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

   1 // RUN: %clang_builtins %s %librt -o %t && %run %t
   2 //===-- compiler_rt_logbf_test.c - Test __compiler_rt_logbf ---------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file checks __compiler_rt_logbf from the compiler_rt library for
  11 // conformance against libm.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #define SINGLE_PRECISION
  16 #include "fp_lib.h"
  17 #include "int_math.h"
  18 #include <math.h>
  19 #include <stdio.h>
  20
  21 int test__compiler_rt_logbf(fp_t x) {
  22   fp_t crt_value = __compiler_rt_logbf(x);
  23   fp_t libm_value = logbf(x);
  24   // `!=` operator on fp_t returns false for NaNs so also check if operands are
  25   // both NaN. We don't do `toRepr(crt_value) != toRepr(libm_value)` because
  26   // that treats different representations of NaN as not equivalent.
  27   if (crt_value != libm_value &&
  28       !(crt_isnan(crt_value) && crt_isnan(libm_value))) {
  29     printf("error: in __compiler_rt_logb(%a [%X]) = %a [%X] !=  %a [%X]\n", x,
  30            toRep(x), crt_value, toRep(crt_value), libm_value,
  31            toRep(libm_value));
  32     return 1;
  33   }
  34   return 0;
  35 }
  36
  37 double cases[] = {
  38     1.e-6, -1.e-6, NAN, -NAN, INFINITY, -INFINITY, -1,
  39     -0.0,  0.0,    1,   -2,   2,        -0.5,      0.5,
  40 };
  41
  42 int main() {
  43   const unsigned N = sizeof(cases) / sizeof(cases[0]);
  44   unsigned i;
  45   for (i = 0; i < N; ++i) {
  46     if (test__compiler_rt_logbf(cases[i])) return 1;
  47   }
  48
  49   // Test a moving 1 bit, especially to handle denormal values.
  50   // Test the negation as well.
  51   rep_t x = signBit;
  52   while (x) {
  53     if (test__compiler_rt_logbf(fromRep(x))) return 1;
  54     if (test__compiler_rt_logbf(fromRep(signBit ^ x))) return 1;
  55     x >>= 1;
  56   }
  57   // Also try a couple moving ones
  58   x = signBit | (signBit >> 1) | (signBit >> 2);
  59   while (x) {
  60     if (test__compiler_rt_logbf(fromRep(x))) return 1;
  61     if (test__compiler_rt_logbf(fromRep(signBit ^ x))) return 1;
  62     x >>= 1;
  63   }
  64
  65   return 0;
  66 }