Allow actual AVX512-related feature names in the case of some misleading aliases

compiler/rustc_codegen_gcc/src/lib.rs

@@ -315,10 +315,10 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
                 false
             }
             /*
-               adx, aes, avx, avx2, avx512bf16, avx512bitalg, avx512bw, avx512cd, avx512dq, avx512er, avx512f, avx512gfni,
-               avx512ifma, avx512pf, avx512vaes, avx512vbmi, avx512vbmi2, avx512vl, avx512vnni, avx512vp2intersect, avx512vpclmulqdq,
-               avx512vpopcntdq, bmi1, bmi2, cmpxchg16b, ermsb, f16c, fma, fxsr, lzcnt, movbe, pclmulqdq, popcnt, rdrand, rdseed, rtm,
-               sha, sse, sse2, sse3, sse4.1, sse4.2, sse4a, ssse3, tbm, xsave, xsavec, xsaveopt, xsaves
+               adx, aes, avx, avx2, avx512bf16, avx512bitalg, avx512bw, avx512cd, avx512dq, avx512er, avx512f, avx512ifma,
+               avx512pf, avx512vbmi, avx512vbmi2, avx512vl, avx512vnni, avx512vp2intersect, avx512vpopcntdq,
+               bmi1, bmi2, cmpxchg16b, ermsb, f16c, fma, fxsr, gfni, lzcnt, movbe, pclmulqdq, popcnt, rdrand, rdseed, rtm,
+               sha, sse, sse2, sse3, sse4.1, sse4.2, sse4a, ssse3, tbm, vaes, vpclmulqdq, xsave, xsavec, xsaveopt, xsaves
              */
             //false
         })

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -163,6 +163,9 @@ pub fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> SmallVec<[&'a str; 2]
         ("x86", "rdrand") => smallvec!["rdrnd"],
         ("x86", "bmi1") => smallvec!["bmi"],
         ("x86", "cmpxchg16b") => smallvec!["cx16"],
+        // FIXME: These aliases are misleading, and should be removed before avx512_target_feature is
+        // stabilized. For now, they must be kept at a minimum because std::arch uses them.
+        // rust#100752
         ("x86", "avx512vaes") => smallvec!["vaes"],
         ("x86", "avx512gfni") => smallvec!["gfni"],
         ("x86", "avx512vpclmulqdq") => smallvec!["vpclmulqdq"],

compiler/rustc_codegen_ssa/src/target_features.rs

@@ -179,6 +179,7 @@ const X86_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
     ("f16c", Some(sym::f16c_target_feature)),
     ("fma", None),
     ("fxsr", None),
+    ("gfni", Some(sym::avx512_target_feature)),
     ("lzcnt", None),
     ("movbe", Some(sym::movbe_target_feature)),
     ("pclmulqdq", None),
@@ -195,6 +196,8 @@ const X86_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
     ("sse4a", Some(sym::sse4a_target_feature)),
     ("ssse3", None),
     ("tbm", Some(sym::tbm_target_feature)),
+    ("vaes", Some(sym::avx512_target_feature)),
+    ("vpclmulqdq", Some(sym::avx512_target_feature)),
     ("xsave", None),
     ("xsavec", None),
     ("xsaveopt", None),