compiler-rt/test/builtins/Unit/compiler_rt_logb_test.c

   1 // RUN: %clang_builtins %s %librt -o %t && %run %t
   2
   3 #define DOUBLE_PRECISION
   4 #include <math.h>
   5 #include <stdio.h>
   6 #include "fp_lib.h"
   7
   8 int test__compiler_rt_logb(fp_t x) {
   9 #if defined(__ve__)
  10   if (fpclassify(x) == FP_SUBNORMAL)
  11     return 0;
  12 #endif
  13   fp_t crt_value = __compiler_rt_logb(x);
  14   fp_t libm_value = logb(x);
  15   // Compare the values, considering all NaNs equivalent, as the spec doesn't
  16   // specify the NaN signedness/payload.
  17   if (crt_value != libm_value &&
  18       !(crt_isnan(crt_value) && crt_isnan(libm_value))) {
  19     printf("error: in __compiler_rt_logb(%a [%lX]) = %a [%lX] !=  %a [%lX]\n",
  20            x, toRep(x), crt_value, toRep(crt_value), libm_value,
  21            toRep(libm_value));
  22     return 1;
  23   }
  24   return 0;
  25 }
  26
  27 double cases[] = {
  28     1.e-6, -1.e-6, NAN, -NAN, INFINITY, -INFINITY, -1,
  29     -0.0,  0.0,    1,   -2,   2,        -0.5,      0.5,
  30 };
  31
  32 #ifndef __GLIBC_PREREQ
  33 #define __GLIBC_PREREQ(x, y) 0
  34 #endif
  35
  36 int main() {
  37   // Do not the run the compiler-rt logb test case if using GLIBC version
  38   // < 2.23. Older versions might not compute to the same value as the
  39   // compiler-rt value.
  40 #if __GLIBC_PREREQ(2, 23)
  41   const unsigned N = sizeof(cases) / sizeof(cases[0]);
  42   unsigned i;
  43   for (i = 0; i < N; ++i) {
  44     if (test__compiler_rt_logb(cases[i])) return 1;
  45   }
  46
  47   // Test a moving 1 bit, especially to handle denormal values.
  48   // Test the negation as well.
  49   rep_t x = signBit;
  50   while (x) {
  51     if (test__compiler_rt_logb(fromRep(x))) return 1;
  52     if (test__compiler_rt_logb(fromRep(signBit ^ x))) return 1;
  53     x >>= 1;
  54   }
  55   // Also try a couple moving ones
  56   x = signBit | (signBit >> 1) | (signBit >> 2);
  57   while (x) {
  58     if (test__compiler_rt_logb(fromRep(x))) return 1;
  59     if (test__compiler_rt_logb(fromRep(signBit ^ x))) return 1;
  60     x >>= 1;
  61   }
  62 #else
  63   printf("skipped\n");
  64 #endif
  65
  66   return 0;
  67 }