compiler: Add target features for LoongArch

(cherry picked from commit cb61816)

Author: heiher

compiler/rustc_codegen_ssa/src/target_features.rs

@@ -297,6 +297,18 @@ const WASM_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
 
 const BPF_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[("alu32", Some(sym::bpf_target_feature))];
 
+const LOONGARCH_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
+    // tidy-alphabetical-start
+    ("d", Some(sym::loongarch_target_feature)),
+    ("f", Some(sym::loongarch_target_feature)),
+    ("lasx", Some(sym::loongarch_target_feature)),
+    ("lbt", Some(sym::loongarch_target_feature)),
+    ("lsx", Some(sym::loongarch_target_feature)),
+    ("lvz", Some(sym::loongarch_target_feature)),
+    ("ual", Some(sym::loongarch_target_feature)),
+    // tidy-alphabetical-end
+];
+
 /// When rustdoc is running, provide a list of all known features so that all their respective
 /// primitives may be documented.
 ///
@@ -312,6 +324,7 @@ pub fn all_known_features() -> impl Iterator<Item = (&'static str, Option<Symbol
         .chain(RISCV_ALLOWED_FEATURES.iter())
         .chain(WASM_ALLOWED_FEATURES.iter())
         .chain(BPF_ALLOWED_FEATURES.iter())
+        .chain(LOONGARCH_ALLOWED_FEATURES)
         .cloned()
 }
 
@@ -326,6 +339,7 @@ pub fn supported_target_features(sess: &Session) -> &'static [(&'static str, Opt
         "riscv32" | "riscv64" => RISCV_ALLOWED_FEATURES,
         "wasm32" | "wasm64" => WASM_ALLOWED_FEATURES,
         "bpf" => BPF_ALLOWED_FEATURES,
+        "loongarch64" => LOONGARCH_ALLOWED_FEATURES,
         _ => &[],
     }
 }
@@ -401,6 +415,7 @@ pub fn from_target_feature(
                 Some(sym::ermsb_target_feature) => rust_features.ermsb_target_feature,
                 Some(sym::bpf_target_feature) => rust_features.bpf_target_feature,
                 Some(sym::aarch64_ver_target_feature) => rust_features.aarch64_ver_target_feature,
+                Some(sym::loongarch_target_feature) => rust_features.loongarch_target_feature,
                 Some(name) => bug!("unknown target feature gate {}", name),
                 None => true,
             };

compiler/rustc_feature/src/active.rs

@@ -260,6 +260,7 @@ declare_features! (
     (active, bpf_target_feature, "1.54.0", Some(44839), None),
     (active, ermsb_target_feature, "1.49.0", Some(44839), None),
     (active, hexagon_target_feature, "1.27.0", Some(44839), None),
+    (active, loongarch_target_feature, "1.72.0", Some(44839), None),
     (active, mips_target_feature, "1.27.0", Some(44839), None),
     (active, powerpc_target_feature, "1.27.0", Some(44839), None),
     (active, riscv_target_feature, "1.45.0", Some(44839), None),

compiler/rustc_span/src/symbol.rs

@@ -906,6 +906,7 @@ symbols! {
         log_syntax,
         logf32,
         logf64,
+        loongarch_target_feature,
         loop_break_value,
         lt,
         macro_at_most_once_rep,