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Diffstat (limited to 'vendor/half/src/binary16/convert.rs')
-rw-r--r-- | vendor/half/src/binary16/convert.rs | 752 |
1 files changed, 752 insertions, 0 deletions
diff --git a/vendor/half/src/binary16/convert.rs b/vendor/half/src/binary16/convert.rs new file mode 100644 index 0000000..b96910f --- /dev/null +++ b/vendor/half/src/binary16/convert.rs @@ -0,0 +1,752 @@ +#![allow(dead_code, unused_imports)] +use crate::leading_zeros::leading_zeros_u16; +use core::mem; + +macro_rules! convert_fn { + (fn $name:ident($($var:ident : $vartype:ty),+) -> $restype:ty { + if feature("f16c") { $f16c:expr } + else { $fallback:expr }}) => { + #[inline] + pub(crate) fn $name($($var: $vartype),+) -> $restype { + // Use CPU feature detection if using std + #[cfg(all( + feature = "use-intrinsics", + feature = "std", + any(target_arch = "x86", target_arch = "x86_64"), + not(target_feature = "f16c") + ))] + { + if is_x86_feature_detected!("f16c") { + $f16c + } else { + $fallback + } + } + // Use intrinsics directly when a compile target or using no_std + #[cfg(all( + feature = "use-intrinsics", + any(target_arch = "x86", target_arch = "x86_64"), + target_feature = "f16c" + ))] + { + $f16c + } + // Fallback to software + #[cfg(any( + not(feature = "use-intrinsics"), + not(any(target_arch = "x86", target_arch = "x86_64")), + all(not(feature = "std"), not(target_feature = "f16c")) + ))] + { + $fallback + } + } + }; +} + +convert_fn! { + fn f32_to_f16(f: f32) -> u16 { + if feature("f16c") { + unsafe { x86::f32_to_f16_x86_f16c(f) } + } else { + f32_to_f16_fallback(f) + } + } +} + +convert_fn! { + fn f64_to_f16(f: f64) -> u16 { + if feature("f16c") { + unsafe { x86::f32_to_f16_x86_f16c(f as f32) } + } else { + f64_to_f16_fallback(f) + } + } +} + +convert_fn! { + fn f16_to_f32(i: u16) -> f32 { + if feature("f16c") { + unsafe { x86::f16_to_f32_x86_f16c(i) } + } else { + f16_to_f32_fallback(i) + } + } +} + +convert_fn! { + fn f16_to_f64(i: u16) -> f64 { + if feature("f16c") { + unsafe { x86::f16_to_f32_x86_f16c(i) as f64 } + } else { + f16_to_f64_fallback(i) + } + } +} + +convert_fn! { + fn f32x4_to_f16x4(f: &[f32; 4]) -> [u16; 4] { + if feature("f16c") { + unsafe { x86::f32x4_to_f16x4_x86_f16c(f) } + } else { + f32x4_to_f16x4_fallback(f) + } + } +} + +convert_fn! { + fn f16x4_to_f32x4(i: &[u16; 4]) -> [f32; 4] { + if feature("f16c") { + unsafe { x86::f16x4_to_f32x4_x86_f16c(i) } + } else { + f16x4_to_f32x4_fallback(i) + } + } +} + +convert_fn! { + fn f64x4_to_f16x4(f: &[f64; 4]) -> [u16; 4] { + if feature("f16c") { + unsafe { x86::f64x4_to_f16x4_x86_f16c(f) } + } else { + f64x4_to_f16x4_fallback(f) + } + } +} + +convert_fn! { + fn f16x4_to_f64x4(i: &[u16; 4]) -> [f64; 4] { + if feature("f16c") { + unsafe { x86::f16x4_to_f64x4_x86_f16c(i) } + } else { + f16x4_to_f64x4_fallback(i) + } + } +} + +convert_fn! { + fn f32x8_to_f16x8(f: &[f32; 8]) -> [u16; 8] { + if feature("f16c") { + unsafe { x86::f32x8_to_f16x8_x86_f16c(f) } + } else { + f32x8_to_f16x8_fallback(f) + } + } +} + +convert_fn! { + fn f16x8_to_f32x8(i: &[u16; 8]) -> [f32; 8] { + if feature("f16c") { + unsafe { x86::f16x8_to_f32x8_x86_f16c(i) } + } else { + f16x8_to_f32x8_fallback(i) + } + } +} + +convert_fn! { + fn f64x8_to_f16x8(f: &[f64; 8]) -> [u16; 8] { + if feature("f16c") { + unsafe { x86::f64x8_to_f16x8_x86_f16c(f) } + } else { + f64x8_to_f16x8_fallback(f) + } + } +} + +convert_fn! { + fn f16x8_to_f64x8(i: &[u16; 8]) -> [f64; 8] { + if feature("f16c") { + unsafe { x86::f16x8_to_f64x8_x86_f16c(i) } + } else { + f16x8_to_f64x8_fallback(i) + } + } +} + +convert_fn! { + fn f32_to_f16_slice(src: &[f32], dst: &mut [u16]) -> () { + if feature("f16c") { + convert_chunked_slice_8(src, dst, x86::f32x8_to_f16x8_x86_f16c, + x86::f32x4_to_f16x4_x86_f16c) + } else { + slice_fallback(src, dst, f32_to_f16_fallback) + } + } +} + +convert_fn! { + fn f16_to_f32_slice(src: &[u16], dst: &mut [f32]) -> () { + if feature("f16c") { + convert_chunked_slice_8(src, dst, x86::f16x8_to_f32x8_x86_f16c, + x86::f16x4_to_f32x4_x86_f16c) + } else { + slice_fallback(src, dst, f16_to_f32_fallback) + } + } +} + +convert_fn! { + fn f64_to_f16_slice(src: &[f64], dst: &mut [u16]) -> () { + if feature("f16c") { + convert_chunked_slice_8(src, dst, x86::f64x8_to_f16x8_x86_f16c, + x86::f64x4_to_f16x4_x86_f16c) + } else { + slice_fallback(src, dst, f64_to_f16_fallback) + } + } +} + +convert_fn! { + fn f16_to_f64_slice(src: &[u16], dst: &mut [f64]) -> () { + if feature("f16c") { + convert_chunked_slice_8(src, dst, x86::f16x8_to_f64x8_x86_f16c, + x86::f16x4_to_f64x4_x86_f16c) + } else { + slice_fallback(src, dst, f16_to_f64_fallback) + } + } +} + +/// Chunks sliced into x8 or x4 arrays +#[inline] +fn convert_chunked_slice_8<S: Copy + Default, D: Copy>( + src: &[S], + dst: &mut [D], + fn8: unsafe fn(&[S; 8]) -> [D; 8], + fn4: unsafe fn(&[S; 4]) -> [D; 4], +) { + assert_eq!(src.len(), dst.len()); + + // TODO: Can be further optimized with array_chunks when it becomes stabilized + + let src_chunks = src.chunks_exact(8); + let mut dst_chunks = dst.chunks_exact_mut(8); + let src_remainder = src_chunks.remainder(); + for (s, d) in src_chunks.zip(&mut dst_chunks) { + let chunk: &[S; 8] = s.try_into().unwrap(); + d.copy_from_slice(unsafe { &fn8(chunk) }); + } + + // Process remainder + if src_remainder.len() > 4 { + let mut buf: [S; 8] = Default::default(); + buf[..src_remainder.len()].copy_from_slice(src_remainder); + let vec = unsafe { fn8(&buf) }; + let dst_remainder = dst_chunks.into_remainder(); + dst_remainder.copy_from_slice(&vec[..dst_remainder.len()]); + } else if !src_remainder.is_empty() { + let mut buf: [S; 4] = Default::default(); + buf[..src_remainder.len()].copy_from_slice(src_remainder); + let vec = unsafe { fn4(&buf) }; + let dst_remainder = dst_chunks.into_remainder(); + dst_remainder.copy_from_slice(&vec[..dst_remainder.len()]); + } +} + +/// Chunks sliced into x4 arrays +#[inline] +fn convert_chunked_slice_4<S: Copy + Default, D: Copy>( + src: &[S], + dst: &mut [D], + f: unsafe fn(&[S; 4]) -> [D; 4], +) { + assert_eq!(src.len(), dst.len()); + + // TODO: Can be further optimized with array_chunks when it becomes stabilized + + let src_chunks = src.chunks_exact(4); + let mut dst_chunks = dst.chunks_exact_mut(4); + let src_remainder = src_chunks.remainder(); + for (s, d) in src_chunks.zip(&mut dst_chunks) { + let chunk: &[S; 4] = s.try_into().unwrap(); + d.copy_from_slice(unsafe { &f(chunk) }); + } + + // Process remainder + if !src_remainder.is_empty() { + let mut buf: [S; 4] = Default::default(); + buf[..src_remainder.len()].copy_from_slice(src_remainder); + let vec = unsafe { f(&buf) }; + let dst_remainder = dst_chunks.into_remainder(); + dst_remainder.copy_from_slice(&vec[..dst_remainder.len()]); + } +} + +/////////////// Fallbacks //////////////// + +// In the below functions, round to nearest, with ties to even. +// Let us call the most significant bit that will be shifted out the round_bit. +// +// Round up if either +// a) Removed part > tie. +// (mantissa & round_bit) != 0 && (mantissa & (round_bit - 1)) != 0 +// b) Removed part == tie, and retained part is odd. +// (mantissa & round_bit) != 0 && (mantissa & (2 * round_bit)) != 0 +// (If removed part == tie and retained part is even, do not round up.) +// These two conditions can be combined into one: +// (mantissa & round_bit) != 0 && (mantissa & ((round_bit - 1) | (2 * round_bit))) != 0 +// which can be simplified into +// (mantissa & round_bit) != 0 && (mantissa & (3 * round_bit - 1)) != 0 + +#[inline] +pub(crate) const fn f32_to_f16_fallback(value: f32) -> u16 { + // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized + // Convert to raw bytes + let x: u32 = unsafe { mem::transmute(value) }; + + // Extract IEEE754 components + let sign = x & 0x8000_0000u32; + let exp = x & 0x7F80_0000u32; + let man = x & 0x007F_FFFFu32; + + // Check for all exponent bits being set, which is Infinity or NaN + if exp == 0x7F80_0000u32 { + // Set mantissa MSB for NaN (and also keep shifted mantissa bits) + let nan_bit = if man == 0 { 0 } else { 0x0200u32 }; + return ((sign >> 16) | 0x7C00u32 | nan_bit | (man >> 13)) as u16; + } + + // The number is normalized, start assembling half precision version + let half_sign = sign >> 16; + // Unbias the exponent, then bias for half precision + let unbiased_exp = ((exp >> 23) as i32) - 127; + let half_exp = unbiased_exp + 15; + + // Check for exponent overflow, return +infinity + if half_exp >= 0x1F { + return (half_sign | 0x7C00u32) as u16; + } + + // Check for underflow + if half_exp <= 0 { + // Check mantissa for what we can do + if 14 - half_exp > 24 { + // No rounding possibility, so this is a full underflow, return signed zero + return half_sign as u16; + } + // Don't forget about hidden leading mantissa bit when assembling mantissa + let man = man | 0x0080_0000u32; + let mut half_man = man >> (14 - half_exp); + // Check for rounding (see comment above functions) + let round_bit = 1 << (13 - half_exp); + if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 { + half_man += 1; + } + // No exponent for subnormals + return (half_sign | half_man) as u16; + } + + // Rebias the exponent + let half_exp = (half_exp as u32) << 10; + let half_man = man >> 13; + // Check for rounding (see comment above functions) + let round_bit = 0x0000_1000u32; + if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 { + // Round it + ((half_sign | half_exp | half_man) + 1) as u16 + } else { + (half_sign | half_exp | half_man) as u16 + } +} + +#[inline] +pub(crate) const fn f64_to_f16_fallback(value: f64) -> u16 { + // Convert to raw bytes, truncating the last 32-bits of mantissa; that precision will always + // be lost on half-precision. + // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized + let val: u64 = unsafe { mem::transmute(value) }; + let x = (val >> 32) as u32; + + // Extract IEEE754 components + let sign = x & 0x8000_0000u32; + let exp = x & 0x7FF0_0000u32; + let man = x & 0x000F_FFFFu32; + + // Check for all exponent bits being set, which is Infinity or NaN + if exp == 0x7FF0_0000u32 { + // Set mantissa MSB for NaN (and also keep shifted mantissa bits). + // We also have to check the last 32 bits. + let nan_bit = if man == 0 && (val as u32 == 0) { + 0 + } else { + 0x0200u32 + }; + return ((sign >> 16) | 0x7C00u32 | nan_bit | (man >> 10)) as u16; + } + + // The number is normalized, start assembling half precision version + let half_sign = sign >> 16; + // Unbias the exponent, then bias for half precision + let unbiased_exp = ((exp >> 20) as i64) - 1023; + let half_exp = unbiased_exp + 15; + + // Check for exponent overflow, return +infinity + if half_exp >= 0x1F { + return (half_sign | 0x7C00u32) as u16; + } + + // Check for underflow + if half_exp <= 0 { + // Check mantissa for what we can do + if 10 - half_exp > 21 { + // No rounding possibility, so this is a full underflow, return signed zero + return half_sign as u16; + } + // Don't forget about hidden leading mantissa bit when assembling mantissa + let man = man | 0x0010_0000u32; + let mut half_man = man >> (11 - half_exp); + // Check for rounding (see comment above functions) + let round_bit = 1 << (10 - half_exp); + if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 { + half_man += 1; + } + // No exponent for subnormals + return (half_sign | half_man) as u16; + } + + // Rebias the exponent + let half_exp = (half_exp as u32) << 10; + let half_man = man >> 10; + // Check for rounding (see comment above functions) + let round_bit = 0x0000_0200u32; + if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 { + // Round it + ((half_sign | half_exp | half_man) + 1) as u16 + } else { + (half_sign | half_exp | half_man) as u16 + } +} + +#[inline] +pub(crate) const fn f16_to_f32_fallback(i: u16) -> f32 { + // Check for signed zero + // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized + if i & 0x7FFFu16 == 0 { + return unsafe { mem::transmute((i as u32) << 16) }; + } + + let half_sign = (i & 0x8000u16) as u32; + let half_exp = (i & 0x7C00u16) as u32; + let half_man = (i & 0x03FFu16) as u32; + + // Check for an infinity or NaN when all exponent bits set + if half_exp == 0x7C00u32 { + // Check for signed infinity if mantissa is zero + if half_man == 0 { + return unsafe { mem::transmute((half_sign << 16) | 0x7F80_0000u32) }; + } else { + // NaN, keep current mantissa but also set most significiant mantissa bit + return unsafe { + mem::transmute((half_sign << 16) | 0x7FC0_0000u32 | (half_man << 13)) + }; + } + } + + // Calculate single-precision components with adjusted exponent + let sign = half_sign << 16; + // Unbias exponent + let unbiased_exp = ((half_exp as i32) >> 10) - 15; + + // Check for subnormals, which will be normalized by adjusting exponent + if half_exp == 0 { + // Calculate how much to adjust the exponent by + let e = leading_zeros_u16(half_man as u16) - 6; + + // Rebias and adjust exponent + let exp = (127 - 15 - e) << 23; + let man = (half_man << (14 + e)) & 0x7F_FF_FFu32; + return unsafe { mem::transmute(sign | exp | man) }; + } + + // Rebias exponent for a normalized normal + let exp = ((unbiased_exp + 127) as u32) << 23; + let man = (half_man & 0x03FFu32) << 13; + unsafe { mem::transmute(sign | exp | man) } +} + +#[inline] +pub(crate) const fn f16_to_f64_fallback(i: u16) -> f64 { + // Check for signed zero + // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized + if i & 0x7FFFu16 == 0 { + return unsafe { mem::transmute((i as u64) << 48) }; + } + + let half_sign = (i & 0x8000u16) as u64; + let half_exp = (i & 0x7C00u16) as u64; + let half_man = (i & 0x03FFu16) as u64; + + // Check for an infinity or NaN when all exponent bits set + if half_exp == 0x7C00u64 { + // Check for signed infinity if mantissa is zero + if half_man == 0 { + return unsafe { mem::transmute((half_sign << 48) | 0x7FF0_0000_0000_0000u64) }; + } else { + // NaN, keep current mantissa but also set most significiant mantissa bit + return unsafe { + mem::transmute((half_sign << 48) | 0x7FF8_0000_0000_0000u64 | (half_man << 42)) + }; + } + } + + // Calculate double-precision components with adjusted exponent + let sign = half_sign << 48; + // Unbias exponent + let unbiased_exp = ((half_exp as i64) >> 10) - 15; + + // Check for subnormals, which will be normalized by adjusting exponent + if half_exp == 0 { + // Calculate how much to adjust the exponent by + let e = leading_zeros_u16(half_man as u16) - 6; + + // Rebias and adjust exponent + let exp = ((1023 - 15 - e) as u64) << 52; + let man = (half_man << (43 + e)) & 0xF_FFFF_FFFF_FFFFu64; + return unsafe { mem::transmute(sign | exp | man) }; + } + + // Rebias exponent for a normalized normal + let exp = ((unbiased_exp + 1023) as u64) << 52; + let man = (half_man & 0x03FFu64) << 42; + unsafe { mem::transmute(sign | exp | man) } +} + +#[inline] +fn f16x4_to_f32x4_fallback(v: &[u16; 4]) -> [f32; 4] { + [ + f16_to_f32_fallback(v[0]), + f16_to_f32_fallback(v[1]), + f16_to_f32_fallback(v[2]), + f16_to_f32_fallback(v[3]), + ] +} + +#[inline] +fn f32x4_to_f16x4_fallback(v: &[f32; 4]) -> [u16; 4] { + [ + f32_to_f16_fallback(v[0]), + f32_to_f16_fallback(v[1]), + f32_to_f16_fallback(v[2]), + f32_to_f16_fallback(v[3]), + ] +} + +#[inline] +fn f16x4_to_f64x4_fallback(v: &[u16; 4]) -> [f64; 4] { + [ + f16_to_f64_fallback(v[0]), + f16_to_f64_fallback(v[1]), + f16_to_f64_fallback(v[2]), + f16_to_f64_fallback(v[3]), + ] +} + +#[inline] +fn f64x4_to_f16x4_fallback(v: &[f64; 4]) -> [u16; 4] { + [ + f64_to_f16_fallback(v[0]), + f64_to_f16_fallback(v[1]), + f64_to_f16_fallback(v[2]), + f64_to_f16_fallback(v[3]), + ] +} + +#[inline] +fn f16x8_to_f32x8_fallback(v: &[u16; 8]) -> [f32; 8] { + [ + f16_to_f32_fallback(v[0]), + f16_to_f32_fallback(v[1]), + f16_to_f32_fallback(v[2]), + f16_to_f32_fallback(v[3]), + f16_to_f32_fallback(v[4]), + f16_to_f32_fallback(v[5]), + f16_to_f32_fallback(v[6]), + f16_to_f32_fallback(v[7]), + ] +} + +#[inline] +fn f32x8_to_f16x8_fallback(v: &[f32; 8]) -> [u16; 8] { + [ + f32_to_f16_fallback(v[0]), + f32_to_f16_fallback(v[1]), + f32_to_f16_fallback(v[2]), + f32_to_f16_fallback(v[3]), + f32_to_f16_fallback(v[4]), + f32_to_f16_fallback(v[5]), + f32_to_f16_fallback(v[6]), + f32_to_f16_fallback(v[7]), + ] +} + +#[inline] +fn f16x8_to_f64x8_fallback(v: &[u16; 8]) -> [f64; 8] { + [ + f16_to_f64_fallback(v[0]), + f16_to_f64_fallback(v[1]), + f16_to_f64_fallback(v[2]), + f16_to_f64_fallback(v[3]), + f16_to_f64_fallback(v[4]), + f16_to_f64_fallback(v[5]), + f16_to_f64_fallback(v[6]), + f16_to_f64_fallback(v[7]), + ] +} + +#[inline] +fn f64x8_to_f16x8_fallback(v: &[f64; 8]) -> [u16; 8] { + [ + f64_to_f16_fallback(v[0]), + f64_to_f16_fallback(v[1]), + f64_to_f16_fallback(v[2]), + f64_to_f16_fallback(v[3]), + f64_to_f16_fallback(v[4]), + f64_to_f16_fallback(v[5]), + f64_to_f16_fallback(v[6]), + f64_to_f16_fallback(v[7]), + ] +} + +#[inline] +fn slice_fallback<S: Copy, D>(src: &[S], dst: &mut [D], f: fn(S) -> D) { + assert_eq!(src.len(), dst.len()); + for (s, d) in src.iter().copied().zip(dst.iter_mut()) { + *d = f(s); + } +} + +/////////////// x86/x86_64 f16c //////////////// +#[cfg(all( + feature = "use-intrinsics", + any(target_arch = "x86", target_arch = "x86_64") +))] +mod x86 { + use core::{mem::MaybeUninit, ptr}; + + #[cfg(target_arch = "x86")] + use core::arch::x86::{ + __m128, __m128i, __m256, _mm256_cvtph_ps, _mm256_cvtps_ph, _mm_cvtph_ps, + _MM_FROUND_TO_NEAREST_INT, + }; + #[cfg(target_arch = "x86_64")] + use core::arch::x86_64::{ + __m128, __m128i, __m256, _mm256_cvtph_ps, _mm256_cvtps_ph, _mm_cvtph_ps, _mm_cvtps_ph, + _MM_FROUND_TO_NEAREST_INT, + }; + + use super::convert_chunked_slice_8; + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f16_to_f32_x86_f16c(i: u16) -> f32 { + let mut vec = MaybeUninit::<__m128i>::zeroed(); + vec.as_mut_ptr().cast::<u16>().write(i); + let retval = _mm_cvtph_ps(vec.assume_init()); + *(&retval as *const __m128).cast() + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f32_to_f16_x86_f16c(f: f32) -> u16 { + let mut vec = MaybeUninit::<__m128>::zeroed(); + vec.as_mut_ptr().cast::<f32>().write(f); + let retval = _mm_cvtps_ph(vec.assume_init(), _MM_FROUND_TO_NEAREST_INT); + *(&retval as *const __m128i).cast() + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f16x4_to_f32x4_x86_f16c(v: &[u16; 4]) -> [f32; 4] { + let mut vec = MaybeUninit::<__m128i>::zeroed(); + ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 4); + let retval = _mm_cvtph_ps(vec.assume_init()); + *(&retval as *const __m128).cast() + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f32x4_to_f16x4_x86_f16c(v: &[f32; 4]) -> [u16; 4] { + let mut vec = MaybeUninit::<__m128>::uninit(); + ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 4); + let retval = _mm_cvtps_ph(vec.assume_init(), _MM_FROUND_TO_NEAREST_INT); + *(&retval as *const __m128i).cast() + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f16x4_to_f64x4_x86_f16c(v: &[u16; 4]) -> [f64; 4] { + let array = f16x4_to_f32x4_x86_f16c(v); + // Let compiler vectorize this regular cast for now. + // TODO: investigate auto-detecting sse2/avx convert features + [ + array[0] as f64, + array[1] as f64, + array[2] as f64, + array[3] as f64, + ] + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f64x4_to_f16x4_x86_f16c(v: &[f64; 4]) -> [u16; 4] { + // Let compiler vectorize this regular cast for now. + // TODO: investigate auto-detecting sse2/avx convert features + let v = [v[0] as f32, v[1] as f32, v[2] as f32, v[3] as f32]; + f32x4_to_f16x4_x86_f16c(&v) + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f16x8_to_f32x8_x86_f16c(v: &[u16; 8]) -> [f32; 8] { + let mut vec = MaybeUninit::<__m128i>::zeroed(); + ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 8); + let retval = _mm256_cvtph_ps(vec.assume_init()); + *(&retval as *const __m256).cast() + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f32x8_to_f16x8_x86_f16c(v: &[f32; 8]) -> [u16; 8] { + let mut vec = MaybeUninit::<__m256>::uninit(); + ptr::copy_nonoverlapping(v.as_ptr(), vec.as_mut_ptr().cast(), 8); + let retval = _mm256_cvtps_ph(vec.assume_init(), _MM_FROUND_TO_NEAREST_INT); + *(&retval as *const __m128i).cast() + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f16x8_to_f64x8_x86_f16c(v: &[u16; 8]) -> [f64; 8] { + let array = f16x8_to_f32x8_x86_f16c(v); + // Let compiler vectorize this regular cast for now. + // TODO: investigate auto-detecting sse2/avx convert features + [ + array[0] as f64, + array[1] as f64, + array[2] as f64, + array[3] as f64, + array[4] as f64, + array[5] as f64, + array[6] as f64, + array[7] as f64, + ] + } + + #[target_feature(enable = "f16c")] + #[inline] + pub(super) unsafe fn f64x8_to_f16x8_x86_f16c(v: &[f64; 8]) -> [u16; 8] { + // Let compiler vectorize this regular cast for now. + // TODO: investigate auto-detecting sse2/avx convert features + let v = [ + v[0] as f32, + v[1] as f32, + v[2] as f32, + v[3] as f32, + v[4] as f32, + v[5] as f32, + v[6] as f32, + v[7] as f32, + ]; + f32x8_to_f16x8_x86_f16c(&v) + } +} |