xref: /wasmtime-44.0.1/cranelift/native/src/lib.rs (revision 331b0dee)
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(
5     missing_docs,
6     trivial_numeric_casts,
7     unused_extern_crates,
8     unstable_features
9 )]
10 #![warn(unused_import_braces)]
11 #![cfg_attr(feature = "clippy", plugin(clippy(conf_file = "../../clippy.toml")))]
12 #![cfg_attr(feature = "cargo-clippy", allow(clippy::new_without_default))]
13 #![cfg_attr(
14     feature = "cargo-clippy",
15     warn(
16         clippy::float_arithmetic,
17         clippy::mut_mut,
18         clippy::nonminimal_bool,
19         clippy::map_unwrap_or,
20         clippy::clippy::print_stdout,
21         clippy::unicode_not_nfc,
22         clippy::use_self
23     )
24 )]
25 
26 use cranelift_codegen::isa;
27 use target_lexicon::Triple;
28 
29 /// Return an `isa` builder configured for the current host
30 /// machine, or `Err(())` if the host machine is not supported
31 /// in the current configuration.
32 pub fn builder() -> Result<isa::Builder, &'static str> {
33     builder_with_options(isa::BackendVariant::Any, true)
34 }
35 
36 /// Return an `isa` builder configured for the current host
37 /// machine, or `Err(())` if the host machine is not supported
38 /// in the current configuration.
39 ///
40 /// Selects the given backend variant specifically; this is
41 /// useful when more than oen backend exists for a given target
42 /// (e.g., on x86-64).
43 pub fn builder_with_options(
44     variant: isa::BackendVariant,
45     infer_native_flags: bool,
46 ) -> Result<isa::Builder, &'static str> {
47     let mut isa_builder =
48         isa::lookup_variant(Triple::host(), variant).map_err(|err| match err {
49             isa::LookupError::SupportDisabled => {
50                 "support for architecture disabled at compile time"
51             }
52             isa::LookupError::Unsupported => "unsupported architecture",
53         })?;
54 
55     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
56     {
57         use cranelift_codegen::settings::Configurable;
58 
59         if !std::is_x86_feature_detected!("sse2") {
60             return Err("x86 support requires SSE2");
61         }
62 
63         if !infer_native_flags {
64             return Ok(isa_builder);
65         }
66 
67         if std::is_x86_feature_detected!("sse3") {
68             isa_builder.enable("has_sse3").unwrap();
69         }
70         if std::is_x86_feature_detected!("ssse3") {
71             isa_builder.enable("has_ssse3").unwrap();
72         }
73         if std::is_x86_feature_detected!("sse4.1") {
74             isa_builder.enable("has_sse41").unwrap();
75         }
76         if std::is_x86_feature_detected!("sse4.2") {
77             isa_builder.enable("has_sse42").unwrap();
78         }
79         if std::is_x86_feature_detected!("popcnt") {
80             isa_builder.enable("has_popcnt").unwrap();
81         }
82         if std::is_x86_feature_detected!("avx") {
83             isa_builder.enable("has_avx").unwrap();
84         }
85         if std::is_x86_feature_detected!("avx2") {
86             isa_builder.enable("has_avx2").unwrap();
87         }
88         if std::is_x86_feature_detected!("bmi1") {
89             isa_builder.enable("has_bmi1").unwrap();
90         }
91         if std::is_x86_feature_detected!("bmi2") {
92             isa_builder.enable("has_bmi2").unwrap();
93         }
94         if std::is_x86_feature_detected!("avx512bitalg") {
95             isa_builder.enable("has_avx512bitalg").unwrap();
96         }
97         if std::is_x86_feature_detected!("avx512dq") {
98             isa_builder.enable("has_avx512dq").unwrap();
99         }
100         if std::is_x86_feature_detected!("avx512f") {
101             isa_builder.enable("has_avx512f").unwrap();
102         }
103         if std::is_x86_feature_detected!("avx512vl") {
104             isa_builder.enable("has_avx512vl").unwrap();
105         }
106         if std::is_x86_feature_detected!("avx512vbmi") {
107             isa_builder.enable("has_avx512vbmi").unwrap();
108         }
109         if std::is_x86_feature_detected!("lzcnt") {
110             isa_builder.enable("has_lzcnt").unwrap();
111         }
112     }
113 
114     // `stdsimd` is necessary for std::is_aarch64_feature_detected!().
115     #[cfg(all(target_arch = "aarch64", feature = "stdsimd"))]
116     {
117         use cranelift_codegen::settings::Configurable;
118 
119         if !infer_native_flags {
120             return Ok(isa_builder);
121         }
122 
123         if std::is_aarch64_feature_detected!("lse") {
124             isa_builder.enable("has_lse").unwrap();
125         }
126     }
127 
128     // There is no is_s390x_feature_detected macro yet, so for now
129     // we use getauxval from the libc crate directly.
130     #[cfg(all(target_arch = "s390x", target_os = "linux"))]
131     {
132         use cranelift_codegen::settings::Configurable;
133 
134         if !infer_native_flags {
135             return Ok(isa_builder);
136         }
137 
138         let v = unsafe { libc::getauxval(libc::AT_HWCAP) };
139         const HWCAP_S390X_VXRS_EXT2: libc::c_ulong = 32768;
140         if (v & HWCAP_S390X_VXRS_EXT2) != 0 {
141             isa_builder.enable("has_vxrs_ext2").unwrap();
142             // There is no separate HWCAP bit for mie2, so assume
143             // that any machine with vxrs_ext2 also has mie2.
144             isa_builder.enable("has_mie2").unwrap();
145         }
146     }
147 
148     // squelch warnings about unused mut/variables on some platforms.
149     drop(&mut isa_builder);
150     drop(infer_native_flags);
151 
152     Ok(isa_builder)
153 }
154 
155 #[cfg(test)]
156 mod tests {
157     use super::builder;
158     use cranelift_codegen::isa::CallConv;
159     use cranelift_codegen::settings;
160 
161     #[test]
162     fn test() {
163         if let Ok(isa_builder) = builder() {
164             let flag_builder = settings::builder();
165             let isa = isa_builder.finish(settings::Flags::new(flag_builder));
166 
167             if cfg!(all(target_os = "macos", target_arch = "aarch64")) {
168                 assert_eq!(isa.default_call_conv(), CallConv::AppleAarch64);
169             } else if cfg!(any(unix, target_os = "nebulet")) {
170                 assert_eq!(isa.default_call_conv(), CallConv::SystemV);
171             } else if cfg!(windows) {
172                 assert_eq!(isa.default_call_conv(), CallConv::WindowsFastcall);
173             }
174 
175             if cfg!(target_pointer_width = "64") {
176                 assert_eq!(isa.pointer_bits(), 64);
177             } else if cfg!(target_pointer_width = "32") {
178                 assert_eq!(isa.pointer_bits(), 32);
179             } else if cfg!(target_pointer_width = "16") {
180                 assert_eq!(isa.pointer_bits(), 16);
181             }
182         }
183     }
184 }
185 
186 /// Version number of this crate.
187 pub const VERSION: &str = env!("CARGO_PKG_VERSION");
188