* FIXME: There is a lot of redundancy between _next* and npy_nextafter*. * refactor this at some point * * p >= 0, returnx x + nulp * p < 0, returnx x - nulp */
| 26 | * p < 0, returnx x - nulp |
| 27 | */ |
| 28 | static double |
| 29 | _next(double x, int p) |
| 30 | { |
| 31 | volatile double t; |
| 32 | npy_int32 hx, hy, ix; |
| 33 | npy_uint32 lx; |
| 34 | |
| 35 | EXTRACT_WORDS(hx, lx, x); |
| 36 | ix = hx & 0x7fffffff; /* |x| */ |
| 37 | |
| 38 | if (((ix >= 0x7ff00000) && ((ix - 0x7ff00000) | lx) != 0)) /* x is nan */ |
| 39 | return x; |
| 40 | if ((ix | lx) == 0) { /* x == 0 */ |
| 41 | if (p >= 0) { |
| 42 | INSERT_WORDS(x, 0x0, 1); /* return +minsubnormal */ |
| 43 | } |
| 44 | else { |
| 45 | INSERT_WORDS(x, 0x80000000, 1); /* return -minsubnormal */ |
| 46 | } |
| 47 | t = x * x; |
| 48 | if (t == x) |
| 49 | return t; |
| 50 | else |
| 51 | return x; /* raise underflow flag */ |
| 52 | } |
| 53 | if (p < 0) { /* x -= ulp */ |
| 54 | if (lx == 0) |
| 55 | hx -= 1; |
| 56 | lx -= 1; |
| 57 | } |
| 58 | else { /* x += ulp */ |
| 59 | lx += 1; |
| 60 | if (lx == 0) |
| 61 | hx += 1; |
| 62 | } |
| 63 | hy = hx & 0x7ff00000; |
| 64 | if (hy >= 0x7ff00000) |
| 65 | return x + x; /* overflow */ |
| 66 | if (hy < 0x00100000) { /* underflow */ |
| 67 | t = x * x; |
| 68 | if (t != x) { /* raise underflow flag */ |
| 69 | INSERT_WORDS(x, hx, lx); |
| 70 | return x; |
| 71 | } |
| 72 | } |
| 73 | INSERT_WORDS(x, hx, lx); |
| 74 | return x; |
| 75 | } |
| 76 | |
| 77 | static float |
| 78 | _next(float x, int p) |