cbc/net/loveruby/cflat/compiler/CodeGenerator.java

1632 lines
50 KiB
Java

package net.loveruby.cflat.compiler;
import net.loveruby.cflat.ast.*;
import net.loveruby.cflat.type.*;
import net.loveruby.cflat.asm.*;
import java.util.*;
public class CodeGenerator
extends Visitor implements ASTLHSVisitor, ELFConstants {
// #@@range/ctor{
protected CodeGeneratorOptions options;
protected ErrorHandler errorHandler;
protected LinkedList<Assembler> asStack;
protected Assembler as;
protected TypeTable typeTable;
protected DefinedFunction currentFunction;
public CodeGenerator(CodeGeneratorOptions options,
ErrorHandler errorHandler) {
this.options = options;
this.errorHandler = errorHandler;
this.asStack = new LinkedList<Assembler>();
}
// #@@}
/** Compiles "ast" and generates assembly code. */
// #@@range/generate{
public String generate(AST ast) {
this.typeTable = ast.typeTable();
pushAssembler();
SymbolTable constSymbols = new SymbolTable(Assembler.CONST_SYMBOL_BASE);
for (ConstantEntry ent : ast.constantTable().entries()) {
locateConstant(ent, constSymbols);
}
for (Variable var : ast.allGlobalVariables()) {
locateGlobalVariable(var);
}
for (Function func : ast.allFunctions()) {
locateFunction(func);
}
compileAST(ast);
return popAssembler().toSource();
}
// #@@}
// #@@range/pushAssembler{
protected void pushAssembler() {
this.as = newAssembler();
asStack.add(this.as);
}
// #@@}
// #@@range/popAssembler{
protected Assembler popAssembler() {
Assembler popped = asStack.removeLast();
this.as = asStack.isEmpty() ? null : asStack.getLast();
return popped;
}
// #@@}
// #@@range/newAssembler{
protected Assembler newAssembler() {
return new Assembler(typeTable.unsignedLong());
}
// #@@}
// #@@range/compileAST{
public void compileAST(AST ast) {
_file(ast.fileName());
// .data
List<DefinedVariable> gvars = ast.definedGlobalVariables();
if (!gvars.isEmpty()) {
_data();
for (DefinedVariable gvar : gvars) {
dataEntry(gvar);
}
}
if (!ast.constantTable().isEmpty()) {
_section(".rodata");
for (ConstantEntry ent : ast.constantTable()) {
compileStringLiteral(ent);
}
}
// .text
if (ast.functionDefined()) {
_text();
for (DefinedFunction func : ast.definedFunctions()) {
compileFunction(func);
}
}
// .bss
for (DefinedVariable var : ast.definedCommonSymbols()) {
compileCommonSymbol(var);
}
// others
if (options.isPositionIndependent()) {
PICThunk(GOTBaseReg());
}
}
// #@@}
// #@@range/locateConstant{
protected void locateConstant(ConstantEntry ent, SymbolTable symbols) {
ent.setSymbol(symbols.newSymbol());
if (options.isPositionIndependent()) {
Symbol offset = localGOTSymbol(ent.symbol());
ent.setMemref(mem(offset, GOTBaseReg()));
}
else {
ent.setMemref(mem(ent.symbol()));
ent.setAddress(imm(ent.symbol()));
}
}
// #@@}
// #@@range/locateGlobalVariable{
protected void locateGlobalVariable(Entity ent) {
Symbol sym = ent.isPrivate() ? privateSymbol(ent.symbolString())
: globalSymbol(ent.symbolString());
if (options.isPositionIndependent()) {
if (ent.isPrivate() || optimizeGvarAccess(ent)) {
ent.setMemref(mem(localGOTSymbol(sym), GOTBaseReg()));
}
else {
ent.setAddress(mem(globalGOTSymbol(sym), GOTBaseReg()));
}
}
else {
ent.setMemref(mem(sym));
}
}
// #@@}
// #@@range/locateFunction{
protected void locateFunction(Function func) {
func.setCallingSymbol(callingSymbol(func));
locateGlobalVariable(func);
}
// #@@}
// #@@range/callingSymbol{
protected Symbol callingSymbol(Function func) {
if (func.isPrivate()) {
return privateSymbol(func.symbolString());
}
else {
Symbol sym = globalSymbol(func.symbolString());
return doesIndirectAccess(func) ? PLTSymbol(sym) : sym;
}
}
// #@@}
// condition to use indirect access (using PLT to call, GOT to refer).
// In PIC, we do use indirect access for all global variables.
// In PIE, we do use direct access for file-local reference.
// #@@range/doesIndirectAccess{
protected boolean doesIndirectAccess(Entity ent) {
return options.isPositionIndependent() && !optimizeGvarAccess(ent);
}
// #@@}
// #@@range/optimizeGvarAccess{
protected boolean optimizeGvarAccess(Entity ent) {
return options.isPIERequired() && ent.isDefined();
}
// #@@}
/** Generates initialized entries */
// #@@range/dataEntry{
protected void dataEntry(DefinedVariable ent) {
Symbol sym = globalSymbol(ent.symbolString());
if (!ent.isPrivate()) {
_globl(sym);
}
_align(ent.alignment());
_type(sym, "@object");
_size(sym, ent.allocSize());
label(sym);
compileImmediate(ent.type(), ent.initializer());
}
// #@@}
/** Generates immediate values for .data section */
// #@@range/compileImmediates{
protected void compileImmediate(Type type, ExprNode node) {
if (node instanceof IntegerLiteralNode) {
IntegerLiteralNode expr = (IntegerLiteralNode)node;
switch ((int)type.allocSize()) {
case 1: _byte(expr.value()); break;
case 2: _value(expr.value()); break;
case 4: _long(expr.value()); break;
case 8: _quad(expr.value()); break;
default:
throw new Error("entry size must be 1,2,4,8");
}
}
else if (node instanceof StringLiteralNode) {
StringLiteralNode expr = (StringLiteralNode)node;
switch ((int)type.allocSize()) {
case 4: _long(expr.symbol()); break;
case 8: _quad(expr.symbol()); break;
default:
throw new Error("pointer size must be 4,8");
}
}
else {
throw new Error("unknown literal node type" + node.getClass());
}
}
// #@@}
/** Generates BSS entries */
// #@@range/compileCommonSymbol{
protected void compileCommonSymbol(DefinedVariable var) {
Symbol sym = globalSymbol(var.symbolString());
if (var.isPrivate()) {
_local(sym);
}
_comm(sym, var.allocSize(), var.alignment());
}
// #@@}
/** Generates .rodata entry (constant strings) */
// #@@range/compileStringLiteral{
protected void compileStringLiteral(ConstantEntry ent) {
label(ent.symbol());
_string(ent.value());
}
// #@@}
// #@@range/globalSymbol{
// platform dependent
protected Symbol globalSymbol(String sym) {
return new NamedSymbol(sym);
}
// #@@}
// #@@range/privateSymbol{
// platform dependent
protected Symbol privateSymbol(String sym) {
return new NamedSymbol(sym);
}
// #@@}
//
// PIC/PIE related constants and codes
//
// #@@range/pic_methods{
static protected final Symbol GOT =
new NamedSymbol("_GLOBAL_OFFSET_TABLE_");
protected void loadGOTBaseAddress(Register reg) {
call(PICThunkSymbol(reg));
add(imm(GOT), reg);
}
protected Register GOTBaseReg() {
return reg("bx");
}
// #@@}
// #@@range/pic_symbols{
protected Symbol globalGOTSymbol(Symbol base) {
return new SuffixedSymbol(base, "@GOT");
}
protected Symbol localGOTSymbol(Symbol base) {
return new SuffixedSymbol(base, "@GOTOFF");
}
protected Symbol PLTSymbol(Symbol base) {
return new SuffixedSymbol(base, "@PLT");
}
// #@@}
// #@@range/pic_thunk_helper{
protected Symbol PICThunkSymbol(Register reg) {
return new NamedSymbol("__i686.get_pc_thunk." + reg.baseName());
}
static protected final String
PICThunkSectionFlags = SectionFlag_allocatable
+ SectionFlag_executable
+ SectionFlag_sectiongroup;
// #@@}
/**
* Output PIC thunk.
* ELF section declaration format is:
*
* .section NAME, FLAGS, TYPE, flag_arguments
*
* FLAGS, TYPE, flag_arguments are optional.
* For "M" flag (a member of a section group),
* following format is used:
*
* .section NAME, "...M", TYPE, section_group_name, linkage
*/
// #@@range/PICThunk{
protected void PICThunk(Register reg) {
Symbol sym = PICThunkSymbol(reg);
_section(".text" + "." + sym.toSource(),
"\"" + PICThunkSectionFlags + "\"",
SectionType_bits, // This section contains data
sym.toSource(), // The name of section group
Linkage_linkonce); // Only 1 copy should be generated
_globl(sym);
_hidden(sym);
_type(sym, SymbolType_function);
label(sym);
mov(mem(sp()), reg); // fetch saved EIP to the GOT base register
ret();
}
// #@@}
//
// Compile Function
//
/* Standard IA-32 stack frame layout
*
* ======================= esp #3 (stack top just before function call)
* next arg 1
* ---------------------
* next arg 2
* ---------------------
* next arg 3
* --------------------- esp #2 (stack top after alloca call)
* alloca area
* --------------------- esp #1 (stack top just after prelude)
* temporary
* variables...
* --------------------- -16(%ebp)
* lvar 3
* --------------------- -12(%ebp)
* lvar 2
* --------------------- -8(%ebp)
* lvar 1
* --------------------- -4(%ebp)
* callee-saved register
* ======================= 0(%ebp)
* saved ebp
* --------------------- 4(%ebp)
* return address
* --------------------- 8(%ebp)
* arg 1
* --------------------- 12(%ebp)
* arg 2
* --------------------- 16(%ebp)
* arg 3
* ...
* ...
* ======================= stack bottom
*/
/*
* Platform Dependent Stack Parameters
*/
// #@@range/stackParams{
static final protected boolean stackGrowsLower = true;
static final protected long stackWordSize = 4;
static final protected long stackAlignment = stackWordSize;
static final protected long paramStartWord = 2;
// return addr and saved bp
// #@@}
/** Compiles a function. */
// #@@range/compileFunction{
protected void compileFunction(DefinedFunction func) {
allocateParameters(func);
allocateLocalVariablesTemp(func.body().scope());
Symbol sym = globalSymbol(func.name());
if (! func.isPrivate()) {
_globl(sym);
}
_type(sym, "@function");
label(sym);
compileFunctionBody(func);
_size(sym, ".-" + sym.toSource());
}
// #@@}
// #@@range/compileFunctionBody{
protected void compileFunctionBody(DefinedFunction func) {
initVirtualStack();
List<Assembly> bodyAsms = compileStmts(func);
long maxTmpBytes = maxTmpBytes();
AsmStatistics stats = AsmStatistics.collect(bodyAsms);
bodyAsms = reduceLabels(bodyAsms, stats);
List<Register> saveRegs = usedCalleeSavedRegistersWithoutBP(stats);
long saveRegsBytes = saveRegs.size() * stackWordSize;
long lvarBytes = allocateLocalVariables(
func.body().scope(), saveRegsBytes);
fixTmpOffsets(bodyAsms, saveRegsBytes + lvarBytes);
if (options.isVerboseAsm()) {
printStackFrameLayout(
saveRegsBytes, lvarBytes, maxTmpBytes,
func.localVariables());
}
initVirtualStack();
prologue(func, saveRegs, saveRegsBytes + lvarBytes + maxTmpBytes);
if (options.isPositionIndependent()
&& stats.doesRegisterUsed(GOTBaseReg())) {
loadGOTBaseAddress(GOTBaseReg());
}
as.addAll(bodyAsms);
epilogue(func, saveRegs, lvarBytes);
}
// #@@}
protected void printStackFrameLayout(
long saveRegsBytes, long lvarBytes, long maxTmpBytes,
List<DefinedVariable> lvars) {
List<MemInfo> vars = new ArrayList<MemInfo>();
for (DefinedVariable var : lvars) {
vars.add(new MemInfo(var.memref(), var.name()));
}
vars.add(new MemInfo(mem(0, bp()), "return address"));
vars.add(new MemInfo(mem(4, bp()), "saved %ebp"));
if (saveRegsBytes > 0) {
vars.add(new MemInfo(mem(-saveRegsBytes, bp()),
"saved callee-saved registers (" + saveRegsBytes + " bytes)"));
}
if (maxTmpBytes > 0) {
long offset = -(saveRegsBytes + lvarBytes + maxTmpBytes);
vars.add(new MemInfo(mem(offset, bp()),
"tmp variables (" + maxTmpBytes + " bytes)"));
}
Collections.sort(vars, new Comparator<MemInfo>() {
public int compare(MemInfo x, MemInfo y) {
return x.mem.compareTo(y.mem);
}
});
comment("---- Stack Frame Layout -----------");
for (MemInfo info : vars) {
comment(info.mem.toString() + ": " + info.name);
}
comment("-----------------------------------");
}
class MemInfo {
MemoryReference mem;
String name;
MemInfo(MemoryReference mem, String name) {
this.mem = mem;
this.name = name;
}
}
// #@@range/compileStmts{
protected List<Assembly> compileStmts(DefinedFunction func) {
pushAssembler();
currentFunction = func;
compileStmt(func.body());
label(func.epilogueLabel());
currentFunction = null;
return options.optimizer().optimize(popAssembler().assemblies());
}
// #@@}
// #@@range/reduceLabels{
protected List<Assembly> reduceLabels(List<Assembly> assemblies, AsmStatistics stats) {
List<Assembly> result = new ArrayList<Assembly>();
for (Assembly asm : assemblies) {
if (asm.isLabel() && ! stats.doesSymbolUsed((Label)asm)) {
;
}
else {
result.add(asm);
}
}
return result;
}
// #@@}
protected List<Register> usedCalleeSavedRegistersWithoutBP(AsmStatistics stats) {
List<Register> result = new ArrayList<Register>();
for (Register reg : calleeSavedRegisters()) {
if (stats.doesRegisterUsed(reg) && !reg.equals(bp())) {
result.add(reg);
}
}
return result;
}
protected List<Register> calleeSavedRegistersCache = null;
// platform dependent
protected List<Register> calleeSavedRegisters() {
if (calleeSavedRegistersCache == null) {
List<Register> regs = new ArrayList<Register>();
regs.add(reg("bx"));
regs.add(reg("si"));
regs.add(reg("di"));
regs.add(reg("bp"));
calleeSavedRegistersCache = regs;
}
return calleeSavedRegistersCache;
}
// #@@range/prologue{
protected void prologue(DefinedFunction func,
List<Register> saveRegs,
long frameSize) {
truePush(bp());
mov(sp(), bp());
saveRegisters(saveRegs);
extendStack(frameSize);
}
// #@@}
// #@@range/epilogue{
protected void epilogue(DefinedFunction func,
List<Register> savedRegs,
long lvarBytes) {
restoreRegisters(savedRegs);
mov(bp(), sp());
truePop(bp());
ret();
}
// #@@}
// #@@range/saveRegisters{
protected void saveRegisters(List<Register> saveRegs) {
for (Register reg : saveRegs) {
push(reg);
}
}
// #@@}
// #@@range/restoreRegisters{
protected void restoreRegisters(List<Register> savedRegs) {
ListIterator<Register> regs = savedRegs.listIterator(savedRegs.size());
while (regs.hasPrevious()) {
pop(regs.previous());
}
}
// #@@}
// #@@range/allocateParameters{
protected void allocateParameters(DefinedFunction func) {
long word = paramStartWord;
for (Parameter var : func.parameters()) {
if (stackGrowsLower) {
var.setMemref(mem(word * stackWordSize, bp()));
}
else {
throw new Error("unsupported stack layout");
}
word++;
}
}
// #@@}
/**
* Allocates addresses of local variables, but offset is still
* not determined, assign unfixed IndirectMemoryReference.
*/
// #@@range/allocateVariablesTemp{
protected void allocateLocalVariablesTemp(LocalScope scope) {
for (DefinedVariable var : scope.allLocalVariables()) {
var.setMemref(new IndirectMemoryReference(bp()));
}
}
// #@@}
/**
* Fixes addresses of local variables.
* Returns byte-length of the local variable area.
* Note that numSavedRegs includes bp.
*/
// #@@range/allocateVariables{
protected long allocateLocalVariables(LocalScope scope, long initLen) {
long maxLen = allocateScope(scope, initLen);
return maxLen - initLen;
}
// #@@}
// #@@range/allocateScope{
protected long allocateScope(LocalScope scope, long parentStackLen) {
long len = parentStackLen;
for (DefinedVariable var : scope.localVariables()) {
if (stackGrowsLower) {
len = Assembler.align(len + var.allocSize(), stackAlignment);
fixMemref((IndirectMemoryReference)var.memref(), -len);
}
else {
fixMemref((IndirectMemoryReference)var.memref(), len);
len = Assembler.align(len + var.allocSize(), stackAlignment);
}
}
// Allocate local variables in child scopes.
// We allocate child scopes in the same area (overrapped).
long maxLen = len;
for (LocalScope s : scope.children()) {
long childLen = allocateScope(s, len);
maxLen = Math.max(maxLen, childLen);
}
return maxLen;
}
// #@@}
// #@@range/fixMemref{
protected void fixMemref(IndirectMemoryReference memref, long offset) {
memref.fixOffset(offset);
}
// #@@}
// #@@range/extendStack{
protected void extendStack(long len) {
if (len > 0) {
if (stackGrowsLower) {
sub(imm(len), sp());
}
else {
add(imm(len), sp());
}
}
}
// #@@}
// #@@range/rewindStack{
protected void rewindStack(long len) {
if (len > 0) {
if (stackGrowsLower) {
add(imm(len), sp());
}
else {
sub(imm(len), sp());
}
}
}
// #@@}
// #@@range/virtual_stack{
protected long stackPointer;
protected long stackPointerMax;
protected void initVirtualStack() {
stackPointer = 0;
stackPointerMax = stackPointer;
}
// #@@}
// #@@range/maxTmpBytes{
protected long maxTmpBytes() {
return stackPointerMax;
}
// #@@}
// #@@range/stackTop{
protected IndirectMemoryReference stackTop() {
if (stackGrowsLower) {
return mem(-stackPointer, bp());
}
else {
return mem(stackPointer - stackWordSize, bp());
}
}
// #@@}
// #@@range/push{
protected void push(Register reg) {
extendVirtualStack(stackWordSize);
as.relocatableMov(reg, stackTop());
if (options.isVerboseAsm()) {
comment("push " + reg.name() + " -> " + stackTop());
}
}
// #@@}
// #@@range/pop{
protected void pop(Register reg) {
if (options.isVerboseAsm()) {
comment("pop " + reg.name() + " <- " + stackTop());
}
as.relocatableMov(stackTop(), reg);
rewindVirtualStack(stackWordSize);
}
// #@@}
// #@@range/extendVirtualStack{
protected void extendVirtualStack(long len) {
stackPointer += len;
stackPointerMax = Math.max(stackPointerMax, stackPointer);
}
// #@@}
// #@@range/rewindVirtualStack{
protected void rewindVirtualStack(long len) {
stackPointer -= len;
}
// #@@}
// #@@range/fixTmpOffsets{
protected void fixTmpOffsets(List<Assembly> asms, long offset) {
for (Assembly asm : asms) {
asm.fixStackOffset(offset * (stackGrowsLower ? -1 : 1));
}
}
// #@@}
/**
* Implements cdecl function call:
* * All arguments are on stack.
* * Rewind stack by caller.
*/
// #@@range/compile_Funcall{
public FuncallNode visit(FuncallNode node) {
// compile function arguments from right to left.
ListIterator<ExprNode> args = node.finalArg();
while (args.hasPrevious()) {
compile(args.previous());
truePush(reg("ax"));
}
// call
if (node.isStaticCall()) {
// call via function name
call(node.function().callingSymbol());
}
else {
// call via pointer
compile(node.expr());
callAbsolute(reg("ax"));
}
// rewind stack
// >4 bytes arguments are not supported.
rewindStack(node.numArgs() * stackWordSize);
return null;
}
// #@@}
// #@@range/compile_Return{
public ReturnNode visit(ReturnNode node) {
if (node.expr() != null) {
compile(node.expr());
}
jmp(currentFunction.epilogueLabel());
return null;
}
// #@@}
//
// Statements
//
// #@@range/compile_Block{
public BlockNode visit(BlockNode node) {
for (DefinedVariable var : node.scope().localVariables()) {
if (var.initializer() != null) {
compile(var.initializer());
save(var.type(), reg("ax"), var.memref());
}
}
for (StmtNode stmt : node.stmts()) {
compileStmt(stmt);
}
return null;
}
// #@@}
// #@@range/compileStmt{
protected void compileStmt(StmtNode node) {
if (options.isVerboseAsm()) {
comment(node.location().numberedLine());
}
node.accept(this);
}
// #@@}
public ExprStmtNode visit(ExprStmtNode node) {
compile(node.expr());
return null;
}
// #@@range/testCond{
private void testCond(Type t, Register reg) {
test(t, reg.forType(t), reg.forType(t));
}
// #@@}
// #@@range/compile_If{
public IfNode visit(IfNode node) {
compile(node.cond());
testCond(node.cond().type(), reg("ax"));
if (node.elseBody() != null) {
jz(node.elseLabel());
compileStmt(node.thenBody());
jmp(node.endLabel());
label(node.elseLabel());
compileStmt(node.elseBody());
label(node.endLabel());
}
else {
jz(node.endLabel());
compileStmt(node.thenBody());
label(node.endLabel());
}
return null;
}
// #@@}
// #@@range/compile_CondExpr{
public CondExprNode visit(CondExprNode node) {
compile(node.cond());
testCond(node.cond().type(), reg("ax"));
jz(node.elseLabel());
compile(node.thenExpr());
jmp(node.endLabel());
label(node.elseLabel());
compile(node.elseExpr());
label(node.endLabel());
return null;
}
// #@@}
// #@@range/compile_Switch{
public SwitchNode visit(SwitchNode node) {
compile(node.cond());
Type t = typeTable.signedInt();
for (CaseNode cn : node.cases()) {
if (! cn.isDefault()) {
for (ExprNode ex : cn.values()) {
IntegerLiteralNode ival = (IntegerLiteralNode)ex;
mov(imm(ival.value()), reg("cx"));
cmp(t, reg("cx", t), reg("ax", t));
je(cn.beginLabel());
}
}
else {
jmp(cn.beginLabel());
}
}
jmp(node.endLabel());
for (CaseNode n : node.cases()) {
compileStmt(n);
}
label(node.endLabel());
return null;
}
// #@@}
// #@@range/compile_Case{
public CaseNode visit(CaseNode node) {
label(node.beginLabel());
compileStmt(node.body());
return null;
}
// #@@}
// #@@range/compile_LogicalAnd{
public LogicalAndNode visit(LogicalAndNode node) {
compile(node.left());
testCond(node.left().type(), reg("ax"));
jz(node.endLabel());
compile(node.right());
label(node.endLabel());
return null;
}
// #@@}
// #@@range/compile_LogicalOr{
public LogicalOrNode visit(LogicalOrNode node) {
compile(node.left());
testCond(node.left().type(), reg("ax"));
jnz(node.endLabel());
compile(node.right());
label(node.endLabel());
return null;
}
// #@@}
// #@@range/compile_While{
public WhileNode visit(WhileNode node) {
label(node.begLabel());
compile(node.cond());
testCond(node.cond().type(), reg("ax"));
jz(node.endLabel());
compileStmt(node.body());
jmp(node.begLabel());
label(node.endLabel());
return null;
}
// #@@}
public DoWhileNode visit(DoWhileNode node) {
label(node.begLabel());
compileStmt(node.body());
label(node.continueLabel());
compile(node.cond());
testCond(node.cond().type(), reg("ax"));
jnz(node.begLabel());
label(node.endLabel());
return null;
}
// #@@range/compile_For{
public ForNode visit(ForNode node) {
compileStmt(node.init());
label(node.begLabel());
compile(node.cond());
testCond(node.cond().type(), reg("ax"));
jz(node.endLabel());
compileStmt(node.body());
label(node.continueLabel());
compileStmt(node.incr());
jmp(node.begLabel());
label(node.endLabel());
return null;
}
// #@@}
// #@@range/compile_Break{
public BreakNode visit(BreakNode node) {
jmp(node.targetLabel());
return null;
}
// #@@}
// #@@range/compile_Continue{
public ContinueNode visit(ContinueNode node) {
jmp(node.targetLabel());
return null;
}
// #@@}
// #@@range/compile_Label{
public LabelNode visit(LabelNode node) {
label(node.label());
compileStmt(node.stmt());
return null;
}
// #@@}
// #@@range/compile_Goto{
public GotoNode visit(GotoNode node) {
jmp(node.targetLabel());
return null;
}
// #@@}
//
// Expressions
//
// #@@range/compile{
protected void compile(ExprNode n) {
if (options.isVerboseAsm()) {
comment(n.getClass().getSimpleName() + " {");
as.indentComment();
}
n.accept(this);
if (options.isVerboseAsm()) {
as.unindentComment();
comment("}");
}
}
// #@@}
// #@@range/compile_BinaryOp{
public BinaryOpNode visit(BinaryOpNode node) {
AsmOperand right = null;
if (!doesRequireRegister(node.operator()) && node.right().isConstant()){
compile(node.left());
right = node.right().asmValue();
}
else if (node.right().isConstantAddress()) {
compile(node.left());
loadVariable(node.right(), reg("cx"));
right = reg("cx", node.type());
}
else {
compile(node.right());
push(reg("ax"));
compile(node.left());
pop(reg("cx"));
right = reg("cx", node.type());
}
compileBinaryOp(node.operator(), node.type(), right);
return null;
}
// #@@}
// #@@range/doesRequireRegister{
protected boolean doesRequireRegister(String op) {
return op.equals("/")
|| op.equals("%")
|| op.equals(">>")
|| op.equals("<<");
}
// #@@}
// #@@range/doesSpillDX{
protected boolean doesSpillDX(String op) {
return op.equals("/") || op.equals("%");
}
// #@@}
// spills: dx
// #@@range/compileBinaryOp_begin{
protected void compileBinaryOp(String op, Type t, AsmOperand right) {
// #@@range/compileBinaryOp_arithops{
if (op.equals("+")) {
add(t, right, reg("ax", t));
}
else if (op.equals("-")) {
sub(t, right, reg("ax", t));
}
// #@@range/compileBinaryOp_begin}
else if (op.equals("*")) {
imul(t, right, reg("ax", t));
}
else if (op.equals("/") || op.equals("%")) {
if (t.isSigned()) {
cltd();
idiv(t, reg("cx", t));
}
else {
mov(imm(0), reg("dx"));
div(t, reg("cx", t));
}
if (op.equals("%")) {
mov(reg("dx"), reg("ax"));
}
}
// #@@}
// #@@range/compileBinaryOp_bitops{
else if (op.equals("&")) {
and(t, right, reg("ax", t));
}
else if (op.equals("|")) {
or(t, right, reg("ax", t));
}
else if (op.equals("^")) {
xor(t, right, reg("ax", t));
}
else if (op.equals(">>")) {
if (t.isSigned()) {
sar(t, cl(), reg("ax", t));
}
else {
shr(t, cl(), reg("ax", t));
}
}
else if (op.equals("<<")) {
sal(t, cl(), reg("ax", t));
}
// #@@}
// #@@range/compileBinaryOp_cmpops{
else {
// Comparison operators
cmp(t, right, reg("ax", t));
if (!t.isPointer() && t.isSigned()) {
if (op.equals("==")) sete (al());
else if (op.equals("!=")) setne(al());
else if (op.equals(">")) setg (al());
else if (op.equals(">=")) setge(al());
else if (op.equals("<")) setl (al());
else if (op.equals("<=")) setle(al());
else {
throw new Error("unknown binary operator: " + op);
}
}
else {
if (op.equals("==")) sete (al());
else if (op.equals("!=")) setne(al());
else if (op.equals(">")) seta (al());
else if (op.equals(">=")) setae(al());
else if (op.equals("<")) setb (al());
else if (op.equals("<=")) setbe(al());
else {
throw new Error("unknown binary operator: " + op);
}
}
movzb(t, al(), reg("ax", t));
}
// #@@}
// #@@range/compileBinaryOp_end{
}
// #@@}
// #@@range/compile_UnaryOp{
public UnaryOpNode visit(UnaryOpNode node) {
compile(node.expr());
if (node.operator().equals("+")) {
;
}
else if (node.operator().equals("-")) {
neg(node.expr().type(), reg("ax", node.expr().type()));
}
else if (node.operator().equals("~")) {
not(node.expr().type(), reg("ax", node.expr().type()));
}
else if (node.operator().equals("!")) {
testCond(node.expr().type(), reg("ax"));
sete(al());
movzbl(al(), reg("ax"));
}
return null;
}
// #@@}
// #@@range/compile_PrefixOp{
public PrefixOpNode visit(PrefixOpNode node) {
if (node.expr().isConstantAddress()) {
load(node.expr().type(), node.expr().memref(), reg("ax"));
compileUnaryArithmetic(node, reg("ax"));
save(node.expr().type(), reg("ax"), node.expr().memref());
}
else {
compileLHS(node.expr());
mov(reg("ax"), reg("cx"));
load(node.expr().type(), mem(reg("cx")), reg("ax"));
compileUnaryArithmetic(node, reg("ax"));
save(node.expr().type(), reg("ax"), mem(reg("cx")));
}
return null;
}
// #@@}
// #@@range/compile_SuffixOp{
public SuffixOpNode visit(SuffixOpNode node) {
if (node.expr().isConstantAddress()) {
load(node.expr().type(), node.expr().memref(), reg("ax"));
mov(reg("ax"), reg("cx"));
compileUnaryArithmetic(node, reg("cx"));
save(node.expr().type(), reg("cx"), node.expr().memref());
}
else {
compileLHS(node.expr());
mov(reg("ax"), reg("cx"));
load(node.expr().type(), mem(reg("cx")), reg("ax"));
mov(reg("ax"), reg("dx"));
compileUnaryArithmetic(node, reg("dx"));
save(node.expr().type(), reg("dx"), mem(reg("cx")));
}
return null;
}
// #@@}
// spills: (none)
// #@@range/compile_UnaryArithmetic{
protected void compileUnaryArithmetic(UnaryArithmeticOpNode node,
AsmOperand dest) {
if (node.operator().equals("++")) {
add(imm(node.amount()), dest);
}
else if (node.operator().equals("--")) {
sub(imm(node.amount()), dest);
}
else {
throw new Error("unknown unary operator: " + node.operator());
}
}
// #@@}
// #@@range/compile_Cast{
public CastNode visit(CastNode node) {
compile(node.expr());
// We need not execute downcast because we can cast big value
// to small value by just cutting off higer bits.
if (node.isEffectiveCast()) {
Type src = node.expr().type();
Type dest = node.type();
if (src.isSigned()) {
movsx(src, dest,
reg("ax").forType(src), reg("ax").forType(dest));
}
else {
movzx(src, dest,
reg("ax").forType(src), reg("ax").forType(dest));
}
}
return null;
}
// #@@}
// #@@range/compile_SizeofExpr{
public SizeofExprNode visit(SizeofExprNode node) {
long val = node.expr().type().allocSize();
mov(node.type(), imm(val), reg("ax", node.type()));
return null;
}
// #@@}
// #@@range/compile_SizeofType{
public SizeofTypeNode visit(SizeofTypeNode node) {
long val = node.operand().allocSize();
mov(node.type(), imm(val), reg("ax", node.type()));
return null;
}
// #@@}
// #@@range/compile_Variable{
public VariableNode visit(VariableNode node) {
loadVariable(node, reg("ax"));
return null;
}
// #@@}
// #@@range/compile_IntegerLiteral{
public IntegerLiteralNode visit(IntegerLiteralNode node) {
loadConstant(node, reg("ax"));
return null;
}
// #@@}
// #@@range/compile_StringLiteral{
public StringLiteralNode visit(StringLiteralNode node) {
loadConstant(node, reg("ax"));
return null;
}
// #@@}
//
// Assignable expressions
//
// #@@range/compile_Assign{
public AssignNode visit(AssignNode node) {
if (node.lhs().isConstantAddress() && node.lhs().memref() != null) {
compile(node.rhs());
save(node.type(), reg("ax"), node.lhs().memref());
}
else if (node.rhs().isConstant()) {
compileLHS(node.lhs());
mov(reg("ax"), reg("cx"));
loadConstant(node.rhs(), reg("ax"));
save(node.type(), reg("ax"), mem(reg("cx")));
}
else {
compile(node.rhs());
push(reg("ax"));
compileLHS(node.lhs());
mov(reg("ax"), reg("cx"));
pop(reg("ax"));
save(node.type(), reg("ax"), mem(reg("cx")));
}
return null;
}
// #@@}
// #@@range/compile_OpAssign{
public OpAssignNode visit(OpAssignNode node) {
if (node.lhs().isConstantAddress() && node.lhs().memref() != null) {
// const += ANY
compile(node.rhs());
mov(reg("ax"), reg("cx"));
load(node.type(), node.lhs().memref(), reg("ax"));
compileBinaryOp(node.operator(), node.type(), reg("cx"));
save(node.type(), reg("ax"), node.lhs().memref());
}
else if (node.rhs().isConstant() && !doesRequireRegister(node.operator())) {
// ANY += const
compileLHS(node.lhs());
mov(reg("ax"), reg("cx"));
load(node.type(), mem(reg("cx")), reg("ax"));
AsmOperand rhs = node.rhs().asmValue();
compileBinaryOp(node.operator(), node.type(), rhs);
save(node.type(), reg("ax"), mem(reg("cx")));
}
else if (node.rhs().isConstantAddress()) {
// ANY += var
compileLHS(node.lhs());
push(reg("ax"));
load(node.type(), mem(reg("ax")), reg("ax"));
loadVariable(node.rhs(), reg("cx"));
compileBinaryOp(node.operator(), node.type(), reg("cx"));
pop(reg("cx"));
save(node.type(), reg("ax"), mem(reg("cx")));
}
else {
// ANY += ANY
// no optimization
compile(node.rhs());
push(reg("ax"));
compileLHS(node.lhs());
Register lhs = doesSpillDX(node.operator()) ? reg("si") : reg("dx");
mov(reg("ax"), lhs);
load(node.type(), mem(lhs), reg("ax"));
pop(reg("cx"));
compileBinaryOp(node.operator(), node.type(), reg("cx"));
save(node.type(), reg("ax"), mem(lhs));
}
return null;
}
// #@@}
// #@@range/compile_Aref{
public ArefNode visit(ArefNode node) {
compileLHS(node);
load(node.type(), mem(reg("ax")), reg("ax"));
return null;
}
// #@@}
// #@@range/compile_Member{
public MemberNode visit(MemberNode node) {
compileLHS(node.expr());
if (node.shouldEvaluatedToAddress()) {
add(imm(node.offset()), reg("ax"));
}
else {
load(node.type(), mem(node.offset(), reg("ax")), reg("ax"));
}
return null;
}
// #@@}
// #@@range/compile_PtrMember{
public PtrMemberNode visit(PtrMemberNode node) {
compile(node.expr());
if (node.shouldEvaluatedToAddress()) {
add(imm(node.offset()), reg("ax"));
}
else {
load(node.type(), mem(node.offset(), reg("ax")), reg("ax"));
}
return null;
}
// #@@}
// #@@range/compile_Dereference{
public DereferenceNode visit(DereferenceNode node) {
compile(node.expr());
load(node.type(), mem(reg("ax")), reg("ax"));
return null;
}
// #@@}
// #@@range/compile_Address{
public AddressNode visit(AddressNode node) {
compileLHS(node.expr());
return null;
}
// #@@}
// #@@range/compileLHS{
protected void compileLHS(Node node) {
if (options.isVerboseAsm()) {
comment("compileLHS: " + node.getClass().getSimpleName() + " {");
as.indentComment();
}
node.acceptLHS(this);
if (options.isVerboseAsm()) {
as.unindentComment();
comment("compileLHS: }");
}
}
// #@@}
// #@@range/compileLHS_Variable{
public void visitLHS(VariableNode node) {
loadVariableAddress(node, reg("ax"));
}
// #@@}
// #@@range/compileLHS_Aref{
public void visitLHS(ArefNode node) {
compileArrayIndex(node);
imul(imm(node.elementSize()), reg("ax"));
push(reg("ax"));
compile(node.baseExpr());
pop(reg("cx"));
add(reg("cx"), reg("ax"));
}
// #@@}
// #@@range/compileArrayIndex{
protected void compileArrayIndex(ArefNode node) {
compile(node.index());
if (node.isMultiDimension()) {
push(reg("ax"));
compileArrayIndex((ArefNode)node.expr());
imul(imm(node.length()), reg("ax"));
pop(reg("cx"));
add(reg("cx"), reg("ax"));
}
}
// #@@}
// #@@range/compileLHS_Member{
public void visitLHS(MemberNode node) {
compileLHS(node.expr());
add(imm(node.offset()), reg("ax"));
}
// #@@}
// #@@range/compileLHS_Dereference{
public void visitLHS(DereferenceNode node) {
compile(node.expr());
}
// #@@}
// #@@range/compileLHS_PtrMember{
public void visitLHS(PtrMemberNode node) {
compile(node.expr());
add(imm(node.offset()), reg("ax"));
}
// #@@}
//
// Utilities
//
/**
* Loads constant value. You must check node by #isConstant
* before calling this method.
*/
// #@@range/loadConstant{
protected void loadConstant(ExprNode node, Register reg) {
if (node.asmValue() != null) {
mov(node.asmValue(), reg);
}
else if (node.memref() != null) {
lea(node.memref(), reg);
}
else {
throw new Error("must not happen: constant has no asm value");
}
}
// #@@}
/**
* Loads variable value to the register. You must check node
* by #isConstantAddress before calling this method.
*/
// #@@range/loadVariable{
protected void loadVariable(ExprNode node, Register dest) {
if (node.shouldEvaluatedToAddress()) {
// "int[4] a; a" implies &a
// "x = puts" implies &puts
loadVariableAddress(node, dest);
}
else if (node.memref() == null) {
mov(node.address(), dest);
load(node.type(), mem(dest), dest);
}
else {
// regular variable
load(node.type(), node.memref(), dest);
}
}
// #@@}
/**
* Loads an address of the variable to the register.
* You must check node by #isConstantAddress before
* calling this method.
*/
// #@@range/loadVariableAddress{
protected void loadVariableAddress(ExprNode node, Register dest) {
if (node.address() != null) {
mov(node.address(), dest);
}
else {
lea(node.memref(), dest);
}
}
// #@@}
//
// x86 assembly DSL
//
// #@@range/dsl_regs{
protected Register bp() { return reg("bp"); }
protected Register sp() { return reg("sp"); }
protected Register al() { return new Register(1, "ax"); }
protected Register cl() { return new Register(1, "cx"); }
// #@@}
// #@@range/reg{
protected Register reg(String name, Type type) {
return new Register(name).forType(type);
}
protected Register reg(String name) {
return new Register(name);
}
// #@@}
// #@@range/mem{
protected DirectMemoryReference mem(Symbol sym) {
return new DirectMemoryReference(sym);
}
protected IndirectMemoryReference mem(Register reg) {
return new IndirectMemoryReference(0, reg);
}
protected IndirectMemoryReference mem(long offset, Register reg) {
return new IndirectMemoryReference(offset, reg);
}
protected IndirectMemoryReference mem(Symbol offset, Register reg) {
return new IndirectMemoryReference(offset, reg);
}
// #@@}
// #@@range/imm{
protected ImmediateValue imm(long n) {
return new ImmediateValue(n);
}
protected ImmediateValue imm(Symbol sym) {
return new ImmediateValue(sym);
}
protected ImmediateValue imm(Literal lit) {
return new ImmediateValue(lit);
}
// #@@}
// #@@range/load{
protected void load(Type type, MemoryReference mem, Register reg) {
switch ((int)type.size()) {
case 1:
if (type.isSigned()) { // signed char
movsbl(mem, reg);
} else { // unsigned char
movzbl(mem, reg);
}
break;
case 2:
if (type.isSigned()) { // signed short
movswl(mem, reg);
} else { // unsigned short
movzwl(mem, reg);
}
break;
default: // int, long, long_long
mov(type, mem, reg.forType(type));
break;
}
}
// #@@}
// #@@range/save{
protected void save(Type type, Register reg, MemoryReference mem) {
mov(type, reg.forType(type), mem);
}
// #@@}
// #@@range/dsl_directives{
public void comment(String str) { as.comment(str); }
public void _file(String name) { as._file(name); }
public void _text() { as._text(); }
public void _data() { as._data(); }
public void _section(String name) { as._section(name); }
// #@@}
public void _section(String name, String flags, String type, String group, String linkage) { as._section(name, flags, type, group, linkage); }
public void _globl(Symbol sym) { as._globl(sym); }
public void _local(Symbol sym) { as._local(sym); }
public void _hidden(Symbol sym) { as._hidden(sym); }
public void _comm(Symbol sym, long sz, long a) { as._comm(sym, sz, a); }
public void _align(long n) { as._align(n); }
public void _type(Symbol sym, String type) { as._type(sym, type); }
public void _size(Symbol sym, long size) { as._size(sym, size); }
public void _size(Symbol sym, String size) { as._size(sym, size); }
public void _byte(long n) { as._byte(new IntegerLiteral(n)); }
public void _value(long n) { as._value(new IntegerLiteral(n)); }
public void _long(long n) { as._long(new IntegerLiteral(n)); }
public void _long(Symbol sym) { as._long(sym); }
public void _quad(long n) { as._quad(new IntegerLiteral(n)); }
public void _quad(Symbol sym) { as._quad(sym); }
public void _string(String str) { as._string(str); }
public void label(Symbol sym) { as.label(sym); }
public void label(Label label) { as.label(label); }
public void jmp(Label label) { as.jmp(label); }
public void jz(Label label) { as.jz(label); }
public void jnz(Label label) { as.jnz(label); }
public void je(Label label) { as.je(label); }
public void jne(Label label) { as.jne(label); }
public void cmp(Type t, AsmOperand a, Register b) { as.cmp(t, a, b); }
public void sete(Register reg) { as.sete(reg); }
public void setne(Register reg) { as.setne(reg); }
public void seta(Register reg) { as.seta(reg); }
public void setae(Register reg) { as.setae(reg); }
public void setb(Register reg) { as.setb(reg); }
public void setbe(Register reg) { as.setbe(reg); }
public void setg(Register reg) { as.setg(reg); }
public void setge(Register reg) { as.setge(reg); }
public void setl(Register reg) { as.setl(reg); }
public void setle(Register reg) { as.setle(reg); }
public void test(Type type, Register a, Register b) { as.test(type, a, b); }
protected void truePush(Register reg) { as.push(reg); }
protected void truePop(Register reg) { as.pop(reg); }
public void call(Symbol sym) { as.call(sym); }
public void callAbsolute(Register reg) { as.callAbsolute(reg); }
public void ret() { as.ret(); }
// #@@range/dsl_ops2{
public void mov(AsmOperand src, AsmOperand dest) { as.mov(src, dest); }
public void mov(Type type, AsmOperand src, AsmOperand dest) { as.mov(type, src, dest); }
public void movsx(Type from, Type to, AsmOperand src, AsmOperand dest) { as.movsx(from, to, src, dest); }
public void movzx(Type from, Type to, AsmOperand src, AsmOperand dest) { as.movzx(from, to, src, dest); }
// #@@}
public void movsbl(AsmOperand src, AsmOperand dest) { as.movsbl(src, dest); }
public void movswl(AsmOperand src, AsmOperand dest) { as.movswl(src, dest); }
public void movzb(Type type, AsmOperand src, AsmOperand dest) { as.movzb(type, src, dest); }
public void movzbl(AsmOperand src, AsmOperand dest) { as.movzbl(src, dest); }
public void movzwl(AsmOperand src, AsmOperand dest) { as.movzwl(src, dest); }
public void lea(AsmOperand src, AsmOperand dest) { as.lea(src, dest); }
public void lea(Type type, AsmOperand src, AsmOperand dest) { as.lea(type, src, dest); }
public void neg(Type type, Register reg) { as.neg(type, reg); }
public void inc(Type type, AsmOperand reg) { as.inc(type, reg); }
public void dec(Type type, AsmOperand reg) { as.dec(type, reg); }
// #@@range/dsl_ops1{
public void add(AsmOperand diff, AsmOperand base) { as.add(diff, base); }
public void add(Type type, AsmOperand diff, AsmOperand base) { as.add(type, diff, base); }
public void sub(AsmOperand diff, AsmOperand base) { as.sub(diff, base); }
public void sub(Type type, AsmOperand diff, AsmOperand base) { as.sub(type, diff, base); }
public void imul(AsmOperand m, Register base) { as.imul(m, base); }
public void imul(Type type, AsmOperand m, Register base) { as.imul(type, m, base); }
public void cltd() { as.cltd(); }
public void div(Type type, Register base) { as.div(type, base); }
public void idiv(Type type, Register base) { as.idiv(type, base); }
// #@@}
public void not(Type type, Register reg) { as.not(type, reg); }
public void and(Type type, AsmOperand bits, Register base) { as.and(type, bits, base); }
public void or(Type type, AsmOperand bits, Register base) { as.or(type, bits, base); }
public void xor(Type type, AsmOperand bits, Register base) { as.xor(type, bits, base); }
public void sar(Type type, Register n, Register base) { as.sar(type, n, base); }
public void sal(Type type, Register n, Register base) { as.sal(type, n, base); }
public void shr(Type type, Register n, Register base) { as.shr(type, n, base); }
}