cranelift_native/
lib.rs

1//! Performs autodetection of the host for the purposes of running
2//! Cranelift to generate code to run on the same machine.
3
4#![deny(missing_docs)]
5
6use cranelift_codegen::isa;
7use cranelift_codegen::settings::Configurable;
8use target_lexicon::Triple;
9
10#[cfg(all(target_arch = "riscv64", target_os = "linux"))]
11mod riscv;
12
13/// Return an `isa` builder configured for the current host
14/// machine, or `Err(())` if the host machine is not supported
15/// in the current configuration.
16pub fn builder() -> Result<isa::Builder, &'static str> {
17    builder_with_options(true)
18}
19
20/// Return an `isa` builder configured for the current host
21/// machine, or `Err(())` if the host machine is not supported
22/// in the current configuration.
23///
24/// Selects the given backend variant specifically; this is
25/// useful when more than one backend exists for a given target
26/// (e.g., on x86-64).
27pub fn builder_with_options(infer_native_flags: bool) -> Result<isa::Builder, &'static str> {
28    let mut isa_builder = isa::lookup(Triple::host()).map_err(|err| match err {
29        isa::LookupError::SupportDisabled => "support for architecture disabled at compile time",
30        isa::LookupError::Unsupported => "unsupported architecture",
31    })?;
32    if infer_native_flags {
33        self::infer_native_flags(&mut isa_builder)?;
34    }
35    Ok(isa_builder)
36}
37
38/// Return an `isa` builder configured for the current host
39/// machine, or `Err(())` if the host machine is not supported
40/// in the current configuration.
41///
42/// Selects the given backend variant specifically; this is
43/// useful when more than one backend exists for a given target
44/// (e.g., on x86-64).
45pub fn infer_native_flags(isa_builder: &mut dyn Configurable) -> Result<(), &'static str> {
46    #[cfg(target_arch = "x86_64")]
47    {
48        if !std::is_x86_feature_detected!("sse2") {
49            return Err("x86 support requires SSE2");
50        }
51
52        if std::is_x86_feature_detected!("sse3") {
53            isa_builder.enable("has_sse3").unwrap();
54        }
55        if std::is_x86_feature_detected!("ssse3") {
56            isa_builder.enable("has_ssse3").unwrap();
57        }
58        if std::is_x86_feature_detected!("sse4.1") {
59            isa_builder.enable("has_sse41").unwrap();
60        }
61        if std::is_x86_feature_detected!("sse4.2") {
62            isa_builder.enable("has_sse42").unwrap();
63        }
64        if std::is_x86_feature_detected!("popcnt") {
65            isa_builder.enable("has_popcnt").unwrap();
66        }
67        if std::is_x86_feature_detected!("avx") {
68            isa_builder.enable("has_avx").unwrap();
69        }
70        if std::is_x86_feature_detected!("avx2") {
71            isa_builder.enable("has_avx2").unwrap();
72        }
73        if std::is_x86_feature_detected!("fma") {
74            isa_builder.enable("has_fma").unwrap();
75        }
76        if std::is_x86_feature_detected!("bmi1") {
77            isa_builder.enable("has_bmi1").unwrap();
78        }
79        if std::is_x86_feature_detected!("bmi2") {
80            isa_builder.enable("has_bmi2").unwrap();
81        }
82        if std::is_x86_feature_detected!("avx512bitalg") {
83            isa_builder.enable("has_avx512bitalg").unwrap();
84        }
85        if std::is_x86_feature_detected!("avx512dq") {
86            isa_builder.enable("has_avx512dq").unwrap();
87        }
88        if std::is_x86_feature_detected!("avx512f") {
89            isa_builder.enable("has_avx512f").unwrap();
90        }
91        if std::is_x86_feature_detected!("avx512vl") {
92            isa_builder.enable("has_avx512vl").unwrap();
93        }
94        if std::is_x86_feature_detected!("avx512vbmi") {
95            isa_builder.enable("has_avx512vbmi").unwrap();
96        }
97        if std::is_x86_feature_detected!("lzcnt") {
98            isa_builder.enable("has_lzcnt").unwrap();
99        }
100    }
101
102    #[cfg(target_arch = "aarch64")]
103    {
104        if std::arch::is_aarch64_feature_detected!("lse") {
105            isa_builder.enable("has_lse").unwrap();
106        }
107
108        if std::arch::is_aarch64_feature_detected!("paca") {
109            isa_builder.enable("has_pauth").unwrap();
110        }
111
112        if cfg!(target_os = "macos") {
113            // Pointer authentication is always available on Apple Silicon.
114            isa_builder.enable("sign_return_address").unwrap();
115            // macOS enforces the use of the B key for return addresses.
116            isa_builder.enable("sign_return_address_with_bkey").unwrap();
117        }
118    }
119
120    // There is no is_s390x_feature_detected macro yet, so for now
121    // we use getauxval from the libc crate directly.
122    #[cfg(all(target_arch = "s390x", target_os = "linux"))]
123    {
124        let v = unsafe { libc::getauxval(libc::AT_HWCAP) };
125        const HWCAP_S390X_VXRS_EXT2: libc::c_ulong = 32768;
126        if (v & HWCAP_S390X_VXRS_EXT2) != 0 {
127            isa_builder.enable("has_vxrs_ext2").unwrap();
128            // There is no separate HWCAP bit for mie2, so assume
129            // that any machine with vxrs_ext2 also has mie2.
130            isa_builder.enable("has_mie2").unwrap();
131        }
132    }
133
134    // `is_riscv_feature_detected` is nightly only for now, use
135    // getauxval from the libc crate directly as a temporary measure.
136    #[cfg(all(target_arch = "riscv64", target_os = "linux"))]
137    {
138        // Try both hwcap and cpuinfo
139        // HWCAP only returns single letter extensions, cpuinfo returns all of
140        // them but may not be available in some systems (QEMU < 8.1).
141        riscv::hwcap_detect(isa_builder)?;
142
143        // Ignore errors for cpuinfo. QEMU versions prior to 8.1 do not emulate
144        // the cpuinfo interface, so we can't rely on it being present for now.
145        let _ = riscv::cpuinfo_detect(isa_builder);
146    }
147
148    // On all other architectures (e.g. wasm32) we won't infer any native flags,
149    // but still need to use the `isa_builder` to avoid compiler warnings.
150    let _ = isa_builder;
151    Ok(())
152}
153
154#[cfg(test)]
155mod tests {
156    use super::builder;
157    use cranelift_codegen::isa::CallConv;
158    use cranelift_codegen::settings;
159
160    #[test]
161    fn test() {
162        if let Ok(isa_builder) = builder() {
163            let flag_builder = settings::builder();
164            let isa = isa_builder
165                .finish(settings::Flags::new(flag_builder))
166                .unwrap();
167
168            if cfg!(all(target_os = "macos", target_arch = "aarch64")) {
169                assert_eq!(isa.default_call_conv(), CallConv::AppleAarch64);
170            } else if cfg!(unix) {
171                assert_eq!(isa.default_call_conv(), CallConv::SystemV);
172            } else if cfg!(windows) {
173                assert_eq!(isa.default_call_conv(), CallConv::WindowsFastcall);
174            }
175
176            if cfg!(target_pointer_width = "64") {
177                assert_eq!(isa.pointer_bits(), 64);
178            } else if cfg!(target_pointer_width = "32") {
179                assert_eq!(isa.pointer_bits(), 32);
180            } else if cfg!(target_pointer_width = "16") {
181                assert_eq!(isa.pointer_bits(), 16);
182            }
183        }
184    }
185}
186
187/// Version number of this crate.
188pub const VERSION: &str = env!("CARGO_PKG_VERSION");
cranelift_native/lib.rs

cranelift_native/
lib.rs
