Added apxf target feature support, under flag apx_target_feature

Author: madhav-madhusoodanan

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -307,6 +307,18 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         ("x86", "avx10.1") => Some(LLVMFeature::new("avx10.1-512")),
         ("x86", "avx10.2") if get_version().0 < 20 => None,
         ("x86", "avx10.2") if get_version().0 >= 20 => Some(LLVMFeature::new("avx10.2-512")),
+        ("x86", "apxf") => 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

@@ -316,6 +316,7 @@ 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

@@ -459,6 +459,7 @@ 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

@@ -393,6 +393,7 @@ 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"]),
     (
         "avx10.1",