llvm-project/flang/unittests/Evaluate/leading-zero-bit-count.cpp

#include "flang/Common/leading-zero-bit-count.h"
#include "testing.h"

using Fortran::common::LeadingZeroBitCount;

int main() {
  MATCH(64, LeadingZeroBitCount(std::uint64_t{0}));
  for (int j{0}; j < 64; ++j) {
    for (int k{0}; k < j; ++k) {
      std::uint64_t x = (std::uint64_t{1} << j) | (std::uint64_t{1} << k);
      MATCH(63 - j, LeadingZeroBitCount(x))("j=%d, k=%d", j, k);
    }
  }
  MATCH(32, LeadingZeroBitCount(std::uint32_t{0}));
  for (int j{0}; j < 32; ++j) {
    for (int k{0}; k < j; ++k) {
      std::uint32_t x = (std::uint32_t{1} << j) | (std::uint32_t{1} << k);
      MATCH(31 - j, LeadingZeroBitCount(x))("j=%d, k=%d", j, k);
    }
  }
  MATCH(16, LeadingZeroBitCount(std::uint16_t{0}));
  for (int j{0}; j < 16; ++j) {
    for (int k{0}; k < j; ++k) {
      std::uint16_t x = (std::uint16_t{1} << j) | (std::uint16_t{1} << k);
      MATCH(15 - j, LeadingZeroBitCount(x))("j=%d, k=%d", j, k);
    }
  }
  MATCH(8, LeadingZeroBitCount(std::uint8_t{0}));
  for (int j{0}; j < 8; ++j) {
    for (int k{0}; k < j; ++k) {
      std::uint8_t x = (std::uint8_t{1} << j) | (std::uint8_t{1} << k);
      MATCH(7 - j, LeadingZeroBitCount(x))("j=%d, k=%d", j, k);
    }
  }
  return testing::Complete();
}