On Sat, 17 Apr 2021 20:18:31 GMT, Doug Simon <dnsi...@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. src/hotspot/cpu/aarch64/vm_version_aarch64.cpp line 198: > 196: sprintf(buf, "0x%02x:0x%x:0x%03x:%d", _cpu, _variant, _model, > _revision); > 197: if (_model2) sprintf(buf+strlen(buf), "(0x%03x)", _model2); > 198: #define ADD_FEATURE_IF_SUPPORTED(id, name, bit) if (_features & > CPU_##id) strcat(buf, ", " name); I'm not sure why only some of the supported AArch64 CPU features were being added to `_features_string` but I assume there's no harm in adding them all. src/hotspot/cpu/x86/vm_version_x86.hpp line 382: > 380: static const char* _features_names[]; > 381: > 382: // NB! When adding new CPU feature detection consider updating > vmStructs_x86.hpp, vmStructs_jvmci.hpp, and > VM_Version::get_processor_features(). No need for this comment any more as the derivative declarations are now automatically kept up to date. src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot.amd64/src/jdk/vm/ci/hotspot/amd64/AMD64HotSpotJVMCIBackendFactory.java line 57: > 55: > 56: Map<String, Long> constants = config.getStore().getConstants(); > 57: Function<String, CPUFeature> nameToFeature = name -> > name.equals("3DNOW_PREFETCH") ? CPUFeature.AMD_3DNOW_PREFETCH : > CPUFeature.valueOf(name); The `AMD_3DNOW_PREFETCH` enum constant has to keep its old name to preserve backward compatibility. ------------- PR: https://git.openjdk.java.net/jdk/pull/3558
