mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-26 08:44:35 +00:00
Auto merge of #117116 - calebzulawski:repr-simd-packed, r=workingjubilee
Implement repr(packed) for repr(simd) This allows creating vectors with non-power-of-2 lengths that do not have padding. See rust-lang/portable-simd#319
This commit is contained in:
commit
8b1ba11cb1
@ -10,7 +10,7 @@ use crate::value::Value;
|
||||
use rustc_codegen_ssa::base::{compare_simd_types, wants_msvc_seh, wants_wasm_eh};
|
||||
use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
|
||||
use rustc_codegen_ssa::errors::{ExpectedPointerMutability, InvalidMonomorphization};
|
||||
use rustc_codegen_ssa::mir::operand::OperandRef;
|
||||
use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
|
||||
use rustc_codegen_ssa::mir::place::PlaceRef;
|
||||
use rustc_codegen_ssa::traits::*;
|
||||
use rustc_hir as hir;
|
||||
@ -946,6 +946,13 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
|
||||
tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), callee_ty.fn_sig(tcx));
|
||||
let arg_tys = sig.inputs();
|
||||
|
||||
// Vectors must be immediates (non-power-of-2 #[repr(packed)] are not)
|
||||
for (ty, arg) in arg_tys.iter().zip(args) {
|
||||
if ty.is_simd() && !matches!(arg.val, OperandValue::Immediate(_)) {
|
||||
return_error!(InvalidMonomorphization::SimdArgument { span, name, ty: *ty });
|
||||
}
|
||||
}
|
||||
|
||||
if name == sym::simd_select_bitmask {
|
||||
let (len, _) = require_simd!(arg_tys[1], SimdArgument);
|
||||
|
||||
|
@ -433,7 +433,21 @@ fn layout_of_uncached<'tcx>(
|
||||
.size
|
||||
.checked_mul(e_len, dl)
|
||||
.ok_or_else(|| error(cx, LayoutError::SizeOverflow(ty)))?;
|
||||
let align = dl.vector_align(size);
|
||||
|
||||
let (abi, align) = if def.repr().packed() && !e_len.is_power_of_two() {
|
||||
// Non-power-of-two vectors have padding up to the next power-of-two.
|
||||
// If we're a packed repr, remove the padding while keeping the alignment as close
|
||||
// to a vector as possible.
|
||||
(
|
||||
Abi::Aggregate { sized: true },
|
||||
AbiAndPrefAlign {
|
||||
abi: Align::max_for_offset(size),
|
||||
pref: dl.vector_align(size).pref,
|
||||
},
|
||||
)
|
||||
} else {
|
||||
(Abi::Vector { element: e_abi, count: e_len }, dl.vector_align(size))
|
||||
};
|
||||
let size = size.align_to(align.abi);
|
||||
|
||||
// Compute the placement of the vector fields:
|
||||
@ -446,7 +460,7 @@ fn layout_of_uncached<'tcx>(
|
||||
tcx.mk_layout(LayoutS {
|
||||
variants: Variants::Single { index: FIRST_VARIANT },
|
||||
fields,
|
||||
abi: Abi::Vector { element: e_abi, count: e_len },
|
||||
abi,
|
||||
largest_niche: e_ly.largest_niche,
|
||||
size,
|
||||
align,
|
||||
|
59
tests/ui/simd/repr_packed.rs
Normal file
59
tests/ui/simd/repr_packed.rs
Normal file
@ -0,0 +1,59 @@
|
||||
// run-pass
|
||||
|
||||
#![feature(repr_simd, platform_intrinsics)]
|
||||
#![allow(non_camel_case_types)]
|
||||
|
||||
#[repr(simd, packed)]
|
||||
struct Simd<T, const N: usize>([T; N]);
|
||||
|
||||
#[repr(simd)]
|
||||
struct FullSimd<T, const N: usize>([T; N]);
|
||||
|
||||
fn check_size_align<T, const N: usize>() {
|
||||
use std::mem;
|
||||
assert_eq!(mem::size_of::<Simd<T, N>>(), mem::size_of::<[T; N]>());
|
||||
assert_eq!(mem::size_of::<Simd<T, N>>() % mem::align_of::<Simd<T, N>>(), 0);
|
||||
}
|
||||
|
||||
fn check_ty<T>() {
|
||||
check_size_align::<T, 1>();
|
||||
check_size_align::<T, 2>();
|
||||
check_size_align::<T, 3>();
|
||||
check_size_align::<T, 4>();
|
||||
check_size_align::<T, 8>();
|
||||
check_size_align::<T, 9>();
|
||||
check_size_align::<T, 15>();
|
||||
}
|
||||
|
||||
extern "platform-intrinsic" {
|
||||
fn simd_add<T>(a: T, b: T) -> T;
|
||||
}
|
||||
|
||||
fn main() {
|
||||
check_ty::<u8>();
|
||||
check_ty::<i16>();
|
||||
check_ty::<u32>();
|
||||
check_ty::<i64>();
|
||||
check_ty::<usize>();
|
||||
check_ty::<f32>();
|
||||
check_ty::<f64>();
|
||||
|
||||
unsafe {
|
||||
// powers-of-two have no padding and work as usual
|
||||
let x: Simd<f64, 4> =
|
||||
simd_add(Simd::<f64, 4>([0., 1., 2., 3.]), Simd::<f64, 4>([2., 2., 2., 2.]));
|
||||
assert_eq!(std::mem::transmute::<_, [f64; 4]>(x), [2., 3., 4., 5.]);
|
||||
|
||||
// non-powers-of-two have padding and need to be expanded to full vectors
|
||||
fn load<T, const N: usize>(v: Simd<T, N>) -> FullSimd<T, N> {
|
||||
unsafe {
|
||||
let mut tmp = core::mem::MaybeUninit::<FullSimd<T, N>>::uninit();
|
||||
std::ptr::copy_nonoverlapping(&v as *const _, tmp.as_mut_ptr().cast(), 1);
|
||||
tmp.assume_init()
|
||||
}
|
||||
}
|
||||
let x: FullSimd<f64, 3> =
|
||||
simd_add(load(Simd::<f64, 3>([0., 1., 2.])), load(Simd::<f64, 3>([2., 2., 2.])));
|
||||
assert_eq!(x.0, [2., 3., 4.]);
|
||||
}
|
||||
}
|
Loading…
Reference in New Issue
Block a user