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1// SPDX-License-Identifier: GPL-2.0
2
3//! Our own `compiler_builtins`.
4//!
5//! Rust provides [`compiler_builtins`] as a port of LLVM's [`compiler-rt`].
6//! Since we do not need the vast majority of them, we avoid the dependency
7//! by providing this file.
8//!
9//! At the moment, some builtins are required that should not be. For instance,
10//! [`core`] has 128-bit integers functionality which we should not be compiling
11//! in. We will work with upstream [`core`] to provide feature flags to disable
12//! the parts we do not need. For the moment, we define them to [`panic!`] at
13//! runtime for simplicity to catch mistakes, instead of performing surgery
14//! on `core.o`.
15//!
16//! In any case, all these symbols are weakened to ensure we do not override
17//! those that may be provided by the rest of the kernel.
18//!
19//! [`compiler_builtins`]: https://github.com/rust-lang/compiler-builtins
20//! [`compiler-rt`]: https://compiler-rt.llvm.org/
21
22#![allow(internal_features)]
23#![feature(compiler_builtins)]
24#![compiler_builtins]
25#![no_builtins]
26#![no_std]
27
28macro_rules! define_panicking_intrinsics(
29 ($reason: tt, { $($ident: ident, )* }) => {
30 $(
31 #[doc(hidden)]
32 #[export_name = concat!("__rust", stringify!($ident))]
33 pub extern "C" fn $ident() {
34 panic!($reason);
35 }
36 )*
37 }
38);
39
40define_panicking_intrinsics!("`f32` should not be used", {
41 __addsf3,
42 __eqsf2,
43 __extendsfdf2,
44 __gesf2,
45 __lesf2,
46 __ltsf2,
47 __mulsf3,
48 __nesf2,
49 __truncdfsf2,
50 __unordsf2,
51});
52
53define_panicking_intrinsics!("`f64` should not be used", {
54 __adddf3,
55 __eqdf2,
56 __ledf2,
57 __ltdf2,
58 __muldf3,
59 __unorddf2,
60});
61
62define_panicking_intrinsics!("`i128` should not be used", {
63 __ashrti3,
64 __muloti4,
65 __multi3,
66});
67
68define_panicking_intrinsics!("`u128` should not be used", {
69 __ashlti3,
70 __lshrti3,
71 __udivmodti4,
72 __udivti3,
73 __umodti3,
74});
75
76#[cfg(target_arch = "arm")]
77define_panicking_intrinsics!("`f32` should not be used", {
78 __aeabi_fadd,
79 __aeabi_fmul,
80 __aeabi_fcmpeq,
81 __aeabi_fcmple,
82 __aeabi_fcmplt,
83 __aeabi_fcmpun,
84});
85
86#[cfg(target_arch = "arm")]
87define_panicking_intrinsics!("`f64` should not be used", {
88 __aeabi_dadd,
89 __aeabi_dmul,
90 __aeabi_dcmple,
91 __aeabi_dcmplt,
92 __aeabi_dcmpun,
93});
94
95#[cfg(target_arch = "arm")]
96define_panicking_intrinsics!("`u64` division/modulo should not be used", {
97 __aeabi_uldivmod,
98});
99
100#[cfg(target_arch = "powerpc")]
101define_panicking_intrinsics!("`u64` division/modulo should not be used", {
102 __udivdi3,
103 __umoddi3,
104});
105
106// NOTE: if you are adding a new intrinsic here, you should also add it to
107// `redirect-intrinsics` in `rust/Makefile`.