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hub / github.com/bytecodealliance/wasmtime / hwcap_detect

Function hwcap_detect

cranelift/native/src/riscv.rs:5–48  ·  view source on GitHub ↗
(isa_builder: &mut dyn Configurable)

Source from the content-addressed store, hash-verified

3use std::io::{BufRead, BufReader};
4
5pub fn hwcap_detect(isa_builder: &mut dyn Configurable) -> Result<(), &'static str> {
6 let v = unsafe { libc::getauxval(libc::AT_HWCAP) };
7
8 const HWCAP_RISCV_EXT_A: libc::c_ulong = 1 << (b'a' - b'a');
9 const HWCAP_RISCV_EXT_C: libc::c_ulong = 1 << (b'c' - b'a');
10 const HWCAP_RISCV_EXT_D: libc::c_ulong = 1 << (b'd' - b'a');
11 const HWCAP_RISCV_EXT_F: libc::c_ulong = 1 << (b'f' - b'a');
12 const HWCAP_RISCV_EXT_M: libc::c_ulong = 1 << (b'm' - b'a');
13 const HWCAP_RISCV_EXT_V: libc::c_ulong = 1 << (b'v' - b'a');
14
15 if (v & HWCAP_RISCV_EXT_A) != 0 {
16 isa_builder.enable("has_a").unwrap();
17 }
18
19 if (v & HWCAP_RISCV_EXT_C) != 0 {
20 isa_builder.enable("has_c").unwrap();
21 }
22
23 if (v & HWCAP_RISCV_EXT_D) != 0 {
24 isa_builder.enable("has_d").unwrap();
25 }
26
27 if (v & HWCAP_RISCV_EXT_F) != 0 {
28 isa_builder.enable("has_f").unwrap();
29
30 // TODO: There doesn't seem to be a bit associated with this extension
31 // rust enables it with the `f` extension:
32 // https://github.com/rust-lang/stdarch/blob/790411f93c4b5eada3c23abb4c9a063fb0b24d99/crates/std_detect/src/detect/os/linux/riscv.rs#L43
33 isa_builder.enable("has_zicsr").unwrap();
34 }
35
36 if (v & HWCAP_RISCV_EXT_M) != 0 {
37 isa_builder.enable("has_m").unwrap();
38 }
39
40 if (v & HWCAP_RISCV_EXT_V) != 0 {
41 isa_builder.enable("has_v").unwrap();
42 }
43
44 // In general extensions that are longer than one letter
45 // won't have a bit associated with them. The Linux kernel
46 // is currently working on a new way to query the extensions.
47 Ok(())
48}
49
50/// Read the /proc/cpuinfo file and detect the extensions.
51///

Callers 1

infer_native_flagsFunction · 0.85

Calls 3

OkFunction · 0.85
unwrapMethod · 0.45
enableMethod · 0.45

Tested by

no test coverage detected