3 files changed, 25 insertions, 0 deletions
diff --git a/compiler/rustc_llvm/build.rs b/compiler/rustc_llvm/build.rs
index f606fa483ca..fe13162cd4a 100644
--- a/compiler/rustc_llvm/build.rs
+++ b/compiler/rustc_llvm/build.rs
@@ -258,6 +258,12 @@ fn main() {
     {
         println!("cargo:rustc-link-lib=z");
     } else if target.contains("netbsd") {
+        // On NetBSD/i386, gcc and g++ is built for i486 (to maximize backward compat)
+        // However, LLVM insists on using 64-bit atomics.
+        // This gives rise to a need to link rust itself with -latomic for these targets
+        if target.starts_with("i586") || target.starts_with("i686") {
+            println!("cargo:rustc-link-lib=atomic");
+        }
         println!("cargo:rustc-link-lib=z");
         println!("cargo:rustc-link-lib=execinfo");
     }
diff --git a/compiler/rustc_target/src/spec/i586_unknown_netbsd.rs b/compiler/rustc_target/src/spec/i586_unknown_netbsd.rs
new file mode 100644
index 00000000000..0d8bdc3f89f
--- /dev/null
+++ b/compiler/rustc_target/src/spec/i586_unknown_netbsd.rs
@@ -0,0 +1,18 @@
+use crate::spec::{StackProbeType, Target, TargetOptions};
+
+pub fn target() -> Target {
+    let mut base = super::netbsd_base::opts();
+    base.cpu = "pentium".into();
+    base.max_atomic_width = Some(64);
+    base.stack_probes = StackProbeType::Call;
+
+    Target {
+        llvm_target: "i586-unknown-netbsdelf".into(),
+        pointer_width: 32,
+        data_layout: "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-\
+            f64:32:64-f80:32-n8:16:32-S128"
+            .into(),
+        arch: "x86".into(),
+        options: TargetOptions { mcount: "__mcount".into(), ..base },
+    }
+}
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 3541810d437..eaaaa4c08ca 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -1564,6 +1564,7 @@ supported_targets! {
     ("aarch64_be-unknown-netbsd", aarch64_be_unknown_netbsd),
     ("armv6-unknown-netbsd-eabihf", armv6_unknown_netbsd_eabihf),
     ("armv7-unknown-netbsd-eabihf", armv7_unknown_netbsd_eabihf),
+    ("i586-unknown-netbsd", i586_unknown_netbsd),
     ("i686-unknown-netbsd", i686_unknown_netbsd),
     ("powerpc-unknown-netbsd", powerpc_unknown_netbsd),
     ("riscv64gc-unknown-netbsd", riscv64gc_unknown_netbsd),