1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
use crate::store::{AutoAssertNoGc, StoreOpaque};
use crate::{Result, ValRaw, ValType, WasmTy};
use core::cmp::Ordering;
use core::mem::MaybeUninit;
use core::{fmt, mem};
/// Representation of a 128-bit vector type, `v128`, for WebAssembly.
///
/// This type corresponds to the `v128` type in WebAssembly and can be used with
/// the [`TypedFunc`] API for example. This is additionally
/// the payload of [`Val::V128`](crate::Val).
///
/// # Platform specifics
///
/// This type can currently only be used on x86_64 and AArch64 with the
/// [`TypedFunc`] API. Rust does not have stable support on other platforms for
/// this type so invoking functions with `v128` parameters requires the
/// [`Func::call`](crate::Func::call) API (or perhaps
/// [`Func::call_unchecked`](crate::Func::call_unchecked).
///
/// [`TypedFunc`]: crate::TypedFunc
#[derive(Copy, Clone)]
#[repr(transparent)]
pub struct V128(
// NB: represent this internally with a `u8` array so that `V128` does not
// have 16-byte alignment and force `Val`'s discriminant to be 16-bytes
// larger. These bytes are always in native-endian order.
[u8; mem::size_of::<u128>()],
);
impl V128 {
/// Returns the representation of this `v128` as a 128-bit integer in Rust.
pub fn as_u128(&self) -> u128 {
u128::from_ne_bytes(self.0)
}
}
/// Primary constructor of a `V128` type.
impl From<u128> for V128 {
fn from(val: u128) -> V128 {
Self(val.to_ne_bytes())
}
}
impl From<V128> for u128 {
fn from(val: V128) -> u128 {
val.as_u128()
}
}
impl fmt::Debug for V128 {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.as_u128().fmt(f)
}
}
impl PartialEq for V128 {
fn eq(&self, other: &V128) -> bool {
self.as_u128() == other.as_u128()
}
}
impl Eq for V128 {}
impl PartialOrd for V128 {
fn partial_cmp(&self, other: &V128) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for V128 {
fn cmp(&self, other: &V128) -> Ordering {
self.as_u128().cmp(&other.as_u128())
}
}
// Note that this trait is conditionally implemented which is intentional. See
// the documentation above in the `cfg_if!` for why this is conditional.
unsafe impl WasmTy for V128 {
#[inline]
fn valtype() -> ValType {
ValType::V128
}
#[inline]
fn compatible_with_store(&self, _: &StoreOpaque) -> bool {
true
}
fn dynamic_concrete_type_check(
&self,
_: &StoreOpaque,
_: bool,
_: &crate::HeapType,
) -> crate::Result<()> {
unreachable!()
}
#[inline]
fn store(self, _store: &mut AutoAssertNoGc<'_>, ptr: &mut MaybeUninit<ValRaw>) -> Result<()> {
ptr.write(ValRaw::v128(self.as_u128()));
Ok(())
}
#[inline]
unsafe fn load(_store: &mut AutoAssertNoGc<'_>, ptr: &ValRaw) -> Self {
V128::from(ptr.get_v128())
}
}