Added apxf target feature support, under flag apx_target_feature

Author: madhav-madhusoodanan

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -297,6 +297,28 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
             None
         }
         ("x86", "movrs") if get_version().0 < 20 => None,
+        ("x86", "egpr" | "push2pop2" | "ppx" | "ndd" | "ccmp" | "cf") if get_version().0 < 18 => {
+            None
+        }
+        ("x86", "nf" | "zu" | "inline-asm-use-gpr32") if get_version() < (19, 1, 0) => None,
+        ("x86", "apxf") => {
+            if get_version() < (19, 1, 0) {
+                None
+            } else {
+                Some(LLVMFeature::with_dependencies(
+                    "egpr",
+                    smallvec![
+                        TargetFeatureFoldStrength::Both("push2pop2"),
+                        TargetFeatureFoldStrength::Both("ppx"),
+                        TargetFeatureFoldStrength::Both("ndd"),
+                        TargetFeatureFoldStrength::Both("ccmp"),
+                        TargetFeatureFoldStrength::Both("cf"),
+                        TargetFeatureFoldStrength::Both("nf"),
+                        TargetFeatureFoldStrength::Both("zu"),
+                    ],
+                ))
+            }
+        }
         (_, s) => Some(LLVMFeature::new(s)),
     }
 }

compiler/rustc_feature/src/unstable.rs

@@ -314,6 +314,7 @@ declare_features! (
     // Unstable `#[target_feature]` directives.
     (unstable, aarch64_unstable_target_feature, "1.82.0", Some(44839)),
     (unstable, aarch64_ver_target_feature, "1.27.0", Some(44839)),
+    (unstable, apx_target_feature, "CURRENT_RUSTC_VERSION", Some(139284)),
     (unstable, arm_target_feature, "1.27.0", Some(44839)),
     (unstable, avx512_target_feature, "1.27.0", Some(44839)),
     (unstable, bpf_target_feature, "1.54.0", Some(44839)),

compiler/rustc_span/src/symbol.rs

@@ -457,6 +457,7 @@ symbols! {
         anonymous_lifetime_in_impl_trait,
         any,
         append_const_msg,
+        apx_target_feature,
         arbitrary_enum_discriminant,
         arbitrary_self_types,
         arbitrary_self_types_pointers,

compiler/rustc_target/src/target_features.rs

@@ -390,6 +390,7 @@ static X86_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("amx-tf32", Unstable(sym::x86_amx_intrinsics), &["amx-tile"]),
     ("amx-tile", Unstable(sym::x86_amx_intrinsics), &[]),
     ("amx-transpose", Unstable(sym::x86_amx_intrinsics), &["amx-tile"]),
+    ("apxf", Unstable(sym::apx_target_feature), &[]),
     ("avx", Stable, &["sse4.2"]),
     ("avx2", Stable, &["avx"]),
     ("avx512bf16", Unstable(sym::avx512_target_feature), &["avx512bw"]),