//-----------------------------------------------------------------------------------
void MathlibNEON::SinCos4( ArrayReal x, ArrayReal &outSin, ArrayReal &outCos )
{
// TODO: Improve accuracy by mapping to the range [-pi/4, pi/4] and swap
// between cos & sin depending on which quadrant it fell:
// Quadrant | sin | cos
// n = 0 -> sin( x ), cos( x )
// n = 1 -> cos( x ), -sin( x )
// n = 2 -> -sin( x ), -cos( x )
// n = 3 -> -sin( x ), sin( x )
// See ARGUMENT REDUCTION FOR HUGE ARGUMENTS:
// Good to the Last Bit
// K. C. Ng and themembers of the FP group of SunPro
// http://www.derekroconnor.net/Software/Ng--ArgReduction.pdf
// -- Perhaps we can leave this to GSoC students? --
// Map arbitrary angle x to the range [-pi; +pi] without using division.
// Code taken from MSDN's HLSL trick. Architectures with fused mad (i.e. NEON)
// can replace the add, the sub, & the two muls for two mad
ArrayReal integralPart;
x = vaddq_f32( vmulq_f32( x, ONE_DIV_2PI ), HALF );
x = Modf4( x, integralPart );
x = vsubq_f32( vmulq_f32( x, TWO_PI ), PI );
sincos_ps( x, &outSin, &outCos );
}
//-----------------------------------------------------------------------------------
ArrayReal MathlibNEON::Cos4( ArrayReal x )
{
// Map arbitrary angle x to the range [-pi; +pi] without using division.
// Code taken from MSDN's HLSL trick. Architectures with fused mad (i.e. NEON)
// can replace the add, the sub, & the two muls for two mad
ArrayReal integralPart;
x = vaddq_f32( vmulq_f32( x, ONE_DIV_2PI ), HALF );
x = Modf4( x, integralPart );
x = vsubq_f32( vmulq_f32( x, TWO_PI ), PI );
return cos_ps( x );
}
ArrayFloat MathlibSSE2::Cos4( ArrayFloat x )
{
// Map arbitrary angle x to the range [-pi; +pi] without using division.
// Code taken from MSDN's HLSL trick. Architectures with fused mad (i.e. NEON)
// can replace the add, the sub, & the two muls for two mad
ArrayFloat integralPart;
x = _mm_add_ps( _mm_mul_ps( x, ONE_DIV_2PI ), HALF );
x = Modf4( x, integralPart );
x = _mm_sub_ps( _mm_mul_ps( x, TWO_PI ), PI );
return cos_ps( x );
}
