submilli-wasm 0.1.5

A WebAssembly interpreter with a wasmtime-compatible API, built for fast compilation and startup
Documentation 
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
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190

//! Numeric conversions: the boundary-sensitive float↔int ops.
//!
//! Trapping truncation checks NaN and range explicitly; saturating truncation
//! relies on Rust's `as` cast (which saturates: NaN→0, out-of-range→clamp).
//! Range bounds use exact powers of two (representable in both f32 and f64).

// int→float conversions lose precision by definition; the explicit `>= lo && < hi`
// bound reads clearer here than `Range::contains`.
#![allow(clippy::cast_precision_loss, clippy::manual_range_contains)]

use crate::trap::Trap;
use crate::{Error, Result};

fn bad_conv() -> Error {
    Trap::BadConversionToInteger.into()
}

fn overflow() -> Error {
    Trap::IntegerOverflow.into()
}

pub(super) fn i32_wrap_i64(x: i64) -> i32 {
    x as i32
}

pub(super) fn i64_extend_i32_s(x: i32) -> i64 {
    i64::from(x)
}

pub(super) fn i64_extend_i32_u(x: i32) -> i64 {
    i64::from(x as u32)
}

// --- trapping truncation ---

pub(super) fn i32_trunc_f32_s(x: f32) -> Result<i32> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= -2_147_483_648.0 && t < 2_147_483_648.0 {
        Ok(t as i32)
    } else {
        Err(overflow())
    }
}

pub(super) fn i32_trunc_f32_u(x: f32) -> Result<i32> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= 0.0 && t < 4_294_967_296.0 {
        Ok(t as u32 as i32)
    } else {
        Err(overflow())
    }
}

pub(super) fn i32_trunc_f64_s(x: f64) -> Result<i32> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= -2_147_483_648.0 && t < 2_147_483_648.0 {
        Ok(t as i32)
    } else {
        Err(overflow())
    }
}

pub(super) fn i32_trunc_f64_u(x: f64) -> Result<i32> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= 0.0 && t < 4_294_967_296.0 {
        Ok(t as u32 as i32)
    } else {
        Err(overflow())
    }
}

pub(super) fn i64_trunc_f32_s(x: f32) -> Result<i64> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= -9_223_372_036_854_775_808.0 && t < 9_223_372_036_854_775_808.0 {
        Ok(t as i64)
    } else {
        Err(overflow())
    }
}

pub(super) fn i64_trunc_f32_u(x: f32) -> Result<i64> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= 0.0 && t < 18_446_744_073_709_551_616.0 {
        Ok(t as u64 as i64)
    } else {
        Err(overflow())
    }
}

pub(super) fn i64_trunc_f64_s(x: f64) -> Result<i64> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= -9_223_372_036_854_775_808.0 && t < 9_223_372_036_854_775_808.0 {
        Ok(t as i64)
    } else {
        Err(overflow())
    }
}

pub(super) fn i64_trunc_f64_u(x: f64) -> Result<i64> {
    if x.is_nan() {
        return Err(bad_conv());
    }
    let t = x.trunc();
    if t >= 0.0 && t < 18_446_744_073_709_551_616.0 {
        Ok(t as u64 as i64)
    } else {
        Err(overflow())
    }
}

// --- saturating truncation (Rust `as` saturates) ---

pub(super) fn i32_trunc_sat_f32_s(x: f32) -> i32 {
    x as i32
}
pub(super) fn i32_trunc_sat_f32_u(x: f32) -> i32 {
    x as u32 as i32
}
pub(super) fn i32_trunc_sat_f64_s(x: f64) -> i32 {
    x as i32
}
pub(super) fn i32_trunc_sat_f64_u(x: f64) -> i32 {
    x as u32 as i32
}
pub(super) fn i64_trunc_sat_f32_s(x: f32) -> i64 {
    x as i64
}
pub(super) fn i64_trunc_sat_f32_u(x: f32) -> i64 {
    x as u64 as i64
}
pub(super) fn i64_trunc_sat_f64_s(x: f64) -> i64 {
    x as i64
}
pub(super) fn i64_trunc_sat_f64_u(x: f64) -> i64 {
    x as u64 as i64
}

// --- int→float conversions and demote/promote ---

pub(super) fn f32_convert_i32_s(x: i32) -> f32 {
    x as f32
}
pub(super) fn f32_convert_i32_u(x: i32) -> f32 {
    (x as u32) as f32
}
pub(super) fn f32_convert_i64_s(x: i64) -> f32 {
    x as f32
}
pub(super) fn f32_convert_i64_u(x: i64) -> f32 {
    (x as u64) as f32
}
pub(super) fn f64_convert_i32_s(x: i32) -> f64 {
    f64::from(x)
}
pub(super) fn f64_convert_i32_u(x: i32) -> f64 {
    f64::from(x as u32)
}
pub(super) fn f64_convert_i64_s(x: i64) -> f64 {
    x as f64
}
pub(super) fn f64_convert_i64_u(x: i64) -> f64 {
    (x as u64) as f64
}
pub(super) fn f32_demote_f64(x: f64) -> f32 {
    x as f32
}
pub(super) fn f64_promote_f32(x: f32) -> f64 {
    f64::from(x)
}