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Move packing functions to top of the module

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This commit is contained in:
Henry de Valence 2018-06-14 15:21:51 -07:00
parent 4dc219910a
commit 97292fef91
1 changed files with 51 additions and 35 deletions
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86
src/backend/avx2/field.rs
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@ -28,6 +28,57 @@ use core::simd::{i32x8, u32x8, u64x4, IntoBits};
use backend::avx2::constants::{P_TIMES_16_HI, P_TIMES_16_LO, P_TIMES_2_HI, P_TIMES_2_LO};
use backend::u64::field::FieldElement64;
/// Unpack
/// ```
/// (a0, b0, a1, b1, c0, d0, c1, d1)
/// ```
/// into
/// ```
/// (a0, 0, b0, 0, c0, 0, d0, 0)
/// (a1, 0, b1, 0, c1, 0, d1, 0)
/// ```
#[inline(always)]
fn unpack_pair(src: u32x8) -> (u32x8, u32x8) {
let a: u32x8;
let b: u32x8;
let zero = i32x8::new(0, 0, 0, 0, 0, 0, 0, 0);
unsafe {
use core::arch::x86_64::_mm256_unpackhi_epi32;
use core::arch::x86_64::_mm256_unpacklo_epi32;
a = _mm256_unpacklo_epi32(src.into_bits(), zero.into_bits()).into_bits();
b = _mm256_unpackhi_epi32(src.into_bits(), zero.into_bits()).into_bits();
}
(a, b)
}
/// Repack
/// ```
/// (a0, 0, b0, 0, c0, 0, d0, 0)
/// (a1, 0, b1, 0, c1, 0, d1, 0)
/// ```
/// into
/// ```
/// (a0, b0, a1, b1, c0, d0, c1, d1)
/// ```
#[inline(always)]
fn repack_pair(x: u32x8, y: u32x8) -> u32x8 {
unsafe {
use core::arch::x86_64::_mm256_blend_epi32;
use core::arch::x86_64::_mm256_shuffle_epi32;
// Input: x = (a0, 0, b0, 0, c0, 0, d0, 0)
// Input: y = (a1, 0, b1, 0, c1, 0, d1, 0)
let x_shuffled = _mm256_shuffle_epi32(x.into_bits(), 0b11_01_10_00);
let y_shuffled = _mm256_shuffle_epi32(y.into_bits(), 0b10_00_11_01);
// x' = (a0, b0, 0, 0, c0, d0, 0, 0)
// y' = ( 0, 0, a1, b1, 0, 0, c1, d1)
return _mm256_blend_epi32(x_shuffled, y_shuffled, 0b11001100).into_bits();
}
}
/// The `Lanes` enum represents a subset of the lanes `A,B,C,D` of a
/// `FieldElement32x4`.
///
@ -430,42 +481,7 @@ impl FieldElement32x4 {
repack_pair(z[8].into_bits(), z[9].into_bits()),
])
}
}
#[inline(always)]
fn unpack_pair(src: u32x8) -> (u32x8, u32x8) {
let a: u32x8;
let b: u32x8;
let zero = i32x8::new(0, 0, 0, 0, 0, 0, 0, 0);
unsafe {
use core::arch::x86_64::_mm256_unpackhi_epi32;
use core::arch::x86_64::_mm256_unpacklo_epi32;
a = _mm256_unpacklo_epi32(src.into_bits(), zero.into_bits()).into_bits();
b = _mm256_unpackhi_epi32(src.into_bits(), zero.into_bits()).into_bits();
}
(a, b)
}
#[inline(always)]
fn repack_pair(x: u32x8, y: u32x8) -> u32x8 {
unsafe {
use core::arch::x86_64::_mm256_blend_epi32;
use core::arch::x86_64::_mm256_shuffle_epi32;
// Input: x = (a0, 0, b0, 0, c0, 0, d0)
// Input: y = (a1, 0, b1, 0, c1, 0, d1)
let x_shuffled = _mm256_shuffle_epi32(x.into_bits(), 0b11_01_10_00);
let y_shuffled = _mm256_shuffle_epi32(y.into_bits(), 0b10_00_11_01);
// x' = (a0, b0, 0, 0, c0, d0, 0, 0)
// y' = ( 0, 0, a1, b1, 0, 0, c1, d1)
return _mm256_blend_epi32(x_shuffled, y_shuffled, 0b11001100).into_bits();
}
}
impl FieldElement32x4 {
/// Square this field element, then conditionally negate according
/// to `neg_mask`. This parameter is hardcoded as `neg_mask =
/// D_LANES64` to negate the \\( D \\) value.