Add new Tier-3 targets: loongarch32-unknown-none*

MCP: rust-lang/compiler-team#865
rust-lang · matthiaskrgr · Jun 4, 2025 · Jan 9, 2025 · May 14, 2025 · Jun 7, 2025
commit 38d69c3f571b668c82cfb90e5bea8bc86530530c
diff --git a/compiler/rustc_codegen_gcc/example/alloc_system.rs b/compiler/rustc_codegen_gcc/example/alloc_system.rs
@@ -8,6 +8,7 @@
 // add fast paths for low alignment values.
 #[cfg(any(target_arch = "x86",
               target_arch = "arm",
+              target_arch = "loongarch32",
               target_arch = "m68k",
               target_arch = "mips",
               target_arch = "mips32r6",

diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -251,7 +251,7 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                 InlineAsmArch::Nvptx64 => {}
                 InlineAsmArch::PowerPC | InlineAsmArch::PowerPC64 => {}
                 InlineAsmArch::Hexagon => {}
-                InlineAsmArch::LoongArch64 => {
+                InlineAsmArch::LoongArch32 | InlineAsmArch::LoongArch64 => {
                     constraints.extend_from_slice(&[
                         "~{$fcc0}".to_string(),
                         "~{$fcc1}".to_string(),

diff --git a/compiler/rustc_codegen_ssa/src/back/link/raw_dylib.rs b/compiler/rustc_codegen_ssa/src/back/link/raw_dylib.rs
@@ -287,6 +287,7 @@ fn create_elf_raw_dylib_stub(sess: &Session, soname: &str, symbols: &[DllImport]
         (Architecture::X86_64, None) => elf::EM_X86_64,
         (Architecture::X86_64_X32, None) => elf::EM_X86_64,
         (Architecture::Hexagon, None) => elf::EM_HEXAGON,
+        (Architecture::LoongArch32, None) => elf::EM_LOONGARCH,
         (Architecture::LoongArch64, None) => elf::EM_LOONGARCH,
         (Architecture::M68k, None) => elf::EM_68K,
         (Architecture::Mips, None) => elf::EM_MIPS,

diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs
@@ -348,7 +348,7 @@ pub(super) fn elf_e_flags(architecture: Architecture, sess: &Session) -> u32 {
 
             e_flags
         }
-        Architecture::LoongArch64 => {
+        Architecture::LoongArch32 | Architecture::LoongArch64 => {
             // Source: https://github.com/loongson/la-abi-specs/blob/release/laelf.adoc#e_flags-identifies-abi-type-and-version
             let mut e_flags: u32 = elf::EF_LARCH_OBJABI_V1;
 

diff --git a/compiler/rustc_target/src/asm/mod.rs b/compiler/rustc_target/src/asm/mod.rs
@@ -226,6 +226,7 @@ pub enum InlineAsmArch {
     RiscV64,
     Nvptx64,
     Hexagon,
+    LoongArch32,
     LoongArch64,
     Mips,
     Mips64,
@@ -260,6 +261,7 @@ impl FromStr for InlineAsmArch {
             "powerpc" => Ok(Self::PowerPC),
             "powerpc64" => Ok(Self::PowerPC64),
             "hexagon" => Ok(Self::Hexagon),
+            "loongarch32" => Ok(Self::LoongArch32),
             "loongarch64" => Ok(Self::LoongArch64),
             "mips" | "mips32r6" => Ok(Self::Mips),
             "mips64" | "mips64r6" => Ok(Self::Mips64),
@@ -365,7 +367,9 @@ impl InlineAsmReg {
                 Self::PowerPC(PowerPCInlineAsmReg::parse(name)?)
             }
             InlineAsmArch::Hexagon => Self::Hexagon(HexagonInlineAsmReg::parse(name)?),
-            InlineAsmArch::LoongArch64 => Self::LoongArch(LoongArchInlineAsmReg::parse(name)?),
+            InlineAsmArch::LoongArch32 | InlineAsmArch::LoongArch64 => {
+                Self::LoongArch(LoongArchInlineAsmReg::parse(name)?)
+            }
             InlineAsmArch::Mips | InlineAsmArch::Mips64 => {
                 Self::Mips(MipsInlineAsmReg::parse(name)?)
             }
@@ -652,7 +656,9 @@ impl InlineAsmRegClass {
                 Self::PowerPC(PowerPCInlineAsmRegClass::parse(name)?)
             }
             InlineAsmArch::Hexagon => Self::Hexagon(HexagonInlineAsmRegClass::parse(name)?),
-            InlineAsmArch::LoongArch64 => Self::LoongArch(LoongArchInlineAsmRegClass::parse(name)?),
+            InlineAsmArch::LoongArch32 | InlineAsmArch::LoongArch64 => {
+                Self::LoongArch(LoongArchInlineAsmRegClass::parse(name)?)
+            }
             InlineAsmArch::Mips | InlineAsmArch::Mips64 => {
                 Self::Mips(MipsInlineAsmRegClass::parse(name)?)
             }
@@ -860,7 +866,7 @@ pub fn allocatable_registers(
             hexagon::fill_reg_map(arch, reloc_model, target_features, target, &mut map);
             map
         }
-        InlineAsmArch::LoongArch64 => {
+        InlineAsmArch::LoongArch32 | InlineAsmArch::LoongArch64 => {
             let mut map = loongarch::regclass_map();
             loongarch::fill_reg_map(arch, reloc_model, target_features, target, &mut map);
             map
@@ -992,7 +998,7 @@ impl InlineAsmClobberAbi {
                 "C" | "system" => Ok(InlineAsmClobberAbi::Avr),
                 _ => Err(&["C", "system"]),
             },
-            InlineAsmArch::LoongArch64 => match name {
+            InlineAsmArch::LoongArch32 | InlineAsmArch::LoongArch64 => match name {
                 "C" | "system" => Ok(InlineAsmClobberAbi::LoongArch),
                 _ => Err(&["C", "system"]),
             },

diff --git a/compiler/rustc_target/src/callconv/mod.rs b/compiler/rustc_target/src/callconv/mod.rs
@@ -648,7 +648,7 @@ impl<'a, Ty> FnAbi<'a, Ty> {
             "amdgpu" => amdgpu::compute_abi_info(cx, self),
             "arm" => arm::compute_abi_info(cx, self),
             "avr" => avr::compute_abi_info(self),
-            "loongarch64" => loongarch::compute_abi_info(cx, self),
+            "loongarch32" | "loongarch64" => loongarch::compute_abi_info(cx, self),
             "m68k" => m68k::compute_abi_info(self),
             "csky" => csky::compute_abi_info(self),
             "mips" | "mips32r6" => mips::compute_abi_info(cx, self),
@@ -691,7 +691,7 @@ impl<'a, Ty> FnAbi<'a, Ty> {
         match &*spec.arch {
             "x86" => x86::compute_rust_abi_info(cx, self),
             "riscv32" | "riscv64" => riscv::compute_rust_abi_info(cx, self),
-            "loongarch64" => loongarch::compute_rust_abi_info(cx, self),
+            "loongarch32" | "loongarch64" => loongarch::compute_rust_abi_info(cx, self),
             "aarch64" => aarch64::compute_rust_abi_info(cx, self),
             _ => {}
         };

diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
@@ -1981,6 +1981,8 @@ supported_targets! {
 
     ("sparc-unknown-none-elf", sparc_unknown_none_elf),
 
+    ("loongarch32-unknown-none", loongarch32_unknown_none),
+    ("loongarch32-unknown-none-softfloat", loongarch32_unknown_none_softfloat),
     ("loongarch64-unknown-none", loongarch64_unknown_none),
     ("loongarch64-unknown-none-softfloat", loongarch64_unknown_none_softfloat),
 
@@ -3502,6 +3504,7 @@ impl Target {
             "msp430" => (Architecture::Msp430, None),
             "hexagon" => (Architecture::Hexagon, None),
             "bpf" => (Architecture::Bpf, None),
+            "loongarch32" => (Architecture::LoongArch32, None),
             "loongarch64" => (Architecture::LoongArch64, None),
             "csky" => (Architecture::Csky, None),
             "arm64ec" => (Architecture::Aarch64, Some(object::SubArchitecture::Arm64EC)),

diff --git a/compiler/rustc_target/src/spec/targets/loongarch32_unknown_none.rs b/compiler/rustc_target/src/spec/targets/loongarch32_unknown_none.rs
@@ -0,0 +1,29 @@
+use crate::spec::{
+    Cc, LinkerFlavor, Lld, PanicStrategy, RelocModel, Target, TargetMetadata, TargetOptions,
+};
+
+pub(crate) fn target() -> Target {
+    Target {
+        llvm_target: "loongarch32-unknown-none".into(),
+        metadata: TargetMetadata {
+            description: Some("Freestanding/bare-metal LoongArch32".into()),
+            tier: Some(3),
+            host_tools: Some(false),
+            std: Some(false),
+        },
+        pointer_width: 32,
+        data_layout: "e-m:e-p:32:32-i64:64-n32-S128".into(),
+        arch: "loongarch32".into(),
+        options: TargetOptions {
+            cpu: "generic".into(),
+            features: "+f,+d".into(),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            linker: Some("rust-lld".into()),
+            llvm_abiname: "ilp32d".into(),
+            max_atomic_width: Some(32),
+            relocation_model: RelocModel::Static,
+            panic_strategy: PanicStrategy::Abort,
+            ..Default::default()
+        },
+    }
+}
diff --git a/compiler/rustc_target/src/spec/targets/loongarch32_unknown_none_softfloat.rs b/compiler/rustc_target/src/spec/targets/loongarch32_unknown_none_softfloat.rs
@@ -0,0 +1,30 @@
+use crate::spec::{
+    Cc, LinkerFlavor, Lld, PanicStrategy, RelocModel, Target, TargetMetadata, TargetOptions,
+};
+
+pub(crate) fn target() -> Target {
+    Target {
+        llvm_target: "loongarch32-unknown-none".into(),
+        metadata: TargetMetadata {
+            description: Some("Freestanding/bare-metal LoongArch32 softfloat".into()),
+            tier: Some(3),
+            host_tools: Some(false),
+            std: Some(false),
+        },
+        pointer_width: 32,
+        data_layout: "e-m:e-p:32:32-i64:64-n32-S128".into(),
+        arch: "loongarch32".into(),
+        options: TargetOptions {
+            cpu: "generic".into(),
+            features: "-f,-d".into(),
+            abi: "softfloat".into(),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            linker: Some("rust-lld".into()),
+            llvm_abiname: "ilp32s".into(),
+            max_atomic_width: Some(32),
+            relocation_model: RelocModel::Static,
+            panic_strategy: PanicStrategy::Abort,
+            ..Default::default()
+        },
+    }
+}
diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
@@ -846,7 +846,7 @@ impl Target {
             "wasm32" | "wasm64" => WASM_FEATURES,
             "bpf" => BPF_FEATURES,
             "csky" => CSKY_FEATURES,
-            "loongarch64" => LOONGARCH_FEATURES,
+            "loongarch32" | "loongarch64" => LOONGARCH_FEATURES,
             "s390x" => IBMZ_FEATURES,
             "sparc" | "sparc64" => SPARC_FEATURES,
             "m68k" => M68K_FEATURES,
@@ -860,7 +860,7 @@ impl Target {
             "aarch64" | "arm64ec" => AARCH64_FEATURES_FOR_CORRECT_VECTOR_ABI,
             "arm" => ARM_FEATURES_FOR_CORRECT_VECTOR_ABI,
             "powerpc" | "powerpc64" => POWERPC_FEATURES_FOR_CORRECT_VECTOR_ABI,
-            "loongarch64" => LOONGARCH_FEATURES_FOR_CORRECT_VECTOR_ABI,
+            "loongarch32" | "loongarch64" => LOONGARCH_FEATURES_FOR_CORRECT_VECTOR_ABI,
             "riscv32" | "riscv64" => RISCV_FEATURES_FOR_CORRECT_VECTOR_ABI,
             "wasm32" | "wasm64" => WASM_FEATURES_FOR_CORRECT_VECTOR_ABI,
             "s390x" => S390X_FEATURES_FOR_CORRECT_VECTOR_ABI,
@@ -1034,7 +1034,7 @@ impl Target {
                     _ => unreachable!(),
                 }
             }
-            "loongarch64" => {
+            "loongarch32" | "loongarch64" => {
                 // LoongArch handles ABI in a very sane way, being fully explicit via `llvm_abiname`
                 // about what the intended ABI is.
                 match &*self.llvm_abiname {

diff --git a/library/core/Cargo.toml b/library/core/Cargo.toml
@@ -29,6 +29,8 @@ debug_typeid = []
 [lints.rust.unexpected_cfgs]
 level = "warn"
 check-cfg = [
+    # #[cfg(bootstrap)] loongarch32
+    'cfg(target_arch, values("loongarch32"))',
     'cfg(no_fp_fmt_parse)',
     # core use #[path] imports to portable-simd `core_simd` crate
     # and to stdarch `core_arch` crate which messes-up with Cargo list

diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs
@@ -178,7 +178,7 @@
 //!
 //! | `target_arch` | Size limit |
 //! |---------------|---------|
-//! | `x86`, `arm`, `mips`, `mips32r6`, `powerpc`, `riscv32`, `sparc`, `hexagon` | 4 bytes |
+//! | `x86`, `arm`, `loongarch32`, `mips`, `mips32r6`, `powerpc`, `riscv32`, `sparc`, `hexagon` | 4 bytes |
 //! | `x86_64`, `aarch64`, `loongarch64`, `mips64`, `mips64r6`, `powerpc64`, `riscv64`, `sparc64`, `s390x` | 8 bytes |
 //!
 //! Atomics loads that are larger than this limit as well as atomic loads with ordering other
@@ -349,8 +349,12 @@ pub type Atomic<T> = <T as AtomicPrimitive>::AtomicInner;
 // This list should only contain architectures which have word-sized atomic-or/
 // atomic-and instructions but don't natively support byte-sized atomics.
 #[cfg(target_has_atomic = "8")]
-const EMULATE_ATOMIC_BOOL: bool =
-    cfg!(any(target_arch = "riscv32", target_arch = "riscv64", target_arch = "loongarch64"));
+const EMULATE_ATOMIC_BOOL: bool = cfg!(any(
+    target_arch = "riscv32",
+    target_arch = "riscv64",
+    target_arch = "loongarch32",
+    target_arch = "loongarch64"
+));
 
 /// A boolean type which can be safely shared between threads.
 ///

diff --git a/library/std/Cargo.toml b/library/std/Cargo.toml
@@ -157,6 +157,8 @@ test = true
 [lints.rust.unexpected_cfgs]
 level = "warn"
 check-cfg = [
+    # #[cfg(bootstrap)] loongarch32
+    'cfg(target_arch, values("loongarch32"))',
     # std use #[path] imports to portable-simd `std_float` crate
     # and to the `backtrace` crate which messes-up with Cargo list
     # of declared features, we therefor expect any feature cfg

diff --git a/library/std/src/env.rs b/library/std/src/env.rs
@@ -1046,6 +1046,7 @@ pub mod consts {
     /// * `"sparc"`
     /// * `"sparc64"`
     /// * `"hexagon"`
+    /// * `"loongarch32"`
     /// * `"loongarch64"`
     ///
     /// </details>

diff --git a/library/std/src/os/linux/raw.rs b/library/std/src/os/linux/raw.rs
@@ -231,6 +231,7 @@ mod arch {
 }
 
 #[cfg(any(
+    target_arch = "loongarch32",
     target_arch = "loongarch64",
     target_arch = "mips64",
     target_arch = "mips64r6",

diff --git a/library/std/src/sys/alloc/mod.rs b/library/std/src/sys/alloc/mod.rs
@@ -17,6 +17,7 @@ const MIN_ALIGN: usize = if cfg!(any(
     target_arch = "arm",
     target_arch = "m68k",
     target_arch = "csky",
+    target_arch = "loongarch32",
     target_arch = "mips",
     target_arch = "mips32r6",
     target_arch = "powerpc",

diff --git a/library/std/src/sys/personality/gcc.rs b/library/std/src/sys/personality/gcc.rs
@@ -86,7 +86,7 @@ const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1
 #[cfg(any(target_arch = "riscv64", target_arch = "riscv32"))]
 const UNWIND_DATA_REG: (i32, i32) = (10, 11); // x10, x11
 
-#[cfg(target_arch = "loongarch64")]
+#[cfg(any(target_arch = "loongarch32", target_arch = "loongarch64"))]
 const UNWIND_DATA_REG: (i32, i32) = (4, 5); // a0, a1
 
 // The following code is based on GCC's C and C++ personality routines.  For reference, see:

diff --git a/library/unwind/Cargo.toml b/library/unwind/Cargo.toml
@@ -37,4 +37,4 @@ system-llvm-libunwind = []
 
 [lints.rust.unexpected_cfgs]
 level = "warn"
-check-cfg = ['cfg(emscripten_wasm_eh)']
+check-cfg = ['cfg(emscripten_wasm_eh)', 'cfg(target_arch, values("loongarch32"))']
diff --git a/library/unwind/src/libunwind.rs b/library/unwind/src/libunwind.rs
@@ -81,7 +81,7 @@ pub const unwinder_private_data_size: usize = 2;
 #[cfg(all(target_arch = "hexagon", target_os = "linux"))]
 pub const unwinder_private_data_size: usize = 35;
 
-#[cfg(target_arch = "loongarch64")]
+#[cfg(any(target_arch = "loongarch32", target_arch = "loongarch64"))]
 pub const unwinder_private_data_size: usize = 2;
 
 #[repr(C)]

diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
@@ -394,6 +394,7 @@ def default_build_triple(verbose):
         "i686": "i686",
         "i686-AT386": "i686",
         "i786": "i686",
+        "loongarch32": "loongarch32",
         "loongarch64": "loongarch64",
         "m68k": "m68k",
         "csky": "csky",

diff --git a/src/bootstrap/src/core/sanity.rs b/src/bootstrap/src/core/sanity.rs
@@ -34,6 +34,8 @@ pub struct Finder {
 // Targets can be removed from this list once they are present in the stage0 compiler (usually by updating the beta compiler of the bootstrap).
 const STAGE0_MISSING_TARGETS: &[&str] = &[
     // just a dummy comment so the list doesn't get onelined
+    "loongarch32-unknown-none",
+    "loongarch32-unknown-none-softfloat",
 ];
 
 /// Minimum version threshold for libstdc++ required when using prebuilt LLVM

diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
@@ -324,6 +324,8 @@ target | std | host | notes
 [`i686-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 [`i686-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  | [^x86_32-floats-return-ABI]
 [`loongarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ✓ |   | LoongArch64 OpenHarmony
+[`loongarch32-unknown-none`](platform-support/loongarch-none.md) | * | LoongArch32 Bare-metal (ILP32D ABI)
+[`loongarch32-unknown-none-softfloat`](platform-support/loongarch-none.md) | * | LoongArch32 Bare-metal (ILP32S ABI)
 [`m68k-unknown-linux-gnu`](platform-support/m68k-unknown-linux-gnu.md) | ? |  | Motorola 680x0 Linux
 [`m68k-unknown-none-elf`](platform-support/m68k-unknown-none-elf.md) |  |  | Motorola 680x0
 `mips-unknown-linux-gnu` | ✓ | ✓ | MIPS Linux (kernel 4.4, glibc 2.23)