Merge pull request #10999 from cladmi/pr/tests/rng/print_float

tests/rng: replace printf_float with fmt/print_float

tests/rng/Makefile

@@ -8,7 +8,6 @@ BOARD_INSUFFICIENT_MEMORY += arduino-duemilanove arduino-uno
 # USEMODULE += prng_minstd
 
 USEMODULE += fmt
-USEMODULE += printf_float
 USEMODULE += random
 USEMODULE += shell
 USEMODULE += xtimer

tests/rng/test.c

@@ -154,7 +154,7 @@ void test_distributions(uint32_t samples)
 
         /* count bits */
         for (int i = 0; i < 32; i++) {
-            if (value & (1 << i)) {
+            if (value & (UINT32_C(1) << i)) {
                 distributions[i]++;
             }
         }
@@ -382,7 +382,15 @@ void test_entropy(uint32_t samples)
     }
 
     /* print results */
-    printf("Calculated %02f bits of entropy from %" PRIu32 " samples.\n", (double) entropy, samples);
+    /* Use 'fmt/print_float' to work on all platforms (atmega)
+     * Stdout should be flushed before to prevent garbled output. */
+    printf("Calculated ");
+#ifdef MODULE_NEWLIB
+    /* no fflush on msp430 */
+    fflush(stdout);
+#endif
+    print_float(entropy, 6);
+    printf(" bits of entropy from %" PRIu32 " samples.\n", samples);
 }
 
 void cb_speed_timeout(void *arg)