> -----Original Message-----
> From: Alice Carlotti <[email protected]>
> Sent: 20 July 2026 13:08
> To: [email protected]
> Cc: [email protected]; Richard Earnshaw
> <[email protected]>; Kyrylo Tkachov <[email protected]>; Alex
> Coplan <[email protected]>; Andrew Pinski
> <[email protected]>; Wilco Dijkstra
> <[email protected]>
> Subject: [PATCH v2] aarch64: Fix assert checking alias feature bits
>
> Adjust the assert in aarch64_get_extension_string_for_isa_flags to check
> that the isa_flags parameter has no alias bits set. This is the check I
> intended to use when adding the assert in r15-7196-gb53781ce1e49fc, but
> I accidentally checked the global aarch64_isa_flags value instead.
>
> Additionally, remove the cpuinfo feature string entries for alias
> features, so that the bits are left unset during host_detect_local_cpu.
> Setting the bits would trigger the fixed assert, but was otherwise
> harmless because aarch64_get_extension_string_for_isa_flags would ignore
> the value of those bits.
>
>
>
> I overlooked an unnecessary use of those bits in the driver. Is this version
> ok for master?
>
So the idea is that the aliases HWCAPS shouldn't participate in cpuinfo
detection
because the non-alias feature already does?
If so, OK for master.
Thanks, sorry for the delay.
Tamar
>
> gcc/ChangeLog:
>
> * common/config/aarch64/aarch64-common.cc
> (aarch64_get_extension_string_for_isa_flags): Check isa_flags.
> * config/aarch64/aarch64-option-extensions.def
> (CRYPTO, SVE2_AES, SVE2_BITPERM, SVE2_SHA3, SVE2_SM4):
> Remove
> cpuinfo feature string.
>
>
> diff --git a/gcc/common/config/aarch64/aarch64-common.cc
> b/gcc/common/config/aarch64/aarch64-common.cc
> index
> fc7e84ae966c889ec1a666677bddc265e9b9e41c..d38ddb41c5964f17290e8
> 8732c83888b7b2597cd 100644
> --- a/gcc/common/config/aarch64/aarch64-common.cc
> +++ b/gcc/common/config/aarch64/aarch64-common.cc
> @@ -642,7 +642,7 @@ aarch64_get_extension_string_for_isa_flags
> /* The alias bits should only be used to support the aliases
> during option processing, and should be cleared at all other times.
> Verify this property for the supplied flags bitmask. */
> - gcc_assert (!(feature_deps::alias_flags & aarch64_isa_flags));
> + gcc_assert (!(feature_deps::alias_flags & isa_flags));
> aarch64_feature_flags current_flags = default_arch_flags;
>
> /* As a special case, do not assume that the assembler will enable CRC
> diff --git a/gcc/config/aarch64/aarch64-option-extensions.def
> b/gcc/config/aarch64/aarch64-option-extensions.def
> index
> 85483f38cc47358333827bf2d70a39522f868074..fbd5ea0d6e5a80ef772f4f
> a4081d049bf6006fbd 100644
> --- a/gcc/config/aarch64/aarch64-option-extensions.def
> +++ b/gcc/config/aarch64/aarch64-option-extensions.def
> @@ -150,7 +150,7 @@ AARCH64_FMV_FEATURE("aes", PMULL, (AES))
> /* +nocrypto disables AES, SHA2 and SM4, and anything that depends on
> them
> (such as SHA3 and the SVE2 crypto extensions). */
> AARCH64_OPT_EXTENSION_ALIAS("crypto", CRYPTO, (AES, SHA2), (), (AES,
> SHA2, SM4),
> - (AES, SHA2), "aes pmull sha1 sha2")
> + (AES, SHA2), "")
>
> AARCH64_OPT_EXTENSION("sha3", SHA3, (SHA2), (), (), "sha3 sha512")
>
> @@ -209,26 +209,26 @@ AARCH64_OPT_FMV_EXTENSION("sve2", SVE2,
> (SVE), (), (), "sve2")
>
> AARCH64_OPT_EXTENSION("sve-aes", SVE_AES, (AES), (), (), "sveaes |
> smeaes")
>
> -AARCH64_OPT_EXTENSION_ALIAS("sve2-aes", SVE2_AES, (SVE2, SVE_AES),
> (), (SVE_AES), (SVE_AES), "sveaes")
> +AARCH64_OPT_EXTENSION_ALIAS("sve2-aes", SVE2_AES, (SVE2, SVE_AES),
> (), (SVE_AES), (SVE_AES), "")
>
> AARCH64_FMV_FEATURE("sve2-aes", SVE_PMULL128, (SVE2, SVE_AES))
>
> AARCH64_OPT_EXTENSION("sve-bitperm", SVE_BITPERM, (), (), (),
> "svebitperm | smesbitperm")
>
> AARCH64_OPT_EXTENSION_ALIAS("sve2-bitperm", SVE2_BITPERM, (SVE2,
> SVE_BITPERM), (), (SVE_BITPERM),
> - (SVE_BITPERM), "svebitperm")
> + (SVE_BITPERM), "")
>
> AARCH64_FMV_FEATURE("sve2-bitperm", SVE_BITPERM, (SVE2,
> SVE_BITPERM))
>
> AARCH64_OPT_EXTENSION("sve-sha3", SVE_SHA3, (SHA3), (), (), "svesha3")
>
> -AARCH64_OPT_EXTENSION_ALIAS("sve2-sha3", SVE2_SHA3, (SVE2,
> SVE_SHA3), (), (SVE_SHA3), (SVE_SHA3), "svesha3")
> +AARCH64_OPT_EXTENSION_ALIAS("sve2-sha3", SVE2_SHA3, (SVE2,
> SVE_SHA3), (), (SVE_SHA3), (SVE_SHA3), "")
>
> AARCH64_FMV_FEATURE("sve2-sha3", SVE_SHA3, (SVE2, SVE_SHA3))
>
> AARCH64_OPT_EXTENSION("sve-sm4", SVE_SM4, (SM4), (), (), "svesm4")
>
> -AARCH64_OPT_EXTENSION_ALIAS("sve2-sm4", SVE2_SM4, (SVE2,
> SVE_SM4), (), (SVE_SM4), (SVE_SM4), "svesm4")
> +AARCH64_OPT_EXTENSION_ALIAS("sve2-sm4", SVE2_SM4, (SVE2,
> SVE_SM4), (), (SVE_SM4), (SVE_SM4), "")
>
> AARCH64_FMV_FEATURE("sve2-sm4", SVE_SM4, (SVE2, SVE_SM4))
>
