Fixed incompatibility with Java 8 by inlining outer class methods

Author: lycoris106

nondex-instrumentation/src/main/java/edu/illinois/nondex/instr/IdentityHashMapShufflingAdder.java

@@ -272,9 +272,23 @@ public void addRemove() {
         mv.visitInsn(Opcodes.ISUB);
         mv.visitFieldInsn(Opcodes.PUTFIELD, "java/util/IdentityHashMap", "size", "I");
 
+        // Inlined nextKeyIndex()
         mv.visitVarInsn(Opcodes.ILOAD, 4);
+        mv.visitInsn(Opcodes.ICONST_2);
+        mv.visitInsn(Opcodes.IADD);
+        mv.visitInsn(Opcodes.DUP);
         mv.visitVarInsn(Opcodes.ILOAD, 3);
-        mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/util/IdentityHashMap", "nextKeyIndex", "(II)I", false);
+
+        Label elseLabel = new Label();
+        Label endLabel = new Label();
+        mv.visitJumpInsn(Opcodes.IF_ICMPGE, elseLabel);
+        mv.visitJumpInsn(Opcodes.GOTO, endLabel);
+        mv.visitLabel(elseLabel);
+        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] { Opcodes.INTEGER });
+        mv.visitInsn(Opcodes.POP);
+        mv.visitInsn(Opcodes.ICONST_0);
+        mv.visitLabel(endLabel);
+        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] { Opcodes.INTEGER });
         mv.visitVarInsn(Opcodes.ISTORE, 6);  // i in local var 6
 
         Label loopStart = new Label();
@@ -293,10 +307,20 @@ public void addRemove() {
         // Check if item==null
         mv.visitJumpInsn(Opcodes.IFNULL, loopEnd);
 
-        // Compute hash
+        // Compute hash by inlining hash(item, len): ((h << 1) - (h << 8)) & (length - 1)
         mv.visitVarInsn(Opcodes.ALOAD, 7);
+        mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/System", "identityHashCode", "(Ljava/lang/Object;)I", false);
+        mv.visitInsn(Opcodes.DUP);
+        mv.visitInsn(Opcodes.ICONST_1);
+        mv.visitInsn(Opcodes.ISHL); // h << 1
+        mv.visitInsn(Opcodes.SWAP);
+        mv.visitIntInsn(Opcodes.BIPUSH, 8);
+        mv.visitInsn(Opcodes.ISHL);
+        mv.visitInsn(Opcodes.ISUB);
         mv.visitVarInsn(Opcodes.ILOAD, 3);
-        mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/util/IdentityHashMap", "hash", "(Ljava/lang/Object;I)I", false);
+        mv.visitInsn(Opcodes.ICONST_1);
+        mv.visitInsn(Opcodes.ISUB);
+        mv.visitInsn(Opcodes.IAND);
         mv.visitVarInsn(Opcodes.ISTORE, 8);  // r in local var 8
 
         // Complex conditional: if ((i < r && (r <= d || d <= i)) || (r <= d && d <= i))
@@ -366,10 +390,23 @@ public void addRemove() {
         mv.visitVarInsn(Opcodes.ILOAD, 6);
         mv.visitVarInsn(Opcodes.ISTORE, 4);
 
-        // Update i = nextKeyIndex(i, len);
+        // Update i = nextKeyIndex(i, len), inlined
         mv.visitVarInsn(Opcodes.ILOAD, 6);
+        mv.visitInsn(Opcodes.ICONST_2);
+        mv.visitInsn(Opcodes.IADD);
+        mv.visitInsn(Opcodes.DUP);
         mv.visitVarInsn(Opcodes.ILOAD, 3);
-        mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/util/IdentityHashMap", "nextKeyIndex", "(II)I", false);
+
+        Label elseLabel2 = new Label();
+        Label endLabel2 = new Label();
+        mv.visitJumpInsn(Opcodes.IF_ICMPGE, elseLabel2);
+        mv.visitJumpInsn(Opcodes.GOTO, endLabel2);
+        mv.visitLabel(elseLabel2);
+        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] { Opcodes.INTEGER });
+        mv.visitInsn(Opcodes.POP);
+        mv.visitInsn(Opcodes.ICONST_0);
+        mv.visitLabel(endLabel2);
+        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] { Opcodes.INTEGER });
         mv.visitVarInsn(Opcodes.ISTORE, 6);
 
         mv.visitJumpInsn(Opcodes.GOTO, loopStart);