193 lines
5.7 KiB
C
193 lines
5.7 KiB
C
|
//==========================================================================;
|
||
|
|
//
|
||
|
|
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
|
||
|
|
// KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
|
||
|
|
// IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
|
||
|
|
// PURPOSE.
|
||
|
|
//
|
||
|
|
// Copyright (c) 1993, 1994 Microsoft Corporation. All Rights Reserved.
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// muldiv32.c
|
||
|
|
//
|
||
|
|
// Description: math routines for 32 bit signed and unsiged numbers.
|
||
|
|
//
|
||
|
|
// MulDiv32(a,b,c) = (a * b) / c (round down, signed)
|
||
|
|
//
|
||
|
|
// MulDivRD(a,b,c) = (a * b) / c (round down, unsigned)
|
||
|
|
// MulDivRN(a,b,c) = (a * b + c/2) / c (round nearest, unsigned)
|
||
|
|
// MulDivRU(a,b,c) = (a * b + c-1) / c (round up, unsigned)
|
||
|
|
//
|
||
|
|
// History:
|
||
|
|
// 9/21/93 cjp [curtisp]
|
||
|
|
// 9/23/93 stl [toddla]
|
||
|
|
//
|
||
|
|
//==========================================================================;
|
||
|
|
|
||
|
|
#include <windows.h>
|
||
|
|
#include "muldiv32.h"
|
||
|
|
|
||
|
|
#if !defined(WIN32) && !defined(_WIN32)
|
||
|
|
|
||
|
|
#pragma warning(disable:4035 4704)
|
||
|
|
|
||
|
|
#define ASM66 _asm _emit 0x66 _asm
|
||
|
|
#define DB _asm _emit
|
||
|
|
|
||
|
|
#define EAX_TO_DXAX \
|
||
|
|
DB 0x66 \
|
||
|
|
DB 0x0F \
|
||
|
|
DB 0xA4 \
|
||
|
|
DB 0xC2 \
|
||
|
|
DB 0x10
|
||
|
|
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// LONG MulDiv32(a,b,c) = (a * b) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
LONG FAR PASCAL MulDiv32(LONG a,LONG b,LONG c)
|
||
|
|
{
|
||
|
|
ASM66 mov ax,word ptr a // mov eax, a
|
||
|
|
ASM66 mov bx,word ptr b // mov ebx, b
|
||
|
|
ASM66 mov cx,word ptr c // mov ecx, c
|
||
|
|
ASM66 imul bx // imul ebx
|
||
|
|
ASM66 idiv cx // idiv ecx
|
||
|
|
EAX_TO_DXAX
|
||
|
|
|
||
|
|
} // MulDiv32()
|
||
|
|
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// DWORD MulDivRN(a,b,c) = (a * b + c/2) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
DWORD FAR PASCAL MulDivRN(DWORD a,DWORD b,DWORD c)
|
||
|
|
{
|
||
|
|
ASM66 mov ax,word ptr a // mov eax, a
|
||
|
|
ASM66 mov bx,word ptr b // mov ebx, b
|
||
|
|
ASM66 mov cx,word ptr c // mov ecx, c
|
||
|
|
ASM66 mul bx // mul ebx
|
||
|
|
ASM66 mov bx,cx // mov ebx,ecx
|
||
|
|
ASM66 shr bx,1 // sar ebx,1
|
||
|
|
ASM66 add ax,bx // add eax,ebx
|
||
|
|
ASM66 adc dx,0 // adc edx,0
|
||
|
|
ASM66 div cx // div ecx
|
||
|
|
EAX_TO_DXAX
|
||
|
|
|
||
|
|
} // MulDiv32()
|
||
|
|
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// DWORD MulDivRU(a,b,c) = (a * b + c-1) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
DWORD FAR PASCAL MulDivRU(DWORD a,DWORD b,DWORD c)
|
||
|
|
{
|
||
|
|
ASM66 mov ax,word ptr a // mov eax, a
|
||
|
|
ASM66 mov bx,word ptr b // mov ebx, b
|
||
|
|
ASM66 mov cx,word ptr c // mov ecx, c
|
||
|
|
ASM66 mul bx // mul ebx
|
||
|
|
ASM66 mov bx,cx // mov ebx,ecx
|
||
|
|
ASM66 dec bx // dec ebx
|
||
|
|
ASM66 add ax,bx // add eax,ebx
|
||
|
|
ASM66 adc dx,0 // adc edx,0
|
||
|
|
ASM66 div cx // div ecx
|
||
|
|
EAX_TO_DXAX
|
||
|
|
|
||
|
|
} // MulDivRU32()
|
||
|
|
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// DWORD MulDivRD(a,b,c) = (a * b) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
DWORD FAR PASCAL MulDivRD(DWORD a,DWORD b,DWORD c)
|
||
|
|
{
|
||
|
|
ASM66 mov ax,word ptr a // mov eax, a
|
||
|
|
ASM66 mov bx,word ptr b // mov ebx, b
|
||
|
|
ASM66 mov cx,word ptr c // mov ecx, c
|
||
|
|
ASM66 mul bx // mul ebx
|
||
|
|
ASM66 div cx // div ecx
|
||
|
|
EAX_TO_DXAX
|
||
|
|
|
||
|
|
} // MulDivRD32()
|
||
|
|
|
||
|
|
#pragma warning(default:4035 4704)
|
||
|
|
|
||
|
|
#else // WIN32
|
||
|
|
|
||
|
|
#include <largeint.h>
|
||
|
|
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// LONG MulDiv32(a,b,c) = (a * b) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
LONG FAR PASCAL MulDiv32(LONG a,LONG b,LONG c)
|
||
|
|
{
|
||
|
|
LARGE_INTEGER lRemain;
|
||
|
|
|
||
|
|
return LargeIntegerDivide(
|
||
|
|
EnlargedIntegerMultiply(a,b),
|
||
|
|
ConvertLongToLargeInteger(c),
|
||
|
|
&lRemain).LowPart;
|
||
|
|
|
||
|
|
} // MulDiv32()
|
||
|
|
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// DWORD MulDivRD(a,b,c) = (a * b) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
DWORD FAR PASCAL MulDivRD(DWORD a,DWORD b,DWORD c)
|
||
|
|
{
|
||
|
|
return ExtendedLargeIntegerDivide(
|
||
|
|
EnlargedUnsignedMultiply(a,b), c, &a).LowPart;
|
||
|
|
|
||
|
|
} // MulDivRD()
|
||
|
|
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// DWORD MulDivRU(a,b,c) = (a * b + c-1) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
DWORD FAR PASCAL MulDivRU(DWORD a,DWORD b,DWORD c)
|
||
|
|
{
|
||
|
|
return ExtendedLargeIntegerDivide(
|
||
|
|
LargeIntegerAdd(
|
||
|
|
EnlargedUnsignedMultiply(a,b),
|
||
|
|
ConvertUlongToLargeInteger(c-1)),
|
||
|
|
c,&a).LowPart;
|
||
|
|
|
||
|
|
} // MulDivRU()
|
||
|
|
|
||
|
|
#if 0 // we use Win32 GDI MulDiv function, not this.
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
//
|
||
|
|
// DWORD MulDivRN(a,b,c) = (a * b + c/2) / c
|
||
|
|
//
|
||
|
|
//--------------------------------------------------------------------------;
|
||
|
|
|
||
|
|
DWORD FAR PASCAL MulDivRN(DWORD a,DWORD b,DWORD c)
|
||
|
|
{
|
||
|
|
return ExtendedLargeIntegerDivide(
|
||
|
|
LargeIntegerAdd(
|
||
|
|
EnlargedUnsignedMultiply(a,b),
|
||
|
|
ConvertUlongToLargeInteger(c/2)),
|
||
|
|
c,&a).LowPart;
|
||
|
|
|
||
|
|
} // MulDivRN()
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#endif // WIN32
|