rustc_target: Add various aarch64 features

Add various aarch64 features already supported by LLVM and Linux.

The features are marked as unstable using a newly added symbol, i.e.
aarch64_unstable_target_feature.

Additionally include some comment fixes to ensure consistency of
feature names with the Arm ARM and support for architecture version
target features up to v9.5a.

This commit adds compiler support for the following features:

- FEAT_CSSC
- FEAT_ECV
- FEAT_FAMINMAX
- FEAT_FLAGM2
- FEAT_FP8
- FEAT_FP8DOT2
- FEAT_FP8DOT4
- FEAT_FP8FMA
- FEAT_FPMR
- FEAT_HBC
- FEAT_LSE128
- FEAT_LSE2
- FEAT_LUT
- FEAT_MOPS
- FEAT_LRCPC3
- FEAT_SVE_B16B16
- FEAT_SVE2p1
- FEAT_WFxT

1 files changed, 49 insertions, 5 deletions

diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
index da66ba270b3..d4b5a5ff675 100644
--- a/compiler/rustc_target/src/target_features.rs
+++ b/compiler/rustc_target/src/target_features.rs
@@ -99,6 +99,8 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("bti", Stable, &[]),
     // FEAT_CRC
     ("crc", Stable, &[]),
+    // FEAT_CSSC
+    ("cssc", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // FEAT_DIT
     ("dit", Stable, &[]),
     // FEAT_DotProd
@@ -107,21 +109,39 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("dpb", Stable, &[]),
     // FEAT_DPB2
     ("dpb2", Stable, &["dpb"]),
+    // FEAT_ECV
+    ("ecv", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // FEAT_F32MM
     ("f32mm", Stable, &["sve"]),
     // FEAT_F64MM
     ("f64mm", Stable, &["sve"]),
+    // FEAT_FAMINMAX
+    ("faminmax", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // FEAT_FCMA
     ("fcma", Stable, &["neon"]),
     // FEAT_FHM
     ("fhm", Stable, &["fp16"]),
     // FEAT_FLAGM
     ("flagm", Stable, &[]),
+    // FEAT_FLAGM2
+    ("flagm2", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // FEAT_FP16
     // Rust ties FP and Neon: https://github.com/rust-lang/rust/pull/91608
     ("fp16", Stable, &["neon"]),
+    // FEAT_FP8
+    ("fp8", Unstable(sym::aarch64_unstable_target_feature), &["faminmax", "lut", "bf16"]),
+    // FEAT_FP8DOT2
+    ("fp8dot2", Unstable(sym::aarch64_unstable_target_feature), &["fp8dot4"]),
+    // FEAT_FP8DOT4
+    ("fp8dot4", Unstable(sym::aarch64_unstable_target_feature), &["fp8fma"]),
+    // FEAT_FP8FMA
+    ("fp8fma", Unstable(sym::aarch64_unstable_target_feature), &["fp8"]),
+    // FEAT_FPMR
+    ("fpmr", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // FEAT_FRINTTS
     ("frintts", Stable, &[]),
+    // FEAT_HBC
+    ("hbc", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // FEAT_I8MM
     ("i8mm", Stable, &[]),
     // FEAT_JSCVT
@@ -131,6 +151,14 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("lor", Stable, &[]),
     // FEAT_LSE
     ("lse", Stable, &[]),
+    // FEAT_LSE128
+    ("lse128", Unstable(sym::aarch64_unstable_target_feature), &["lse"]),
+    // FEAT_LSE2
+    ("lse2", Unstable(sym::aarch64_unstable_target_feature), &[]),
+    // FEAT_LUT
+    ("lut", Unstable(sym::aarch64_unstable_target_feature), &[]),
+    // FEAT_MOPS
+    ("mops", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // FEAT_MTE & FEAT_MTE2
     ("mte", Stable, &[]),
     // FEAT_AdvSimd & FEAT_FP
@@ -143,14 +171,16 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("pan", Stable, &[]),
     // FEAT_PMUv3
     ("pmuv3", Stable, &[]),
-    // FEAT_RAND
+    // FEAT_RNG
     ("rand", Stable, &[]),
     // FEAT_RAS & FEAT_RASv1p1
     ("ras", Stable, &[]),
-    // FEAT_RCPC
+    // FEAT_LRCPC
     ("rcpc", Stable, &[]),
-    // FEAT_RCPC2
+    // FEAT_LRCPC2
     ("rcpc2", Stable, &["rcpc"]),
+    // FEAT_LRCPC3
+    ("rcpc3", Unstable(sym::aarch64_unstable_target_feature), &["rcpc2"]),
     // FEAT_RDM
     ("rdm", Stable, &["neon"]),
     // FEAT_SB
@@ -173,9 +203,11 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     //
     // "For backwards compatibility, Neon and VFP are required in the latest architectures."
     ("sve", Stable, &["neon"]),
+    // FEAT_SVE_B16B16 (SVE or SME Instructions)
+    ("sve-b16b16", Unstable(sym::aarch64_unstable_target_feature), &["bf16"]),
     // FEAT_SVE2
     ("sve2", Stable, &["sve"]),
-    // FEAT_SVE2_AES
+    // FEAT_SVE_AES & FEAT_SVE_PMULL128
     ("sve2-aes", Stable, &["sve2", "aes"]),
     // FEAT_SVE2_BitPerm
     ("sve2-bitperm", Stable, &["sve2"]),
@@ -183,6 +215,8 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("sve2-sha3", Stable, &["sve2", "sha3"]),
     // FEAT_SVE2_SM4
     ("sve2-sm4", Stable, &["sve2", "sm4"]),
+    // FEAT_SVE2p1
+    ("sve2p1", Unstable(sym::aarch64_unstable_target_feature), &["sve2"]),
     // FEAT_TME
     ("tme", Stable, &[]),
     (
@@ -199,9 +233,19 @@ const AARCH64_ALLOWED_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("v8.4a", Unstable(sym::aarch64_ver_target_feature), &["v8.3a", "dotprod", "dit", "flagm"]),
     ("v8.5a", Unstable(sym::aarch64_ver_target_feature), &["v8.4a", "ssbs", "sb", "dpb2", "bti"]),
     ("v8.6a", Unstable(sym::aarch64_ver_target_feature), &["v8.5a", "bf16", "i8mm"]),
-    ("v8.7a", Unstable(sym::aarch64_ver_target_feature), &[]),
+    ("v8.7a", Unstable(sym::aarch64_ver_target_feature), &["v8.6a", "wfxt"]),
+    ("v8.8a", Unstable(sym::aarch64_ver_target_feature), &["v8.7a", "hbc", "mops"]),
+    ("v8.9a", Unstable(sym::aarch64_ver_target_feature), &["v8.8a", "cssc"]),
+    ("v9.1a", Unstable(sym::aarch64_ver_target_feature), &["v9a", "v8.6a"]),
+    ("v9.2a", Unstable(sym::aarch64_ver_target_feature), &["v9.1a", "v8.7a"]),
+    ("v9.3a", Unstable(sym::aarch64_ver_target_feature), &["v9.2a", "v8.8a"]),
+    ("v9.4a", Unstable(sym::aarch64_ver_target_feature), &["v9.3a", "v8.9a"]),
+    ("v9.5a", Unstable(sym::aarch64_ver_target_feature), &["v9.4a"]),
+    ("v9a", Unstable(sym::aarch64_ver_target_feature), &["v8.5a", "sve2"]),
     // FEAT_VHE
     ("vh", Stable, &[]),
+    // FEAT_WFxT
+    ("wfxt", Unstable(sym::aarch64_unstable_target_feature), &[]),
     // tidy-alphabetical-end
 ];