Cleanups related to object and code headers

hpi-swa · Oct 19, 2024 · 6ca84ad · 6ca84ad
1 parent 49a46bc
commit 6ca84ad
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Showing 7 changed files with 35 additions and 51 deletions.
diff --git a/....hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/AbstractSqueakTestCase.java b/....hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/AbstractSqueakTestCase.java
@@ -50,7 +50,7 @@ protected static final CompiledCodeObject makeMethod(final long header, final Ob
             bytes[i] = (byte) intbytes[i];
         }
         bytes[intbytes.length] = 0; // Set flagByte = 0 for no method trailer.
-        int numLiterals = (int) header & 0x7FFF;
+        final int numLiterals = (int) header & 0x7FFF;
         final Object[] allLiterals = Arrays.copyOf(literals, numLiterals);
         allLiterals[numLiterals - 2] = image.asByteString("DoIt"); // compiledInSelector
         allLiterals[numLiterals - 1] = nilClassBinding; // methodClassAssociation

diff --git a/...hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/SqueakMiscellaneousTest.java b/...hpi.swa.trufflesqueak.test/src/de/hpi/swa/trufflesqueak/test/SqueakMiscellaneousTest.java
@@ -125,8 +125,8 @@ public void testSource() {
 
     @Test
     public void testSourceAllBytecodes() {
-        final long header = 17235971L;
         final Object[] literals = {image.asByteString("someSelector"), image.asByteString("someOtherSelector"), 63, nilClassBinding};
+        final long header = makeHeader(0, 0, literals.length, false, true);
         final CompiledCodeObject code = makeMethod(header, literals,
                         139, 31, 0,
                         31, 32, 67, 96, 97, 98, 99, 103, 111, 112, 113, 114, 115, 116,

diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/image/SqueakImageConstants.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/image/SqueakImageConstants.java
@@ -6,8 +6,6 @@
  */
 package de.hpi.swa.trufflesqueak.image;
 
-import de.hpi.swa.trufflesqueak.util.MiscUtils;
-
 public final class SqueakImageConstants {
 
     /** General. */
@@ -22,6 +20,7 @@ public final class SqueakImageConstants {
     /** Object Header. */
     public static final long OVERFLOW_SLOTS = 255;
     public static final long SLOTS_MASK = 0xFFL << 56;
+    public static final int IDENTITY_HASH_HALF_WORD_MASK = (1 << 22) - 1;
 
     /** Object Header Tag Bits. */
     public static final int NUM_TAG_BITS = 3;
@@ -99,33 +98,28 @@ public static int classTableIndexFor(final int majorIndex, final int minorIndex)
      * </pre>
      */
     public static final class ObjectHeader {
-        private static final int NUM_SLOTS_SIZE = 1 << 8;
-        public static final int HASH_AND_CLASS_INDEX_SIZE = 1 << 22;
-        private static final int FORMAT_SIZE = 1 << 5;
-        private static final int PINNED_BIT_SHIFT = 30;
-
-        public static int getClassIndex(final long headerWord) {
-            return MiscUtils.bitSplit(headerWord, 0, HASH_AND_CLASS_INDEX_SIZE);
+        public static int getClassIndex(final long header) {
+            return (int) header & CLASS_INDEX_MASK;
         }
 
-        public static int getFormat(final long headerWord) {
-            return MiscUtils.bitSplit(headerWord, 24, FORMAT_SIZE);
+        public static int getFormat(final long header) {
+            return (int) (header >> 24) & 0x1f;
         }
 
-        public static int getHash(final long headerWord) {
-            return MiscUtils.bitSplit(headerWord, 32, HASH_AND_CLASS_INDEX_SIZE);
+        public static int getHash(final long header) {
+            return (int) (header >> 32) & IDENTITY_HASH_HALF_WORD_MASK;
         }
 
-        public static int getNumSlots(final long headerWord) {
-            return MiscUtils.bitSplit(headerWord, 56, NUM_SLOTS_SIZE);
+        public static int getNumSlots(final long header) {
+            return (int) (header >> 56) & 255;
         }
 
-        public static boolean isPinned(final long headerWord) {
-            return (headerWord >> PINNED_BIT_SHIFT & 1) == 1;
+        public static boolean isPinned(final long header) {
+            return (header >> 30 & 1) == 1;
         }
 
         public static long getHeader(final long numSlots, final long identityHash, final long format, final long classIndex) {
-            assert numSlots < NUM_SLOTS_SIZE && identityHash < HASH_AND_CLASS_INDEX_SIZE && format < FORMAT_SIZE && classIndex < HASH_AND_CLASS_INDEX_SIZE;
+            assert numSlots < 0x100 && identityHash < 0x400000 && format < 0x20 && classIndex < 0x400000;
             return numSlots << 56 | identityHash << 32 | format << 24 | classIndex;
         }
 

diff --git a/...rufflesqueak/src/de/hpi/swa/trufflesqueak/model/AbstractSqueakObjectWithClassAndHash.java b/...rufflesqueak/src/de/hpi/swa/trufflesqueak/model/AbstractSqueakObjectWithClassAndHash.java
@@ -23,7 +23,6 @@
 import de.hpi.swa.trufflesqueak.util.ObjectGraphUtils.ObjectTracer;
 
 public abstract class AbstractSqueakObjectWithClassAndHash extends AbstractSqueakObject {
-    public static final int SQUEAK_HASH_MASK = ObjectHeader.HASH_AND_CLASS_INDEX_SIZE - 1;
     private static final int MARK_BIT = 1 << 24;
     /* Generate new hash if hash is 0 (see SpurMemoryManager>>#hashBitsOf:). */
     private static final int HASH_UNINITIALIZED = 0;
@@ -38,15 +37,15 @@ public abstract class AbstractSqueakObjectWithClassAndHash extends AbstractSquea
      * can be represented by just one 64-bit word.
      */
     private ClassObject squeakClass;
-    private int squeahHashAndBits;
+    private int squeakHashAndBits;
 
     // For special/well-known objects only.
     protected AbstractSqueakObjectWithClassAndHash() {
         this(HASH_UNINITIALIZED, null);
     }
 
     protected AbstractSqueakObjectWithClassAndHash(final long header, final ClassObject klass) {
-        squeahHashAndBits = ObjectHeader.getHash(header);
+        squeakHashAndBits = ObjectHeader.getHash(header);
         squeakClass = klass;
         // mark bit zero when loading image
     }
@@ -56,15 +55,15 @@ protected AbstractSqueakObjectWithClassAndHash(final SqueakImageContext image, f
     }
 
     private AbstractSqueakObjectWithClassAndHash(final boolean markingFlag, final ClassObject klass) {
-        squeahHashAndBits = AbstractSqueakObjectWithClassAndHash.HASH_UNINITIALIZED;
+        squeakHashAndBits = AbstractSqueakObjectWithClassAndHash.HASH_UNINITIALIZED;
         squeakClass = klass;
         if (markingFlag) {
             toggleMarkingFlag();
         }
     }
 
     protected AbstractSqueakObjectWithClassAndHash(final AbstractSqueakObjectWithClassAndHash original) {
-        squeahHashAndBits = original.squeahHashAndBits;
+        squeakHashAndBits = original.squeakHashAndBits;
         setSqueakHash(HASH_UNINITIALIZED);
         squeakClass = original.squeakClass;
     }
@@ -112,30 +111,30 @@ public final long getOrCreateSqueakHash(final InlinedBranchProfile needsHashProf
         if (needsSqueakHash()) {
             /** Lazily initialize squeakHash and derive value from hashCode. */
             needsHashProfile.enter(node);
-            setSqueakHash(System.identityHashCode(this) & SQUEAK_HASH_MASK);
+            setSqueakHash(System.identityHashCode(this) & SqueakImageConstants.IDENTITY_HASH_HALF_WORD_MASK);
         }
         return getSqueakHash();
     }
 
     public long getSqueakHash() {
-        return squeahHashAndBits & SQUEAK_HASH_MASK;
+        return squeakHashAndBits & SqueakImageConstants.IDENTITY_HASH_HALF_WORD_MASK;
     }
 
     public final boolean needsSqueakHash() {
         return getSqueakHash() == HASH_UNINITIALIZED;
     }
 
     public final void setSqueakHash(final int newHash) {
-        assert newHash <= SQUEAK_HASH_MASK;
-        squeahHashAndBits = (squeahHashAndBits & ~SQUEAK_HASH_MASK) + newHash;
+        assert newHash <= SqueakImageConstants.IDENTITY_HASH_HALF_WORD_MASK;
+        squeakHashAndBits = (squeakHashAndBits & ~SqueakImageConstants.IDENTITY_HASH_HALF_WORD_MASK) + newHash;
     }
 
     public final boolean getMarkingFlag() {
-        return (squeahHashAndBits & MARK_BIT) != 0;
+        return (squeakHashAndBits & MARK_BIT) != 0;
     }
 
     private void toggleMarkingFlag() {
-        squeahHashAndBits ^= MARK_BIT;
+        squeakHashAndBits ^= MARK_BIT;
     }
 
     public final boolean isMarked(final boolean currentMarkingFlag) {

diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/CompiledCodeObject.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/model/CompiledCodeObject.java
@@ -48,7 +48,6 @@
 import de.hpi.swa.trufflesqueak.shared.SqueakLanguageConfig;
 import de.hpi.swa.trufflesqueak.util.ArrayUtils;
 import de.hpi.swa.trufflesqueak.util.FrameAccess;
-import de.hpi.swa.trufflesqueak.util.MiscUtils;
 import de.hpi.swa.trufflesqueak.util.ObjectGraphUtils.ObjectTracer;
 import de.hpi.swa.trufflesqueak.util.UnsafeUtils;
 
@@ -681,28 +680,24 @@ public CompiledCodeObject getMethodUnsafe() {
      * </pre>
      */
     private static final class CompiledCodeHeaderDecoder {
-        private static final int NUM_LITERALS_SIZE = 1 << 15;
-        private static final int NUM_TEMPS_TEMPS_SIZE = 1 << 6;
-        private static final int NUM_ARGUMENTS_SIZE = 1 << 4;
-
-        private static int getNumLiterals(final long headerWord) {
-            return MiscUtils.bitSplit(headerWord, 0, NUM_LITERALS_SIZE);
+        private static int getNumLiterals(final long header) {
+            return (int) (header & 0x7FFF);
         }
 
-        private static boolean getHasPrimitive(final long headerWord) {
-            return (headerWord & 1 << 16) != 0;
+        private static boolean getHasPrimitive(final long header) {
+            return (header & 0x10000) != 0;
         }
 
-        private static boolean getNeedsLargeFrame(final long headerWord) {
-            return (headerWord & 1 << 17) != 0;
+        private static boolean getNeedsLargeFrame(final long header) {
+            return (header & 0x20000) != 0;
         }
 
-        private static int getNumTemps(final long headerWord) {
-            return MiscUtils.bitSplit(headerWord, 18, NUM_TEMPS_TEMPS_SIZE);
+        private static int getNumTemps(final long header) {
+            return (int) (header >> 18) & 0x3F;
         }
 
-        private static int getNumArguments(final long headerWord) {
-            return MiscUtils.bitSplit(headerWord, 24, NUM_ARGUMENTS_SIZE);
+        private static int getNumArguments(final long header) {
+            return (int) (header >> 24) & 0x0F;
         }
 
         private static boolean getSignFlag(final long headerWord) {

diff --git a/...flesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/MiscellaneousPrimitives.java b/...flesqueak/src/de/hpi/swa/trufflesqueak/nodes/primitives/impl/MiscellaneousPrimitives.java
@@ -803,7 +803,7 @@ protected static final AbstractSqueakObject doCopy(final AbstractSqueakObjectWit
     public static final class PrimMaxIdentityHashNode extends AbstractSingletonPrimitiveNode {
         @Override
         public Object execute() {
-            return (long) AbstractSqueakObjectWithClassAndHash.SQUEAK_HASH_MASK;
+            return (long) SqueakImageConstants.IDENTITY_HASH_HALF_WORD_MASK;
         }
     }
 

diff --git a/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/MiscUtils.java b/src/de.hpi.swa.trufflesqueak/src/de/hpi/swa/trufflesqueak/util/MiscUtils.java
@@ -53,10 +53,6 @@ public final class MiscUtils {
     private MiscUtils() {
     }
 
-    public static int bitSplit(final long value, final int offset, final int size) {
-        return (int) (value >> offset & size - 1);
-    }
-
     public static long clamp(final long value, final long min, final long max) {
         return Math.max(min, Math.min(value, max));
     }