RFR: 8265403: consolidate definition of CPU features [v3]

[Vladimir Kozlov]

On Mon, 19 Apr 2021 09:46:17 GMT, Doug Simon <dnsimon at openjdk.org> wrote:

>> While porting [JDK-8224974](https://bugs.openjdk.java.net/browse/JDK-8224974) to Graal, I noticed that new CPU features were defined for x86 and AArch64 without being exposed via JVMCI. To avoid this problem in future, this PR updates x86 and AArch64 to define CPU features with a single macro that is used to generate enum declarations as well as vmstructs entries.
>> 
>> In addition, the JVMCI API is updated to exposes the new CPU feature constants and now has a check that ensure these constants are in sync with the underlying macro definition.
>
> Doug Simon has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:
> 
>   avoid use of a lambda in JVMCI initialization

Please, update copyright years in files you touched.

src/hotspot/cpu/aarch64/vm_version_aarch64.hpp line 118:

> 116:     decl(STXR_PREFETCH, "stxr_prefetch", 29)  \
> 117:     decl(A53MAC,        "a53mac",        30)
> 118: #define DECLARE_CPU_FEATURE_FLAG(id, name, bit) CPU_##id = (1 << bit),

Add empty line before to separate `CPU_FEATURE_FLAGS` macro.

src/hotspot/cpu/x86/vmStructs_x86.hpp line 45:

> 43: 
> 44: #define DECLARE_LONG_CPU_FEATURE_CONSTANT(id, name, bit) GENERATE_VM_LONG_CONSTANT_ENTRY(VM_Version::CPU_##id)
> 45: #define VM_LONG_CPU_FEATURE_CONSTANTS CPU_FEATURE_FLAGS(DECLARE_LONG_CPU_FEATURE_CONSTANT)

Do we need to keep `VM_LONG_CONSTANTS_CPU` after you removed its body here and in vmStructs_jvmci.cpp?

What about `VM_INT_CONSTANTS_CPU` here? vmStructs_jvmci.cpp duplicates it.

src/hotspot/cpu/x86/vm_version_x86.hpp line 363:

> 361:     decl(AVX512_VBMI,       "avx512_vbmi",       45) /* Vector BMI instructions */ \
> 362:     decl(HV,                "hv",                46) /* Hypervisor instructions */
> 363: #define DECLARE_CPU_FEATURE_FLAG(id, name, bit) CPU_##id = (1ULL << bit),

Add empty line before it to separate `CPU_FEATURE_FLAGS` macro more clear.

src/hotspot/share/jvmci/vmStructs_jvmci.cpp line 753:

> 751: 
> 752: #define DECLARE_INT_CPU_FEATURE_CONSTANT(id, name, bit) GENERATE_VM_INT_CONSTANT_ENTRY(VM_Version::CPU_##id)
> 753: #define VM_INT_CPU_FEATURE_CONSTANTS CPU_FEATURE_FLAGS(DECLARE_INT_CPU_FEATURE_CONSTANT)

Missing `#undef DECLARE_INT_CPU_FEATURE_CONSTANT`.

src/hotspot/share/jvmci/vmStructs_jvmci.cpp line 769:

> 767: 
> 768: #define DECLARE_LONG_CPU_FEATURE_CONSTANT(id, name, bit) GENERATE_VM_LONG_CONSTANT_ENTRY(VM_Version::CPU_##id)
> 769: #define VM_LONG_CPU_FEATURE_CONSTANTS CPU_FEATURE_FLAGS(DECLARE_LONG_CPU_FEATURE_CONSTANT)

Missing `#undef DECLARE_LONG_CPU_FEATURE_CONSTANT`.

src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotJVMCIBackendFactory.java line 66:

> 64:             long bitMask = e.getValue();
> 65:             String key = e.getKey();
> 66:             if (key.startsWith("VM_Version::CPU_")) {

As I understand this code, it goes over `constants` values passed from VM and Trying to map them to `enumType`. It catches cases when a value is missing in `enumType`. What about case when `enumType` has `extra` value which is not defined in `constants`?

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PR: https://git.openjdk.java.net/jdk/pull/3558