Andrew Carlotti <andrew.carlo...@arm.com> writes:
> This feature flag bit only exists to support the +crypto alias. Outside
> of option processing this bit needs to be set or unset consistently.
> This patch goes with the latter option.
>
> gcc/ChangeLog:
>
> * common/config/aarch64/aarch64-common.cc: Assert that CRYPTO
> bit is not set.
> * config/aarch64/aarch64-feature-deps.h
> (info<FEAT>.explicit_on): Unset CRYPTO bit.
> (cpu_##CORE_IDENT): Ditto.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/crypto-alias-1.c: New test.
OK, thanks. I'd rather get rid of AARCH64_FL_CRYPTO instead (without
changing observable behaviour), but that's a bigger project and not
suitable for this stage.
Richard
> diff --git a/gcc/common/config/aarch64/aarch64-common.cc
> b/gcc/common/config/aarch64/aarch64-common.cc
> index
> 1848d31c2c23e053535458044e0fcfd38b8f659b..8af3aa71be8a8d56ea3654e194dc58e81345178f
> 100644
> --- a/gcc/common/config/aarch64/aarch64-common.cc
> +++ b/gcc/common/config/aarch64/aarch64-common.cc
> @@ -620,6 +620,10 @@ aarch64_get_extension_string_for_isa_flags
> {
> std::string outstr = "";
>
> + /* The CRYPTO bit should only be used to support the +crypto alias
> + during option processing, and should be cleared at all other times.
> + Verify this property for the supplied flags bitmask. */
> + gcc_assert (!(AARCH64_FL_CRYPTO & aarch64_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-feature-deps.h
> b/gcc/config/aarch64/aarch64-feature-deps.h
> index
> 67c3a5da8aa3f59607b9eb20fb329c6fdef2d46f..55a0dbfae6107388d97528b637f9120cc6b933a1
> 100644
> --- a/gcc/config/aarch64/aarch64-feature-deps.h
> +++ b/gcc/config/aarch64/aarch64-feature-deps.h
> @@ -56,7 +56,8 @@ get_enable (T1 i, Ts... args)
>
> - explicit_on: the transitive closure of the features that an
> explicit +FEATURE enables, including FLAG itself. This is
> - always a superset of ENABLE
> + always a superset of ENABLE, except that the CRYPTO alias bit is
> + explicitly unset for consistency.
>
> Also define a function FEATURE () that returns an info<FEATURE>
> (which is an empty structure, since all members are static).
> @@ -69,7 +70,8 @@ template<aarch64_feature> struct info;
> template<> struct info<aarch64_feature::IDENT> { \
> static constexpr auto flag = AARCH64_FL_##IDENT; \
> static constexpr auto enable = flag | get_enable REQUIRES;
> \
> - static constexpr auto explicit_on = enable | get_enable EXPLICIT_ON; \
> + static constexpr auto explicit_on \
> + = (enable | get_enable EXPLICIT_ON) & ~AARCH64_FL_CRYPTO; \
> }; \
> constexpr aarch64_feature_flags info<aarch64_feature::IDENT>::flag;
> \
> constexpr aarch64_feature_flags info<aarch64_feature::IDENT>::enable;
> \
> @@ -114,9 +116,11 @@ get_flags_off (aarch64_feature_flags mask)
> #include "config/aarch64/aarch64-option-extensions.def"
>
> /* Define cpu_<NAME> variables for each CPU, giving the transitive
> - closure of all the features that the CPU supports. */
> + closure of all the features that the CPU supports. The CRYPTO bit is just
> + an alias, so explicitly unset it for consistency. */
> #define AARCH64_CORE(A, CORE_IDENT, C, ARCH_IDENT, FEATURES, F, G, H, I) \
> - constexpr auto cpu_##CORE_IDENT = ARCH_IDENT ().enable | get_enable
> FEATURES;
> + constexpr auto cpu_##CORE_IDENT \
> + = (ARCH_IDENT ().enable | get_enable FEATURES) & ~AARCH64_FL_CRYPTO;
> #include "config/aarch64/aarch64-cores.def"
>
> /* Define fmv_deps_<NAME> variables for each FMV feature, giving the
> transitive
> diff --git a/gcc/testsuite/gcc.target/aarch64/crypto-alias-1.c
> b/gcc/testsuite/gcc.target/aarch64/crypto-alias-1.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..e2662b44e2db0b26f30c44e62c4b873a12a37972
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/crypto-alias-1.c
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mcpu=ampere1" } */
> +
> +__attribute__ ((__always_inline__))
> +__attribute__ ((target ("arch=armv8-a+crypto")))
> +inline int bar()
> +{
> + return 5;
> +}
> +
> +int foo()
> +{
> + return bar();
> +}
