/*

* Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

* e32\nklib\x86\vchelp.cpp

*

*/

#ifndef __NAKED__

#define __NAKED__	__declspec(naked)

#endif

#include <e32def.h>

#pragma warning ( disable : 4414 )  // short jump to function converted to near

extern "C" {

__NAKED__ void _allmul()

//

// Multiply two 64 bit integers returning a 64 bit result

// On entry:

//		[esp+4], [esp+8] = arg 1

//		[esp+12], [esp+16] = arg 1

// Return result in edx:eax

// Remove arguments from stack

//

	{

	_asm mov eax, [esp+4]			// eax = low1

	_asm mul dword ptr [esp+16]		// edx:eax = low1*high2

	_asm mov ecx, eax				// keep low 32 bits of product

	_asm mov eax, [esp+8]			// eax = high1

	_asm mul dword ptr [esp+12]		// edx:eax = high1*low2

	_asm add ecx, eax				// accumulate low 32 bits of product

	_asm mov eax, [esp+4]			// eax = low1

	_asm mul dword ptr [esp+12]		// edx:eax = low1*low2

	_asm add edx, ecx				// add cross terms to high 32 bits

	_asm ret 16

	}

void udiv64_divby0()

	{

	_asm int 0						// division by zero exception

	_asm ret

	}

__NAKED__ void UDiv64()

	{

	// unsigned divide edx:eax by edi:esi

	// quotient in ebx:eax, remainder in edi:edx

	// ecx, ebp, esi also modified

	_asm test edi, edi

	_asm jnz short UDiv64a				// branch if divisor >= 2^32

	_asm test esi, esi

//	_ASM_j(z,DivisionByZero)			// if divisor=0, branch to error routine

	_asm jz udiv64_divby0

	_asm mov ebx, eax					// ebx=dividend low

	_asm mov eax, edx					// eax=dividend high

	_asm xor edx, edx					// edx=0

	_asm div esi						// quotient high now in eax

	_asm xchg eax, ebx					// quotient high in ebx, dividend low in eax

	_asm div esi						// quotient now in ebx:eax, remainder in edi:edx

	_asm ret

	UDiv64e:

	_asm xor eax, eax					// set result to 0xFFFFFFFF

	_asm dec eax

	_asm jmp short UDiv64f

	UDiv64a:

	_asm js short UDiv64b				// skip if divisor msb set

	_asm bsr ecx, edi					// ecx=bit number of divisor msb - 32

	_asm inc cl

	_asm push edi						// save divisor high

	_asm push esi						// save divisor low

	_asm shrd esi, edi, cl				// shift divisor right so that msb is bit 31

	_asm mov ebx, edx					// dividend into ebx:ebp

	_asm mov ebp, eax

	_asm shrd eax, edx, cl				// shift dividend right same number of bits

	_asm shr edx, cl

	_asm cmp edx, esi					// check if approx quotient will be 2^32

	_asm jae short UDiv64e				// if so, true result must be 0xFFFFFFFF

	_asm div esi						// approximate quotient now in eax

	UDiv64f:

	_asm mov ecx, eax					// into ecx

	_asm mul edi						// multiply approx. quotient by divisor high

	_asm mov esi, eax					// ls dword into esi, ms into edi

	_asm mov edi, edx

	_asm mov eax, ecx					// approx. quotient into eax

	_asm mul dword ptr [esp]			// multiply approx. quotient by divisor low

	_asm add edx, esi					// edi:edx:eax now equals approx. quotient * divisor

	_asm adc edi, 0

	_asm xor esi, esi

	_asm sub ebp, eax					// subtract dividend - approx. quotient *divisor

	_asm sbb ebx, edx

	_asm sbb esi, edi

	_asm jnc short UDiv64c				// if no borrow, result OK

	_asm dec ecx						// else result is one too big

	_asm add ebp, [esp]					// and add divisor to get correct remainder

	_asm adc ebx, [esp+4]

	UDiv64c:

	_asm mov eax, ecx					// result into ebx:eax, remainder into edi:edx

	_asm mov edi, ebx

	_asm mov edx, ebp

	_asm xor ebx, ebx

	_asm add esp, 8						// remove temporary values from stack

	_asm ret

	UDiv64b:

	_asm mov ebx, 1

	_asm sub eax, esi					// subtract divisor from dividend

	_asm sbb edx, edi

	_asm jnc short UDiv64d				// if no borrow, result=1, remainder in edx:eax

	_asm add eax, esi					// else add back

	_asm adc edx, edi

	_asm dec ebx						// and decrement quotient

	UDiv64d:

	_asm mov edi, edx					// remainder into edi:edx

	_asm mov edx, eax

	_asm mov eax, ebx					// result in ebx:eax

	_asm xor ebx, ebx

	_asm ret

	}

__NAKED__ void _aulldiv()

//

// Divide two 64 bit unsigned integers returning a 64 bit result

// On entry:

//		[esp+4], [esp+8] = dividend

//		[esp+12], [esp+16] = divisor

// Return result in edx:eax

// Remove arguments from stack

//

	{

	_asm push ebp

	_asm push edi

	_asm push esi

	_asm push ebx

	_asm mov eax, [esp+20]

	_asm mov edx, [esp+24]

	_asm mov esi, [esp+28]

	_asm mov edi, [esp+32]

	_asm call UDiv64

	_asm mov edx, ebx

	_asm pop ebx

	_asm pop esi

	_asm pop edi

	_asm pop ebp

	_asm ret 16

	}

__NAKED__ void _alldiv()

//

// Divide two 64 bit signed integers returning a 64 bit result

// On entry:

//		[esp+4], [esp+8] = dividend

//		[esp+12], [esp+16] = divisor

// Return result in edx:eax

// Remove arguments from stack

//

	{

	_asm push ebp

	_asm push edi

	_asm push esi

	_asm push ebx

	_asm mov eax, [esp+20]

	_asm mov edx, [esp+24]

	_asm mov esi, [esp+28]

	_asm mov edi, [esp+32]

	_asm test edx, edx

	_asm jns dividend_nonnegative

	_asm neg edx

	_asm neg eax

	_asm sbb edx, 0

	dividend_nonnegative:

	_asm test edi, edi

	_asm jns divisor_nonnegative

	_asm neg edi

	_asm neg esi

	_asm sbb edi, 0

	divisor_nonnegative:

	_asm call UDiv64

	_asm mov ecx, [esp+24]

	_asm mov edx, ebx

	_asm xor ecx, [esp+32]

	_asm jns quotient_nonnegative

	_asm neg edx

	_asm neg eax

	_asm sbb edx, 0

	quotient_nonnegative:

	_asm pop ebx

	_asm pop esi

	_asm pop edi

	_asm pop ebp

	_asm ret 16

	}

__NAKED__ void _aullrem()

//

// Divide two 64 bit unsigned integers and return 64 bit remainder

// On entry:

//		[esp+4], [esp+8] = dividend

//		[esp+12], [esp+16] = divisor

// Return result in edx:eax

// Remove arguments from stack

//

	{

	_asm push ebp

	_asm push edi

	_asm push esi

	_asm push ebx

	_asm mov eax, [esp+20]

	_asm mov edx, [esp+24]

	_asm mov esi, [esp+28]

	_asm mov edi, [esp+32]

	_asm call UDiv64

	_asm mov eax, edx

	_asm mov edx, edi

	_asm pop ebx

	_asm pop esi

	_asm pop edi

	_asm pop ebp

	_asm ret 16

	}

__NAKED__ void _allrem()

//

// Divide two 64 bit signed integers and return 64 bit remainder

// On entry:

//		[esp+4], [esp+8] = dividend

//		[esp+12], [esp+16] = divisor

// Return result in edx:eax

// Remove arguments from stack

//

	{

	_asm push ebp

	_asm push edi

	_asm push esi

	_asm push ebx

	_asm mov eax, [esp+20]

	_asm mov edx, [esp+24]

	_asm mov esi, [esp+28]

	_asm mov edi, [esp+32]

	_asm test edx, edx

	_asm jns dividend_nonnegative

	_asm neg edx

	_asm neg eax

	_asm sbb edx, 0

	dividend_nonnegative:

	_asm test edi, edi

	_asm jns divisor_nonnegative

	_asm neg edi

	_asm neg esi

	_asm sbb edi, 0

	divisor_nonnegative:

	_asm call UDiv64

	_asm mov eax, edx

	_asm mov edx, edi

	_asm cmp dword ptr [esp+24], 0

	_asm jns rem_nonnegative

	_asm neg edx

	_asm neg eax

	_asm sbb edx, 0

	rem_nonnegative:

	_asm pop ebx

	_asm pop esi

	_asm pop edi

	_asm pop ebp

	_asm ret 16

	}

__NAKED__ void _allshr()

//

// Arithmetic shift right EDX:EAX by ECX

//

	{

	_asm cmp ecx, 64

	_asm jae asr_count_ge_64

	_asm cmp cl, 32

	_asm jae asr_count_ge_32

	_asm shrd eax, edx, cl

	_asm sar edx, cl

	_asm ret

	asr_count_ge_32:

	_asm sub cl, 32

	_asm mov eax, edx

	_asm cdq

	_asm sar eax, cl

	_asm ret

	asr_count_ge_64:

	_asm sar edx, 32

	_asm mov eax, edx

	_asm ret

	}

__NAKED__ void _allshl()

//

// shift left EDX:EAX by ECX

//

	{

	_asm cmp ecx, 64

	_asm jae lsl_count_ge_64

	_asm cmp cl, 32

	_asm jae lsl_count_ge_32

	_asm shld edx, eax, cl

	_asm shl eax, cl

	_asm ret

	lsl_count_ge_32:

	_asm sub cl, 32

	_asm mov edx, eax

	_asm xor eax, eax

	_asm shl edx, cl

	_asm ret

	lsl_count_ge_64:

	_asm xor edx, edx

	_asm xor eax, eax

	_asm ret

	}

__NAKED__ void _aullshr()

//

// Logical shift right EDX:EAX by ECX

//

	{

	_asm cmp ecx, 64

	_asm jae lsr_count_ge_64

	_asm cmp cl, 32

	_asm jae lsr_count_ge_32

	_asm shrd eax, edx, cl

	_asm shr edx, cl

	_asm ret

	lsr_count_ge_32:

	_asm sub cl, 32

	_asm mov eax, edx

	_asm xor edx, edx

	_asm shr eax, cl

	_asm ret

	lsr_count_ge_64:

	_asm xor edx, edx

	_asm xor eax, eax

	_asm ret

	}

}