/**
* Create an EmitterDescriptor for the given methodName. This conmstructor creates a descriptor
* that represents explicitly the types and size of the operands of the given emit* method. This
* constructor encapsulate the logic to parse the given method name into the appropriate
* explicit representation.
*/
EmitterDescriptor(String methodName, Class<?>[] argTypes) {
StringTokenizer toks = new StringTokenizer(methodName, "_");
toks.nextElement(); // first element is emitXXX;
args = new ArgumentType[toks.countTokens()];
ArgumentType size = null;
int count = 0;
int argTypeNum = 0;
for (int i = 0; i < args.length; i++) {
String cs = toks.nextToken();
ArgumentType code;
if (argTypeNum < argTypes.length) {
code = getEncoding(cs, argTypes[argTypeNum]);
} else {
code = getEncoding(cs, null);
}
argTypeNum += code.getParameters();
if (DEBUG) {
System.err.println(methodName + "[" + i + "] is " + code + " for " + cs);
}
args[count] = code;
count++;
if (code.isSize()) {
size = code;
count--;
}
}
this.size = size;
this.count = count;
}
/**
* Write the Java code required for error checking and calling the emit method represented by a
* singleton EmitterSet. A singleton EmiiterSet will typically be the result of a series of
* splits of bigger sets, where the splits represent emitted queries of operand types and sizes.
* (See emitSet) However, there may be cases when some operand has only one possible options, so
* the splitting will not have generated any tests for it. In this case, we will emit assertions
* that guarantee the operand is of the expected type. Note that the answers to queries
* alrrready performed by splitting are known to be fine, so no additional error checking is
* needed for cases they cover.
*
* @see #emitSet
* @param opcode the IA32 opcode to generate
* @param testsPerformed the set of queries already performed by splitting.
* @param level level of indentation for prett printing
*/
private void emitSingleton(String opcode, boolean[][] testsPerformed, int level) {
EmitterDescriptor ed = (EmitterDescriptor) emitters.iterator().next();
ArgumentType[] args = ed.getArgs();
int count = ed.getCount();
for (int i = 0; i < count; i++)
if (!testsPerformed[i][args[i].ordinal()]) emitVerify(i, args[i], level);
ArgumentType size = ed.getSize();
if (size != null) {
boolean needed = true;
for (int i = 0; i < count; i++) if (testsPerformed[i][size.ordinal()]) needed = false;
if (needed) emitVerify(0, size, level);
if (size == ArgumentType.Byte)
for (int i = 0; i < count; i++)
if (args[i] == ArgumentType.GPRegister)
if (currentOpcode.indexOf("MOVZX") == -1 && currentOpcode.indexOf("MOVSX") == -1) {
emitTab(level);
emit("if (VM.VerifyAssertions) opt_assert(");
emitArgs(i, ArgumentType.GPRegister);
emit(".isValidAs8bitRegister());\n");
}
}
emitEmitCall(opcode, args, count, level, ed.getSize());
}
/**
* Emit the Java code to call a particular emit method for a particular opcode. This method
* takes representations of the opcode and operands of a given emit method, and generates the
* appropriate Java source code to call it. It synthesizes the encoded emit method name, and
* uses emitArgs to pass all the required arguments.
*
* @see #emitArgs
* @param opcode the IA32 opcode of the emit method
* @param args the encoding of each operand to the emit method
* @param count the number of operands
* @param level the level of tabbing for pretty output
*/
private void emitEmitCall(
String opcode, ArgumentType[] args, int count, int level, ArgumentType size) {
if (DEBUG) {
System.err.print("Emitting call for " + opcode + " with args: ");
for (ArgumentType arg : args) {
System.err.print(arg + " ");
}
System.err.println(" count=" + count + " level=" + level + " size=" + size);
}
emitTab(level);
emit("emit" + opcode);
for (int i = 0; i < count; i++) emit("_" + args[i].getAssemblerName());
if (size != null) emit("_" + size.getAssemblerName());
if (count == 0) emit("();\n");
else {
emit("(");
for (int i = 0; i < count; i++) {
emit("\n");
emitTab(level + 1);
emitArgs(i, args[i]);
if (i == count - 1) emit(");\n");
else emit(",");
}
}
}
/**
* Generate code to fetch all the arguments needed for a given operand number and encoding. The
* different argument encodings of the Assembler need different arguments to be passed to the
* emitter function. For instance, a register-displacement mode operand needs to be given a base
* register and an immediate displacement. This function generates the appropriate arguments given
* the operand number and encoding; that is, it generates reads of the appropriate Instruction
* argument and fetches of the appropriate pieces of information from the operand.
*
* @param argNumber The argument being generated.
* @param argEcoding The encoding to use.
*/
private static void emitArgs(int argNumber, ArgumentType argEncoding) {
String op = getOperand(argNumber);
switch (argEncoding) {
case LabelOrImmediate:
emit("getImm(" + op + "), getLabel(" + op + ")");
break;
case RegisterDisplacement:
emit("getBase(" + op + "), getDisp(" + op + ")");
break;
case Absolute:
emit("getDisp(" + op + ").toWord().toAddress()");
break;
case RegisterOffset:
emit("getIndex(" + op + "), getScale(" + op + "), getDisp(" + op + ")");
break;
case RegisterIndexed:
emit(
"getBase(" + op + "), getIndex(" + op + "), getScale(" + op + "), getDisp(" + op + ")");
break;
case RegisterIndirect:
emit("getBase(" + op + ")");
break;
default:
emit("get" + argEncoding.getOptName() + "(" + op + ")");
}
}
/**
* For a given string representing a valid operand encoding for the Assembler, return the
* corresponding Assembler constant. This function only looks for encodings of operand types, and
* will not accept strings that correspond to size encodings.
*
* @param str A valid Assembler encoding of operand type
* @return The Assembler constant corresponding to str, or -1 if none
*/
private static ArgumentType getEncoding(String str, Class<?> type) {
if (str.equals("Reg")) {
if (type == null) {
throw new Error("Unable to encode Reg with no type information");
}
String typeName = type.getName();
str = typeName.substring(typeName.lastIndexOf('$') + 1) + "_Reg";
}
for (ArgumentType arg : ArgumentType.values()) {
if (arg.getOptName().equals(str)) {
return arg;
}
}
throw new Error(
"Unable to encode the argument " + str + " of type " + type + " as a valid argument type");
}
/**
* Find the best operand type or size and operand number to partition this EmitterSet. This
* method searches across all possible ways of splitting this set--all possible operand types
* and sizes, and all possible operands--to determine which one splits the set most evenly.
*
* @return a SplitRecord representing the most-even split
*/
SplitRecord split() {
int splitArg = -1;
ArgumentType splitTest = null;
int splitDiff = 1000;
for (int arg = 0; arg < 4; arg++) {
for (ArgumentType test : ArgumentType.values()) {
int c = getEncodingSplit(arg, test);
if (c == 0) return new SplitRecord(arg, test);
else if (c < splitDiff) {
splitArg = arg;
splitTest = test;
splitDiff = c;
}
}
}
return new SplitRecord(splitArg, splitTest);
}
/**
* This method checks whether the emit* method represented by this EmitterDescriptor expects the
* argument type represented by enc as its argument'th operand. If enc is an operand type
* encoding, this method checks wether the given argument is of the appropriate type. If enc is
* an operand size encoding, the argument parameter is ignored, and this method checks whether
* the emit* method represented operates upon data of the desired size.
*
* <p><EM>See the descriptions of the GenerateAssembler constants:</EM>
*
* <DL>
* <DT><EM>Operand types</EM> <DI>
* <UL>
* <LI>{@link #Immediate}
* <LI>{@link #Label}
* <LI>{@link #LabelOrImmediate}
* <LI>{@link #Absolute}
* <LI>{@link #Register}
* <LI>{@link #RegisterIndirect}
* <LI>{@link #RegisterOffset}
* <LI>{@link #RegisterIndexed}
* </UL>
* <DT><EM>Data size</EM>
* <UL>
* <LI>{@link #Byte}
* <LI>{@link #Word}
* <LI>{@link #Quad}
* </UL>
* </DL>
*
* <p>
*
* @param argument The operand number examined
* @param enc The argument type queried, as encoded as one of the operand type constants used
* throughout GenerateAssembler.
* @return True if this method expects an argument type encoded by enc as its argument'th
* operand, and false otherwise.
*/
boolean argMatchesEncoding(int argument, ArgumentType enc) {
if (!enc.isSize()) return (count > argument) && args[argument] == enc;
else return size == enc;
}
/**
* Given an operand number and an encoding, generate a test to determine whether the given operand
* matches the encoding. That is, generate code to the Assembler that examines a given operand of
* the current Instruction, and determines whether it is of the type encoded by the given
* encoding. This is used to generate the if statements of the dispatch functions for each opt
* compiler opcode.
*
* @param argNumber The argument to examine
* @param argEncoding The encoding for which to check
*/
private static void emitTest(int argNumber, ArgumentType argEncoding) {
if (argEncoding.isSize()) emit("is" + argEncoding.getOptName() + "(inst)");
else emit("is" + argEncoding.getOptName() + "(" + getOperand(argNumber) + ")");
}
/** Generate an assembler for the opt compiler */
public static void main(String[] args) {
try {
out = new FileWriter(System.getProperty("generateToDir") + "/AssemblerOpt.java");
} catch (IOException e) {
throw new Error(e);
}
emit("package org.jikesrvm.compilers.opt.mir2mc.ia32;\n\n");
emit("import org.jikesrvm.*;\n\n");
emit("import org.jikesrvm.compilers.opt.*;\n\n");
emit("import org.jikesrvm.compilers.opt.ir.*;\n\n");
emit("import org.jikesrvm.compilers.opt.ir.ia32.*;\n\n");
emit("import static org.jikesrvm.compilers.opt.ir.ia32.ArchOperators.*;\n\n");
emit("import static org.jikesrvm.compilers.opt.OptimizingCompilerException.opt_assert;\n\n");
emit("\n\n");
emit("/**\n");
emit(" * This class is the automatically-generated assembler for\n");
emit(" * the optimizing compiler. It consists of methods that\n");
emit(" * understand the possible operand combinations of each\n");
emit(" * instruction type, and how to translate those operands to\n");
emit(" * calls to the Assember low-level emit method\n");
emit(" *\n");
emit(" * It is generated by GenerateAssembler.java\n");
emit(" *\n");
emit(" */\n");
emit("public class AssemblerOpt extends AssemblerBase {\n\n");
emitTab(1);
emit("/**\n");
emitTab(1);
emit(" * @see org.jikesrvm.ArchitectureSpecific.Assembler\n");
emitTab(1);
emit(" */\n");
emitTab(1);
emit("public AssemblerOpt(int bcSize, boolean print, IR ir) {\n");
emitTab(2);
emit("super(bcSize, print, ir);\n");
emitTab(1);
emit("}");
emit("\n\n");
Method[] emitters = lowLevelAsm.getDeclaredMethods();
Set<String> opcodes = getOpcodes(emitters);
Iterator<String> i = opcodes.iterator();
while (i.hasNext()) {
String opcode = (String) i.next();
setCurrentOpcode(opcode);
emitTab(1);
emit("/**\n");
emitTab(1);
emit(" * Emit the given instruction, assuming that\n");
emitTab(1);
emit(" * it is a " + currentFormat + " instruction\n");
emitTab(1);
emit(" * and has a " + currentOpcode + " operator\n");
emitTab(1);
emit(" *\n");
emitTab(1);
emit(" * @param inst the instruction to assemble\n");
emitTab(1);
emit(" */\n");
emitTab(1);
emit("private void do" + opcode + "(Instruction inst) {\n");
EmitterSet emitter = buildSetForOpcode(emitters, opcode);
boolean[][] tp = new boolean[4][ArgumentType.values().length];
emitter.emitSet(opcode, tp, 2);
emitTab(1);
emit("}\n\n");
}
emitTab(1);
emit("/**\n");
emitTab(1);
emit(" * The number of instructions emitted so far\n");
emitTab(1);
emit(" */\n");
emitTab(1);
emit("private int instructionCount = 0;\n\n");
emitTab(1);
emit("/**\n");
emitTab(1);
emit(" * Assemble the given instruction\n");
emitTab(1);
emit(" *\n");
emitTab(1);
emit(" * @param inst the instruction to assemble\n");
emitTab(1);
emit(" */\n");
emitTab(1);
emit("public void doInst(Instruction inst) {\n");
emitTab(2);
emit("instructionCount++;\n");
emitTab(2);
emit("resolveForwardReferences(instructionCount);\n");
emitTab(2);
emit("switch (inst.getOpcode()) {\n");
Set<String> emittedOpcodes = new HashSet<String>();
i = opcodes.iterator();
while (i.hasNext()) {
String opcode = i.next();
Iterator<String> operators = getMatchingOperators(opcode).iterator();
while (operators.hasNext()) {
String operator = operators.next();
emitTab(3);
emittedOpcodes.add(operator);
emit("case IA32_" + operator + "_opcode:\n");
}
emitTab(4);
emit("do" + opcode + "(inst);\n");
emitTab(4);
emit("break;\n");
}
// Special case because doJCC is handwritten to add
// logic for short-forward branches
emittedOpcodes.add("JCC");
emitTab(3);
emit("case IA32_JCC_opcode:\n");
emitTab(4);
emit("doJCC(inst);\n");
emitTab(4);
emit("break;\n");
// Special case because doJMP is handwritten to add
// logic for short-forward branches
emittedOpcodes.add("JMP");
emitTab(3);
emit("case IA32_JMP_opcode:\n");
emitTab(4);
emit("doJMP(inst);\n");
emitTab(4);
emit("break;\n");
// Kludge for IA32_LOCK which needs to call emitLockNextInstruction
emittedOpcodes.add("LOCK");
emitTab(3);
emit("case IA32_LOCK_opcode:\n");
emitTab(4);
emit("emitLockNextInstruction();\n");
emitTab(4);
emit("break;\n");
// Kludge for PATCH_POINT
emitTab(3);
emit("case IG_PATCH_POINT_opcode:\n");
emitTab(4);
emit("emitPatchPoint();\n");
emitTab(4);
emit("break;\n");
// Kludge for LOWTABLESWITCH
emitTab(3);
emit("case MIR_LOWTABLESWITCH_opcode:\n");
emitTab(4);
emit("doLOWTABLESWITCH(inst);\n");
emitTab(4);
emit("// kludge table switches that are unusually long instructions\n");
emitTab(4);
emit("instructionCount += MIR_LowTableSwitch.getNumberOfTargets(inst);\n");
emitTab(4);
emit("break;\n");
Set<String> errorOpcodes = getErrorOpcodes(emittedOpcodes);
if (!errorOpcodes.isEmpty()) {
i = errorOpcodes.iterator();
while (i.hasNext()) {
emitTab(3);
emit("case IA32_" + i.next() + "_opcode:\n");
}
emitTab(4);
emit(
"throw new OptimizingCompilerException(inst + \" has unimplemented IA32 opcode (check excludedOpcodes)\");\n");
}
emitTab(2);
emit("}\n");
emitTab(2);
emit("inst.setmcOffset( mi );\n");
emitTab(1);
emit("}\n\n");
emit("\n}\n");
try {
out.close();
} catch (IOException e) {
throw new Error(e);
}
}