Fixed critical bug in the generic C++ code of DotProduct_SIMD that caused massive errors in the physics system

This commit is contained in:
Robert Beckebans 2013-06-01 18:29:12 +02:00
parent 2a4970c86c
commit 3b67eabf79

View file

@ -220,31 +220,49 @@ static float DotProduct_SIMD( const float* src0, const float* src1, const int co
#else
// RB: the old loop caused completely broken rigid body physics and NaN errors
#if 1
float s0 = 0.0f;
float s1 = 0.0f;
float s2 = 0.0f;
float s3 = 0.0f;
int i = 0;
for( ; i < count - 3; i += 4 )
for( ; i + 4 <= count; i += 4 )
{
s0 += src0[i + 4] * src1[i + 4];
s1 += src0[i + 5] * src1[i + 5];
s2 += src0[i + 6] * src1[i + 6];
s3 += src0[i + 7] * src1[i + 7];
s0 += src0[i + 0] * src1[i + 0];
s1 += src0[i + 1] * src1[i + 1];
s2 += src0[i + 2] * src1[i + 2];
s3 += src0[i + 3] * src1[i + 3];
}
switch( count - i )
{
NODEFAULT;
case 4:
s3 += src0[i + 3] * src1[i + 3];
case 3:
s0 += src0[i + 2] * src1[i + 2];
s2 += src0[i + 2] * src1[i + 2];
case 2:
s1 += src0[i + 1] * src1[i + 1];
case 1:
s2 += src0[i + 0] * src1[i + 0];
s0 += src0[i + 0] * src1[i + 0];
case 0:
break;
}
return s0 + s1 + s2 + s3;
#else
float s = 0;
for( int i = 0; i < count; i++ )
{
s += src0[i] * src1[i];
}
return s;
#endif
// RB end
#endif
}
@ -1519,114 +1537,64 @@ static void GetMaxStep_SIMD( const float* f, const float* a, const float* delta_
_mm_store_ss( & maxStep, vMaxStep );
limit = _mm_cvtsi128_si32( vLimit );
limitSide = _mm_cvtsi128_si32( vLimitSide );
#else
int i;
float s;
// default to a full step for the current variable
if( idMath::Fabs( delta_a[d] ) > LCP_DELTA_ACCEL_EPSILON )
{
maxStep = -a[d] / delta_a[d];
}
else
{
maxStep = 0.0f;
}
float negAccel = -a[d];
float deltaAccel = delta_a[d];
int m0 = ( fabs( deltaAccel ) > LCP_DELTA_ACCEL_EPSILON );
float step = negAccel / ( m0 ? deltaAccel : 1.0f );
maxStep = m0 ? step : 0.0f;
limit = d;
limitSide = 0;
}
// test the current variable
if( dir < 0.0f )
{
if( lo[d] != -idMath::INFINITY )
{
s = ( lo[d] - f[d] ) / dir;
if( s < maxStep )
{
maxStep = s;
limitSide = -1;
}
}
}
else
{
if( hi[d] != idMath::INFINITY )
{
s = ( hi[d] - f[d] ) / dir;
if( s < maxStep )
{
maxStep = s;
limitSide = 1;
}
}
float deltaForce = dir;
float forceLimit = ( deltaForce < 0.0f ) ? lo[d] : hi[d];
float step = ( forceLimit - f[d] ) / deltaForce;
int setSide = ( deltaForce < 0.0f ) ? -1 : 1;
int m0 = ( fabs( deltaForce ) > LCP_DELTA_FORCE_EPSILON );
int m1 = ( fabs( forceLimit ) != idMath::INFINITY );
int m2 = ( step < maxStep );
int m3 = ( m0 & m1 & m2 );
maxStep = m3 ? step : maxStep;
limit = m3 ? d : limit;
limitSide = m3 ? setSide : limitSide;
}
// test the clamped bounded variables
for( i = numUnbounded; i < numClamped; i++ )
for( int i = numUnbounded; i < numClamped; i++ )
{
if( delta_f[i] < -LCP_DELTA_FORCE_EPSILON )
{
// if there is a low boundary
if( lo[i] != -idMath::INFINITY )
{
s = ( lo[i] - f[i] ) / delta_f[i];
if( s < maxStep )
{
maxStep = s;
limit = i;
limitSide = -1;
}
}
}
else if( delta_f[i] > LCP_DELTA_FORCE_EPSILON )
{
// if there is a high boundary
if( hi[i] != idMath::INFINITY )
{
s = ( hi[i] - f[i] ) / delta_f[i];
if( s < maxStep )
{
maxStep = s;
limit = i;
limitSide = 1;
}
}
}
float deltaForce = delta_f[i];
float forceLimit = ( deltaForce < 0.0f ) ? lo[i] : hi[i];
int m0 = ( fabs( deltaForce ) > LCP_DELTA_FORCE_EPSILON );
float step = ( forceLimit - f[i] ) / ( m0 ? deltaForce : 1.0f );
int setSide = ( deltaForce < 0.0f ) ? -1 : 1;
int m1 = ( fabs( forceLimit ) != idMath::INFINITY );
int m2 = ( step < maxStep );
int m3 = ( m0 & m1 & m2 );
maxStep = m3 ? step : maxStep;
limit = m3 ? i : limit;
limitSide = m3 ? setSide : limitSide;
}
// test the not clamped bounded variables
for( i = numClamped; i < d; i++ )
for( int i = numClamped; i < d; i++ )
{
if( side[i] == -1 )
{
if( delta_a[i] >= -LCP_DELTA_ACCEL_EPSILON )
{
continue;
}
}
else if( side[i] == 1 )
{
if( delta_a[i] <= LCP_DELTA_ACCEL_EPSILON )
{
continue;
}
}
else
{
continue;
}
// ignore variables for which the force is not allowed to take any substantial value
if( lo[i] >= -LCP_BOUND_EPSILON && hi[i] <= LCP_BOUND_EPSILON )
{
continue;
}
s = -a[i] / delta_a[i];
if( s < maxStep )
{
maxStep = s;
limit = i;
limitSide = 0;
}
float negAccel = -a[i];
float deltaAccel = delta_a[i];
int m0 = ( side[i] * deltaAccel > LCP_DELTA_ACCEL_EPSILON );
float step = negAccel / ( m0 ? deltaAccel : 1.0f );
int m1 = ( lo[i] < -LCP_BOUND_EPSILON || hi[i] > LCP_BOUND_EPSILON );
int m2 = ( step < maxStep );
int m3 = ( m0 & m1 & m2 );
maxStep = m3 ? step : maxStep;
limit = m3 ? i : limit;
limitSide = m3 ? 0 : limitSide;
}
#endif