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 6 use cranelift_codegen::isa; 7 use cranelift_codegen::settings::Configurable; 8 use target_lexicon::Triple; 9 10 #[cfg(all(target_arch = "riscv64", target_os = "linux"))] 11 mod 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. 16 pub 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). 27 pub 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). 45 pub 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)] 155 mod 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. 188 pub const VERSION: &str = env!("CARGO_PKG_VERSION"); 189