#[repr(simd)]pub struct __m128i(_, _);This is supported on x86 only.
Expand description
128-bit wide integer vector type, x86-specific
This type is the same as the __m128i type defined by Intel,
representing a 128-bit SIMD register. Usage of this type typically
corresponds to the sse and up target features for x86/x86_64.
Internally this type may be viewed as:
i8x16- sixteeni8variables packed togetheri16x8- eighti16variables packed togetheri32x4- fouri32variables packed togetheri64x2- twoi64variables packed together
(as well as unsigned versions). Each intrinsic may interpret the internal bits differently, check the documentation of the intrinsic to see how it’s being used.
Note that this means that an instance of __m128i typically just means
a “bag of bits” which is left up to interpretation at the point of use.
Most intrinsics using __m128i are prefixed with _mm_ and the
integer types tend to correspond to suffixes like “epi8” or “epi32”.
Examples
#[cfg(target_arch = "x86")]
use std::arch::x86::*;
#[cfg(target_arch = "x86_64")]
use std::arch::x86_64::*;
let all_bytes_zero = _mm_setzero_si128();
let all_bytes_one = _mm_set1_epi8(1);
let four_i32 = _mm_set_epi32(1, 2, 3, 4);