Unit Test: use range from 0 to 1 for floating point test data (#459)

* Unit Test: use range from 0 to 1 for floating point test data

* gtest: Update init data and bfloat16 threshold

test/CorrectnessTest.hpp

@@ -689,15 +689,15 @@ dropback:
             // NOTE: Currently half-precision float tests are unsupported due to half being supported
             //       on GPU only and not host
 
-            // Fills input  data[i][j] with (i + j) % 6
+            // Fills input  data[i][j] with (i + j) % 256
             // - Keeping range small to reduce likelihood of overflow
             // - Sticking with floating points values that are perfectly representable
             for (int i = 0; i < dataset.numDevices; i++)
             {
                 for (int j = 0; j < dataset.NumBytes(ncclInputBuffer)/DataTypeToBytes(dataset.dataType); j++)
                 {
-                    int    valueI = (i + j) % 6;
-                    float  valueF = (float)valueI;
+                    int    valueI = (i + j) % 256;
+                    double  valueF = 1.0L/((double)valueI+1.0L);
 
                     switch (dataset.dataType)
                     {
@@ -812,7 +812,7 @@ dropback:
                     case ncclUint64:  isMatch &= (outputU8[j] == expectedU8[j]); break;
                     case ncclFloat32: isMatch &= (fabs(outputF4[j] - expectedF4[j]) < 1e-5); break;
                     case ncclFloat64: isMatch &= (fabs(outputF8[j] - expectedF8[j]) < 1e-12); break;
-                    case ncclBfloat16: isMatch &= (fabs((float)outputB2[j] - (float)expectedB2[j]) < 1e-2); break;
+                    case ncclBfloat16: isMatch &= (fabs((float)outputB2[j] - (float)expectedB2[j]) < 5e-2); break;
                     default:
                         fprintf(stderr, "[ERROR] Unsupported datatype\n");
                         exit(0);