fixed pexp<Packet2d>, was failing tests

This commit is contained in:
Konstantinos Margaritis 2016-06-19 16:11:58 -03:00
parent 87294c84a6
commit b80379bda0

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@ -83,6 +83,10 @@ static _EIGEN_DECLARE_CONST_Packet2d(cephes_exp_q3, 2.00000000000000000009e0);
static _EIGEN_DECLARE_CONST_Packet2d(cephes_exp_C1, 0.693145751953125);
static _EIGEN_DECLARE_CONST_Packet2d(cephes_exp_C2, 1.42860682030941723212e-6);
static Packet2l p2l_1023 = { 1023, 1023 };
static Packet2ul p2ul_52 = { 52, 52 };
#endif
template<> EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS EIGEN_UNUSED
@ -160,7 +164,7 @@ Packet4f pexp<Packet4f>(const Packet4f& _x)
/* express exp(x) as exp(g + n*log(2)) */
fx = pmadd(x, p4f_cephes_LOG2EF, p4f_half);
fx = vec_floor(fx);
fx = pfloor(fx);
tmp = pmul(fx, p4f_cephes_exp_C1);
Packet4f z = pmul(fx, p4f_cephes_exp_C2);
@ -219,9 +223,11 @@ Packet2d psqrt<Packet2d>(const Packet2d& x)
// versions of the same compiler. For gcc version >= 4.9.3, we can use
// vec_cts to efficiently convert Packet2d to Packet2l. Otherwise, use
// a slow version that works with older compilers.
// Update: apparently vec_cts/vec_ctf intrinsics for 64-bit doubles
// are buggy, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70963
static inline Packet2l ConvertToPacket2l(const Packet2d& x) {
#if EIGEN_GNUC_AT_LEAST(5, 0) || \
(EIGEN_GNUC_AT(4, 9) && __GNUC_PATCHLEVEL__ >= 3)
#if EIGEN_GNUC_AT_LEAST(5, 4) || \
(EIGEN_GNUC_AT(6, 1) && __GNUC_PATCHLEVEL__ >= 1)
return vec_cts(x, 0); // TODO: check clang version.
#else
double tmp[2];
@ -242,10 +248,11 @@ Packet2d pexp<Packet2d>(const Packet2d& _x)
// clamp x
x = pmax(pmin(x, p2d_exp_hi), p2d_exp_lo);
/* express exp(x) as exp(g + n*log(2)) */
fx = pmadd(p2d_cephes_LOG2EF, x, p2d_half);
fx = vec_floor(fx);
/* express exp(x) as exp(g + n*log(2)) */
fx = pmadd(x, p2d_cephes_LOG2EF, p2d_half);
fx = pfloor(fx);
tmp = pmul(fx, p2d_cephes_exp_C1);
Packet2d z = pmul(fx, p2d_cephes_exp_C2);
@ -271,9 +278,6 @@ Packet2d pexp<Packet2d>(const Packet2d& _x)
emm0 = ConvertToPacket2l(fx);
#ifdef __POWER8_VECTOR__
static const Packet2l p2l_1023 = { 1023, 1023 };
static const Packet2ul p2ul_52 = { 52, 52 };
emm0 = vec_add(emm0, p2l_1023);
emm0 = vec_sl(emm0, p2ul_52);
#else