Fix handling of LoongArch target features not supported by LLVM 19

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -273,6 +273,12 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         ("aarch64", "fpmr") => None, // only existed in 18
         ("arm", "fp16") => Some(LLVMFeature::new("fullfp16")),
         // Filter out features that are not supported by the current LLVM version
+        ("loongarch64", "div32" | "lam-bh" | "lamcas" | "ld-seq-sa" | "scq")
+            if get_version().0 < 20 =>
+        {
+            None
+        }
+        // Filter out features that are not supported by the current LLVM version
         ("riscv32" | "riscv64", "zacas") if get_version().0 < 20 => None,
         // Enable the evex512 target feature if an avx512 target feature is enabled.
         ("x86", s) if s.starts_with("avx512") => {

compiler/rustc_target/src/target_features.rs

@@ -102,6 +102,9 @@ impl Stability {
 // check whether they're named already elsewhere in rust
 // e.g. in stdarch and whether the given name matches LLVM's
 // if it doesn't, to_llvm_feature in llvm_util in rustc_codegen_llvm needs to be adapted.
+// Additionally, if the feature is not available in older version of LLVM supported by the current
+// rust, the same function must be updated to filter out these features to avoid triggering
+// warnings.
 //
 // Also note that all target features listed here must be purely additive: for target_feature 1.1 to
 // be sound, we can never allow features like `+soft-float` (on x86) to be controlled on a

tests/ui/abi/compatibility.rs

@@ -40,7 +40,6 @@
 //@ revisions: loongarch64
 //@[loongarch64] compile-flags: --target loongarch64-unknown-linux-gnu
 //@[loongarch64] needs-llvm-components: loongarch
-//@[loongarch64] min-llvm-version: 20
 //FIXME: wasm is disabled due to <https://github.com/rust-lang/rust/issues/115666>.
 //FIXME @ revisions: wasm
 //FIXME @[wasm] compile-flags: --target wasm32-unknown-unknown

tests/ui/asm/loongarch/bad-reg.loongarch64_lp64d.stderr

@@ -1,35 +1,35 @@
 error: invalid register `$r0`: constant zero cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:23:18
+  --> $DIR/bad-reg.rs:22:18
    |
 LL |         asm!("", out("$r0") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$tp`: reserved for TLS
-  --> $DIR/bad-reg.rs:25:18
+  --> $DIR/bad-reg.rs:24:18
    |
 LL |         asm!("", out("$tp") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$sp`: the stack pointer cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:27:18
+  --> $DIR/bad-reg.rs:26:18
    |
 LL |         asm!("", out("$sp") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$r21`: reserved by the ABI
-  --> $DIR/bad-reg.rs:29:18
+  --> $DIR/bad-reg.rs:28:18
    |
 LL |         asm!("", out("$r21") _);
    |                  ^^^^^^^^^^^^^
 
 error: invalid register `$fp`: the frame pointer cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:31:18
+  --> $DIR/bad-reg.rs:30:18
    |
 LL |         asm!("", out("$fp") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$r31`: $r31 is used internally by LLVM and cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:33:18
+  --> $DIR/bad-reg.rs:32:18
    |
 LL |         asm!("", out("$r31") _);
    |                  ^^^^^^^^^^^^^

tests/ui/asm/loongarch/bad-reg.loongarch64_lp64s.stderr

@@ -1,59 +1,59 @@
 error: invalid register `$r0`: constant zero cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:23:18
+  --> $DIR/bad-reg.rs:22:18
    |
 LL |         asm!("", out("$r0") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$tp`: reserved for TLS
-  --> $DIR/bad-reg.rs:25:18
+  --> $DIR/bad-reg.rs:24:18
    |
 LL |         asm!("", out("$tp") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$sp`: the stack pointer cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:27:18
+  --> $DIR/bad-reg.rs:26:18
    |
 LL |         asm!("", out("$sp") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$r21`: reserved by the ABI
-  --> $DIR/bad-reg.rs:29:18
+  --> $DIR/bad-reg.rs:28:18
    |
 LL |         asm!("", out("$r21") _);
    |                  ^^^^^^^^^^^^^
 
 error: invalid register `$fp`: the frame pointer cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:31:18
+  --> $DIR/bad-reg.rs:30:18
    |
 LL |         asm!("", out("$fp") _);
    |                  ^^^^^^^^^^^^
 
 error: invalid register `$r31`: $r31 is used internally by LLVM and cannot be used as an operand for inline asm
-  --> $DIR/bad-reg.rs:33:18
+  --> $DIR/bad-reg.rs:32:18
    |
 LL |         asm!("", out("$r31") _);
    |                  ^^^^^^^^^^^^^
 
 error: register class `freg` requires at least one of the following target features: d, f
-  --> $DIR/bad-reg.rs:37:26
+  --> $DIR/bad-reg.rs:36:26
    |
 LL |         asm!("/* {} */", in(freg) f);
    |                          ^^^^^^^^^^
 
 error: register class `freg` requires at least one of the following target features: d, f
-  --> $DIR/bad-reg.rs:39:26
+  --> $DIR/bad-reg.rs:38:26
    |
 LL |         asm!("/* {} */", out(freg) _);
    |                          ^^^^^^^^^^^
 
 error: register class `freg` requires at least one of the following target features: d, f
-  --> $DIR/bad-reg.rs:41:26
+  --> $DIR/bad-reg.rs:40:26
    |
 LL |         asm!("/* {} */", in(freg) d);
    |                          ^^^^^^^^^^
 
 error: register class `freg` requires at least one of the following target features: d, f
-  --> $DIR/bad-reg.rs:43:26
+  --> $DIR/bad-reg.rs:42:26
    |
 LL |         asm!("/* {} */", out(freg) d);
    |                          ^^^^^^^^^^^

tests/ui/asm/loongarch/bad-reg.rs

@@ -1,7 +1,6 @@
 //@ add-core-stubs
 //@ needs-asm-support
 //@ revisions: loongarch64_lp64d loongarch64_lp64s
-//@ min-llvm-version: 20
 //@[loongarch64_lp64d] compile-flags: --target loongarch64-unknown-linux-gnu
 //@[loongarch64_lp64d] needs-llvm-components: loongarch
 //@[loongarch64_lp64s] compile-flags: --target loongarch64-unknown-none-softfloat