libclc/generic/lib/math/logb.cl

   1 #include "math.h"
   2 #include <clc/clc.h>
   3 #include <clc/clcmacro.h>
   4
   5 _CLC_OVERLOAD _CLC_DEF float logb(float x) {
   6     int ax = as_int(x) & EXSIGNBIT_SP32;
   7     float s = -118 - clz(ax);
   8     float r = (ax >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32;
   9     r = ax >= PINFBITPATT_SP32 ? as_float(ax) : r;
  10     r = ax < 0x00800000 ? s : r;
  11     r = ax == 0 ? as_float(NINFBITPATT_SP32) : r;
  12     return r;
  13 }
  14
  15 _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, logb, float);
  16
  17 #ifdef cl_khr_fp64
  18 #pragma OPENCL EXTENSION cl_khr_fp64 : enable
  19
  20 _CLC_OVERLOAD _CLC_DEF double logb(double x) {
  21     long ax = as_long(x) & EXSIGNBIT_DP64;
  22     double s = -1011L - clz(ax);
  23     double r = (int) (ax >> EXPSHIFTBITS_DP64) - EXPBIAS_DP64;
  24     r = ax >= PINFBITPATT_DP64 ? as_double(ax) : r;
  25     r = ax < 0x0010000000000000L ? s : r;
  26     r = ax == 0L ? as_double(NINFBITPATT_DP64) : r;
  27     return r;
  28 }
  29
  30 _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, logb, double)
  31 #endif
  32
  33 _CLC_DEFINE_UNARY_BUILTIN_FP16(logb)