--- /dev/null
+/*
+ * 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.dex.code.form;
+
+import com.android.dexgen.dex.code.CstInsn;
+import com.android.dexgen.dex.code.DalvInsn;
+import com.android.dexgen.dex.code.InsnFormat;
+import com.android.dexgen.rop.code.RegisterSpec;
+import com.android.dexgen.rop.code.RegisterSpecList;
+import com.android.dexgen.rop.cst.Constant;
+import com.android.dexgen.rop.cst.CstMethodRef;
+import com.android.dexgen.rop.cst.CstType;
+import com.android.dexgen.rop.type.Type;
+import com.android.dexgen.util.AnnotatedOutput;
+
+/**
+ * Instruction format {@code 35c}. See the instruction format spec
+ * for details.
+ */
+public final class Form35c extends InsnFormat {
+ /** {@code non-null;} unique instance of this class */
+ public static final InsnFormat THE_ONE = new Form35c();
+
+ /** Maximal number of operands */
+ private static final int MAX_NUM_OPS = 5;
+
+ /**
+ * Constructs an instance. This class is not publicly
+ * instantiable. Use {@link #THE_ONE}.
+ */
+ private Form35c() {
+ // This space intentionally left blank.
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public String insnArgString(DalvInsn insn) {
+ RegisterSpecList regs = explicitize(insn.getRegisters());
+ return regListString(regs) + ", " + cstString(insn);
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public String insnCommentString(DalvInsn insn, boolean noteIndices) {
+ if (noteIndices) {
+ return cstComment(insn);
+ } else {
+ return "";
+ }
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public int codeSize() {
+ return 3;
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public boolean isCompatible(DalvInsn insn) {
+ if (!(insn instanceof CstInsn)) {
+ return false;
+ }
+
+ CstInsn ci = (CstInsn) insn;
+ int cpi = ci.getIndex();
+
+ if (! unsignedFitsInShort(cpi)) {
+ return false;
+ }
+
+ Constant cst = ci.getConstant();
+ if (!((cst instanceof CstMethodRef) ||
+ (cst instanceof CstType))) {
+ return false;
+ }
+
+ RegisterSpecList regs = ci.getRegisters();
+ return (wordCount(regs) >= 0);
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public InsnFormat nextUp() {
+ return Form3rc.THE_ONE;
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public void writeTo(AnnotatedOutput out, DalvInsn insn) {
+ int cpi = ((CstInsn) insn).getIndex();
+ RegisterSpecList regs = explicitize(insn.getRegisters());
+ int sz = regs.size();
+ int r0 = (sz > 0) ? regs.get(0).getReg() : 0;
+ int r1 = (sz > 1) ? regs.get(1).getReg() : 0;
+ int r2 = (sz > 2) ? regs.get(2).getReg() : 0;
+ int r3 = (sz > 3) ? regs.get(3).getReg() : 0;
+ int r4 = (sz > 4) ? regs.get(4).getReg() : 0;
+
+ write(out,
+ opcodeUnit(insn,
+ makeByte(r4, sz)), // encode the fifth operand here
+ (short) cpi,
+ codeUnit(r0, r1, r2, r3));
+ }
+
+ /**
+ * Gets the number of words required for the given register list, where
+ * category-2 values count as two words. Return {@code -1} if the
+ * list requires more than five words or contains registers that need
+ * more than a nibble to identify them.
+ *
+ * @param regs {@code non-null;} the register list in question
+ * @return {@code >= -1;} the number of words required, or {@code -1}
+ * if the list couldn't possibly fit in this format
+ */
+ private static int wordCount(RegisterSpecList regs) {
+ int sz = regs.size();
+
+ if (sz > MAX_NUM_OPS) {
+ // It can't possibly fit.
+ return -1;
+ }
+
+ int result = 0;
+
+ for (int i = 0; i < sz; i++) {
+ RegisterSpec one = regs.get(i);
+ result += one.getCategory();
+ /*
+ * The check below adds (category - 1) to the register, to
+ * account for the fact that the second half of a
+ * category-2 register has to be represented explicitly in
+ * the result.
+ */
+ if (!unsignedFitsInNibble(one.getReg() + one.getCategory() - 1)) {
+ return -1;
+ }
+ }
+
+ return (result <= MAX_NUM_OPS) ? result : -1;
+ }
+
+ /**
+ * Returns a register list which is equivalent to the given one,
+ * except that it splits category-2 registers into two explicit
+ * entries. This returns the original list if no modification is
+ * required
+ *
+ * @param orig {@code non-null;} the original list
+ * @return {@code non-null;} the list with the described transformation
+ */
+ private static RegisterSpecList explicitize(RegisterSpecList orig) {
+ int wordCount = wordCount(orig);
+ int sz = orig.size();
+
+ if (wordCount == sz) {
+ return orig;
+ }
+
+ RegisterSpecList result = new RegisterSpecList(wordCount);
+ int wordAt = 0;
+
+ for (int i = 0; i < sz; i++) {
+ RegisterSpec one = orig.get(i);
+ result.set(wordAt, one);
+ if (one.getCategory() == 2) {
+ result.set(wordAt + 1,
+ RegisterSpec.make(one.getReg() + 1, Type.VOID));
+ wordAt += 2;
+ } else {
+ wordAt++;
+ }
+ }
+
+ result.setImmutable();
+ return result;
+ }
+}
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