libclc/generic/lib/math/clc_nextafter.cl

   1 #include <clc/clc.h>
   2 #include <clc/clcmacro.h>
   3 #include <clc/relational/clc_isnan.h>
   4
   5 // This file provides OpenCL C implementations of nextafter for
   6 // targets that don't support the clang builtin.
   7
   8 #define AS_TYPE(x) as_##x
   9
  10 #define NEXTAFTER(FLOAT_TYPE, UINT_TYPE, INT_TYPE)                             \
  11   _CLC_OVERLOAD _CLC_DEF FLOAT_TYPE __clc_nextafter(FLOAT_TYPE x,              \
  12                                                     FLOAT_TYPE y) {            \
  13     const UINT_TYPE sign_bit = (UINT_TYPE)1 << (sizeof(INT_TYPE) * 8 - 1);     \
  14     const UINT_TYPE sign_bit_mask = sign_bit - 1;                              \
  15     INT_TYPE ix = AS_TYPE(INT_TYPE)(x);                                        \
  16     INT_TYPE ax = ix & sign_bit_mask;                                          \
  17     INT_TYPE mx = sign_bit - ix;                                               \
  18     mx = ix < 0 ? mx : ix;                                                     \
  19     INT_TYPE iy = AS_TYPE(INT_TYPE)(y);                                        \
  20     INT_TYPE ay = iy & sign_bit_mask;                                          \
  21     INT_TYPE my = sign_bit - iy;                                               \
  22     my = iy < 0 ? my : iy;                                                     \
  23     INT_TYPE t = mx + (mx < my ? 1 : -1);                                      \
  24     INT_TYPE r = sign_bit - t;                                                 \
  25     r = t < 0 ? r : t;                                                         \
  26     r = __clc_isnan(x) ? ix : r;                                               \
  27     r = __clc_isnan(y) ? iy : r;                                               \
  28     r = ((ax | ay) == 0 | ix == iy) ? iy : r;                                  \
  29     return AS_TYPE(FLOAT_TYPE)(r);                                             \
  30   }
  31
  32 NEXTAFTER(float, uint, int)
  33 _CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, __clc_nextafter, float,
  34                       float)
  35
  36 #ifdef cl_khr_fp64
  37 #pragma OPENCL EXTENSION cl_khr_fp64 : enable
  38
  39 NEXTAFTER(double, ulong, long)
  40 _CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, __clc_nextafter, double,
  41                       double)
  42 #endif
  43
  44 #ifdef cl_khr_fp16
  45 #pragma OPENCL EXTENSION cl_khr_fp16 : enable
  46
  47 NEXTAFTER(half, ushort, short)
  48 _CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, half, __clc_nextafter, half, half)
  49 #endif