tests/c_lib: Skip double sqrt test when double is not 64 bits

This test only works for 64-bit values. On targets which use 32 bits for
double, skip this version. The float test will check the 32-bit math for
that.

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>

tests/lib/c_lib/common/src/test_sqrt.c

@@ -29,6 +29,7 @@ static float test_floats[] = {
 	};
 #define	NUM_TEST_FLOATS	(sizeof(test_floats)/sizeof(float))
 
+#if __SIZEOF_DOUBLE__ == 8
 	static double test_doubles[] = {
 		1.0, 2.0, 3.0, 4.0,
 		5.0, 6.0, 7.0, 8.0, 9.0,	/* numbers across the decade */
@@ -59,6 +60,7 @@ static int isnan(double x)
 		((ieee754.u & 0x000fffffffffffff) != 0);
 }
 #endif
+#endif /* __SIZEOF_DOUBLE__ == 8 */
 
 #ifndef	isinff
 static int isinff(float x)
@@ -147,6 +149,10 @@ int32_t *p_root_squared = (int32_t *)&root_squared;
 
 ZTEST(libc_common, test_sqrt)
 {
+#if __SIZEOF_DOUBLE__ != 8
+	TC_PRINT("test_sqrt skipped, double not 64 bits\n");
+	ztest_test_skip();
+#else
 int i;
 double	resd, error, square, root_squared, exponent;
 uint64_t max_error;
@@ -202,4 +208,5 @@ int64_t *p_root_squared = (int64_t *)&root_squared;
 	zassert_true(max_error < 0x04, "huge errors in sqrt implementation");
 	/* print the max error */
 	TC_PRINT("test_sqrt max error %d counts\n", (uint32_t)max_error);
+#endif
 }