support reset

sample/test0.cpp

@@ -94,6 +94,37 @@ public:
 	int (*get() const)(const char *) { return (int (*)(const char *))(const void*)getCode(); }
 };
 
+struct Reset : public Xbyak::CodeGenerator {
+	void init(int n)
+	{
+		xor(eax, eax);
+		mov(ecx, n);
+		test(ecx, ecx);
+		jnz("@f");
+		ret();
+	L("@@");
+		for (int i = 0; i < 10 - n; i++) {
+			add(eax, ecx);
+		}
+		sub(ecx, 1);
+		jnz("@b");
+		ret();
+	}
+};
+
+void testReset()
+{
+	puts("tsetReset");
+	Reset code;
+	int (*f)(int) = (int (*)(int))code.getCode();
+	for (int i = 0; i < 10; i++) {
+		code.init(i);
+		int v = f(i);
+		printf("%d %d\n", i, v);
+		code.reset();
+	}
+}
+
 int main()
 {
 	try {
@@ -137,6 +168,7 @@ int main()
 			CodeArray::protect(p, codeSize, false);
 		}
 		puts("OK");
+		testReset();
 	} catch (Xbyak::Error err) {
 		printf("ERR:%s(%d)\n", Xbyak::ConvertErrorToString(err), err);
 	} catch (...) {

xbyak/xbyak.h

@@ -542,6 +542,11 @@ public:
 		if (type_ != FIXED_BUF) throw ERR_CODE_ISNOT_COPYABLE;
 		for (size_t i = 0; i < size_; i++) top_[i] = rhs.top_[i];
 	}
+	void resetSize()
+	{
+		size_ = 0;
+		addrInfoList_.clear();
+	}
 	void db(int code)
 	{
 		if (size_ >= maxSize_) {
@@ -795,6 +800,16 @@ public:
 		, localCount_(0)
 	{
 	}
+	void reset()
+	{
+		base_ = 0;
+		anonymousCount_ = 0;
+		stackPos_ = 1;
+		usedCount_ = 0;
+		localCount_ = 0;
+		definedList_.clear();
+		undefinedList_.clear();
+	}
 	void enterLocal()
 	{
 		if (stackPos_ == maxStack) throw ERR_OVER_LOCAL_LABEL;
@@ -1603,6 +1618,12 @@ public:
 	{
 		label_.set(this);
 	}
+	void reset()
+	{
+		resetSize();
+		label_.reset();
+		label_.set(this);
+	}
 	bool hasUndefinedLabel() const { return label_.hasUndefinedLabel(); }
 	/*
 		call ready() to complete generating code on AutoGrow