steve
/
winamp
mirror of https://github.com/WinampDesktop/winamp.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
winamp/Src/Plugins/Input/in_dshow/base/arithutil.cpp

361 lines
10 KiB
C++
Raw Blame History

//------------------------------------------------------------------------------
// File: ArithUtil.cpp
//
// Desc: DirectShow base classes - implements helper classes for building
// multimedia filters.
//
// Copyright (c) 1992-2004 Microsoft Corporation. All rights reserved.
//------------------------------------------------------------------------------
#include <streams.h>
//
// Declare function from largeint.h we need so that PPC can build
//
//
// Enlarged integer divide - 64-bits / 32-bits > 32-bits
//
#ifndef _X86_
#define LLtoU64(x) (*(unsigned __int64*)(void*)(&(x)))
__inline
ULONG
WINAPI
EnlargedUnsignedDivide (
IN ULARGE_INTEGER Dividend,
IN ULONG Divisor,
IN PULONG Remainder
)
{
// return remainder if necessary
if (Remainder != NULL)
*Remainder = (ULONG)(LLtoU64(Dividend) % Divisor);
return (ULONG)(LLtoU64(Dividend) / Divisor);
}
#else
__inline
ULONG
WINAPI
EnlargedUnsignedDivide (
IN ULARGE_INTEGER Dividend,
IN ULONG Divisor,
IN PULONG Remainder
)
{
ULONG ulResult;
_asm {
mov eax,Dividend.LowPart
mov edx,Dividend.HighPart
mov ecx,Remainder
div Divisor
or ecx,ecx
jz short label
mov [ecx],edx
label:
mov ulResult,eax
}
return ulResult;
}
#endif
/* Arithmetic functions to help with time format conversions
*/
#ifdef _M_ALPHA
// work around bug in version 12.00.8385 of the alpha compiler where
// UInt32x32To64 sign-extends its arguments (?)
#undef UInt32x32To64
#define UInt32x32To64(a, b) (((ULONGLONG)((ULONG)(a)) & 0xffffffff) * ((ULONGLONG)((ULONG)(b)) & 0xffffffff))
#endif
/* Compute (a * b + d) / c */
LONGLONG WINAPI llMulDiv(LONGLONG a, LONGLONG b, LONGLONG c, LONGLONG d)
{
/* Compute the absolute values to avoid signed arithmetic problems */
ULARGE_INTEGER ua, ub;
DWORDLONG uc;
ua.QuadPart = (DWORDLONG)(a >= 0 ? a : -a);
ub.QuadPart = (DWORDLONG)(b >= 0 ? b : -b);
uc = (DWORDLONG)(c >= 0 ? c : -c);
BOOL bSign = (a < 0) ^ (b < 0);
/* Do long multiplication */
ULARGE_INTEGER p[2];
p[0].QuadPart = UInt32x32To64(ua.LowPart, ub.LowPart);
/* This next computation cannot overflow into p[1].HighPart because
the max number we can compute here is:
(2 ** 32 - 1) * (2 ** 32 - 1) + // ua.LowPart * ub.LowPart
(2 ** 32) * (2 ** 31) * (2 ** 32 - 1) * 2 // x.LowPart * y.HighPart * 2
== 2 ** 96 - 2 ** 64 + (2 ** 64 - 2 ** 33 + 1)
== 2 ** 96 - 2 ** 33 + 1
< 2 ** 96
*/
ULARGE_INTEGER x;
x.QuadPart = UInt32x32To64(ua.LowPart, ub.HighPart) +
UInt32x32To64(ua.HighPart, ub.LowPart) +
p[0].HighPart;
p[0].HighPart = x.LowPart;
p[1].QuadPart = UInt32x32To64(ua.HighPart, ub.HighPart) + x.HighPart;
if (d != 0) {
ULARGE_INTEGER ud[2];
if (bSign) {
ud[0].QuadPart = (DWORDLONG)(-d);
if (d > 0) {
/* -d < 0 */
ud[1].QuadPart = (DWORDLONG)(LONGLONG)-1;
} else {
ud[1].QuadPart = (DWORDLONG)0;
}
} else {
ud[0].QuadPart = (DWORDLONG)d;
if (d < 0) {
ud[1].QuadPart = (DWORDLONG)(LONGLONG)-1;
} else {
ud[1].QuadPart = (DWORDLONG)0;
}
}
/* Now do extended addition */
ULARGE_INTEGER uliTotal;
/* Add ls DWORDs */
uliTotal.QuadPart = (DWORDLONG)ud[0].LowPart + p[0].LowPart;
p[0].LowPart = uliTotal.LowPart;
/* Propagate carry */
uliTotal.LowPart = uliTotal.HighPart;
uliTotal.HighPart = 0;
/* Add 2nd most ls DWORDs */
uliTotal.QuadPart += (DWORDLONG)ud[0].HighPart + p[0].HighPart;
p[0].HighPart = uliTotal.LowPart;
/* Propagate carry */
uliTotal.LowPart = uliTotal.HighPart;
uliTotal.HighPart = 0;
/* Add MS DWORDLONGs - no carry expected */
p[1].QuadPart += ud[1].QuadPart + uliTotal.QuadPart;
/* Now see if we got a sign change from the addition */
if ((LONG)p[1].HighPart < 0) {
bSign = !bSign;
/* Negate the current value (ugh!) */
p[0].QuadPart = ~p[0].QuadPart;
p[1].QuadPart = ~p[1].QuadPart;
p[0].QuadPart += 1;
p[1].QuadPart += (p[0].QuadPart == 0);
}
}
/* Now for the division */
if (c < 0) {
bSign = !bSign;
}
/* This will catch c == 0 and overflow */
if (uc <= p[1].QuadPart) {
return bSign ? (LONGLONG)0x8000000000000000 :
(LONGLONG)0x7FFFFFFFFFFFFFFF;
}
DWORDLONG ullResult;
/* Do the division */
/* If the dividend is a DWORD_LONG use the compiler */
if (p[1].QuadPart == 0) {
ullResult = p[0].QuadPart / uc;
return bSign ? -(LONGLONG)ullResult : (LONGLONG)ullResult;
}
/* If the divisor is a DWORD then its simpler */
ULARGE_INTEGER ulic;
ulic.QuadPart = uc;
if (ulic.HighPart == 0) {
ULARGE_INTEGER uliDividend;
ULARGE_INTEGER uliResult;
DWORD dwDivisor = (DWORD)uc;
// ASSERT(p[1].HighPart == 0 && p[1].LowPart < dwDivisor);
uliDividend.HighPart = p[1].LowPart;
uliDividend.LowPart = p[0].HighPart;
#ifndef USE_LARGEINT
uliResult.HighPart = (DWORD)(uliDividend.QuadPart / dwDivisor);
p[0].HighPart = (DWORD)(uliDividend.QuadPart % dwDivisor);
uliResult.LowPart = 0;
uliResult.QuadPart = p[0].QuadPart / dwDivisor + uliResult.QuadPart;
#else
/* NOTE - this routine will take exceptions if
the result does not fit in a DWORD
*/
if (uliDividend.QuadPart >= (DWORDLONG)dwDivisor) {
uliResult.HighPart = EnlargedUnsignedDivide(
uliDividend,
dwDivisor,
&p[0].HighPart);
} else {
uliResult.HighPart = 0;
}
uliResult.LowPart = EnlargedUnsignedDivide(
p[0],
dwDivisor,
NULL);
#endif
return bSign ? -(LONGLONG)uliResult.QuadPart :
(LONGLONG)uliResult.QuadPart;
}
ullResult = 0;
/* OK - do long division */
for (int i = 0; i < 64; i++) {
ullResult <<= 1;
/* Shift 128 bit p left 1 */
p[1].QuadPart <<= 1;
if ((p[0].HighPart & 0x80000000) != 0) {
p[1].LowPart++;
}
p[0].QuadPart <<= 1;
/* Compare */
if (uc <= p[1].QuadPart) {
p[1].QuadPart -= uc;
ullResult += 1;
}
}
return bSign ? - (LONGLONG)ullResult : (LONGLONG)ullResult;
}
LONGLONG WINAPI Int64x32Div32(LONGLONG a, LONG b, LONG c, LONG d)
{
ULARGE_INTEGER ua;
DWORD ub;
DWORD uc;
/* Compute the absolute values to avoid signed arithmetic problems */
ua.QuadPart = (DWORDLONG)(a >= 0 ? a : -a);
ub = (DWORD)(b >= 0 ? b : -b);
uc = (DWORD)(c >= 0 ? c : -c);
BOOL bSign = (a < 0) ^ (b < 0);
/* Do long multiplication */
ULARGE_INTEGER p0;
DWORD p1;
p0.QuadPart = UInt32x32To64(ua.LowPart, ub);
if (ua.HighPart != 0) {
ULARGE_INTEGER x;
x.QuadPart = UInt32x32To64(ua.HighPart, ub) + p0.HighPart;
p0.HighPart = x.LowPart;
p1 = x.HighPart;
} else {
p1 = 0;
}
if (d != 0) {
ULARGE_INTEGER ud0;
DWORD ud1;
if (bSign) {
//
// Cast d to LONGLONG first otherwise -0x80000000 sign extends
// incorrectly
//
ud0.QuadPart = (DWORDLONG)(-(LONGLONG)d);
if (d > 0) {
/* -d < 0 */
ud1 = (DWORD)-1;
} else {
ud1 = (DWORD)0;
}
} else {
ud0.QuadPart = (DWORDLONG)d;
if (d < 0) {
ud1 = (DWORD)-1;
} else {
ud1 = (DWORD)0;
}
}
/* Now do extended addition */
ULARGE_INTEGER uliTotal;
/* Add ls DWORDs */
uliTotal.QuadPart = (DWORDLONG)ud0.LowPart + p0.LowPart;
p0.LowPart = uliTotal.LowPart;
/* Propagate carry */
uliTotal.LowPart = uliTotal.HighPart;
uliTotal.HighPart = 0;
/* Add 2nd most ls DWORDs */
uliTotal.QuadPart += (DWORDLONG)ud0.HighPart + p0.HighPart;
p0.HighPart = uliTotal.LowPart;
/* Add MS DWORDLONGs - no carry expected */
p1 += ud1 + uliTotal.HighPart;
/* Now see if we got a sign change from the addition */
if ((LONG)p1 < 0) {
bSign = !bSign;
/* Negate the current value (ugh!) */
p0.QuadPart = ~p0.QuadPart;
p1 = ~p1;
p0.QuadPart += 1;
p1 += (p0.QuadPart == 0);
}
}
/* Now for the division */
if (c < 0) {
bSign = !bSign;
}
/* This will catch c == 0 and overflow */
if (uc <= p1) {
return bSign ? (LONGLONG)0x8000000000000000 :
(LONGLONG)0x7FFFFFFFFFFFFFFF;
}
/* Do the division */
/* If the divisor is a DWORD then its simpler */
ULARGE_INTEGER uliDividend;
ULARGE_INTEGER uliResult;
DWORD dwDivisor = uc;
uliDividend.HighPart = p1;
uliDividend.LowPart = p0.HighPart;
/* NOTE - this routine will take exceptions if
the result does not fit in a DWORD
*/
if (uliDividend.QuadPart >= (DWORDLONG)dwDivisor) {
uliResult.HighPart = EnlargedUnsignedDivide(
uliDividend,
dwDivisor,
&p0.HighPart);
} else {
uliResult.HighPart = 0;
}
uliResult.LowPart = EnlargedUnsignedDivide(
p0,
dwDivisor,
NULL);
return bSign ? -(LONGLONG)uliResult.QuadPart :
(LONGLONG)uliResult.QuadPart;
}
Reference in New Issue View Git Blame Copy Permalink