Add several classes from dx tool to the dexgen project

[android-x86/dalvik.git] / dexgen / src / com / android / dexgen / rop / code / DexTranslationAdvice.java

diff --git a/dexgen/src/com/android/dexgen/rop/code/DexTranslationAdvice.java b/dexgen/src/com/android/dexgen/rop/code/DexTranslationAdvice.java
new file mode 100644 (file)
index 0000000..b46182d
--- /dev/null
+++ b/dexgen/src/com/android/dexgen/rop/code/DexTranslationAdvice.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.dexgen.rop.code;
+
+import com.android.dexgen.rop.cst.CstInteger;
+import com.android.dexgen.rop.type.Type;
+
+/**
+ * Implementation of {@link TranslationAdvice} which represents what
+ * the dex format will be able to represent.
+ */
+public final class DexTranslationAdvice
+        implements TranslationAdvice {
+    /** {@code non-null;} standard instance of this class */
+    public static final DexTranslationAdvice THE_ONE =
+        new DexTranslationAdvice();
+
+    /** debug advice for disabling invoke-range optimization */
+    public static final DexTranslationAdvice NO_SOURCES_IN_ORDER =
+        new DexTranslationAdvice(true);
+
+    /**
+     * The minimum source width, in register units, for an invoke
+     * instruction that requires its sources to be in order and contiguous.
+     */
+    private static final int MIN_INVOKE_IN_ORDER = 6;
+
+    /** when true: always returns false for requiresSourcesInOrder */
+    private final boolean disableSourcesInOrder;
+
+    /**
+     * This class is not publicly instantiable. Use {@link #THE_ONE}.
+     */
+    private DexTranslationAdvice() {
+        disableSourcesInOrder = false;
+    }
+
+    private DexTranslationAdvice(boolean disableInvokeRange) {
+        this.disableSourcesInOrder = disableInvokeRange;
+    }
+
+    /** {@inheritDoc} */
+    public boolean hasConstantOperation(Rop opcode,
+            RegisterSpec sourceA, RegisterSpec sourceB) {
+        if (sourceA.getType() != Type.INT) {
+            return false;
+        }
+
+        if (! (sourceB.getTypeBearer() instanceof CstInteger)) {
+            return false;
+        }
+
+        CstInteger cst = (CstInteger) sourceB.getTypeBearer();
+
+        // TODO handle rsub
+        switch (opcode.getOpcode()) {
+            // These have 8 and 16 bit cst representations
+            case RegOps.REM:
+            case RegOps.ADD:
+            case RegOps.MUL:
+            case RegOps.DIV:
+            case RegOps.AND:
+            case RegOps.OR:
+            case RegOps.XOR:
+                return cst.fitsIn16Bits();
+            // These only have 8 bit cst reps
+            case RegOps.SHL:
+            case RegOps.SHR:
+            case RegOps.USHR:
+                return cst.fitsIn8Bits();
+            default:
+                return false;
+        }
+    }
+
+    /** {@inheritDoc} */
+    public boolean requiresSourcesInOrder(Rop opcode,
+            RegisterSpecList sources) {
+
+        return !disableSourcesInOrder && opcode.isCallLike()
+                && totalRopWidth(sources) >= MIN_INVOKE_IN_ORDER;
+    }
+
+    /**
+     * Calculates the total rop width of the list of SSA registers
+     *
+     * @param sources {@code non-null;} list of SSA registers
+     * @return {@code >= 0;} rop-form width in register units
+     */
+    private int totalRopWidth(RegisterSpecList sources) {
+        int sz = sources.size();
+        int total = 0;
+
+        for (int i = 0; i < sz; i++) {
+            total += sources.get(i).getCategory();
+        }
+
+        return total;
+    }
+
+    /** {@inheritDoc} */
+    public int getMaxOptimalRegisterCount() {
+        return 16;
+    }
+}