+ static const double exp2_lut[4] = {
+ 1.00000000000000000000, /* 2 ^ (0 * 0.25) */
+ 1.18920711500272106672, /* 2 ^ (1 * 0.25) */
+ M_SQRT2 , /* 2 ^ (2 * 0.25) */
+ 1.68179283050742908606, /* 2 ^ (3 * 0.25) */
+ };
+ static double pow43_lut[16];
+ double exp2_base = 2.11758236813575084767080625169910490512847900390625e-22; // 2^(-72)
+ double exp2_val;
+ double pow43_val = 0;
+ for (i = 0; i < 16; ++i)
+ pow43_lut[i] = i * cbrt(i);
+