diff options
Diffstat (limited to 'newlib/libm/machine/spu/headers/expd2.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/expd2.h | 67 |
1 files changed, 55 insertions, 12 deletions
diff --git a/newlib/libm/machine/spu/headers/expd2.h b/newlib/libm/machine/spu/headers/expd2.h index 19d77dd51..1a8581292 100644 --- a/newlib/libm/machine/spu/headers/expd2.h +++ b/newlib/libm/machine/spu/headers/expd2.h @@ -56,7 +56,6 @@ #include <spu_intrinsics.h> #include "floord2.h" -#include "ldexpd2.h" #define LOG2E 1.4426950408889634073599 // 1/log(2) @@ -101,15 +100,12 @@ static __inline vector double _expd2(vector double x) { - vec_uchar16 even2odd = ((vec_uchar16){0x80, 0x80, 0x80, 0x80, 0, 1, 2, 3, - 0x80, 0x80, 0x80, 0x80, 8, 9, 10, 11}); - // log(2) in extended machine representable precision vec_double2 ln2_hi = spu_splats(6.9314575195312500E-1); // 3FE62E4000000000 vec_double2 ln2_lo = spu_splats(1.4286068203094172E-6); // 3EB7F7D1CF79ABCA - // coefficients for the power series + // vec_double2 f01 = spu_splats(1.00000000000000000000E0); // 1/(1!) vec_double2 f02 = spu_splats(5.00000000000000000000E-1); // 1/(2!) vec_double2 f03 = spu_splats(1.66666666666666666667E-1); // 1/(3!) vec_double2 f04 = spu_splats(4.16666666666666666667E-2); // 1/(4!) @@ -126,19 +122,42 @@ static __inline vector double _expd2(vector double x) vec_double2 rx = _floord2(spu_madd(x,spu_splats(LOG2E),spu_splats(0.5))); // extract the exponent of reduction - vec_int4 nint = spu_convts(spu_roundtf(rx),0); - vec_llong2 n = spu_extend(spu_shuffle(nint, nint, even2odd)); + vec_int4 exp = spu_convts(spu_roundtf(rx),0); // reduce the input to within [ -ln(2)/2 ... ln(2)/2 ] vec_double2 r; r = spu_nmsub(rx,ln2_hi,x); r = spu_nmsub(rx,ln2_lo,r); - vec_double2 result; vec_double2 r2 = spu_mul(r,r); // Use Horner's method on the power series + /* result = ((((c12*x + c11)*x + c10)*x + c9)*x + c8)*x + c7)*x + c6)*x^6 + + ((((((c5*x + c4)*x + c3)*x + c2)*x + c1)*x + c0 + */ + +#ifdef __SPU_EDP__ + vec_double2 p1, p2, r4, r6; + + p1 = spu_madd(f12, r, f11); + p2 = spu_madd(f05, r, f04); + r4 = spu_mul(r2, r2); + p1 = spu_madd(p1, r, f10); + p2 = spu_madd(p2, r, f03); + p1 = spu_madd(p1, r, f09); + p2 = spu_madd(p2, r, f02); + p1 = spu_madd(p1, r, f08); + r6 = spu_mul(r2, r4); + p1 = spu_madd(p1, r, f07); + p2 = spu_madd(p2, r2, r); + p1 = spu_madd(p1, r, f06); + + result = spu_madd(r6, p1, p2); + result = spu_add(result, spu_splats(1.0)); + +#else + result = spu_madd(r,f12,f11); result = spu_madd(result,r,f10); result = spu_madd(result,r,f09); @@ -152,14 +171,38 @@ static __inline vector double _expd2(vector double x) result = spu_madd(result,r2,r); result = spu_add(result,spu_splats(1.0)); - // Scale the result - result = _ldexpd2(result, n); +#endif /* __SPU_EDP__ */ - return result; + // Scale the result - basically a call to ldexpd2() + vec_int4 e1, e2; + vec_int4 min = spu_splats(-2044); + vec_int4 max = spu_splats(2046); + vec_uint4 cmp_min, cmp_max; + vec_uint4 shift = (vec_uint4) { 20, 32, 20, 32 }; + vec_double2 f1, f2; -} + /* Clamp the specified exponent to the range -2044 to 2046. + */ + cmp_min = spu_cmpgt(exp, min); + cmp_max = spu_cmpgt(exp, max); + exp = spu_sel(min, exp, cmp_min); + exp = spu_sel(exp, max, cmp_max); + /* Generate the factors f1 = 2^e1 and f2 = 2^e2 + */ + e1 = spu_rlmaska(exp, -1); + e2 = spu_sub(exp, e1); + + f1 = (vec_double2)spu_sl(spu_add(e1, 1023), shift); + f2 = (vec_double2)spu_sl(spu_add(e2, 1023), shift); + + /* Compute the product x * 2^e1 * 2^e2 + */ + result = spu_mul(spu_mul(result, f1), f2); + + return result; +} #endif /* _EXPD2_H_ */ #endif /* __SPU__ */ |