// This is the stubbed out runtime for D.

// It is magical and full of nondescriptive mystical creatures.

module kernel.core.dstubs;

// some utility functions and routines for the runtime
import kernel.runtime.util;

// for printing out runtime errors
import kernel.core.kprintf;

// magical gcc business (BEWARE THE MAGICAL EMPTY FILE!!!)
static import gcc.builtins;

extern(C)
{

alias gcc.builtins.__builtin_alloca alloca;

private
{
	struct Array
	{
		size_t length;
		byte *data;
	}

	struct aaA
	{
		aaA *left;
		aaA *right;
		hash_t hash;
		/* key	 */
		/* value */
	}

	struct BB
	{
		aaA*[] b;
		size_t nodes;
	}

	struct AA
	{
		BB* a;
	}

	alias long ArrayRet_t;
	extern(D) typedef int delegate(void *) aa_dg_t;
	extern(D) typedef int delegate(void *, void *) aa_dg2_t;
	extern(D) typedef int delegate(void *) array_dg_t;
	extern(D) typedef int delegate(void *, void *) array_dg2_t;

	enum BlkAttr : uint
	{
		FINALIZE = 0b0000_0001,
		NO_SCAN  = 0b0000_0010,
		NO_MOVE  = 0b0000_0100,
		ALL_BITS = 0b1111_1111
	}

	template Stub(char[] signature)
	{
		const char[] Stub = signature ~ " { assert(false, \"Undefined runtime stub executed: " ~ signature ~ "\"); }";
	}
}

/**************************************************
 Random stubs (they'll go somewhere eventually)
**************************************************/

mixin(Stub!("void abort()"));
mixin(Stub!("bool rt_isHalting()"));
mixin(Stub!("bool runModuleUnitTests()"));
mixin(Stub!("void _d_monitordelete(Object h, bool det = true)"));

/******************************************
 * Given a pointer:
 *		If it is an Object, return that Object.
 *		If it is an interface, return the Object implementing the interface.
 *		If it is null, return null.
 *		Else, undefined crash
 */

Object _d_toObject(void* p)
{	Object o;

	if (p)
	{
		o = cast(Object)p;
		ClassInfo oc = o.classinfo;
		Interface *pi = **cast(Interface ***)p;

		/* Interface.offset lines up with ClassInfo.name.ptr,
		 * so we rely on pointers never being less than 64K,
		 * and Objects never being greater.
		 */
		if (pi.offset < 0x10000)
		{
			//printf("\tpi.offset = %d\n", pi.offset);
			o = cast(Object)(p - pi.offset);
		}
	}
	return o;
}


/*************************************
 * Attempts to cast Object o to class c.
 * Returns o if successful, null if not.
 */

Object _d_interface_cast(void* p, ClassInfo c)
{	Object o;

	//printf("_d_interface_cast(p = %p, c = '%.*s')\n", p, c.name);
	if (p)
	{
		Interface *pi = **cast(Interface ***)p;

		//printf("\tpi.offset = %d\n", pi.offset);
		o = cast(Object)(p - pi.offset);
		return _d_dynamic_cast(o, c);
	}
	return o;
}

Object _d_dynamic_cast(Object o, ClassInfo c)
{	ClassInfo oc;
	size_t offset = 0;

	//printf("_d_dynamic_cast(o = %p, c = '%.*s')\n", o, c.name);

	if (o)
	{
		oc = o.classinfo;
		if (_d_isbaseof2(oc, c, offset))
		{
			//printf("\toffset = %d\n", offset);
			o = cast(Object)(cast(void*)o + offset);
		}
		else
			o = null;
	}
	//printf("\tresult = %p\n", o);
	return o;
}

int _d_isbaseof2(ClassInfo oc, ClassInfo c, inout size_t offset)
{	int i;

	if (oc is c)
		return 1;
	do
	{
		if (oc.base is c)
			return 1;
		for (i = 0; i < oc.interfaces.length; i++)
		{
			ClassInfo ic;

			ic = oc.interfaces[i].classinfo;
			if (ic is c)
			{	offset = oc.interfaces[i].offset;
				return 1;
			}
		}
		for (i = 0; i < oc.interfaces.length; i++)
		{
			ClassInfo ic;

			ic = oc.interfaces[i].classinfo;
			if (_d_isbaseof2(ic, c, offset))
			{	offset = oc.interfaces[i].offset;
				return 1;
			}
		}
		oc = oc.base;
	} while (oc);
	return 0;
}

int _d_isbaseof(ClassInfo oc, ClassInfo c)
{	int i;

	if (oc is c)
		return 1;
	do
	{
		if (oc.base is c)
			return 1;
		for (i = 0; i < oc.interfaces.length; i++)
		{
			ClassInfo ic;

			ic = oc.interfaces[i].classinfo;
			if (ic is c || _d_isbaseof(ic, c))
				return 1;
		}
		oc = oc.base;
	} while (oc);
	return 0;
}

/*********************************
 * Find the vtbl[] associated with Interface ic.
 */

void *_d_interface_vtbl(ClassInfo ic, Object o)
{	int i;
	ClassInfo oc;

	//printf("__d_interface_vtbl(o = %p, ic = %p)\n", o, ic);

	assert(o);

	oc = o.classinfo;
	for (i = 0; i < oc.interfaces.length; i++)
	{
		ClassInfo oic;

		oic = oc.interfaces[i].classinfo;
		if (oic is ic)
		{
			return cast(void *)oc.interfaces[i].vtbl;
		}
	}
	assert(0);
}

int _d_obj_eq(Object o1, Object o2)
{
    return o1 is o2 || (o1 && o1.opEquals(o2));
}

int _d_obj_cmp(Object o1, Object o2)
{
    return o1.opCmp(o2);
}

int _d_switch_string(char[][] table, char[] ca)
{
	int low;
	int high;
	int mid;
	int c;
	char[] pca;

	low = 0;
	high = table.length;

	if (high &&
		ca.length >= table[0].length &&
		ca.length <= table[high - 1].length)
	{
		// Looking for 0 length string, which would only be at the beginning
		if (ca.length == 0)
			return 0;

		char c1 = ca[0];

		// Do binary search
		while (low < high)
		{
			mid = (low + high) >> 1;
			pca = table[mid];
			c = ca.length - pca.length;
			if (c == 0)
			{
				c = cast(ubyte)c1 - cast(ubyte)pca[0];
				if (c == 0)
				{
					c = memcmp(ca.ptr, pca.ptr, ca.length);
					if (c == 0)
					{
						return mid;
					}
				}
			}
			if (c < 0)
			{
				high = mid;
			}
			else
			{
				low = mid + 1;
			}
		}
	}

	return -1;				// not found
}

int _d_switch_ustring(wchar[][] table, wchar[] ca)
{
	int low;
	int high;
	int mid;
	int c;
	wchar[] pca;

	low = 0;
	high = table.length;

	// Do binary search
	while (low < high)
	{
		mid = (low + high) >> 1;
		pca = table[mid];
		c = ca.length - pca.length;
		if (c == 0)
		{
			c = memcmp(ca.ptr, pca.ptr, ca.length * wchar.sizeof);
			if (c == 0)
			{
				return mid;
			}
		}
		if (c < 0)
		{
			high = mid;
		}
		else
		{
			low = mid + 1;
		}
	}

	return -1;				// not found
}

int _d_switch_dstring(dchar[][] table, dchar[] ca)
{
	int low;
	int high;
	int mid;
	int c;
	dchar[] pca;

	low = 0;
	high = table.length;

	// Do binary search
	while (low < high)
	{
		mid = (low + high) >> 1;
		pca = table[mid];
		c = ca.length - pca.length;
		if (c == 0)
		{
			c = memcmp(ca.ptr, pca.ptr, ca.length * dchar.sizeof);
			if (c == 0)
			{
				return mid;
			}
		}
		if (c < 0)
		{
			high = mid;
		}
		else
		{
			low = mid + 1;
		}
	}

	return -1;				// not found
}

/**************************************************
 Lifetime stubs
**************************************************/

mixin(Stub!("Object _d_newclass(ClassInfo ci)"));
mixin(Stub!("void _d_delinterface(void** p)"));
mixin(Stub!("void _d_delclass(Object* p)"));
mixin(Stub!("Array _d_newarrayT(TypeInfo ti, size_t length)"));
mixin(Stub!("Array _d_newarrayiT(TypeInfo ti, size_t length)"));
mixin(Stub!("void[] _d_newarraymTp(TypeInfo ti, int ndims, size_t* pdim)"));
mixin(Stub!("void[] _d_newarraymiTp(TypeInfo ti, int ndims, size_t* pdim)"));
mixin(Stub!("void _d_delarray(Array *p)"));
mixin(Stub!("void _d_delmemory(void* *p)"));
mixin(Stub!("void _d_callfinalizer(void* p)"));
mixin(Stub!("void rt_finalize(void* p, bool det = true)"));
mixin(Stub!("byte[] _d_arraysetlengthT(TypeInfo ti, size_t newlength, Array *p)"));
mixin(Stub!("byte[] _d_arraysetlengthiT(TypeInfo ti, size_t newlength, Array *p)"));
mixin(Stub!("Array _d_arrayappendT(TypeInfo ti, Array *px, byte[] y)"));
mixin(Stub!("byte[] _d_arrayappendcTp(TypeInfo ti, inout byte[] x, void *argp)"));
mixin(Stub!("byte[] _d_arraycatT(TypeInfo ti, byte[] x, byte[] y)"));
mixin(Stub!("byte[] _d_arraycatnT(TypeInfo ti, uint n, ...)"));
mixin(Stub!("Array _adDupT(TypeInfo ti, Array a)"));

/**************************************************
 GC stubs
**************************************************/

mixin(Stub!("void gc_init()"));
mixin(Stub!("void gc_term()"));
mixin(Stub!("void gc_enable()"));
mixin(Stub!("void gc_disable()"));
mixin(Stub!("void gc_collect()"));
mixin(Stub!("uint gc_getAttr( void* p )"));
mixin(Stub!("uint gc_setAttr( void* p, uint a )"));
mixin(Stub!("uint gc_clrAttr( void* p, uint a )"));
mixin(Stub!("void* gc_malloc( size_t sz, uint ba = 0 )"));
mixin(Stub!("void* gc_calloc( size_t sz, uint ba = 0 )"));
mixin(Stub!("void* gc_realloc( void* p, size_t sz, uint ba = 0 )"));
mixin(Stub!("size_t gc_extend( void* p, size_t mx, size_t sz )"));
mixin(Stub!("void gc_free( void* p )"));
mixin(Stub!("size_t gc_sizeOf( void* p )"));
mixin(Stub!("void gc_addRoot( void* p )"));
mixin(Stub!("void gc_addRange( void* p, size_t sz )"));
mixin(Stub!("void gc_removeRoot( void *p )"));
mixin(Stub!("void gc_removeRange( void *p )"));
mixin(Stub!("bool onCollectResource( Object obj )"));

/**************************************************
 Exception stubs
**************************************************/

void _d_assert( char[] file, uint line )
{
    onAssertError( file, line );
}

void _d_assert_msg( char[] msg, char[] file, uint line )
{
    onAssertErrorMsg( file, line, msg );
}

void _d_array_bounds( char[] file, uint line )
{
    onArrayBoundsError( file, line );
}

void _d_switch_error( char[] file, uint line )
{
    onSwitchError( file, line );
}

private void onAssertError(char[] file, size_t line)
{
	kprintfln!("Error in {}, line {}: assertion failed.")(file, line);
	asm { l: hlt; jmp l; }
}

private void onAssertErrorMsg(char[] file, size_t line, char[] msg)
{
	kprintfln!("Error in {}, line {}: assertion failed: \"{}\"")(file, line, msg);
	asm { l: hlt; jmp l; }
}

private void onArrayBoundsError(char[] file, size_t line)
{
	kprintfln!("Error in {}, line {}: array index out of bounds.")(file, line);
	asm { l: hlt; jmp l; }
}

private void onSwitchError(char[] file, size_t line)
{
	kprintfln!("Error in {}, line {}: switch has no case or default to handle the switched-upon value.")(file, line);
	asm { l: hlt; jmp l; }
}

mixin(Stub!("void onFinalizeError( ClassInfo info, Exception ex )"));
mixin(Stub!("void onOutOfMemoryError()"));
mixin(Stub!("void onUnicodeError( char[] msg, size_t idx )"));

/**************************************************
 DEH and Unwind stubs
**************************************************/

mixin(Stub!("void _gdc_cleanupException()"));
mixin(Stub!("void _d_throw(Object obj)"));
mixin(Stub!("int __gdc_personality_v0()"));
mixin(Stub!("void _Unwind_RaiseException ()"));
mixin(Stub!("void _Unwind_ForcedUnwind ()"));
mixin(Stub!("void _Unwind_DeleteException ()"));
mixin(Stub!("void _Unwind_Resume()"));
mixin(Stub!("void _Unwind_Resume_or_Rethrow ()"));
mixin(Stub!("void _Unwind_Backtrace ()"));
mixin(Stub!("void _Unwind_GetGR ()"));
mixin(Stub!("void _Unwind_SetGR ()"));
mixin(Stub!("void _Unwind_GetIP ()"));
mixin(Stub!("void _Unwind_SetIP ()"));
mixin(Stub!("void _Unwind_GetCFA ()"));
mixin(Stub!("void *_Unwind_GetLanguageSpecificData ()"));
mixin(Stub!("void _Unwind_GetRegionStart ()"));
mixin(Stub!("void _Unwind_SjLj_RaiseException()"));
mixin(Stub!("void _Unwind_SjLj_ForcedUnwind()"));
mixin(Stub!("void _Unwind_SjLj_Resume ()"));
mixin(Stub!("void _Unwind_GetDataRelBase ()"));
mixin(Stub!("void _Unwind_GetTextRelBase ()"));
mixin(Stub!("uint size_of_encoded_value (ubyte encoding)"));
mixin(Stub!("void base_of_encoded_value ()"));
mixin(Stub!("void read_uleb128()"));
mixin(Stub!("void read_sleb128()"));
mixin(Stub!("void read_encoded_value_with_base()"));
mixin(Stub!("void read_encoded_value()"));

/**************************************************
 AA stubs
**************************************************/

mixin(Stub!("size_t _aaLen(AA aa)"));
mixin(Stub!("void *_aaGetp(AA* aa, TypeInfo keyti, size_t valuesize, void *pkey)"));
mixin(Stub!("void *_aaGetRvaluep(AA aa, TypeInfo keyti, size_t valuesize, void *pkey)"));
mixin(Stub!("void* _aaInp(AA aa, TypeInfo keyti, void *pkey)"));
mixin(Stub!("void _aaDelp(AA aa, TypeInfo keyti, void *pkey)"));
mixin(Stub!("Array _aaValues(AA aa, size_t keysize, size_t valuesize)"));
mixin(Stub!("AA _aaRehash(AA* paa, TypeInfo keyti)"));
mixin(Stub!("Array _aaKeys(AA aa, size_t keysize)"));
mixin(Stub!("int _aaApply(AA aa, size_t keysize, aa_dg_t dg)"));
mixin(Stub!("int _aaApply2(AA aa, size_t keysize, aa_dg2_t dg)"));
mixin(Stub!("BB* _d_assocarrayliteralTp(TypeInfo_AssociativeArray ti, size_t length, void *keys, void *values)"));

/**************************************************
 Array stubs
**************************************************/

mixin(Stub!("int _aApplycw1(char[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplycd1(char[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplywc1(wchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplywd1(wchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplydc1(dchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplydw1(dchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplycw2(char[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplycd2(char[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplywc2(wchar[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplywd2(wchar[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplydc2(dchar[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplydw2(dchar[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplyRcw1(char[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplyRcd1(char[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplyRwc1(wchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplyRwd1(wchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplyRdc1(dchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplyRdw1(dchar[] aa, array_dg_t dg)"));
mixin(Stub!("int _aApplyRcw2(char[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplyRcd2(char[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplyRwc2(wchar[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplyRwd2(wchar[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplyRdc2(dchar[] aa, array_dg2_t dg)"));
mixin(Stub!("int _aApplyRdw2(dchar[] aa, array_dg2_t dg)"));
mixin(Stub!("char[] _adSortChar(char[] a)"));
mixin(Stub!("wchar[] _adSortWchar(wchar[] a)"));


const ubyte[256] UTF8stride =
[
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
	2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
	3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
	4,4,4,4,4,4,4,4,5,5,5,5,6,6,0xFF,0xFF,
];

Array _adReverseChar(char[] a)
{
	if(a.length > 1)
	{
		char[6] tmp;
		char[6] tmplo;
		char* lo = a.ptr;
		char* hi = &a[length - 1];

		while (lo < hi)
		{	auto clo = *lo;
			auto chi = *hi;

			if (clo <= 0x7F && chi <= 0x7F)
			{
				*lo = chi;
				*hi = clo;
				lo++;
				hi--;
				continue;
			}

			uint stridelo = UTF8stride[clo];

			uint stridehi = 1;
			while ((chi & 0xC0) == 0x80)
			{
				chi = *--hi;
				stridehi++;
				assert(hi >= lo);
			}
			if (lo == hi)
				break;

			if (stridelo == stridehi)
			{

				memcpy(tmp.ptr, lo, stridelo);
				memcpy(lo, hi, stridelo);
				memcpy(hi, tmp.ptr, stridelo);
				lo += stridelo;
				hi--;
				continue;
			}

			/* Shift the whole array. This is woefully inefficient
			 */
			memcpy(tmp.ptr, hi, stridehi);
			memcpy(tmplo.ptr, lo, stridelo);
			memmove(lo + stridehi, lo + stridelo , (hi - lo) - stridelo);
			memcpy(lo, tmp.ptr, stridehi);
			memcpy(hi + cast(int) stridehi - cast(int) stridelo, tmplo.ptr, stridelo);

			lo += stridehi;
			hi = hi - 1 + (cast(int) stridehi - cast(int) stridelo);
		}
	}

	Array aaa = *cast(Array*)(&a);
	return aaa;
}

Array _adReverseWchar(wchar[] a)
{
	if (a.length > 1)
	{
		wchar[2] tmp;
		wchar* lo = a.ptr;
		wchar* hi = &a[length - 1];

		while (lo < hi)
		{	auto clo = *lo;
			auto chi = *hi;

			if ((clo < 0xD800 || clo > 0xDFFF) &&
				(chi < 0xD800 || chi > 0xDFFF))
			{
				*lo = chi;
				*hi = clo;
				lo++;
				hi--;
				continue;
			}

			int stridelo = 1 + (clo >= 0xD800 && clo <= 0xDBFF);

			int stridehi = 1;
			if (chi >= 0xDC00 && chi <= 0xDFFF)
			{
				chi = *--hi;
				stridehi++;
				assert(hi >= lo);
			}
			if (lo == hi)
				break;

			if (stridelo == stridehi)
			{	int stmp;

				assert(stridelo == 2);
				assert(stmp.sizeof == 2 * (*lo).sizeof);
				stmp = *cast(int*)lo;
				*cast(int*)lo = *cast(int*)hi;
				*cast(int*)hi = stmp;
				lo += stridelo;
				hi--;
				continue;
			}

			/* Shift the whole array. This is woefully inefficient
			 */
			memcpy(tmp.ptr, hi, stridehi * wchar.sizeof);
			memcpy(hi + cast(int) stridehi - cast(int) stridelo, lo, stridelo * wchar.sizeof);
			memmove(lo + stridehi, lo + stridelo , (hi - (lo + stridelo)) * wchar.sizeof);
			memcpy(lo, tmp.ptr, stridehi * wchar.sizeof);

			lo += stridehi;
			hi = hi - 1 + (cast(int) stridehi - cast(int) stridelo);
		}
	}

	Array aaa = *cast(Array*)(&a);
	return aaa;
}

int _adCmpChar(Array a1, Array a2)
{
	version (Asm86)
	{
		asm
		{	naked					;

			push	EDI 			;
			push	ESI 			;

			mov    ESI,a1+4[4+ESP]	;
			mov    EDI,a2+4[4+ESP]	;

			mov    ECX,a1[4+ESP]	;
			mov    EDX,a2[4+ESP]	;

			cmp 	ECX,EDX 		;
			jb		GotLength		;

			mov 	ECX,EDX 		;

	GotLength:
			cmp    ECX,4			;
			jb	  DoBytes			;

			// Do alignment if neither is dword aligned
			test	ESI,3			;
			jz	  Aligned			;

			test	EDI,3			;
			jz	  Aligned			;
	DoAlign:
			mov    AL,[ESI] 		; //align ESI to dword bounds
			mov    DL,[EDI] 		;

			cmp    AL,DL			;
			jnz    Unequal			;

			inc    ESI				;
			inc    EDI				;

			test	ESI,3			;

			lea    ECX,[ECX-1]		;
			jnz    DoAlign			;
	Aligned:
			mov    EAX,ECX			;

			// do multiple of 4 bytes at a time

			shr    ECX,2			;
			jz	  TryOdd			;

			repe					;
			cmpsd					;

			jnz    UnequalQuad		;

	TryOdd:
			mov    ECX,EAX			;
	DoBytes:
			// if still equal and not end of string, do up to 3 bytes slightly
			// slower.

			and    ECX,3			;
			jz	  Equal 			;

			repe					;
			cmpsb					;

			jnz    Unequal			;
	Equal:
			mov    EAX,a1[4+ESP]	;
			mov    EDX,a2[4+ESP]	;

			sub    EAX,EDX			;
			pop    ESI				;

			pop    EDI				;
			ret 					;

	UnequalQuad:
			mov    EDX,[EDI-4]		;
			mov    EAX,[ESI-4]		;

			cmp    AL,DL			;
			jnz    Unequal			;

			cmp    AH,DH			;
			jnz    Unequal			;

			shr    EAX,16			;

			shr    EDX,16			;

			cmp    AL,DL			;
			jnz    Unequal			;

			cmp    AH,DH			;
	Unequal:
			sbb    EAX,EAX			;
			pop    ESI				;

			or	   EAX,1			;
			pop    EDI				;

			ret 					;
		}
	}
	else
	{
		int len;
		int c;

		len = a1.length;
		if (a2.length < len)
			len = a2.length;
		c = memcmp(cast(char *)a1.data, cast(char *)a2.data, len);
		if (!c)
			c = cast(int)a1.length - cast(int)a2.length;
		return c;
	}
}

Array _adReverse(Array a, size_t szelem)
{
	if (a.length >= 2)
	{
		byte*	 tmp;
		byte[16] buffer;

		void* lo = a.data;
		void* hi = a.data + (a.length - 1) * szelem;

		tmp = buffer.ptr;
		if (szelem > 16)
			tmp = cast(byte*)alloca(szelem);

		for (; lo < hi; lo += szelem, hi -= szelem)
		{
			memcpy(tmp, lo,  szelem);
			memcpy(lo,	hi,  szelem);
			memcpy(hi,	tmp, szelem);
		}
	}
	return a;
}

int _adEq(Array a1, Array a2, TypeInfo ti)
{
	if(a1.length != a2.length)
		return 0;				// not equal

	auto sz = ti.tsize();
	auto p1 = a1.data;
	auto p2 = a2.data;

	if(sz == 1)
		// We should really have a ti.isPOD() check for this
		return (memcmp(p1, p2, a1.length) == 0);

	for(size_t i = 0; i < a1.length; i++)
	{
		if(!ti.equals(p1 + i * sz, p2 + i * sz))
			return 0;			// not equal
	}

	return 1;					// equal
}

int _adCmp(Array a1, Array a2, TypeInfo ti)
{
	//printf("adCmp()\n");
	auto len = a1.length;
	if (a2.length < len)
		len = a2.length;
	auto sz = ti.tsize();
	void *p1 = a1.data;
	void *p2 = a2.data;

	if (sz == 1)
	{	// We should really have a ti.isPOD() check for this
		auto c = memcmp(p1, p2, len);
		if (c)
			return c;
	}
	else
	{
		for (size_t i = 0; i < len; i++)
		{
			auto c = ti.compare(p1 + i * sz, p2 + i * sz);
			if (c)
				return c;
		}
	}
	if (a1.length == a2.length)
		return 0;
	return (a1.length > a2.length) ? 1 : -1;
}

Array _adSort(Array a, TypeInfo ti)
{
	static const uint Qsort_Threshold = 7;

	struct StackEntry {
		byte *l;
		byte *r;
	}

	size_t elem_size = ti.tsize();
	size_t qsort_limit = elem_size * Qsort_Threshold;

	static assert(ubyte.sizeof == 1);
	static assert(ubyte.max == 255);

	StackEntry[size_t.sizeof * 8] stack; // log2( size_t.max )
	StackEntry * sp = stack.ptr;
	byte* lbound = cast(byte *) a.data;
	byte* rbound = cast(byte *) a.data + a.length * elem_size;
	byte* li = void;
	byte* ri = void;

	while (1)
	{
		if (rbound - lbound > qsort_limit)
		{
			ti.swap(lbound,
				lbound + (
						  ((rbound - lbound) >>> 1) -
						  (((rbound - lbound) >>> 1) % elem_size)
						  ));

			li = lbound + elem_size;
			ri = rbound - elem_size;

			if (ti.compare(li, ri) > 0)
				ti.swap(li, ri);
			if (ti.compare(lbound, ri) > 0)
				ti.swap(lbound, ri);
			if (ti.compare(li, lbound) > 0)
				ti.swap(li, lbound);

			while (1)
			{
				do
					li += elem_size;
				while (ti.compare(li, lbound) < 0);
				do
					ri -= elem_size;
				while (ti.compare(ri, lbound) > 0);
				if (li > ri)
					break;
				ti.swap(li, ri);
			}
			ti.swap(lbound, ri);
			if (ri - lbound > rbound - li)
			{
				sp.l = lbound;
				sp.r = ri;
				lbound = li;
			}
			else
			{
				sp.l = li;
				sp.r = rbound;
				rbound = ri;
			}
			++sp;
		} else {
			// Use insertion sort
			for (ri = lbound, li = lbound + elem_size;
				 li < rbound;
				 ri = li, li += elem_size)
			{
				for ( ; ti.compare(ri, ri + elem_size) > 0;
					  ri -= elem_size)
				{
					ti.swap(ri, ri + elem_size);
					if (ri == lbound)
						break;
				}
			}
			if (sp != stack.ptr)
			{
				--sp;
				lbound = sp.l;
				rbound = sp.r;
			}
			else
				return a;
		}
	}
}

void[] _d_arraycast(size_t tsize, size_t fsize, void[] a)
{
	auto length = a.length;
	auto nbytes = length * fsize;

	if(nbytes % tsize != 0)
		throw new Exception("array cast misalignment");

	length = nbytes / tsize;
	*cast(size_t *)&a = length; // jam new length
	return a;
}

byte[] _d_arraycopy(size_t size, byte[] from, byte[] to)
{
	if(to.length != from.length)
		throw new Exception("lengths don't match for array copy");
	else if(cast(byte *)to + to.length * size <= cast(byte *)from || cast(byte *)from + from.length * size <= cast(byte *)to)
		memcpy(cast(byte *)to, cast(byte *)from, to.length * size);
	else
		throw new Exception("overlapping array copy");

	return to;
}

}