Compare FP16 results of Soft Float's sqrt to Converting FP16 to F32 and using std::sqrt

test_fp16_sqrt.cpp

/*
 * Using https://www.jhauser.us/arithmetic/SoftFloat.html
 * and https://github.com/Maratyszcza/FP16
 * compiling with: 
 * clang++ -std=c++20  -o sf -I ../../source/include/ -I  ~/projects/binaryen/third_party/FP16/include/  main.cpp softfloat.a && ./sf
 */
extern "C" {
    #include "softfloat.h"
}
#include <cmath>
#include <stdio.h>
#include <fp16.h>

bool IsNaN(uint16_t f) {
	return ((f & 0x7c00) == 0x7c00) && ((f & 0x03ff) != 0);
}

int main() {
  float16_t a_f16;

  for (int i = 0; i < 65536; i++) {
    a_f16.v = i;
    float a_f = fp16_ieee_to_fp32_value(i);
    uint16_t soft_float_result = f16_sqrt(a_f16).v;
    uint16_t fp16_result = fp16_ieee_from_fp32_value(std::sqrt(a_f));  
    // Print out the results if they are different, but ignore NaN value differences.
    if (soft_float_result != fp16_result && IsNaN(soft_float_result) != IsNaN(fp16_result)) {
      printf("%hx %hx\n", soft_float_result, fp16_result);
    }
  }

  printf("done\n");

  return 0;
}