8365218: [JVMCI] AArch64 CPU features are not computed correctly after 8364128

Reviewed-by: dnsimon
(cherry picked from commit e320162)

Author: Yudi Zheng

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

@@ -27,10 +27,10 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.function.LongFunction;
 
 import jdk.vm.ci.common.JVMCIError;
 import jdk.vm.ci.runtime.JVMCIBackend;
-import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE;
 
 public interface HotSpotJVMCIBackendFactory {
 
@@ -48,7 +48,8 @@ public interface HotSpotJVMCIBackendFactory {
      * @param enumType the class of {@code CPUFeatureType}
      * @param constants VM constants. Each entry whose key starts with {@code "VM_Version::CPU_"}
      *            specifies a CPU feature and its value is a mask for a bit in {@code features}
-     * @param features bits specifying CPU features
+     * @param bitMaskSupplier supplier to get the bit mask for the corresponding VM constant
+     * @param featuresSupplier supplier to get the bits specifying CPU features
      * @param renaming maps from VM feature names to enum constant names where the two differ
      * @throws IllegalArgumentException if any VM CPU feature constant cannot be converted to an
      *             enum value
@@ -57,18 +58,19 @@ public interface HotSpotJVMCIBackendFactory {
     static <CPUFeatureType extends Enum<CPUFeatureType>> EnumSet<CPUFeatureType> convertFeatures(
                     Class<CPUFeatureType> enumType,
                     Map<String, Long> constants,
-                    long features,
+                    LongFunction<Long> bitMaskSupplier,
+                    LongFunction<Long> featuresSupplier,
                     Map<String, String> renaming) {
         EnumSet<CPUFeatureType> outFeatures = EnumSet.noneOf(enumType);
         List<String> missing = new ArrayList<>();
         for (Entry<String, Long> e : constants.entrySet()) {
-            long bitMask = e.getValue();
+            long bitMask = bitMaskSupplier.apply(e.getValue());
             String key = e.getKey();
             if (key.startsWith("VM_Version::CPU_")) {
                 String name = key.substring("VM_Version::CPU_".length());
                 try {
                     CPUFeatureType feature = Enum.valueOf(enumType, renaming.getOrDefault(name, name));
-                    if ((features & bitMask) != 0) {
+                    if ((featuresSupplier.apply(e.getValue()) & bitMask) != 0) {
                         outFeatures.add(feature);
                     }
                 } catch (IllegalArgumentException iae) {
@@ -82,57 +84,4 @@ static <CPUFeatureType extends Enum<CPUFeatureType>> EnumSet<CPUFeatureType> con
         return outFeatures;
     }
 
-    /**
-     * Converts CPU features bit map into enum constants.
-     *
-     * @param <CPUFeatureType> CPU feature enum type
-     * @param enumType the class of {@code CPUFeatureType}
-     * @param constants VM constants. Each entry whose key starts with {@code "VM_Version::CPU_"}
-     *            specifies a CPU feature and its value is a mask for a bit in {@code features}
-     * @param featuresBitMapAddress pointer to {@code VM_Features::_features_bitmap} field of {@code VM_Version::_features}
-     * @param featuresBitMapSize size of feature bit map in bytes
-     * @param renaming maps from VM feature names to enum constant names where the two differ
-     * @throws IllegalArgumentException if any VM CPU feature constant cannot be converted to an
-     *             enum value
-     * @return the set of converted values
-     */
-    static <CPUFeatureType extends Enum<CPUFeatureType>> EnumSet<CPUFeatureType> convertFeatures(
-                    Class<CPUFeatureType> enumType,
-                    Map<String, Long> constants,
-                    long featuresBitMapAddress,
-                    long featuresBitMapSize,
-                    Map<String, String> renaming) {
-        EnumSet<CPUFeatureType> outFeatures = EnumSet.noneOf(enumType);
-        List<String> missing = new ArrayList<>();
-
-        for (Entry<String, Long> e : constants.entrySet()) {
-            String key = e.getKey();
-            long bitIndex = e.getValue();
-            if (key.startsWith("VM_Version::CPU_")) {
-                String name = key.substring("VM_Version::CPU_".length());
-                try {
-                    final long featuresElementShiftCount = 6; // log (# of bits per long)
-                    final long featuresElementMask = (1L << featuresElementShiftCount) - 1;
-
-                    CPUFeatureType feature = Enum.valueOf(enumType, renaming.getOrDefault(name, name));
-
-                    long featureIndex = bitIndex >>> featuresElementShiftCount;
-                    long featureBitMask = 1L << (bitIndex & featuresElementMask);
-                    assert featureIndex < featuresBitMapSize;
-
-                    long featuresElement = UNSAFE.getLong(featuresBitMapAddress + featureIndex * Long.BYTES);
-
-                    if ((featuresElement & featureBitMask) != 0) {
-                        outFeatures.add(feature);
-                    }
-                } catch (IllegalArgumentException iae) {
-                    missing.add(name);
-                }
-            }
-        }
-        if (!missing.isEmpty()) {
-            throw new JVMCIError("Missing CPU feature constants: %s", missing);
-        }
-        return outFeatures;
-    }
 }

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/aarch64/AArch64HotSpotJVMCIBackendFactory.java

@@ -49,7 +49,7 @@ public class AArch64HotSpotJVMCIBackendFactory implements HotSpotJVMCIBackendFac
     private static EnumSet<AArch64.CPUFeature> computeFeatures(AArch64HotSpotVMConfig config) {
         // Configure the feature set using the HotSpot flag settings.
         Map<String, Long> constants = config.getStore().getConstants();
-        return HotSpotJVMCIBackendFactory.convertFeatures(CPUFeature.class, constants, config.vmVersionFeatures, emptyMap());
+        return HotSpotJVMCIBackendFactory.convertFeatures(CPUFeature.class, constants, idx -> 1L << idx, _ -> config.vmVersionFeatures, emptyMap());
     }
 
     private static TargetDescription createTarget(AArch64HotSpotVMConfig config) {

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/amd64/AMD64HotSpotJVMCIBackendFactory.java

@@ -26,6 +26,8 @@
 
 import java.util.EnumSet;
 import java.util.Map;
+
+import jdk.internal.misc.Unsafe;
 import jdk.internal.util.OperatingSystem;
 import jdk.vm.ci.amd64.AMD64;
 import jdk.vm.ci.amd64.AMD64.CPUFeature;
@@ -50,11 +52,15 @@ private static EnumSet<CPUFeature> computeFeatures(AMD64HotSpotVMConfig config)
         Map<String, Long> constants = config.getStore().getConstants();
         Map<String, String> renaming = Map.of("3DNOW_PREFETCH", "AMD_3DNOW_PREFETCH");
         long featuresBitMapAddress = config.vmVersionFeatures + config.vmFeaturesFeaturesOffset;
-        EnumSet<CPUFeature> features = HotSpotJVMCIBackendFactory.convertFeatures(CPUFeature.class,
-                                                                                  constants,
-                                                                                  featuresBitMapAddress,
-                                                                                  config.vmFeaturesFeaturesSize,
-                                                                                  renaming);
+        EnumSet<CPUFeature> features = HotSpotJVMCIBackendFactory.convertFeatures(CPUFeature.class, constants, idx -> {
+            final long featuresElementShiftCount = 6; // log (# of bits per long)
+            final long featuresElementMask = (1L << featuresElementShiftCount) - 1;
+            return 1L << (idx & featuresElementMask);
+        }, idx -> {
+            final long featuresElementShiftCount = 6; // log (# of bits per long)
+            long featureIndex = idx >>> featuresElementShiftCount;
+            return Unsafe.getUnsafe().getLong(featuresBitMapAddress + featureIndex * Long.BYTES);
+        }, renaming);
         assert features.contains(AMD64.CPUFeature.SSE) : "minimum config for x64";
         assert features.contains(AMD64.CPUFeature.SSE2) : "minimum config for x64";
         return features;

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/riscv64/RISCV64HotSpotJVMCIBackendFactory.java

@@ -49,7 +49,7 @@ public class RISCV64HotSpotJVMCIBackendFactory implements HotSpotJVMCIBackendFac
     private static EnumSet<RISCV64.CPUFeature> computeFeatures(RISCV64HotSpotVMConfig config) {
         // Configure the feature set using the HotSpot flag settings.
         Map<String, Long> constants = config.getStore().getConstants();
-        return HotSpotJVMCIBackendFactory.convertFeatures(CPUFeature.class, constants, config.vmVersionFeatures, emptyMap());
+        return HotSpotJVMCIBackendFactory.convertFeatures(CPUFeature.class, constants, mask -> mask, _ -> config.vmVersionFeatures, emptyMap());
     }
 
     private static TargetDescription createTarget(RISCV64HotSpotVMConfig config) {