Unify SSE/AVX psin functions.

It is based on the SSE version which is much more accurate, though very slightly slower.
This changeset also includes the following required changes:
 - add packet-float to packet-int type traits
 - add packet float<->int reinterpret casts
 - add faster pselect for AVX based on blendv
This commit is contained in:
Gael Guennebaud
2018-11-27 22:41:51 +01:00
parent 08edbc8cfe
commit fa7fd61eda
10 changed files with 171 additions and 168 deletions

View File

@@ -54,101 +54,7 @@ Packet2d pexp<Packet2d>(const Packet2d& x)
template<> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED
Packet4f psin<Packet4f>(const Packet4f& _x)
{
Packet4f x = _x;
_EIGEN_DECLARE_CONST_Packet4f(1 , 1.0f);
_EIGEN_DECLARE_CONST_Packet4f(half, 0.5f);
_EIGEN_DECLARE_CONST_Packet4i(1, 1);
_EIGEN_DECLARE_CONST_Packet4i(not1, ~1);
_EIGEN_DECLARE_CONST_Packet4i(2, 2);
_EIGEN_DECLARE_CONST_Packet4i(4, 4);
_EIGEN_DECLARE_CONST_Packet4f_FROM_INT(sign_mask, 0x80000000u);
_EIGEN_DECLARE_CONST_Packet4f(minus_cephes_DP1,-0.78515625f);
_EIGEN_DECLARE_CONST_Packet4f(minus_cephes_DP2, -2.4187564849853515625e-4f);
_EIGEN_DECLARE_CONST_Packet4f(minus_cephes_DP3, -3.77489497744594108e-8f);
_EIGEN_DECLARE_CONST_Packet4f(sincof_p0, -1.9515295891E-4f);
_EIGEN_DECLARE_CONST_Packet4f(sincof_p1, 8.3321608736E-3f);
_EIGEN_DECLARE_CONST_Packet4f(sincof_p2, -1.6666654611E-1f);
_EIGEN_DECLARE_CONST_Packet4f(coscof_p0, 2.443315711809948E-005f);
_EIGEN_DECLARE_CONST_Packet4f(coscof_p1, -1.388731625493765E-003f);
_EIGEN_DECLARE_CONST_Packet4f(coscof_p2, 4.166664568298827E-002f);
_EIGEN_DECLARE_CONST_Packet4f(cephes_FOPI, 1.27323954473516f); // 4 / M_PI
Packet4f xmm1, xmm2, xmm3, sign_bit, y;
Packet4i emm0, emm2;
sign_bit = x;
/* take the absolute value */
x = pabs(x);
/* take the modulo */
/* extract the sign bit (upper one) */
sign_bit = _mm_and_ps(sign_bit, p4f_sign_mask);
/* scale by 4/Pi */
y = pmul(x, p4f_cephes_FOPI);
/* store the integer part of y in mm0 */
emm2 = _mm_cvttps_epi32(y);
/* j=(j+1) & (~1) (see the cephes sources) */
emm2 = _mm_add_epi32(emm2, p4i_1);
emm2 = _mm_and_si128(emm2, p4i_not1);
y = _mm_cvtepi32_ps(emm2);
/* get the swap sign flag */
emm0 = _mm_and_si128(emm2, p4i_4);
emm0 = _mm_slli_epi32(emm0, 29);
/* get the polynom selection mask
there is one polynom for 0 <= x <= Pi/4
and another one for Pi/4<x<=Pi/2
Both branches will be computed.
*/
emm2 = _mm_and_si128(emm2, p4i_2);
emm2 = _mm_cmpeq_epi32(emm2, _mm_setzero_si128());
Packet4f swap_sign_bit = _mm_castsi128_ps(emm0);
Packet4f poly_mask = _mm_castsi128_ps(emm2);
sign_bit = _mm_xor_ps(sign_bit, swap_sign_bit);
/* The magic pass: "Extended precision modular arithmetic"
x = ((x - y * DP1) - y * DP2) - y * DP3; */
xmm1 = pmul(y, p4f_minus_cephes_DP1);
xmm2 = pmul(y, p4f_minus_cephes_DP2);
xmm3 = pmul(y, p4f_minus_cephes_DP3);
x = padd(x, xmm1);
x = padd(x, xmm2);
x = padd(x, xmm3);
/* Evaluate the first polynom (0 <= x <= Pi/4) */
y = p4f_coscof_p0;
Packet4f z = _mm_mul_ps(x,x);
y = pmadd(y, z, p4f_coscof_p1);
y = pmadd(y, z, p4f_coscof_p2);
y = pmul(y, z);
y = pmul(y, z);
Packet4f tmp = pmul(z, p4f_half);
y = psub(y, tmp);
y = padd(y, p4f_1);
/* Evaluate the second polynom (Pi/4 <= x <= 0) */
Packet4f y2 = p4f_sincof_p0;
y2 = pmadd(y2, z, p4f_sincof_p1);
y2 = pmadd(y2, z, p4f_sincof_p2);
y2 = pmul(y2, z);
y2 = pmul(y2, x);
y2 = padd(y2, x);
/* select the correct result from the two polynoms */
y2 = _mm_and_ps(poly_mask, y2);
y = _mm_andnot_ps(poly_mask, y);
y = _mm_or_ps(y,y2);
/* update the sign */
return _mm_xor_ps(y, sign_bit);
return psin_float(_x);
}
/* almost the same as psin */

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@@ -158,9 +158,22 @@ template<> struct packet_traits<int> : default_packet_traits
};
};
template<> struct unpacket_traits<Packet4f> { typedef float type; enum {size=4, alignment=Aligned16}; typedef Packet4f half; };
template<> struct unpacket_traits<Packet2d> { typedef double type; enum {size=2, alignment=Aligned16}; typedef Packet2d half; };
template<> struct unpacket_traits<Packet4i> { typedef int type; enum {size=4, alignment=Aligned16}; typedef Packet4i half; };
template<> struct unpacket_traits<Packet4f> {
typedef float type;
typedef Packet4f half;
typedef Packet4i integer_packet;
enum {size=4, alignment=Aligned16};
};
template<> struct unpacket_traits<Packet2d> {
typedef double type;
typedef Packet2d half;
enum {size=2, alignment=Aligned16};
};
template<> struct unpacket_traits<Packet4i> {
typedef int type;
typedef Packet4i half;
enum {size=4, alignment=Aligned16};
};
#ifndef EIGEN_VECTORIZE_AVX
template<> struct scalar_div_cost<float,true> { enum { value = 7 }; };
@@ -184,6 +197,7 @@ template<> EIGEN_STRONG_INLINE Packet4f pset1frombits<Packet4f>(unsigned int fro
template<> EIGEN_STRONG_INLINE Packet4f pzero(const Packet4f& /*a*/) { return _mm_setzero_ps(); }
template<> EIGEN_STRONG_INLINE Packet2d pzero(const Packet2d& /*a*/) { return _mm_setzero_pd(); }
template<> EIGEN_STRONG_INLINE Packet4i pzero(const Packet4i& /*a*/) { return _mm_setzero_si128(); }
// GCC generates a shufps instruction for _mm_set1_ps/_mm_load1_ps instead of the more efficient pshufd instruction.
// However, using inrinsics for pset1 makes gcc to generate crappy code in some cases (see bug 203)
@@ -338,6 +352,8 @@ template<> EIGEN_STRONG_INLINE Packet4f pcmp_lt(const Packet4f& a, const Packet4
template<> EIGEN_STRONG_INLINE Packet4f pcmp_eq(const Packet4f& a, const Packet4f& b) { return _mm_cmpeq_ps(a,b); }
template<> EIGEN_STRONG_INLINE Packet4f pcmp_lt_or_nan(const Packet4f& a, const Packet4f& b) { return _mm_cmpnge_ps(a,b); }
template<> EIGEN_STRONG_INLINE Packet4i pcmp_eq(const Packet4i& a, const Packet4i& b) { return _mm_cmpeq_epi32(a,b); }
template<> EIGEN_STRONG_INLINE Packet4f pand<Packet4f>(const Packet4f& a, const Packet4f& b) { return _mm_and_ps(a,b); }
template<> EIGEN_STRONG_INLINE Packet2d pand<Packet2d>(const Packet2d& a, const Packet2d& b) { return _mm_and_pd(a,b); }
template<> EIGEN_STRONG_INLINE Packet4i pand<Packet4i>(const Packet4i& a, const Packet4i& b) { return _mm_and_si128(a,b); }
@@ -354,6 +370,8 @@ template<> EIGEN_STRONG_INLINE Packet4f pandnot<Packet4f>(const Packet4f& a, con
template<> EIGEN_STRONG_INLINE Packet2d pandnot<Packet2d>(const Packet2d& a, const Packet2d& b) { return _mm_andnot_pd(b,a); }
template<> EIGEN_STRONG_INLINE Packet4i pandnot<Packet4i>(const Packet4i& a, const Packet4i& b) { return _mm_andnot_si128(b,a); }
template<> EIGEN_STRONG_INLINE Packet4i pshiftleft<Packet4i>(const Packet4i& a, int n) { return _mm_slli_epi32(a,n); }
#ifdef EIGEN_VECTORIZE_SSE4_1
template<> EIGEN_STRONG_INLINE Packet4f pround<Packet4f>(const Packet4f& a) { return _mm_round_ps(a, 0); }
template<> EIGEN_STRONG_INLINE Packet2d pround<Packet2d>(const Packet2d& a) { return _mm_round_pd(a, 0); }

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@@ -69,6 +69,13 @@ template<> EIGEN_STRONG_INLINE Packet2d pcast<Packet4f, Packet2d>(const Packet4f
return _mm_cvtps_pd(a);
}
template<> EIGEN_STRONG_INLINE Packet4i preinterpret<Packet4i,Packet4f>(const Packet4f& a) {
return _mm_castps_si128(a);
}
template<> EIGEN_STRONG_INLINE Packet4f preinterpret<Packet4f,Packet4i>(const Packet4i& a) {
return _mm_castsi128_ps(a);
}
} // end namespace internal