with eight elements of type
u16
. - u16x16ExperimentalA SIMD vector with 16 elements of type
u16
. - u16x32ExperimentalA SIMD vector with 32 elements of type
u16
. - u16x64ExperimentalA SIMD vector with 64 elements of type
u16
. - u32x1ExperimentalA SIMD vector with one element of type
u32
. - u32x2ExperimentalA SIMD vector with two elements of type
u32
. - u32x4ExperimentalA SIMD vector with four elements of type
u32
. - u32x8ExperimentalA SIMD vector with eight elements of type
u32
. - u32x16ExperimentalA SIMD vector with 16 elements of type
u32
. - u32x32ExperimentalA SIMD vector with 32 elements of type
u32
. - u32x64ExperimentalA SIMD vector with 64 elements of type
u32
. - u64x1ExperimentalA SIMD vector with one element of type
u64
. - u64x2ExperimentalA SIMD vector with two elements of type
u64
. - u64x4ExperimentalA SIMD vector with four elements of type
u64
. - u64x8ExperimentalA SIMD vector with eight elements of type
u64
. - u64x16ExperimentalA SIMD vector with 16 elements of type
u64
. - u64x32ExperimentalA SIMD vector with 32 elements of type
u64
. - u64x64ExperimentalA SIMD vector with 64 elements of type
u64
. - usizex1ExperimentalA SIMD vector with one element of type
usize
. - usizex2ExperimentalA SIMD vector with two elements of type
usize
. - usizex4ExperimentalA SIMD vector with four elements of type
usize
. - usizex8ExperimentalA SIMD vector with eight elements of type
usize
. - usizex16ExperimentalA SIMD vector with 16 elements of type
usize
. - usizex32ExperimentalA SIMD vector with 32 elements of type
usize
. - usizex64ExperimentalA SIMD vector with 64 elements of type
usize
.