SimdTypes.h File Reference

#include "Chaos/Core.h"
#include "Chaos/VectorUtility.h"
#include "Math/VectorRegister.h"

Go to the source code of this file.

Classes
struct	Chaos::Private::TSimdSelector< TNumLanes >
struct	Chaos::Private::TSimdValue< T, TNumLanes >
struct	Chaos::Private::TSimdInt32< TNumLanes >
struct	Chaos::Private::TSimdRealf< TNumLanes >
struct	Chaos::Private::TSimdVec3f< TNumLanes >

Namespaces
namespace	Chaos
namespace	Chaos::Private

Detailed Description

This file contains a set of classes to help with SIMD data storage and operations on that data. E.g., sets of N 3-vectors are stored as 3 arrays of N floats (one for the X elements, one for Y, one for Z).

Arranging data this way allows us to process N datasets for the cost of 1, and eliminates the need to call any horizontal vector operations (such as is required for the summation in a dot product of two vectors).

Examples:

For a real-world example see methods in FPBDCollisionSolverSimd like SolvePositionNoFriction, SolvePositionWithFriction, and SolveVelocity.

// Hopefully your data is already stored in SIMD lanes, but if not you // can load it into SIMD registers with the factory functions and SetValue // methods. This should be avoided if possible.

FSimd4Realf R0; SimdR0.SetValue(0, -1); SimdR0.SetValue(1, 0); SimdR0.SetValue(2, 1); SimdR0.SetValue(3, 2); FSimd4Realf R1; SimdR1.SetValue(0, 3); SimdR1.SetValue(1, 4); SimdR1.SetValue(2, 5); SimdR1.SetValue(3, 6);

FSim4Selector IsR0GreaterThanZero = SimdGreater(R0, FSimd4Realf::Zero());

// If it's likely that all lanes will agree on IsGreaterZero, it may be worth // skipping the code block when possible. This will depend how expensive the // branch is vs the code we skip and the probability of doing so. FSimd4Realf R2 = FSimd4Realf::Zero(); if (SimdAnyTrue(IsR0GreaterThanZero)) { R2 = SimdSelect(IsR0GreaterThanZero, R0, R1); // -> (3,4,1,2) }